Rodent models are used to examine the neural processing of auditory information, which is disturbed in certain neuropsychiatric disorders, and to develop new treatment concepts like targeted stimulation. However, the hearing range of rats differs from that of humans. Also, rats require extensive training for complex tasks, in contrast to humans. We investigated how rats learn an auditory oddball paradigm, if they can be trained with auditory stimuli used in humans, and whether thalamic event-related potentials (ERPs) are similar to those recorded from humans. Sprague-Dawley rats (n=9) were trained in a three-class oddball paradigm to respond to a rare Target tone (either 5 kHz [high subgroup: n=5] or 1.5 kHz [low subgroup: n=4]), while ignoring a rare Distractor (1.5 or 5 kHz), and a frequent Standard tone (3 kHz). Training phases sequentially introduced Target, Standard and Distractor tones. The number of days to achieve 80% correct responses to Target while ignoring the Distractor and Standard tones, the number and reaction times of correct responses to Target, respectively incorrect rejection of Standard and Distractor were used to characterize the learning process. Thalamic ERPs were derived from stereotaxically implanted electrodes during the oddball paradigm. Rats learned the oddball paradigm in 6-7 weeks, with no difference between high and low Target frequency subgroups (p=0.141). Initially, rats responded randomly to Targets, then showed improved accuracy and shorter reaction times in later training phases (p<0.001). Upon introduction, the reaction times of incorrect responses to Standard and Distractor tones were similar to Target responses (p=0.123 and p=0.531), but later during training rats ceased responding to these tones. Thalamic ERPs did not differ between rats trained for the high or low target frequency, with highest amplitude after Target compared to that after Distractor and Standard. We here show that rats can be trained in auditory paradigms with frequencies used in humans, which is relevant to advance future research. While humans ignore the Standard and Distractor when instructed, rats initially identify them as Target before ignoring them. Similar to humans, the thalamic ERP amplitude is highest after Target. This setting will allow to address attention deficits in neuropsychiatric conditions.

Background: Implantation of deep brain electrodes for stereoelectroencephalography (SEEG) is essential for locating epileptic foci in patients with drug-resistant epilepsy. The use of frameless navigation systems, such as Stealth Autoguide® robotic guidance system combined with intraoperative O-ARM®, offers advantages in speed and safety, but their accuracy must be evaluated in clinical practice. Objectives: The main goal of this study is to determine the accuracy of deep electrode placement using the Stealth Autoguide® robot guidance system with intraoperative O-ARM® in patients with refractory epilepsy, measuring the margin of error in three-dimensional planes (x, y, z) both at the entry point and at the final target. Materials and Methods: An observational retrospective study was conducted on 12 patients (7 females; mean age 14 years) who underwent implantation of 138 electrodes at Hospital Ruber Internacional (Madrid, Spain) between February 2022 and February 2025. Preoperative planning included 3D magnetic resonance imaging (MRI), AngioCT, and FDG-PET. The implantation was performed under general anesthesia, using the Stealth Autoguide® system for automatic alignment and the O-ARM® for intraoperative image acquisition fused with MRI and AngioCT. Accuracy was assessed by measuring the Euclidean distance between planned trajectories and actual trajectories on fused postoperative images, calculating errors at both the entry points and targets. Results: A total of 138 electrodes were implanted in 12 patients, with an average of 10 electrodes per patient. The median error at the entry point (EPE) was 1.05 mm (95% CI: 0.69–1.73 mm), and at the target point (TPE) it was 1.22 mm (95% CI: 0.77–1.82 mm). Most errors (84.78% at EPE and 78.99% at TPE) were below 2 mm, and only 2.9% and 3.6%, respectively, exceeded 3 mm. No major complications were reported, and all electrodes provided adequate recordings for epileptic focus localization. Conclusion: The combination of the Sealth Autoguide® robot guidance system with intraoperative O-ARM® offers a safe, precise, and efficient technique for deep electrode implantation in patients with refractory epilepsy.These results suggest that this technology is a viable alternative to frame-based systems, with a low complication rate and high accuracy in electrode placement.

Introduction: Cognitive deficits, particularly those affecting memory, are common in patients with chronic epilepsy. Interictal epileptiform discharges (IEDs) have been implicated in long-term memory impairment, potentially by disrupting hippocampal–neocortical interactions critical for memory consolidation. This disruption may involve interference with sleep spindle generation—producing aberrant or ineffective spindles that fail to support normal engram processing. These effects may be observable in spindle characteristics. This study aimed to investigate the network-level effects of both spontaneous interictal activity and single pulse electrical stimulation (SPES) on spindle dynamics in medication-resistant epilepsy (MRE) patients. Methods: We analyzed spindle characteristics (duration, amplitude, frequency) in 14 MRE patients implanted with stereo-EEG electrodes. SPES (biphasic, bipolar; 0.5–1 Hz; pulse width: 0.2–0.5 ms; amplitude: 5–10 mA) was applied from bilateral hippocampal contacts during NREM stage 2 sleep. Spontaneous hippocampal IEDs were also detected. Scalp spindles were categorized according to their temporal relationship with either SPS or IED events into three groups: (1) co-occurring spindles, (2) spindles potentially "induced," and (3) spindles with no temporal association to either event. Results: Spindles coinciding with hIEDs or SPES showed altered characteristics across all measured parameters. These spindles were prolonged by approximately 100 ms, exhibited higher amplitudes (by ~3 μV), and demonstrated a frequency shift toward faster spindle bands. In contrast, spindles temporally linked to IEDs—but not coinciding—did not differ from baseline spindles. In over half of the patients, we observed consistent temporal coherence between hippocampal IEDs and scalp spindles. Conclusion: This study demonstrates that both hippocampal SPES and spontaneous IEDs can alter neocortical spindle activity, suggesting a disruptive influence on physiological memory-related processes. These altered spindle responses may serve as markers of pathological hippocampal–neocortical communication. Targeting this mechanism could represent a novel therapeutic approach to mitigate memory dysfunction in epilepsy.

Background: Deep brain stimulation of the anterior nucleus of the thalamus (ANT DBS) is a neuromodulation therapy for patients with refractory epilepsy. The precise mechanism of action of ANT DBS is unknown but clinical observations indicate that therapeutic effects are mediated by stimulation-induced long-term neoplastic changes. ANT DBS is usually administered as open-loop stimulation by intermittent or continuous mode of stimulation. Relatively high stimulation settings may deplete faster implantable pulse generator (IPG) causing fast withdrawal of ANT stimulation. Little is known about the rapid depletion of IPG with subsequent effects on seizure outcome. Moreover, sparse clinical date are contradictory reporting no increase, worsening of seizure frequency including also a case of status epilepticus. The aim of the present study was to gain information about modulatory effect of ANT DBS in patients with depleted IPGs. Methods: The study group consisted of 4 adult patients with refractory epilepsy treated with at least two years of ANT DBS who developed IPGs depletion. All patients treated by ANT DBS have strict postoperative scheduled follow-up visits every 3 months after initial ANT DBS surgery. The postoperative follow-up period in all patients after replacement of IPGs was at least 3 months. Results: All 4 patients experienced within one month gradual increase of seizure frequency. Mean seizure frequency increase was twofold when compared to last ambulatory follow-up visit. The patients underwent urgent IPG replacements with normalization of seizure frequency within a time of 2 to 5 weeks. In all patients depleted non-rechargeable IPGs were replaced for rechargeable IPGs except 1 patient who had also replacement for a non-rechargeable IPG due to technical problems. IPG replacements were associated with high impedance in 3 patients and charging problems of an IPG in 1 patient. No patient with depleted IPGs developed status epilepticus although all 4 patients had history of status epilepticus in pre-DBS period and 3 patients experienced status epilepticus within one year after initial ANT DBS. Conclusions: We present 4 patients after ANT DBS who developed abrupt seizure frequency increase due to depletion of IPGs. None of these patients developed status epilepticus. The mean increase of seizures frequency was twofold. We encountered a lot of hardware-related complications related to exchange the IPGs (high impedances in 3 patients and charging IPG problems in 1 patient). We postulate that upfront rechargeable IPGs should be implanted in patients with drug-resistant epilepsy.

Background: Refractory generalized epilepsy remains a significant clinical challenge, especially in pediatric patients with Lennox-Gastaut syndrome. Directional deep brain stimulation (DBS) targeting the centromedian nucleus of the thalamus has emerged as a potential therapeutic option for reducing seizure frequency and improving associated cognitive deficits. Objective: To describe the clinical course and outcomes of bilateral directional DBS targeting the centromedian nucleus in a 12-year-old patient with refractory generalized epilepsy. Materials and Methods: A 12-year-old patient with a history of generalized tonic-clonic seizures beginning at age 1 was treated with multiple antiepileptic drugs, ketogenic diet, and vagus nerve stimulation (VNS), which was discontinued due to inefficacy. Preoperative assessments included EEG showing Lennox-Gastaut syndrome features and clinical evaluation revealing developmental regression, language loss, hypotonia, and gait ataxia. In June 2024, bilateral implantation of SenSightTM directional electrodes targeting the centromedian nucleus and a Medtronic PerceptTM RC neurostimulator was performed. Postoperative stimulation parameters were adjusted over six months, starting with ring mode at 130Hz, 90μs and reaching 2.5 mA. Results: During follow-up, seizure frequency decreased by up to 40% with stimulation in ring mode. One medication was discontinued, and prolonged video EEG showed a 50% reduction in paroxysmal fast activity during sleep. Side effects included worsening dysphagia, which improved after switching to directional stimulation directed toward the posteromedial region. Clinically, the patient exhibited increased alertness and began producing words after years of speech absence. Local field potential recordings revealed peaks coinciding with tonic seizure events. Conclusions: This case suggests that DBS targeting the centromedian nucleus may be an effective intervention for reducing seizure burden and enhancing cognitive function in patients with refractory generalized epilepsy. Further studies are warranted to optimize stimulation parameters and evaluate long-term outcomes.

Background: The KCNC1 mutation is responsible for specific clinical phenotype of progressive myoclonic epilepsy which has been defined as myoclonic epilepsy and ataxia due to potassium channel mutation (MEAK). We present the results of 4-year follow-up of a patient treated with deep brain stimulation (DBS). This patient underwent subthalamic nucleus/substantia nigra (STN/SNr) deep brain stimulation (DBS) for severe pharmacological-refractory myoclonus and co-existence of drug-resistant epilepsy (DRE). Methods: We present the case history of a 46-year-old man who was finally diagnosed with MEAK at the age of 41. Since the age of 10, he had been suffering from an intention tremor affecting especially the left upper limb, but also the right upper limb. Subsequently, myoclonic jerks intensified, which significantly affected the patient’s performance of daily activities. Subsequently, ataxia involving the upper limbs and walking difficulties worsened. The first bilateral tonic-clonic seizure (BTCS) occurred at the age of 22. This epileptic seizure was preceded by long work on the computer and fatigue. From the patient’s history, it was known that this BTCS was preceded by focal impaired awareness seizures (FIAS). The FIASs occurred around two years before first BTCS manifestation. The genetic testing revealed the KCNC1 mutation mainly c959G>(p.Arg320His) ultimately diagnosing MEAK. The pharmacological treatment has failed in controlling myoclonic jerks and seizures. The patient was offered DBS procedure as a last resort of treatment. The patient underwent staged bilateral implantation of DBS electrodes placed in the STN/SNr region. Results: The follow-up lasts 48 months. The myoclonic jerks and intention tremor were reduced by nearly 85 % at 4-year follow-up when compared to the baseline preoperative scores. Under bilateral STN/SNr stimulation BTCS were completely abolished. The FIAS were reduced by around 80 %. The patient’s ataxia and dysarthria did not improve. The functional benefit consists of improvement in activities of daily living like eating, drinking and use of the keyboard. The depletion of both IPGs (Activa 37603, Medtronic, Minneapolis, USA) caused rapid clinical deterioration. Replacement surgery with new rechargeable IPGs on both sides (Percept RC, Medtronic, Minneapolis, USA) brought rapid clinical benefit. Conclusions: Severe pharmacological-refractory myoclonus and drug-resistant epilepsy due to a potassium channel mutation may be successfully treated by STN/SNr DBS. This positive effect of neuromodulation was confirmed during a 4-year follow-up period in the presented patient.

Introduction: Epilepsy in the eloquent cortex may present several issues owing to the critical role of these brain areas, such as language, motor skills, and sensory processing. Moreover, surgical interventions in these areas are quite complex for balancing between controlling seizures and preserving essential neurological functions. Surgical resection of the epileptogenic zone in the eloquent cortex seems to have a high risk of postoperative neurological deficits, such as speech impairment, paralysis, or sensory loss. Case presentation: The patient is an 18-year-old male, right-handed, known case of refractory epilepsy, who came to the neurology ward with a chief complaint of abnormal movement. His head suddenly turned to the left and became motionless. Besides, there was some increase in the tone of his extremities, which is prominent in his left hand. Additionally, in his ictal Electroencephalography (EEG), signals started as 20hz low voltage fast activity in left frontal max F3, F7 that evolved to 4hz high voltage spike and wave. Right frontal involvement occurred after 0.5 seconds, and spreading to the right temporal area was revealed after one second. The seizure lasted about 12 seconds. At the end of his seizure, there was evidence of bradycardia. There was a postictal left frontal spike and wave. Also, his brain magnetic resonance imaging (MRI) showed cortical high signal intensity with Gary white matter junction blurring in the posterior of left middle frontal gyrus junction with inferior frontal gyrus suggestive of focal cortical dysplasia (FCD) type 2a. Furthermore, owing to the suspicion of FCD in his frontal lobe, fMRI was performed. His fMRI depicted the activation area Broca’s is close to the mentioned lesion on the left side. Hence, since the lesion is located near Broca's area, and traditional surgical resection might have a high risk of neurological deficits, the patient is a candidate for Gamma Knife radiosurgery. The Gamma Knife protocol of 24 Gy at 50% isodose applied for him. The fixation was done with the G frame and the beam on time was about 120 minutes. As a consequence, 4 months after radiosurgery the frequency of his seizure decreased significantly. Also, it is worth mentioning, that the patient did not show any side effects except losing hair at the site of irradiation. Conclusion: Gamma Knife radiosurgery seems to be a suitable choice for treating FCD Type 2a in the eloquent cortex due to its precision and non-invasive nature.

Introduction: Anterior nucleus of thalamus (ANT) deep-brain stimulation (DBS) is an approved neuromodulation therapy for drug resistant epilepsy. In the last decades several studies focused on thalamus and its participation of the epileptogenic networks. ANT is the part of the Papez circuit and long term stimulation can reduce or alleviate epileptic seizures. Although approximately 50% of patients respond to ANT-DBS therapy, there is a lack of reliable biomarkers to predict treatment outcomes. Methods: We implanted bilateral ANT-DBS electrodes in 21 patients with drug-resistant epilepsy. Prior to initiating stimulation therapy, patients underwent overnight monitoring for two consecutive nights with externalized thalamic leads. Ictal events and interictal epileptiform discharges (IEDs) were analyzed in the ANT and correlated with scalp EEG and long-term clinical response. Results: Eighty-five percent of the electrodes accurately targeted the ANT. Ictal activity was observed in 40% of patients, with all seizures initially detected on scalp EEG and subsequently observed in the thalamus. Interictal discharges in the ANT (TIEDs) were present in 87% of patients during sleep and in 73% during wakefulness. Notably, all DBS responders exhibited TIEDs within the ANT. Electrodes located in the anteroventral subregion of the ANT showed 92% spike activity, which correlated most strongly with favorable therapeutic outcomes. The overall response rate at one-year follow-up was 35%. Conclusion: There is a pressing need for reliable biomarkers to predict responsiveness to ANT-DBS therapy in drug-resistant epilepsy. Our findings suggest that thalamic ictal and interictal activity may reflect a pathophysiological connection between the ANT and the seizure onset zone. This connectivity may help identify patients who are more likely to benefit from stimulation, as targeting regions with such activity could enhance the seizure-suppressing effect of DBS.

Background: Temporal lobe epilepsy (TLE) is the most common drug resistant form of epilepsy. The underlying pathological changes predominantly involve hippocampal sclerosis (HS). Not all patients are good candidates for resective surgery of mesial temporal lobe structures. Therefore, other treatment modalities should be sought. Patients with HS as opposed to non-lesional TLE have generally worse treatment outcome and require higher stimulation settings. These clinical observations may point to the fact that sclerotic hippocampal tissue may be resistant to stimulation. HS involves generally the hippocampus proper and dentate gyrus (DG) sparing the subiculum. The subiculum is a critical brain region in TLE. Its position as the output gate of the hippocampus allows it to modulate epileptic discharges as they exit the hippocampus. We present a case of a 52-year-old right-handed woman with left HS who underwent unilateral subiculum stimulation for drug-resistant epilepsy Methods: The female right-handed patient aged 52 years has been diagnosed with DRE, according to the ILAE criteria. By the medical history, the patient has been suffering from focal onset seizures with impaired consciousness (FIAS) progressing to BTCS since the age of 10. Ever since seizures occurred every 10-15 days in a series of 2-3 seizures per day in clusters of 2-4 days. Magnetic resonance imaging revealed the left hippocampal atrophy, hiperintensity of the left hippocampus, and hippocampal architectural malformation with MRI signs consistent with mesial temporal sclerosis. Despite multiple antiepileptic drugs (AEDs) she had 12 to 17 FBTCS per month in the last two years. Due to possible memory decline concerns and personal preference she refused resective surgery. As alternative the patient underwent left unilateral subiculum stimulation. The surgery was done in general anesthesia and DBS lead 3387 was implanted in the left subiculum/hippocampal region. The surgery was uneventful. Results: At 30 months, under unilateral subicular DBS, FBTCS were reduced by 78 %. The patient noticed that the postictal confusion and headaches become milder and short-lasting. Over the entire follow-up period (30 months) the patient had only 7 craniofacial injuries compared to 1 or 2 injuries each month before surgery. There were no hardware-related complications in this patient. Conclusions: In the presented case the patient refused open resective surgery due to memory concerns and personal preference. DBS of the subiculum may be the preferred structure to target because of its function and the minor changes in its structure found in HS. Theoretically, patients with non-lesional MTLE may benefit from hippocampal stimulation with leads implanted within hippocampus proper and those with lesional-TLE from subicular or parahippocampal stimulation. The subicular stimulation provided the significant reduction of FBTCS in our patient.

Background and aims: Stereoelectroencephalography (stereo-EEG) is a minimally invasive surgical procedure employed mainly as a diagnostic tool in patients with drug-resistant epilepsy. Frame-based or frameless stereotactic instruments are utilized to place depth electrodes within the brain with high precision and accuracy. Over the past two decades, there has been an increase in the use of robotic systems for these procedures. In this study, we aimed to evaluate the performance of a table-mounted robotic platform (Cirq®, Brainlab AG, Germany) using an anthropomorphic skull phantom. The primary objective was implantation accuracy at the entry and target points, and the secondary objectives were angular error and implantation time. Material and methods: Based on patient-specific radiologic images, we 3D-printed a silicon-coated skull phantom and filled it with a medium to mimic the brain. A preimplantation plan included 540 trajectories, 270 per side, each side subdivided into 9 head regions. The phantom was attached to the surgical table in supine position using Vantage head frame (Elekta, Stockholm, Sweden) and registered to the optical navigation system using automatic intraoperative registration (AIR) with CT scanner. Stylets were implanted systemically with Cirq® in sessions of 18 trajectories (9 on each side), alternating the sides between sessions. Stylet implantation time was recorded, and postoperative CT scan was acquired to localize stylet position. The stylet entry point (EP) was set at dura level, and the target point (TP) at the deepest visible stylet artifact, obtaining XYZ coordinates. 3D differences between planned and obtained XYZ coordinates were calculated using Euclidean equation √((Xe-Xp)^2+(Ye-Yp)^2+(Ze-Zp)^2 ). The vector-based angular error was assessed using dot product angle equation 〖theta=cos^(-1)〗⁡〖(ab/(∥a∥∥b∥)〗). Results: The data from 378 (70%) implanted stylets were analyzed. The mean EP error was 1.04 +/- 0.59 mm, and the mean TP error was 1.28 +/- 0.73 mm. The mean 3D angular error was 0.81 +/- 0.53 degrees. The mean stylet implantation time was 3.23 +/- 0.92 min. Conclusions: In this phantom setup, stylet implantation using Cirq® and CT-based AIR demonstrated EP/TP accuracy comparable to other robotic systems used in clinical practice. The mean stylet implantation time was short. To corroborate this, a prospective clinical study with larger data set is warranted.

Topic: Neuro-imaging Type of communication: Poster and/or oral presentation Introduction: Deep brain stimulation of the subthalamic nucleus (STN-DBS) is a well-accepted advanced therapy in Parkinson’s disease (PD). However, its therapeutic effect strongly depends on electrode position and stimulation programming. Brain templates play a central role in optimizing both aspects by serving as a reference space for group analyses and model creation. Existing templates are typically based on healthy, young individuals. PD-specific templates often lack T2-imaging (which visualizes the STN), use MNI as initial template and are based on smaller datasets than recommended. Consequently, a brain template that accurately reflects the anatomical characteristics of PD-patients eligible for STN-DBS has not yet been established. Methods: MRI data from 254 patients, who underwent asleep MRI-guided and CT-verified STN-DBS-surgery for PD at the Radboud University Medical Centre, were collected. All MRI-scans were acquired under general anaesthesia and included a 3D T2 SPACE and T1 MPRAGE sequence. Of these, 230 scans were used for template creation and 24 for evaluation. Pre-processing included rigid alignment of T1- to T2-images, bias field correction, brain extraction, Nyul intensity normalization and intensity scaling. AntsMultivariateTemplateConstruction2.sh from the Advanced Normalization Tools ecosystem was used for unbiased template creation, driven by the T2-weighted images. Four iterations of non-linear registration resulted in both a T1- and T2-weighted template with a 1.1mm isotropic resolution. Through upsampling a 0.5mm isotropic version was created. Evaluation included assessing convergence of the template creation algorithm and inter-subject similarity within the template compared with other established templates. Results: Figure 1 shows the resulting NeuTraNe brain template, in both T1- and T2-weighting, representing the average anatomy of 230 images with the STN visible in the T2-weighted template. Convergence was achieved with 100% similarity between the final two iterations. NeuTraNe demonstrates significantly improved alignment of patient images compared to existing templates such as MNI2009b and PD126. Further evaluation will include the assessment of inter-subject similarity using open-access datasets and performance in atlas-based STN segmentation relative to established atlases. Discussion: As only patients eligible for STN-DBS were included, the template represents the anatomy of this PD-subgroup. The T1-images contain contrast, reflecting their clinical acquisition during STN-DBS-surgery. Conclusion: A T2-weighted PD specific brain template is created of 230 patients who received STN-DBS in our centre. This template offers a reference system tailored to the anatomical characteristics op PD-patients getting STN-DBS. It provides a strong foundation for advancing STN-DBS treatment and enhancing clinical outcomes for PD-patients.

Background: Precise localization of deep brain targets is essential for optimal clinical outcomes in Parkinson’s disease (PD) patients undergoing deep brain stimulation (DBS). Radiological targeting softwares provides advanced image-based planning of lead trajectories. However, electrophysiological techniques such as microelectrode recordings (MER) remain the gold standard for verifying target engagement intraoperatively. Understanding the concordance between these two approaches is vital for improving surgical accuracy. We aimed to evaluate the spatial concordance between radiological targeting and intraoperative electrophysiological mapping during subthalamic nucleus (STN) DBS in PD patients. Methods: A total of 103 patients undergoing bilateral subthalamic nucleus (STN) DBS were included. Radiological targets were planned using Brainlab Elements™ based on preoperative MRI, while intraoperative microelectrode recordings (MER) defined electrophysiological targets. Spatial concordance was assessed by calculating the three-dimensional Euclidean distance between Brainlab and MER coordinates for each hemisphere. Directional discrepancies (ΔX, ΔY, ΔZ) were also analyzed. Threshold-based concordance (<1 mm and <2 mm) was reported. Associations with sex, age, and disease duration were evaluated using t-tests and Pearson correlation coefficients. Results: The mean Euclidean distance between radiological targets and electrophysiological sites was 2.51 ± 1.91 mm (left) and 2.49 ± 1.78 mm (right). 13.6% of leads on the left and 11.7% on the right showed a discrepancy of less than 1 mm, and approximately 53% were within 2 mm. The highest deviations were observed along the Y-axis, with mean absolute differences of 1.54 mm (left) and 1.49 mm (right). The smallest deviations were seen in the X-axis, with mean values below 1.05 mm. No significant differences in concordance were observed between hemispheres (p = 0.86), or when stratified by sex, age, or disease duration. Patients with the highest bilateral concordance (<1 mm, n = 9) were predominantly male and younger on average. Conclusion: Radiological targeting demonstrates moderate spatial agreement with intraoperative MER mapping in STN-DBS. Although more than half of the leads were within 2 mm, deviations above 1 mm were common, especially in the anteroposterior and axial directions. These findings highlight the current limitations of direct radiological targeting and underscore the importance of ongoing efforts to improve its accuracy. As image-guided techniques continue to evolve, understanding the sources of deviation will be key to enhancing the precision of future DBS workflows and potentially reducing reliance on intraoperative electrophysiology.

Deep brain stimulation (DBS) has demonstrated robust therapeutic benefits for movement- and treatment-refractory psychiatric disorders such as obsessive-compulsive disorder (OCD). However, using magnetic resonance imaging (MRI) in individuals with implanted DBS systems can pose safety challenges. While Medtronic DBS devices are approved as MRI-conditional at 3T, concerns regarding radiofrequency-induced heating and implantable pulse generator (IPG) instability continue to limit MRI accessibility, especially in much-needed research-related sequences. The current study systematically evaluated temperature changes and DBS functionality using a realistic head-torso phantom under different MRI sequences. A custom-made anthropomorphic phantom was constructed with a brain-shaped agar-filled head and saline-filled torso to replicate human tissue conductivity. A clinically used DBS system (Medtronic Percept PC with Sensight leads) was bilaterally implanted following standard surgical targeting for OCD around the ventral capsule/ventral striatum. Temperature probes were affixed at the electrode tips and along a wire loop. Temperature measurements were conducted across several conditions: stimulation ON versus OFF, stimulation parameters (average versus intense), active contact points (4 contact points versus all), and different MRI sequences (T1 turbo spin echo, T2 fast spin echo, resting-state fMRI, and diffusion-weighted imaging [DWI]). A general linear model assessed the dependance of temperature changes on the different conditions. DBS system integrity was verified pre- and post-scanning by impedance measurement. Additionally, specific absorption rate (SAR) values were recorded. Overall, results showed that for most sequences, temperature increases at electrode tips and wire loop remained below 2°C, aligning with established safety thresholds. However, for the DWI sequence, temperature increases exceeded 2°C at the electrode tips, with a maximum rise of 2.9°C. No cumulative heating was observed during scanning sessions. Statistical analyses revealed significant interactions between MRI sequence and IPG status, notably with higher temperature rises when the DBS was ON during DWI and T1-TSE scans. DBS system functionality was preserved after scanning, with minor impedance fluctuations that normalized within minutes. These findings support carefully controlled MRI use in DBS patients and highlight the need for further optimization of high-SAR sequences such as DWI. Future work will explore alternative DWI protocols and test additional DBS-models. These findings advance efforts to expand safe MRI access for patients with implanted neurostimulation devices.

Introduction The brain functions have a network-based organization. The subcortical connection of these networks can be identified by probabilistic tractography (PT). In brain tumor patients it would be crucial to localize the networks to decrease the risk of surgery. However it can be challenging due to the distortion of the normal anatomy. Our goal was to create a standard map of the brain networks’ subcortical connections and identify reference areas which can be used to reliably reconstruct the networks. Materials and methods From the Human Connectome Project database 20 subjects were included in our study. Cortical brain subregions were created from the T1 image using the Freesurfer software. From these areas the cortical centers of the 7 most important networks (default mode, salience, central executive, sensorimotos, language, sensorimotor and visual network) were reconstructed. Two types of tractography were done. 1, using these regions as seed masks, PT (FDT toolbox of the FSL) was done to identify the networks. 2, subcortical reference areas were identified in each networks and PT was done from these. Results We identified two subcortical reference areas between each cortical center of a network. Using these as seed masks for PT we were able to reconstruct the subcortical pathways of the 7 brain networks with a 100% success rate. Conclusions Subcortical standard reference areas can be used to identify the structural connections of brain networks. These could be used in brain tumor patients to localize functional subcortical areas and decreas surgical risk.

Deep brain stimulation targeting the subcallosal cingulate area (SCC-DBS) is a promising therapy for treatment-resistant depression. However, the absence of a consistent, rapid behavioral response to SCC-DBS complicates the selection of optimal stimulation parameters after implantation, necessitating a lengthy and burdensome trial-and-error process. Immediate biomarkers of effective stimulation could address this challenge. In this proof-of-concept study, we used 3T functional MRI (fMRI) to scan three SCC-DBS patients. A block-design paradigm was implemented, with participants’ DBS settings alternating between "on" and "off" states in 30-second cycles during a single acquisition sequence. Comparing these conditions revealed regional BOLD signal changes linked to DBS, demonstrating consistent hemodynamic alterations (pFDR<0.01) in multiple brain regions during active stimulation. Specifically, decreased BOLD responses were observed in the precuneus, posterior cingulate cortex, middle frontal gyrus, and frontal pole, while increased responses were seen in the occipital cortex, middle temporal gyrus, inferior parietal lobule, and superior frontal gyrus. Exploratory analysis also suggested a possible correlation between BOLD signal change in the precuneus – a region directly connected to the SCC-DBS target area by the cingulum bundle – and clinical improvement (R=-0.98, ppermute=0.09). These findings highlight the potential of block-design fMRI with cycling DBS stimulation as a method for identifying objective, brain-based biomarkers of effective SCC-DBS, potentially accelerating stimulation parameter selection and therapeutic optimization.

Deep brain stimulation is a well-established therapeutic option for patients with advanced Parkinson’s disease. The clinical effectiveness of this intervention depends, among other factors, on the precision of electrode placement within the subthalamic nucleus. This study evaluates the impact of intraoperative three-dimensional O-Arm imaging on surgical accuracy and its association with clinical outcomes. A retrospective analysis was performed on 90 patients who underwent surgery at Hospital de Sant Pau between 2019 and 2024. Two groups were compared: one in which intraoperative O-Arm imaging was used (36 patients), and another in which the traditional method without intraoperative imaging was applied (54 patients). Euclidean distances between the electrode contacts and the motor region of the subthalamic nucleus were calculated. Clinical outcomes were evaluated using the motor section of the Movement Disorder Society-sponsored revision of the Unified Parkinson’s Disease Rating Scale, as well as changes in the daily dosage of antiparkinsonian medication expressed in levodopa equivalents, both at six and twelve months postoperatively. The findings showed significantly higher accuracy in electrode placement in the group that used intraoperative O-Arm imaging, with a lower average global error (1.35 millimeters versus 1.66 millimeters; p = 0.02) and a higher percentage of active contacts located within the target region (94.4 percent versus 66.7 percent; p = 0.01). A significant reduction in stimulation amplitude was also observed in the O-Arm group at twelve months. However, no statistically significant differences were found between groups in terms of clinical motor improvement or medication reduction. In conclusion, the use of intraoperative three-dimensional imaging with the O-Arm system increases surgical accuracy in deep brain stimulation procedures and may contribute to more efficient programming. Nonetheless, the improved precision did not translate into significantly better clinical outcomes. These results highlight the relevance of precise targeting in functional neurosurgery while suggesting that other factors—such as trajectory planning and patient-specific anatomy—also play a critical role in achieving optimal therapeutic results. Further prospective studies are warranted to confirm the long-term clinical impact of advanced intraoperative imaging technologies.

Introduction : Preoperative brain mapping in tumors involving the speech areas has an important role to reduce surgical risk. Functional magnetic resonance imaging (fMRI) is the gold standard method to localize cortical speech areas preoperatively but its availability in clinical routine is difficult. Diffusion MRI based probabilistic tractography is available in head MRI. It can be used to segment cortical subregions by their structural connectivity. In our study we used probabilistic tractography to localize the frontal and temporal cortical speech areas. Methods: 15 patients with left frontal tumor were enrolled to our study. Speech fMRI and diffusion MRI were acquired preoperatively. The standard AAL3 cortical atlas was used to define 76 left frontal and 118 left temporal potential speech areas. 4 types of tractography were done according to the structural connection of these regions to the left arcuate fascicle (FA) to localize those cortical areas which have speech functions: 1, frontal through FA; 2, frontal with FA; 3, temporal to FA; 4, temporal with FA connections were determined. Thresholds of 1%, 5%, 10% and 15% were applied. At each levels the number of affected frontal and temporal regions by fMRI and tractography were defined and sensitivity and specificity were calculated. Results: 1 % threshold has the best result. Sensitivity was 61,631,4% and 67,1523,12%, specificity was 87,210,4% and 75,611,37% for frontal and temporal regions, respectively. Conclusion: Probabilistic tractography is a reliable preoperative technique to localize cortical speech areas but the surgeon should not rely on its results only during the operation.

Background: The subthalamic nucleus (STN) is a well-established target for deep brain stimulation (DBS) in patients with Parkinson’s disease (PD). Traditional DBS targeting relies on indirect anatomical methods referencing stereotactic atlases; however, increasing evidence suggests that the STN is not a static structure in PD and that its functional and structural properties may change over time. We aimed to investigate whether the stereotactic localization of STN targets shifts posteriorly in relation to PD progression. Methods: We retrospectively analyzed intraoperative microelectrode recording (MER) coordinates from 103 PD patients who underwent bilateral STN-DBS. Y-coordinates for both hemispheres were averaged to determine each patient’s mean STN Y-position. To control for variations in frame placement, all Y-coordinates were normalized using a standard external auditory meatus reference level of 85 mm. Correlation analyses were performed between normalized Y-coordinates and disease duration, and a linear regression model adjusted for age was constructed. Results: Normalized Y-coordinates exhibited a weak but consistent negative correlation with disease duration (Pearson r = -0.29, p = 0.08; Spearman ρ = -0.28, p = 0.09), suggesting a posterior shift in the STN target with advancing disease. Multivariable regression analysis, however, did not reach statistical significance (p = 0.50), and explained variance was low (R² = 0.014). Conclusion: Our findings support a trend toward posterior migration of optimal STN targets in relation to disease progression in PD. Although the observed association did not reach statistical significance, the results highlight the potential importance of individualizing targeting strategies based on disease duration. Larger prospective datasets and postoperative imaging validations are warranted to further investigate this phenomenon.

Background: Rubral tremor is a coarse tremor typically occurring unilaterally at frequencies below 5 Hz, caused by lesions around the red nucleus. It is often associated with brainstem or cerebellar dysfunction due to brainstem lesions near the red nucleus. Head trauma and cerebrovascular disorders are commonly cited as etiological factors. The tremor often appears as a delayed symptom, emerging 1 to 24 months after the onset of the primary disease. In this case, we report a patient with rubral tremor associated with arteriovenous malformation (AVM), who showed significant improvement after thalamic coagulation following Gamma Knife treatment for AVM. Case Report: A 30-year-old female presented with tremor in her right upper limb. She first noticed the tremor in her right hand while writing and drawing in year X, and it gradually worsened. In year X+10, MRI revealed a brainstem AVM, and she was referred to our department. Gamma Knife treatment for AVM was performed in year X+11, resulting in temporary improvement of the tremor, but it worsened over the years. From year X+12, various therapies, including medication and Botox injections, were attempted, but with poor improvement. In year X+17, surgical treatment was performed for the tremor. Preoperative symptoms included involuntary movements of the right wrist in a clockwise direction, making it impossible to use her right hand in daily activities. Coagulation of the left ventral intermediate nucleus (Vim) of the thalamus was performed, and immediately after surgery, the tremor in the right upper limb became mild, with the FTM-TRS score improving from 56 to 12. The patient regained the ability to perform actions such as eating, writing, and buttoning with her right hand, and the improvement was maintained two months post-surgery. Discussion: Rubral tremor is a type of Holmes tremor caused by lesions around the red nucleus. It is characterized by significant amplitude tremor at frequencies below 5 Hz, occurring at rest and during posture. In this case, it is hypothesized that the AVM centered in the left midbrain compressed the red nucleus in the left midbrain tegmentum, leading to tremor in the right upper limb. Following Gamma Knife treatment, the AVM reduced in size, leading to temporary symptom improvement, but the tremor re-emerged due to the effects of irradiation on the red nucleus. Given the patient's young age and the localized tremor in the distal upper limb, Vim coagulation was chosen over DBS, which requires device implantation. DBS and coagulation have comparable tremor suppression effects, with fewer adverse events and better functional improvement reported for DBS. However, Vim coagulation significantly reduces distal limb tremor on the contralateral side. Conclusion: Coagulation of the thalamic Vim nucleus can effectively treat rubral tremor associated with AVM, provided the AVM is controlled.

Introduction: Dystonic tremor and tremor associated with dystonia may manifest at rest, during posture holding or specific tasks, exhibiting variability in distribution and severity. Clinical assessment of these tremors using motor rating scales suffers from inherent inter-rater variability, highlighting the need for an objective gold standard in clinical examinations. This study aims to propose a method to detect the presence of tremor associated with dystonia during standardized clinical assessments. Methods: This study included 20 subjects sufferring from tremor. Kinematic motion trackers were positioned on the subjects' forehead, left and right wrists. Participants underwent a standardized clinical examination involving three motor tasks: (1) resting arms on the thighs, (2) maintaining out-stretched arms, and (3) performing a finger-to-nose test. Each test lasted 30 seconds and was conducted with both, eyes open and closed. Motor signs were annotated based on video recordings by two independent clinical examiners to ensure accuracy. Tremor detection is achieved using two metrics: absolute tremor power and relative tremor power. Absolute tremor power measures the power around the fundamental tremor frequency and its first harmonic, while relative tremor power is defined as the ratio of the absolute tremor power to the power within the 3-12 Hz frequency band. The separation of tremor from non-tremor data points is achieved by thresholding both metrics in combination with Boolean operations. Results: In this study, a total of 360 motion signals (20 participants, 6 tests, 3 trackers) were annotated and analysed. Out of these, 152 signals (42%) were identified as containing tremor, while 208 signals (58%) were annotated as not containing tremor. The tremor detection method achieved an accuracy of 89.2%, a precision of 92.5%, a recall of 80.9%, and an F1 score of 86.3%. No significant difference was found between the tests performed with eyes open and closed or between the different limbs. Conclusion: The findings suggest that an effective separation can be achieved using only two features in the frequency domain: absolute and relative tremor power. Incorporating movement noise detection and/or rejection holds significant potential for improving the accuracy of the proposed algorithm. Introducing an additional metric for noise may help identify some misclassified cases without overcomplicating the algorithm. The proposed method will be compared with deep learning-based pose estimation and machine learning pattern recognition methods in future work.

Background Despite two decades of research, the comparative effectiveness of awake versus asleep subthalamic nucleus deep brain stimulation (STN-DBS) in Parkinson’s disease (PD) remains under debate. While awake surgery allows intraoperative clinical testing and microelectrode recordings (MER), asleep surgery benefits from advanced imaging and improved tolerability. Existing studies vary in design, outcomes, and sample size, limiting the ability to draw robust conclusions—particularly regarding treatment effects in specific patient subgroups. Objective This protocol outlines a planned individual participant data (IPD) meta-analysis to compare the overall effectiveness of awake versus asleep STN-DBS in PD and to identify patient subgroups that may benefit more from either surgical approach. Methods A systematic search will be conducted in PubMed, Scopus, Web of Science, and the Cochrane Library to identify clinical trials and observational studies comparing awake and asleep STN-DBS in PD. Authors of eligible studies will be invited to share anonymised individual participant data. Both one-stage and two-stage IPD meta-analyses will be conducted to estimate treatment effects and explore subgroups. Subgroup analyses will incorporate expert-defined variables (e.g., age, disease duration, cognitive status, baseline severity, and MER use) alongside data-driven methods using generalized linear mixed-effects model (GLMM) trees. Non-linear associations will be examined. Missing data will be handled through multiple imputation. Sensitivity analyses will assess the robustness of findings across imputation methods and study designs. Discussion This IPD meta-analysis protocol aims to provide the most comprehensive evaluation to date of awake versus asleep STN-DBS. By pooling individual-level data across studies, this project will go beyond average treatment effects to explore which patients benefit most from each surgical approach—offering an evidence base for more tailored and informed decision-making in DBS practice. Challenges of the IPD meta-analyses include the time-intensive nature of data acquisition and harmonisation, potential data sharing restrictions, variable outcome definitions. An IPD meta-analysis offers superior analytical power and clinical relevance to traditional meta-analysis. By contributing data, collaborators will help generate high-impact evidence that addresses a long-standing debate in functional neurosurgery and supports the optimisation of patient selection. Together, we can move the field forward and provide the clarity needed to guide future DBS practice and policy. Study status The study is actively inviting investigators to collaborate their individual participant data to collaborate in this IPD meta-analysis.

Deep brain stimulation (DBS) is regularly used in people with advanced Parkinson’s disease (PD). Although recent reports suggest the non inferiority of asleep DBS, we still routinely perform an awake implantation of DBS electrodes, including intra-operative micro-recordings and clinical testing during macro-stimulation. Here, we report successful awake implantation of DBS electrodes in the ventral intermediate thalamic nucleus (VIM), bilaterally in a 67 years-old, deaf mute patient with severe, drug-refractory, PD tremor who carried two mutations in the connexin 26 gene. After multi-disciplinary discussion about the best surgical procedure, we chose to perform an awake implantation of DBS electrodes as routinely performed in our center, despite requiring an active patient participation during per-op stimulation tests. Some family members proposed to assist during surgery for help with translation by sign language, but this option was discarded given the risk of stress and infection. Finally, we found help from a speech therapist from our hospital, knowing the sign language, that accepted to come in the operating theater during the surgery. First a meeting was organised a few days before surgery to ensure adequate mutual communication between the patient and the speech therapist using sign language. Then awake surgery was performed under local anesthesia, with the help of the speech therapist inside the operating theater, translating informations from and to the patient throughout the surgical procedure. It was particularly important to explain the different steps of the awake surgery and avoid unnecessary anxiety during the procedure. We will present some photos and videos of the procedure in the operating theater. This procedure was performed without any surgical complication, with a very good collaboration of the patient, and an excellent immediate post-operative result on the tremor, which was maintained at 2 years of follow up without need to reintroduce any antiparkinsonian medications To our knowledge, we present here the first case ever of awake DBS in a deaf mute patient, with the help of a speech therapist familiar with the sign language in the operating theater. We suggest that, whenever possible, we must try to give to all disabled patients the highest level of care, as usually done in non-disabled patients.

Objective: To examine the effectiveness of a Deep Brain Stimulation (DBS) system with 16-contact Directional Leads for the treatment of Parkinson’s Disease (PD). Background: Directional DBS leads have been recently developed to expand the therapeutic window while minimizing stimulation-induced side effects.1-3 Current directional Leads enable more precise targeting of specific brain regions using multiple independent current control through segmented leads with eight contacts across four levels. In this study, we tested the effectiveness of two novel 16-contact directional leads (3-3-3-3-3-1 and 3-3-3-3-1-1-1-1 configuration) for the treatment of symptoms of PD. Methods: For this prospective, multi-center, open-label confirmatory study, we enrolled patients with PD eligible for DBS based on clinical indication. Each subject received a Multiple Independent Current Controlled DBS system which included two 16-contact directional leads targeting bilaterally the subthalamic nucleus. Subjects were followed from device activation through the primary effectiveness endpoint of 3-months. Follow-up assessments were carried at 6 and 12-months follow up. During each visit, DBS programming was carried per clinician’s standard of care and the following assessments were collected: MDS-UPDRS I-IV, PDQ-39, antiparkinsonian medication use, and global impression of change. Results: We present preliminary findings from 49 subjects (40 male, mean age=62.5±6.7 years, mean disease duration=11.7 ± 4.1 years). At 3-months post DBS activation, compared to Baseline (pre-DBS), motor symptoms significantly improved by an absolute difference of 20-points (Meds-OFF, MDS-UPDRS III, p<0.0001). Mean change in medication use was significantly lower between Baseline and 12-weeks (32% reduction, p<0.001). Quality of life improvement (6.1-point improvement, p<0.005) was also observed at 3-months. These improvements persisted through 6 and 12-month follow up. Conclusions: Results from this study confirm the effectiveness of a DBS system delivering stimulation to the STN via novel 16-contact directional leads to manage PD symptoms. Our data demonstrate the usefulness of a new DBS system that extend the span of directional contacts and open new avenues to deliver multi-level stimulation to manage PD symptoms.

Among patients diagnosed with dystonia, initial improvement after surgery can fade away. The authors analyzed the effectiveness and safety of a second or third surgical approach that include ablative procedures or deep brain stimulation (DBS) in the treatment for of generalized dystonia (GD). Background: Ablative procedures like thalamotomy and pallidotomy remained the primary stereotactic treatment methods for GD until recently. Today the DBS has become a standard surgical tool for various movement disorders treatment that include GD. Complex neuromodulative treatment can be implemented to achieve better clinical results. Methods: 14 GD patients with the history of bilateral GPi DBS or thalamotomy, or pallidotomy were qualified for a second or third stage surgical treatment. The whole group demonstrated significant clinical improvement that faded away six months to eleven years after initial surgery. 7 of them, who underwent ablative procedures in the past were qualified for DBS: GPi (3 patients) and STN (4 patient). Four patients, who underwent GPi stimulation in past received additional STN DBS treatment. 4 patients who underwent unilateral thalamotomy and bilateral GPi DBS received additionally STN DBS. Results: The complex neuromodulative treatment that included multimodal and multifocal DBS caused sustained improvement in dystonic movement in the whole group. The improvement measured with Unified Dystonia Rating Scale (UDRS) lasted from two years to 11 years follow-up. No surgical or stimulation related complications were reported. Conclusions: Combined neuromodulative treatment of dystonia: should be considered when dystonic symptoms aggravate over time.

Background: Hemorrhage is a dangerous complication resulting from deep brain stimulation (DBS) surgery, but a comprehensive explanation of the risk factors associated with its occurrence remains inconclusive, particularly application of microelectrode recording (MER). We conducted a comparative analysis of MER and macrostimulation techniques, evaluating the impact of brain penetrations using guiding cannulas on the occurrence of intracranial hemorrhagic events. Methods: This retrospective study included all DBS procedures performed at a single medical center from November 2008 to June 2023. All patients underwent comprehensive pre- and postoperative evaluations, including postoperative CT scans to assess lead placement and intracranial bleeding, categorized as symptomatic or asymptomatic. Statistical analyses were conducted to ascertain the correlation between different surgical techniques and the risk of hemorrhagic complications. Results: In a cohort of 618 patients, a total of 1096 electrodes were implanted during 672 consecutive DBS procedures. There were 21 asymptomatic intracranial hemorrhages (ICH) and 6 symptomatic ICH, including 1 death. Bleeding rate was 4.37% per patient and 2.92% per implanted electrode. Patients who developed hematomas were more prevalent in the MER group compared to the non-MER group and had a higher number of brain penetrations by guiding cannulas. Conclusions: DBS procedures are generally safe, with only 0.97% resulting in long-term or permanent deficits. All symptomatic ICH occurred in MER patients, while macrostimulation was associated with only two asymptomatic ICH cases. More brain penetrations performed by guiding cannulas in MER correlate with higher bleeding rates.

Objective: We present 14 patients who underwent robot-assisted deep brain stimulation (DBS) electrode implantation in Japan, describing their early experiences and workflow in awake or asleep state during surgery. Methods: After attaching the Leksell frame to the head in the operating room, the patients were moved to the computed tomography room for scanning with an indicator. The ROSA one brain system (Zimmer Biomet, Indiana, US) was affixed diagonally to the Leksell frame to set up the X-ray system (Fig. 1). Registration used the centre of each Leksell pin opening. The coordination data defined by Elements (BrainLab AG, Munchen, Germany) were moved to the ROSA, and tentative DBS targets were decided. Front and lateral radiographs indicated whether the electrode tip contained tentative targets (Fig. 2). Surgery time was the time from skin incision to bilateral DBS electrode implantation completion. The DBS targets were the subthalamic nucleus (STN) (6/14), anterior thalamic nucleus (ANT) (5/14), and globus pallidus internus (GPi) (3/14). Electrode implantation was performed under general anaesthesia in patients undergoing ANT and GPi DBS and under local and intravenous anaesthesia for STN DBS to confirm the STN location with semi-microelectrode recording (sMER). sMER was also performed to confirm the inferior border of the GPi. Deep brain encephalography was performed on patients after electrodes were inserted into the ANT. Results: There were no intraoperative complications or major complications immediately after DBS. The surgery time ranged from 115 to 186 (average: 138) min for STN DBS, 38 to 124 (average: 78) min for ANT DBS, and 60 to 183 (average: 108) min for GPi DBS. For STN DBS implantation using the Leksell frame, the surgery time ranged from 118 to 192 (average: 149) min, similar to that in six patients who underwent robot-assisted implantation (p = 0.51). Conclusions: Robot-assisted DBS electrode implantation had similar safety and efficiency to the frame-based technique. Robotic assistance is likely useful for DBS implantation in awake or asleep state, with or without sMER.

Patients with Parkinson's disease (PD) may present a loss or reduction in spontaneous facial expression. Deep brain stimulation (DBS) of the basal ganglia is an effective treatment to improve the motor symptoms of PD but may be associated with the onset of non-motor manifestations, such as cognitive and mood disorders. To our knowledge, no study has investigated the effects of DBS on facial emotional expression. This study aims to investigate the impact of subthalamic deep brain stimulation (STN-DBS) on mimicry. Specifically, we compare the facial emotion expression in two conditions: DBS on vs DBS OFF. 15 patients with idiopathic PD were enrolled in this study who underwent subthalamic DBS between 2019 and 2023. OpenFace 2.0 software was used to analyze the facial expression through the Facial Action Coding System (FACS; Ekman and Friesen, 1978) quantifying the movements through Action Units (AUs). We assessed the intensity of the 17 AUs, for each of 6 basic universal expressions (fear, anger, disgust, happiness, sadness and surprise). Facial emotion assessment was performed under med optimal conditions, with stimulation ON vs. stimulation OFF (Med best on/Stim on vs. Med best on/Stim off). Variables were compared by Student t-test. Significant changes in happiness-AUs (p = 0.043, t(5) = 2.701) and anger-AUs (p = 0.046, t(5) = 2.633) were found in PD patients between StimON vs StimOFF, while no significant differences were observed in other emotional expressions. These results suggest that DBS may have a selective impact on the motor components of emotional facial expressions. The study of facial expressions in PD patients undergoing DBS is important for assessing the effectiveness of treatment and monitoring behavioral changes. Analysis of emotional expressions can help assess how DBS affects patients' social spheres, thus helping to improve their quality of life. Future analyses could correlate facial expressions and electrode location in the STN to better understand the neural mechanisms involved in emotion. This result would highlight the possibility that the subthalamic nucleus may influence not only voluntary movement but also the capacity for emotional communication. 1. Ekman, P.; Friesen, W.V. Facial Action Coding Systems; Consulting Psychologists Press: Berkeley, UK, 1978.

Background: Patients with advanced Parkinson’s disease (PD) or dystonia undergoing deep brain stimulation (DBS) often require regular outpatient visits for device maintenance. However, frequent visits impose a considerable burden on both patients and caregivers. With the development of digital technologies, telemedicine has the potential to alleviate this burden without worsening symptoms of involuntary movement disorders. In 2021, Abbott Medical launched the NeuroSphere™ Virtual Clinic (NSVC), a remote neuromodulation management platform that enables remote programming for patients implanted with Infinity® or Proclaim® systems for DBS or spinal cord stimulation (SCS). A prospective multicenter randomized controlled trial (ROAM-DBS study) comparing in-person and remote DBS care using NSVC reported earlier access to programming and faster subjective improvement in the remote care group. However, this study only included patients newly implanted with implantable pulse generators (IPGs), leaving the efficacy of remote care for existing DBS patients unclear. Objective: To evaluate the effectiveness and usability of remote DBS care using NSVC in patients with previously implanted Infinity® systems. Methods: Sixteen PD patients with previously implanted Infinity® systems who were receiving outpatient care at Tokushima University Hospital or Kurashiki Heisei Hospital and provided informed consent were enrolled. Evaluations were conducted at three time points: baseline, after two in-person visits, and after two remote visits using NSVC. The following parameters were assessed and analyzed: MDS-UPDRS Part III, MIPIC-J, PGIC, a remote effectiveness score, and the Telehealth Usability Questionnaire (TUQ). Results: Remote DBS care using NSVC resulted in a degree of symptom improvement comparable to in-person visits, with no adverse events reported. Patient satisfaction with remote care was 68%, and 75% of participants chose to continue with remote programming. However, older or more severely affected patients tended to experience difficulty with communication via the online platform, which was reflected in lower satisfaction scores. Among the study participants, each outpatient visit incurred an estimated burden of 4.6 hours and approximately 8,000 yen (including caregiver support), suggesting that remote care can significantly reduce the physical and financial burden associated with frequent clinic visits. Conclusion: Remote programming using the NSVC platform is a feasible and effective alternative to in-person DBS follow-up for patients with pre-implanted systems. While overall satisfaction and retention rates were favorable, attention should be given to the digital accessibility needs of elderly or severely disabled patients. Remote care may play an important role in reducing patient and caregiver burden in the management of chronic movement disorders.

Title Fewer return visits and less optimizing needed when image guided programming is utilized in DBS treatment in Parkinson’s disease. Authors Anette Nobrell (presenting author), MSc, DBS-nurse at the department of Neurology, Skåne University Hospital, Lund, Sweden Hjalmar Bjartmarz, neurosurgeon and head of stereotactic functional neurosurgery at the department of Neurosurgery in Lund, Sweden Topic Deep Brain Stimulation – Programming strategies Poster presentation Keywords Parkinson’s disease, image-guided programming, deep brain stimulation Abstract Background: Until recently, DBS programming initiation relied on monopolar review, which is a time-intensive process, dependent on the clinician’s experience and patient cooperation. Recent advances have introduced image-guided programming (IGP), enabling visualization of the patient’s neuroanatomy and electrode placement based on preoperative MRI and postoperative CT. After we started IGP in our clinic in 2023, a change in patients’ behaviors was noted, as requests for follow-up visits decreased and the follow-up meetings also became less complicated and shorter. Objective: This retrospective study compares number of return visits when regular monopolar review was used with the number of visits when image-guided programming was used and number of required adjustments after DBS initiation. Population: Sixteen patients with bilateral subthalamic nucleus DBS for PD were included: 8 initiated with image-guided programming (IGP group) using StimView XT, BSC, and 8 initiated with conventional monopolar review (MPR group). The demographics for both groups were similar regarding age, disease duration, symptom characteristics, and preoperative UPDRS III scores. All patients were operated with directional leads with programming on several levels/segments. The number of follow-up visits and visits resulting in adjustments beyond amplitude change over the first 8 months were counted. Results: During the 8-month follow-up period, the MPR group had 40 visits, with 22 involving treatment adjustments. The IGP group had 21 follow-ups, with 10 requiring adjustments. Patients declined routine return visits since they were satisfied with the symptom control. Conclusion: In this retrospective real-world single center study Image-guided STN DBS programming for PD resulted in fewer follow-up visits and treatment modifications compared to monopolar review. In conclusion, applying IGP saves time for both clinicians and patients and reduced clinical workload at our DBS-center. Further research will involve large number of cases and prospective evaluation to further validate these observations.

Background MRI-guided focused ultrasound (MRgFUS) has emerged as a non-invasive therapeutic approach for movement disorders, particularly essential tremor and Parkinson’s disease tremor. By targeting deep brain structures (e.g., the thalamus), MRgFUS achieves precise lesioning while avoiding the risks associated with open surgery. However, perilesional oedema may contribute to transient adverse events—such as gait imbalance and sensory disturbances—especially when oedema extends into cerebellothalamic pathways, the internal capsule or the more posterior sensory thalamus in the hours following the thalamotomy. While volume lesion has been associated with side effects, its role in sustaining clinical benefit remains unclear. Despite the worldwide growing adoption of MRgFUS, no standardized intraprocedural protocols currently exist. This study aimed to explore current perioperative practices—including pharmacological management and procedural staffing—across MRgFUS centers in the Europe, Middle East and Africa (EMEA) region. Methods A 36-item online survey was distributed to the 40 active MRgFUS centers MRgFUS in the EMEA region between February and March 2025. The questionnaire addressed steroid protocols, symptomatic premedication, anaesthesia practices, and the involvement of specialized personnel during the procedure. Three reminder emails were sent to maximize the response rate. Data were collected anonymously and analysed using descriptive statistics. Results Twenty-five centers from 13 countries completed the survey (response rate: 62.5%). All centers treated essential tremor, and 72% also treated Parkinson’s disease. The thalamus was the primary target (100%), followed by the subthalamus (36%) and globus pallidus internus (16%). Steroids were routinely used by 60% of centers—mainly dexamethasone (84%). An additional 32% of centers administered steroids selectively, typically in cases with relatively large lesions and/or significant perilesional oedema to mitigate early post-treatment adverse effects. The remaining 8% reported never using steroids. Timing of administration varied: 16% preoperatively, 36% postoperatively, and 40% both. Tapering protocols were inconsistent. Analgesics (primarily paracetamol) were used routinely in 84% of centers, and antiemetics (mainly ondansetron) were used always or as needed in 88%. Only 3 centers reported routine use of anaesthetics, especially during the stereotactic frame placement. A dedicated nurse was present in 60% of centers; anaesthesiologist support was routine in 40%. Discharge at home occurred on the same day in 28% of centers and on the following day in 56%. Conclusion Our findings highlight substantial variability in intraprocedural MRgFUS practices across EMEA centers, particularly regarding steroid medication and perioperative management. This underscores the need for harmonized guidelines to improve patient safety, standardize treatment, and enhance comparability across future multicenter trials, especially those investigating the role of steroids in determining the final lesion volume and potentially preventing adverse effects.

Background: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an established treatment for Parkinson’s disease patients with motor response fluctuations. To date, initial DBS settings are based on a monopolar review (MPR). MPR is time-consuming and subject to patient fatigue. Imaging-based programming (IBP) has emerged as an alternative to MPR, using preoperative MRI and postoperative CT to determine optimal initial DBS settings based on individualized anatomy. Objectives: To evaluate the efficacy of IBP compared to MPR by assessing differences in motor symptom improvement for STN DBS in patients with Parkinson’s disease. Methods: For this systematic review and meta-analysis, a literature search was conducted in MEDLINE, Cochrane Library, Embase, and Web of Science databases using the following search terms: Parkinson’s disease, STN DBS, and IBP. Inclusion criteria for studies were: Parkinson’s disease, STN-DBS, IBP, and the use of the MDS-UPDRS III as outcome measure. The primary outcome was motor symptom improvement measured with the MDS-UPDRS III after STN-DBS (preoperative medication OFF-state to postoperative medication OFF and stimulation ON-state). Secondary outcomes included: time needed to determine the initial DBS settings, adverse effects, and battery consumption. For the primary outcome data were pooled using a random-effects model. Results: Eleven studies were included, of which eight directly compared IBP and MPR. Six of the eight studies had a randomized cross-over design and two were cohort studies. One cross-over study had a follow-up duration of three months (eight patients), another of four weeks (ten patients), and four studies assessed the MDS-UPDRS III within the same day (92 patients). The follow-up duration in cohort studies was twelve months (142 patients) or the same day (25 patients). No difference in MDS-UPDRS III motor improvement was found between the two methods (absolute mean difference -0.2 points, p = 0.83, 95% confidence interval -1.8 to 1.5 points). The reporting of secondary outcomes was inconsistent. In six studies, IBP appeared to be less time-consuming compared to MPR. One study reported fewer adverse effects with IBP, while another found no significant differences between IBP and MPR. Findings on battery consumption were mixed: two studies reported no difference, while others indicated that IBP may reduce consumption compared to MPR. Conclusion: This systematic review suggests IBP is a possible alternative to MPR for determining initial STN- DBS settings in Parkinson’s disease, as it provides comparable motor outcomes while requiring less time to identify the optimal initial DBS settings compared to MPR.

Background: Respiratory dysfunction is an underrecognized non-motor symptom in Parkinson’s disease (PD), contributing to morbidity and mortality, particularly through aspiration pneumonia. Previous studies have reported restrictive pulmonary patterns, upper airway obstruction, and decreased respiratory muscle strength in PD. While the impact of dopaminergic therapies on respiratory function is variable, the effect of surgical interventions such as deep brain stimulation (DBS) on oxygenation remains unclear. We aimed to evaluate the long-term effects of DBS on peripheral oxygen saturation (SpO₂) in PD patients, by comparing preoperative values with those obtained during routine follow-up visits for internal pulse generator (IPG) replacement. Methods: We retrospectively analyzed data from 67 patients with idiopathic PD who underwent bilateral subthalamic nucleus implantation. The mean disease duration prior to DBS was 9.9 ± 6.4 years. Peripheral oxygen saturation (SpO₂) values were recorded in room air at rest both prior to surgery and at the time of IPG replacement, which occurred after a mean duration of 4.95 years. Patients with known pulmonary disease, cardiac failure, or active infection were excluded. Statistical comparison was performed using paired t-test. Results: Mean preoperative SpO₂ was 95.7 ± 1.15% (range: 92-98%), whereas follow-up SpO₂ at the time of IPG replacement was 96.6 ± 2.17% (range: 96-100%), representing a statistically significant increase (p = 0.0023). The improvement in oxygenation was consistent across patients and was not associated with changes in medication dose or respiratory comorbidities. No patients were receiving supplemental oxygen. Conclusion: Our findings suggest that DBS may confer long-term benefits on SpO₂ in PD patients, potentially through improved motor function, posture, and respiratory mechanics. While causality cannot be confirmed in this retrospective design, the observed increase in SpO₂ supports the hypothesis that neuromodulation might positively influence non-motor symptoms such as subclinical respiratory dysfunction. Further prospective studies incorporating objective respiratory function tests and imaging are warranted to elucidate the underlying mechanisms.

Background: Although Deep Brain Stimulation (DBS) is a safe and proven treatment modality for patients suffering from debilitating movement and neuropsychiatric disorders, it is not free from complications. Surgical procedures with medical implant placement carry a higher risk of skin-related complications but also constitute the danger of intracerebral infection by spread of an infection from extracranial part of DBS system to DBS electrodes implanted in the brain. The aim of this study was to report the incidence and management of patients with intracranial infections in a large cohort of patients after DBS surgery. Methods: A retrospective analysis of clinical data was performed on patients who underwent DBS surgery between November 2008 and April 2025 at the Department of Neurosurgery, Institute of Psychiatry and Neurology, Warsaw. We included data of 683 patients who underwent 1227 DBS lead implantations. Of the 683 patients, 6 (0,88 %) patients experienced intracranial infection episode. Thus, of the 1227 DBS lead implantations, intracranial infection affected 6 DBS leads (0.49%). There was no case of bilateral intracerebral DBS lead infection. The intracranial infection episodes were diagnosed by computed tomography in all patients and in one by additional magnetic resonance imaging. The most common pathogen was methicillin-sensitive Staphylococcus aureus found in 5 patients. All patents with intracerebral infections required revisions surgeries. The total number of revisions surgeries including DBS hardware reimplantation was 20. No patient with a reimplanted DBS system experienced a further episode of intracerebral infection. Conclusions: Our study suggests that intracerebral infection affect around 0.88 % patients and 0.49 % implanted DBS electrodes. Proper management of skin erosion and infection following DBS surgery constitutes a challenge in everyday clinical practice. These skin-related complications should be managed timely to avoid the spread to the cranial vault by DBS leads. In cases of infection of DBS hardware the neuroimaging examination at least computed tomography should be done to exclude intracranial infection.

Background: Despite well-established selection criteria, clinical outcomes following subthalamic nucleus deep brain stimulation (STN-DBS) in Parkinson’s disease (PD) remain variable. This heterogeneity highlights the importance of individualized factors such as comorbidities, biochemical, metabolic, inflammatory states, given the multifactorial nature of PD pathophysiology. In this study, we aimed to identify clinical, demographic, and laboratory predictors of early motor response after DBS using machine learning models. Methods: Sixty PD patients (MMSE ≥27) who underwent bilateral STN-DBS were evaluated. Preoperative variables included age at DBS, disease duration, comorbidities, and laboratory parameters (urea, glucose, creatinine, HbA1c, thyroid function, vitamin B12, ferritin). UPDRS-III total and subscale scores (tremor, rigidity, bradykinesia, axial) were assessed before and one month after surgery. Classification models (Random Forest, CatBoost, Gradient Boosting, XGBoost, LightGBM, logistic regression, deep learning) were applied to predict good vs. poor motor response (≥33% improvement). For continuous outcome prediction (UPDRS total and subscale score changes), Random Forest, Gradient Boosting, CatBoost, LightGBM, XGBoost, and linear regression models were used, with performance assessed via MSE, RMSE, MAE, and R². Results: CatBoost achieved the best classification accuracy (0.83, ROC-AUC: 0.88), with Random Forest showing the highest ROC-AUC (0.90). The key predictors of favorable response included younger DBS age, earlier disease onset, higher preoperative tremor scores, lower urea, and elevated B12 levels. In regression models, Random Forest best predicted total UPDRS change (R² = 0.60), linked primarily to higher UPDRS III total score, bradikinesia, and tremor scores, lower HbA1c, and earlier disease onset. XGBoost best predicted bradykinesia (R² = 0.66) and rigidity changes (R² = 0.64), with lower GFR and higher B12 favoring bradykinesia, and absence of hypertension and lower HbA1c favoring rigidity. Tremor improvement (R² = 0.84, Random Forest) was mainly influenced by higher UPDRS III score and lower HbA1c. Axial gains (R² = 0.50, Random Forest) were moderately predicted by longer disease duration, higher baseline UPDRS III score, lower urea, and lower glucose. Conclusion: Machine learning models successfully identified clinical and biochemical factors predictive of early motor outcomes of STN-DBS. In this study, alongside clinical factors such as earlier disease onset, lower DBS age, and higher baseline UPDRS III scores, glucose metabolism and renal function markers emerged as key predictors. These findings support a personalized approach integrating routine blood biomarkers and patient-specific traits into DBS prognosis.

1. Introduction Deep brain stimulation (DBS) of the globus pallidus internus (GPI) has proven an effective treatment for various dystonias, including genetic forms such as DYT28, a rare subtype associated with a KMT2B-gene mutation. This case report describes the first DYT28 patient who underwent asleep bilateral GPi-DBS in our hospital. 2. Material and methods The patient’s motor and functional impairment was assessed using standardized rating (BFMDRS and TWSTRS). The GPi-DBS implantation occured in early February 2025 with only short-term follow-up data available. 3. Result We report the case of a 55-year old male diagnosed with DYT28-dystonia undergoing GPi-DBS. The patient presents with progressive generalised dystonia in the upper limbs, neck and head with diskinesia, spasticity, progressive gait impairment, bilateral hearing loss and speech difficulties. His symptoms started at around 30 years old. He scored a 26/28 on the MMSE during the cognitive testing, writing task could not be performed. A lumbar puncture excluded a GLUT-1 deficiency. Brain MRI showed no abnormalities. Genetic screening revealed a heterozygote frameshift variant in exon 27/37 of the KMT2B-gene, c.5558dup, p.(Pro1854SerfsTer118) classified as pathogenic. Bilateral electrodes (Cartesia®, Boston Scientific®) were implanted in the GPi under general anaesthesia. Stereotactic targeting was performed (Elements©, Brainlab©) using pre-operative high resolution MRI sequences (i.e. T1 MPRAGE, PD axial and coronal) merged with a pre-operative CT localisation scan. Intraoperative imaging (O-Arm Medtronic®) confirmed appropriate electrode placement. The DBS device was activated directly postoperatively, with a significant improvement in dystonic movements within 24 hours. At four weeks postoperatively, we observed a significant reduction in upper limb, neck and head dystonia and diskinesia, along with complete pain relief. 4. Conclusion KMT2B related dystonia presents unique challenges due to its progressive and generalized nature. GPi-DBS has emerged as a promising intervention for refractory cases. In this patient, bilateral GPi-DBS resulted in significant motor improvement consistent with prior reports on the efficacy of DBS in rare genetic dystonias, including DYT28 dystonia.

Objective: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a well-established treatment for patients with advanced Parkinson’s disease (PD). Intraoperative microelectrode recording (MER) is commonly used to electrophysiological delineate the STN and guide selection of the optimal implantation site for the DBS electrode. However, the extent to which MER-based trajectory selection correlates with intraoperative clinical testing remains under investigation. Therefore, we aimed to evaluate the predictive value of MER signal quality in identifying the optimal stimulation trajectory during intraoperative testing in patients undergoing STN-DBS for PD. Methods: We retrospectively assessed intraoperative data from 110 consecutive PD patients who underwent bilateral STN-DBS implantation at a single center. For each implantation side, an average of 3 trajectories were preoperatively planned using stereotactic MRI with a combined coordinate-based and direct visualization targeting approach and subsequently evaluated intraoperatively using MER. The electrophysiological signals of each trajectory were qualitatively classified by a neurologist specialized in movement disorders, based on signal amplitude, neuronal firing pattern and background activity. Independently, intraoperative stimulation with awake clinical evaluation was performed to determine the trajectory yielding the best acute symptom control at the highest threshold for side effects. We then assessed the concordance between the trajectory with the most favorable MER signal and the one selected based on intraoperative clinical outcome. Procedural safety was assessed using cranial CT to detect hemorrhagic complications after surgery. Results: In approximately 82% of cases, the trajectory classified as having the best MER signal matched the trajectory selected for final lead implantation based on intraoperative clinical testing (p<0.05). This correlation supports the hypothesis that high-quality MER signals are predictive of optimal stimulation sites for intraoperative testing. Importantly, no serious adverse events, especially no intracerebral hemorrhage or brain edema were detected on postoperative imaging, supporting the procedural safety of multi-trajectory MER. Conclusion: Our findings highlight the value of MER in electrode placement during STN targeting. The strong correlation between the best electrophysiological trajectory and intraoperative clinical outcomes suggests that MER may serve as a reliable proxy for identifying the optimal stimulation site. Additionally, the absence of SAEs despite multi-trajectory exploration confirms the safety of this approach. This may help reduce reliance on awake testing during surgery and support continued use of MER as a valuable adjunct to intraoperative evaluation for optimal DBS lead placement.

The process of deep brain stimulation (DBS) programming -- determining active contacts and the optimal stimulation parameters -- remains largely manual, time-consuming, and reliant on trial-and-error. To address this challenge, we present TuneS, an automated open-source pipeline for model-based DBS programming, designed to support clinicians in identifying patient-specific stimulation strategies that maximize therapeutic benefit while minimizing side effects. The pipeline reconstructs the DBS scenario in silico based on individual patient imaging data, including pre- and post-operative MRI and CT scans. This reconstruction enables patient-specific modeling of the volume of tissue activated (VTA), quantifying the spatial extent of stimulation spread. Stimulation targets and regions where stimulation has to be avoided due to possible side effects are defined using either standard neuroanatomical atlases or segmentations derived from the patient’s own imaging data. Importantly, the framework allows for targeting of both traditional subcortical nuclei and white matter tracts, thereby broadening the scope of optimization beyond conventional approaches. Tunes applies mathematical optimization techniques to patient-specific models and determines the most effective DBS contact configurations given a set of user-defined anatomical targets and constraints. In particular, it enables constraint-aware stimulation design that accounts for individual neuroanatomical variability and complex lead geometries. The pipeline supports different optimization strategies, including Linear Programming and Mixed Integer Linear Programming formulations, the latter allowing for discrete control over contact selection and non-uniform current distributions. TuneS is currently used as a clinical research tool for DBS individualization in Parkinson’s Disease (PD) and Essential Tremor. Extensions allowing for application of the platform to psychiatric conditions and blepharospasm are under way. Preliminary results from a cohort of PD patients show that motor-related streamlines within the subthalamic nucleus consistently receive a high portion of the VTA in clinically effective stimulation configurations. These findings suggest that streamlines may serve as valuable optimization targets, emphasizing the importance of incorporating tractography into DBS planning. The ability of TuneS to evaluate multiple target configurations and observe anatomical constraints makes it a promising research tool for exploring alternative stimulation strategies across various disorders. To recapitulate, the TuneS pipeline enables systematic, model-based, and patient-specific DBS programming. It provides a structured approach for evaluating stimulation targets, a better understanding of the mechanisms underlying DBS, and facilitating informed, reproducible parameter selection. This work contributes to the growing field of precision neuromodulation and supports the long-term goal of improving clinical outcomes through individualized DBS therapy.

Parkinson’s disease (PD) is caused by the depletion of the dopaminergic neurons in the substiantia nigra. The cardinal symptoms are tremor, bradykinesia, rigidity and typically treated by medications. When it fails, deep brain stimulation (DBS) targeting the subthalamic nucleus (STN) is the next step. However, it provides a decent tremor control, the stimulation of the ventral intermediate nucleus of the thalamus (VIM) is more effective. In our study we present two special cases of Parkinson’s’ disease. The patients had disabling tremor as the leading symptom. To achieve best therapeutic effect of DBS, both the VIM and the STN should be targeted. This is surgically challenging. Instead of the standard frontal approach we used parietal entry to hit both VIM and STN by one electrode. The STN was identified on T2 images and the VIM by connectivity-based segmentation of the thalamus based on probabilistic tractography. Surgery was performed by a stereotactic frame-based technique. Intraoperative verification of the lead position was done by electrophysiology, functional testing and 3D X-ray imaging. Both patients had remarkable improvement (UPDRS III 17/132 vs 9/132 and 31/132 vs 17/132; Fahn-Tolosa-Marin Tremor Rating Scale 51/140 vs 12/140 and 43/140 vs 13/140) without any disabling complications. The presented cases are good examples that even standardized therapy provides good results for most of the patients, sometimes we have to come up with unique solutions to achieve the best outcome.

Introduction DBS is a safe and effective therapy for selected patients with advanced Parkinson’s Disease (PD), but it still is greatly underutilized, sometimes because of patient refusal. Patient reluctance to undergo DBS is a complex issue influenced by many factors. We analyzed key studies to understand the underlying causes. Methods In April 2025 we conducted a review of the literature on Pubmed search engine, using various combination of the terms: “Deep Brain Stimulation”, “Parkinson Disease”, “Parkinson”, “Underutilization”, “Underuse”, “Adoption Barriers”, “Low Usage”, “Refusal”, “healthcare patient acceptance”, with and without MESH terms. No costraints were applied regarding publication date, language or type of article. We also searched the bibliography of the selected papers to find additional material. Results We found 68 papers, of which were excluded: 15 because were duplicates, 20 weren’t about PD, 28 were about DBS for PD, but not pertinent to the topic of this review. Only five articles could be included in this review. Searching their bibliography we found 3 other papers, 2 of which weren’t pertinent and 1 was a duplicate. Das et al. (2021) showed that while most patients know about DBS, many express concerns regarding its safety, efficacy, invasiveness, and reversibility. Such concerns appear independent of the source of information, highlighting the need for improved healthcare communication across all channels. Dinkelbach et al. (2017) demonstrated that personalized education using targeted materials significantly boosts patient willingness to consider DBS. Addressing the optimal timing for surgery and side effects of both DBS and pharmacological therapy were crucial in influencing patient decisions. Kim et al. (2015) emphasized psychological barriers, mainly fear of complications and financial burden. However, they also found that trust in the physician's recommendations and encouragement from family members play a decisive role in overcoming initial hesitation. Südmeyer et al. (2012) observed that patient expectations range from realistic goals (symptom control and medication reduction) to unrealistic ones (complete cure). Therefore, correcting misperceptions through structured education is essential. Finally, Lange et al. (2017) pointed out that even neurologists often have incomplete knowledge about DBS, overestimating surgical risks and underestimating patient openness. This calls for improved physician education to enhance patient selection. Conclusions Patient reluctance toward DBS is a complex and often overlooked problem that requires a multifaceted approach: strengthening patient-physician communication, optimizing educational tools, offering psychological and financial support, enhancing neurologist training. Such efforts could significantly improve patient acceptance to this effective therapy.

Objective: This study aimed to evaluate the safety and effectiveness of a specific surgical protocol for internal pulse generator (IPG) placement during deep brain stimulation (DBS) surgeries, to reduce hardware-related complications such as infection, wound dehiscence, and erosion. Materials and Methods: We retrospectively analyzed patients who underwent initial IPG implantation or IPG replacement by a single neurosurgeon between October 2016 and June 2022. Patients with prior surgeries or follow-up in other institutions were excluded. A total of 54 IPG surgeries in 30 eligible patients were included. All procedures followed a standardized surgical protocol involving extended antibiotic prophylaxis consisting of intravenous administration of ceftriaxone and metronidazole during hospitalization and oral moxifloxacin until the suture removal on postoperative 21st day and more importantly, subpectoral IPG placement with blunt dissection to reach outer thoracic wall under major pectoral muscle. The primary outcome was incidence of IPG-related complications. Results: The mean patient age was 55.6 ± 11.2 years. The cohort had a male predominance (70%). The mean modified Rankin Scale (mRS) score was 2.57 ± 0.63, and the mean ASA score was 2.13 ± 0.35. Parkinson’s disease was the most common diagnosis (66.7%), followed by dystonia and essential tremor. Among 54 IPG surgeries (initial and replacements), no infections, skin erosions, or wound dehiscence were observed during a median follow-up of 5.33 years (range: 2.08–7.58 years). One patient (1.85%) developed a seroma after an IPG replacement; this patient had undergone thyroidectomy and tracheostomy due to thyroid cancer between the initial and replacement surgeries which imposed additional systemic stress and likely contributed to their susceptibility to postoperative complications. The seroma resolved without intervention. Conclusion: Subpectoral placement of the IPG from the initial surgery may significantly reduce hardware-related complications in DBS procedures. The absence of major complications across long-term follow-up—even in a population including smokers and patients with comorbidities—suggests that this protocol is a safe and effective approach. The only complication observed occurred in a high-risk patient with significant medical history, highlighting the importance of individualized risk assessment. Further prospective studies are needed to validate these findings and explore alternatives to extended systemic antibiotic use to prevent possible antibiotic resistance.

Objective: Here, we evaluate ongoing registry outcomes derived from patients implanted with directional Deep Brain Stimulation (DBS) systems with Multiple Independent Current Control (MICC) technology for treatment of Essential Tremor (ET). Background: Large, multicenter patient outcome registries are an important source from which to collect real-world clinical evidence. Ventral intermediate nucleus (Vim) DBS is a widely accepted therapeutic approach in properly selected candidates to manage ET. This clinical evaluation will help provide evidence in patients implanted with a DBS system for ET. Design/Methods: In this prospective, on-label, multi-center, international DBS registry, enrolled patients are implanted with a directional MICC-based DBS system (Vercise, Boston Scientific). Patients are followed up to 3-years where ET symptoms and overall improvement in quality of life are evaluated. Clinical endpoint evaluated at baseline and during study follow-up timepoints include Fahn-Tolosa-Marin Rating Scale (FTMTRS), the Essential Tremor Rating Assessment Scale (TETRAS), Quality-of-Life in Essential Tremor Questionnaire (QUEST), and Global Impression of change. Adverse events are also being collected. Results: Results from this registry demonstrate significant improvement in ET related symptoms and quality-of-life up to 12-month follow-up. A total of 63-patients (32 males, mean age= 66.1 years, mean disease duration= 20.4 years) received DBS. At the 12-month follow-up, a mean 7.4-hours/day reduction in tremor was noted (self­ reported, QUEST). Clinically significant quality-of-life improvement was observed at 6-months (mean QUEST SI score Δ from Baseline of 18.3 points; n = 39), and at 12-months (mean Δ in QUEST SI score from Baseline of 23.0 points; n = 33). No lead breakages/fractures were reported. Additional clinical and safety outcomes derived from on-going data collection and analysis will be reported. Conclusions: Results from this ongoing, prospective, multicenter, international real-world outcomes study using multiple­ source constant-current Directional DBS Systems for the treatment of Essential Tremor continue to demonstrate positive outcomes after 12-months follow-up.

Objective: This on-going registry seeks to collect/analyze real-world clinical outcomes out to 2-years follow-up in levodopa-responsive Parkinson's disease (PD) patients implanted with Deep Brain Stimulation (DBS) systems equipped with Multiple Independent Current Control (MICC) and Directionality. Background: Tracking those being treated for PD motor symptoms offers insight regarding the outcomes associated with the implanted DBS systems that are utilized by patients in the real-world clinical setting. Design/Methods: Prospectively-enrolled participants were implanted with Vercise DBS systems (Boston Scientific), a multiple-­ source, constant-current system, and assessed up to 3-years post-implantation as part of an on-going DBS patient outcomes registry (clinicaltrials.gov identifier: NCT02071134). Clinical measures recorded at baseline and during follow-up included MOS-Unified Parkinson's disease Rating Scale (MDS-UPDRS), Parkinson's Disease Questionnaire (PDQ-39), Global Impression of Change (GI(), and the Non-Motor Symptom Assessment Scale (NMSS). Adverse events and device-related complications are also collected. Results: Enrollment and device activation consists of 174-subjects (mean age: 64.2 ± 8.7 years, 68.5% male, disease duration 9.3 ± 5.1 years, n = 168) and 142-subjects, respectively. Assessment of MDS-UPDRS Ill in "off" medication condition demonstrated a 51% improvement (25-points, p<0.0001) in motor function at 6- months. This level of motor function improvement was maintained out to 1-year (22-point improvement) and to 2-years (24-point improvement) follow-up. As compared with baseline, over 93% of patients and over 89% of clinicians noted improvement (GIC) at 6-, 12-, and 24-months follow-up. Outcomes were improved in various quality life measures (PDQ-39): mobility, activities of daily living, bodily discomfort, emotional well­ being, and stigma. To date, no lead fractures or unanticipated adverse events were reported. Additional results derived from on-going data collection will be presented. Conclusions: Following DBS, outcomes derived from this on-going multicenter, prospective registry demonstrated improved motor function, quality-of-life, and satisfaction. This on-going registry will continue to provide insight regarding application of MICC-based directional DBS systems for PD as applied in real-world settings.

**RELATIONSHIP BETWEEN THE LOCALIZATION OF THE SUBTHALAMIC NUCLEUS AND THIRD VENTRICLE WIDTH IN PARKINSON’S DISEASE** **ABSTRACT** **Introduction:** Indirect targeting of the subthalamic nucleus (STN) is widely employed in deep brain stimulation (DBS) centers worldwide. Conventionally, STN targeting is performed based on the anterior commissure–posterior commissure (AC–PC) reference coordinates, which are clearly visualized on 1.5T or 3T high-resolution MRI scans. However, the location and size of the STN vary significantly among patients, which may impact surgical accuracy and outcomes. Recent studies have suggested a strong correlation between third ventricle width and the lateral positioning of the STN. In this study, we aimed to systematically perform a retrospective radiological analysis to investigate the relationship between third ventricle diameter and STN coordinates in patients with Parkinson’s disease. **Materials and Methods:** This study included data from 70 patients diagnosed with Parkinson’s disease who underwent DBS targeting the STN at our Neuromodulation Center between 2019 and 2024. The relationship between third ventricle width and the lateral position of the STN was evaluated. Findings were compared with targeting accuracy and electrode placement results. To minimize error margins, special attention was paid to the imaging quality, and 3 Tesla MRI scans acquired according to the deep brain stimulation protocol were used. Following the identification of AC–PC points and STN measurements, axial images at the same level were used to measure the third ventricle width. **Results:** Of the 70 patients included in the study, 51 (73%) were male and 19 (27%) were female. The mean disease duration was 9.68 (±4.29) years. Patient ages ranged from 32 to 83 years, with a mean age of 56.88 (±9.01) years for males and 55.0 (±7.33) years for females. The mean disease duration was 9.13 (±4.25) years for males and 11.15 (±4.16) years for females. The mean AC–PC distance was 24.53 (±1.45) mm overall, 24.78 (±1.43) mm in males, and 23.87 (±1.31) mm in females. The mean third ventricle width was 5.73 (±2.57) mm overall, 6.37 (±2.63) mm in males, and 4.04 (±1.39) mm in females. A significant correlation (p<0.05) was observed between third ventricle width and AC–PC distance in males. Furthermore, increased third ventricle width was associated with a more lateral position of the STN. This finding suggests the need for individualized targeting beyond the standard atlas coordinates. However, no clear relationship was detected between AC–PC distance and third ventricle width itself. **Discussion:** In Parkinson’s disease, variations in third ventricle size due to age, brain atrophy, and other anatomical factors are commonly observed. This study demonstrates that third ventricle width may serve as an effective predictor of lateral STN position relative to the AC–PC line. The AC–PC distances recorded were consistent with values reported in similar studies. These findings emphasize the potential importance of third ventricle width in improving targeting accuracy. **Conclusion:** A review of the literature reveals a scarcity of studies investigating the relationship between third ventricle width and STN coordinates. Our findings indicate that third ventricle width could be considered in indirect targeting strategies to minimize errors, though further studies with larger patient populations are required to validate this approach. Notably, the lack of volumetric measurement of the third ventricle represents a limitation of the present study.

Objectives: Methemoglobinemia (MetHb) occurs when Fe+2 in hemoglobin oxidizes to Fe+3 and this causes increased affinity to oxygen and may cause subsequent tissue hypoxemia. Patients with MetHb levels >10% may present symptoms of cyanosis. One of the most common reasons for acquiring MetHb is local anesthetics. Deep brain stimulation (DBS) surgery is used in Parkinson’s disease (PD), essential tremor and dystonia in our country and it is mostly done with awake surgery with infiltration anesthesia. But due to highly vascularized scalp, infiltration anesthesia is prone to systemic effects of local anesthetics like MetHb. In this study, we aimed to evaluate the risk of methemoglobinemia by reviewing methemoglobin values after infiltration anesthesia in patients with DBS surgery. Methods: The study included 62 patients aged >18 years who were admitted between January 2024 and February 2025 for DBS surgery (n = 62). All patients were administered infiltration anesthesia (n = 62). 7 of patients were done under general anesthesia, while rest of them (n = 55) were done with regional anesthesia. All patients received infiltration anesthesia with a mixture of prilocaine and isotonic (1:1) during frame insertion and with a mixture of prilocaine, bupivacaine and isotonic (1:1:2) during surgery (n = 62). Results: 54 patients (%87) had DBS surgery for PD while 8 patients are operated for dystonia and tremor. Mean age of patients was 57,3 while mean BMI was 68,5 kg. While the mean preoperative MetHb level was 0.74, the postoperative average was 3.49. An average of 25.36 ml of local anesthetic was administered. The MetHb level was >5% in 12 patients who underwent procedures (%19,3). Methylene blue is applied in 12 patients (%19,3), 2 of them had MetHb <%5; while in 2 patients with MetHb>%5, no treatment applied. Other than the mild decrease in O2 saturation, no findings obtained in patients. Discussion: DBS is most used surgery in movement disorders. It can be done both asleep and awake but mostly awake DBS surgery is used. However, it is stressful for patients and most DBS patients already have comorbidities. While postoperative pain is common in patients, hemodynamic stability should be achieved by suppressing surgical stress with optimal pain treatment to prevent complications in DBS surgery, like intracerebral hematoma, seizures or ischemic stroke. The risk of MetHb increases when therapeutic doses are increased or combinations of local anesthetics are used. MetHb is likely to occur in patients receiving prilocaine; therefore, clinicians must remain aware of this issue. In our practice, we prefer it, because it is non-vasoconstrictive and has no negative effects on wound healing. Conclusion: Especially patients operated under infiltration anesthesia have significantly higher risk of developing MetHb, so caution should be exercised when administering local anesthesia in areas with high blood flow, such as the scalp. This has even more importance in DBS patients who can have comorbidities and less tolerance to any additional surgical burden.

Background: Pantothenate kinase–associated neurodegeneration (PKAN) is a progressive autosomal recessive neurological disorder linked to PANK2 gene mutations that causes progressive generalized dystonia. Although there is wide phenotypic heterogeneity in PKAN cases, generalized dystonia is frequently a prominent clinical sign, which can be very disabling and the most severe manifestation is the emergence of status dystonicus (SD) a life-threatening condition in PKAN patients. Methods: Herein, we report on the effectiveness of bilateral pallidal deep brain stimulation (DBS) for disruption of SD in a 9 year-old girl with PKAN. The triggering factor for SD was an infection episode of respiratory tract. The patient needed urgent admission to the Pediatric Intensive Care Unity (PICU) with sedation and mechanical intubation. Any titration of sedative drugs resulted in quick reappearance of SD. A few weeks prior to SD, the patient was assessed during a routine visit with the disease-specific PKAN-DRS. Before deterioration, the scores in each subscale were: SC I – 0, SC II – 0, SC III – 15, SC IV – 3, SC V – 12, SC VI – 5. The patient was transferred to neurosurgical department. Under general anesthesia, bilateral implantation of directional DBS leads (Boston Scientific Vercise Cartesia Directional Lead) in globus pallidus pars interna was done. Intraoperative stereotactic CT confirmed proper placement of DBS leads by merging preoperative MR (Brain Lab Neuronavigation). Then, a rechargeable pulse generator was implanted in the left subclavicular region under the pectoral muscle. Stimulation was started immediately after surgery. Results: The SD resolved within 3 weeks. The patient was discharged home. 6 weeks post-operation, the patient is cooperative, communicates with parents, and has regained sitting tolerance. She hasn’t regained her prior neurological status yet; the second evaluation is planned within 4 weeks. Conclusions: This case demonstrates that emergent bilateral pallidal DBS may be life-saving procedure in PKAN patients experiencing SD. The follow-up period is relatively short, but based on previous cases of this type (10 cases described in the world literature), we assume that the presumed recurrence of SD in this patient was stopped.

Introduction: Deep brain stimulation (DBS) surgery is an effective method in the treatment of movement disorders. Different skin incisions such as bicoronal and semilunar are preferred in DBS surgery. However, linear incision is a less preferred method, especially if there is a foreign body under the skin, like DBS, and its effects on surgical recovery process, infection rates and cosmetic results have not been sufficiently studied. In this study, we aimed to evaluate the effect of the linear incision technique on electrode entry side we applied in DBS surgery on infection rates and cosmetic results. Methods: We retrospectively analyzed 450 patients who underwent DBS surgery in 2021-2025 with the diagnoses of Parkinson's disease, essential tremor and dystonia in our clinic. All patients underwent intervention with linear incision technique by same senior surgeon. During surgery, the incisions were carefully closed in accordance with the anatomical layers. Special care was taken to suture the fascia, subcutaneous and skin tissues separately. Before the closure process, vancomycin powder was applied into wounds. No additional bone drilling applied around burr holes to countersink burr hole cap. Patients were evaluated for postoperative infection development and cosmetic results. Infection rates were compared with standard data reported in the literature. Results: Only 5 patients had minor skin problems which necessitate local procedure so electrode entry site infection rates were determined as 1.1%. This is comparable to the superficial infection rate of 1.5% reported in the literature (Morita et al., 2017). Cosmetic evaluation revealed that the linear incision yielded aesthetically favorable outcomes. Compared to bicoronal and semilunar incisions, the linear approach resulted in smaller scars, avoided skin bulging, and better aligned with the natural hairline—benefits particularly appreciated by patients with sparse or no hair. However, further prospective studies with larger cohorts are needed to validate long-term cosmetic and clinical benefits. Conclusion: The linear incision technique for electrode entry side in DBS surgery demonstrated a low infection rate of 1.1%, which is comparable to previously reported superficial infection rates of 1.5%, and provided cosmetically satisfactory results, even without any drilling for countersinking burr hole cap. Although linear incision is less preferred in cases where there is a foreign body under the skin, a closure technique appropriate to anatomical layers including fascia and the application of intra-wound vancomycin may be effective in reducing infection rates. Our findings support the wider use of linear incision in DBS surgery, and more comprehensive studies are needed to clarify the advantages of this technique.

Objective: This study aimed to investigate the role of hyperdirect pathway (HDP) invasion, identified through deterministic tractography, in predicting clinical outcomes after subthalamic nucleus deep brain stimulation (STN-DBS) in patients with Parkinson’s disease. Methods: A total of 67 patients who underwent bilateral STN-DBS were included. Electrodes that showed therapeutic efficacy below 2 mA and induced side effects above 4 mA were defined as "sweet spot" contacts. The spatial relationship of these contacts to the HDP was analyzed, specifically whether the contact was located within the HDP and the distance from the pathway. The HDP was defined as fibers passing through the STN and projecting directly to motor and supplementary motor areas without passing through the striatum. Patients were divided into two groups based on their clinical outcomes: good outcome and poor outcome. Results: Active contacts in the good outcome group were more frequently located within the HDP. In contrast, active contacts in the poor outcome group were found to be more distant from the HDP compared to the good outcome group. Conclusion: Invasion of the hyperdirect pathway appears to be strongly associated with favorable clinical outcomes following STN-DBS. Targeting stimulation within the HDP using deterministic DTI may serve as a valuable strategy for optimizing surgical efficacy.

Objective: To describe the protocol of a multicenter, prospective, randomized controlled trial (EarlyFocus II) which evaluates the efficacy and safety of unilateral magnetic resonance-guided focused ultrasound subthalamotomy (STN-MRgFUS) in patients with early-stage Parkinson’s disease (ESPD) (i.e., <5 years from diagnosis). Background: Unilateral STN-MRgFUS improves motor manifestations in patients with PD.1 A pilot study suggested it may also be effective in patients with ESPD.2 Methods: People with PD of less than 5 years and Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) motor score 32 will be randomized 2:1 (n=36:18) to receive STN-MRgFUS or best medical treatment (BMT), respectively (Figure 1). Participating centers had extensive experience in functional neurosurgery, including STN-MRgFUS for PD. The primary efficacy endpoint is the between-group difference (STN-MRgFUS vs. BMT) in the change in the MDS-UPDRS Part III score off-medication at 12 months. Safety endpoint includes treatment-related adverse events. Secondary endpoints are changes in brain PD-related metabolic pattern (using 18F-fluorodeoxyglucose-PET), MDS-UPDRS I, II, IV, Unified Dyskinesia Rating Scale, PD-39 questionnaire and MDS-NMSS. Exploratory endpoints include striatal dopaminergic denervation (using 18F-fluorodihydroxyphenylalanine-PET) and time to PD progression milestones. The skull density ratio will serve for patient arm allocation3 adding a BMT arm to extend the long-term (36-month) follow-up pool, allowing for further comparison and disease progression assessment. Results: Thirty patients have been enrolled so far: 19 STN-MRgFUS, 9-BMT, 2 Low SDR and 2 pending screening. Conclusions: This randomized controlled trial primary aim is to evaluate the efficacy and safety of unilateral STN-MRgFUS in patients with ESPD. Furthermore, it will assess any effect on disease progression. 1. Martínez-Fernández R, Máñez-Miró JU, Rodríguez-Rojas R, et al. Randomized Trial of Focused Ultrasound Subthalamotomy for Parkinson’s Disease. N Engl J Med. 2020;383(26):2501-2513. doi:10.1056/nejmoa2016311 2. Martínez Fernández R, Natera Villalba E, Rodriguez-Rojas R, et al. Unilateral focused ultrasound subthalamotomy in early Parkinson’s disease: a pilot study. J Neurol Neurosurg Psychiatry. 2023;95(3):206-213. doi:10.1136/jnnp-2023-331211 3. Pineda‐Pardo JA, Martínez‐Fernández R, Natera‐Villalba E, et al. Skull Density Ratio as Arm‐Allocation Parameter for a Controlled Focused Ultrasound Trial in Parkinson’s Disease. Mov Disord Clin Pract. 2024;11(7):825-829. doi:10.1002/mdc3.14040

Data-driven guidance for thoracic spinal cord stimulation (SCS) programming remains essential for optimizing therapy. Our analysis of 9,197 unique stimulation trials from 19 patients implanted with Boston Scientific Artisan paddle leads at thoracic levels Th8-11 sought to identify robust relationships between stimulation parameters and sensory outcomes. First, contact orientation significantly impacts stimulation specificity. Comparing two-contact configurations, medio-lateral arrangements (contacts horizontally aligned across the spinal columns) produced substantially more focal stimulation than conventional rostro-caudal alignments (contacts vertically aligned along the spine). Medio-lateral stimulation activated significantly fewer dermatomes on average (approx. 1.8-1.9 segments vs. ~3.2 segments for rostro-caudal) and achieved single-dermatome activation several-fold more frequently (approx. 55-57% vs. 13-18% of trials). This highly statistically significant effect challenges standard programming paradigms favouring rostro-caudal setups. Second, waveform characteristics showed meaningful and consistent differences in perception dynamics. A custom stimulation waveform we developed (using a flattened low-amplitude but long-pulse width second phase), compared to symmetric biphasic waveforms, consistently required slightly higher threshold amplitudes for initial sensory detection. However, at higher stimulation intensities, our custom waveform reliably produced stronger sensations, resulting in a wider effective dynamic range. This characteristic offers potential advantages for therapeutic titration. Third, regional differences in sensory thresholds were consistently observed. Specifically, knee-related sensations typically require higher current amplitudes than thigh-related sensations (mean ≈ 7 mA vs 5.4 mA), although there is considerable overlap between the two distributions. This aligns with clinical observations regarding the specific challenges often encountered in achieving adequate coverage for patellar pain. These commonly confirmed findings-the superior specificity of medio-lateral contact orientation, the distinct dynamic range profile of symmetric vs custom waveforms, and elevated thresholds for the knee region-provide robust, data-driven principles. Utilizing these verified relationships can potentially enhance SCS programming efficiency and precision in targeting specific dermatomes based on validated parameter interactions.

Introduction Brain biopsy is a minimally invasive surgical technique which allows the surgeon to obtain a sample of abnormal brain tissue for diagnosis and research. Robotic devices have evolved significantly over the last years becoming an accurate and safe tool for stereotactic neurosurgery. The purpose of this study was to evaluate the feasibility and safety of the robot-assisted compared with navigation-guide biopsy techniques in our institution. Material and Methods We retrospectively reviewed the medical records of 102 patients diagnosed with brain lesions, that underwent a cerebral biopsy procedure in our department over the course of 4 years (May 2021 to April 2025). The planning of the procedures was on pre-biopsy imaging scans (MRI or/and CT). The stereotactic and neuroimaging tools used for the biopsy procedure included the frameless Stealth Station S8 Surgical Navigation System (Medtronic) and Zimmer Biomet ROSA ONE Brain robot. We have performed ROSA robotic assisted stereotactic brain biopsy starting from October 2024. Results In total, 102 patients underwent a brain biopsy procedure, of which 56 males (54,9%) and 46 females (45,1%). The mean (±SD) age at diagnosis was 50.8 (± 16.8) years. We accomplished navigation-guided brain biopsies in 88 cases (86,3%) and robot-assisted brain biopsies in 14 cases (13,7%). The most common diagnosis was glioblastoma (57 cases - 55,9%) followed by grade 2 or 3 astrocytoma (17 cases - 16.6%), brain metastases (10 cases – 9,8%) and primary central nervous system lymphoma (9 cases – 8,8%). The diagnostic yield was 96,6% (85 cases) for navigation-guided biopsy and 100% (14 cases) for robot-assisted biopsy. In 9 patients of the robot-assisted cohort (64,3%) multiple tumor samples of gliomas have been obtained along the trajectory of the needle (from periphery to the tumor core) and preserved for further research purpose (with the written consent of the patients). Postoperative neurological morbidity rate was 2.9% (3 cases), of which 2 cases for navigation-guided and 1 case for robot-assisted brain biopsy. Postoperative mortality rate was 0.98% (1 case in navigation-guided biopsy series). Conclusions Brain biopsy represents the main choice for the approach of small or deep-seated lesions which are infiltrative or located in eloquent areas of the brain. Robot-assisted brain biopsy is a precise, safe, and easy to perform procedure. It is preferable to navigation-guided biopsy, being more precise and less time-consuming procedure, especially in the case of multi-target biopsy approach of the lesion. This work is partially supported by the grant COFUND-EP-PERMED-PerCareGlio 89/2025.

Objective: Preoperative differentiation between primary central nervous system lymphoma (PCNSL) and glioblastoma (GBM) is crucial for appropriate management and surgical planning. Clinically relevant, in cases of PCNSL, treatment with corticosteroids severely hinders pathological diagnosis, which remains absolutely necessary , putting neurologists and neurosurgeons in peripheral hospitals or emergencies in the conflict, whether to treat patients with corticosteroids for symptom relief, risking inconclusive pathology results in case of PCNSL or forcing patients to endure the debilitating symptoms of cerebral edema until a biopsy can be performed. Our group previously developed and in-silico validated a neural network capable of diagnosing PCNSL [1]. This study aims to evaluate the diagnostic performance of an AI-assisted workflow, LINNDA (Lymphoma Identification through Neural Network Detection Aid), integrating human and artificial diagnostic performance, compared to human raters in distinguishing these two entities. Methods: 26 patients with histopathologically confirmed PCNSL or GBM operated via stereotactic frame-based biopsy at our center between 06/2022 and 04/2023 were included in this study. Ten expert raters independently reviewed the same set of images. LINNDA employed a DenseNet169 neural network trained on radiological images to generate diagnostic predictions in cases when expert raters disagreed on the diagnosis. Diagnostic accuracy, sensitivity, specificity, and interrater agreement were calculated for both LINNDA and human raters. Results: Overall, human raters achieved 83.46 ± 7.26% accuracy for the entire collective, with a slightly lower for GBM (81.05 ± 9.99%) than PCNSL patients (88.57±9.04%). In clinical decision-making, the final diagnosis is usually dependent on a consensus. We tested how two raters performed when their diagnosis was counted only correctly when both individual diagnoses were, in fact, correct. In 82% of cases (957/1170) combinations, the two human raters agreed, yielding a correct diagnosis in 90.39% . In the remaining 223 cases, the neural network was tasked with diagnosing the tumor in a secondary step. In 61.43% of these cases, the neural network could determine the correct diagnosis. Using this approach, through the integration of human and artificial intelligence, we could yield a significantly higher diagnostic accuracy for both PCNSL and GBM, with a notably high PPV for GBM at 97.78%. Conclusion: In this current study, we combined the artificial intelligence of our algorithm with the experience of clinicians in a clinical workflow. We evaluated, in a group of ten clinical raters and 26 prospectively enrolled novel patients, in which patients exactly the algorithm can aid in diagnosis. We found that while the neural network alone was not superior to skilled clinicians, in cases where two clinicians disagreed on their diagnosis, consulting the algorithm as a third, tie-breaking, vote resulted in a significant improvement in diagnostic accuracy. Overall, using the LINNDA approach, we could reach a positive predicative value for PCNSL of over 97.7%.   References: [1]: Naser, P.V., Maurer, M.C., Fischer, M., Karimian-Jazi, K., Ben-Salah, C., Bajwa, A.A., Jakobs, M., Jungk, C., Jesser, J., Bendszus, M., et al. (2024). Deep learning aided preoperative diagnosis of primary central nervous system lymphoma. iScience, 109023. https://doi.org/10.1016/j.isci.2024.109023.

Trigeminal neuralgia (TN) is characterized by recurrent, paroxysmal, unilateral facial pain originating from one or more branches of the trigeminal nerve. It is often triggered by activities such as chewing, talking, or even light touch. First-line treatment is pharmacologic, typically with carbamazepine or oxcarbazepine. For patients who do not respond adequately to medical therapy, surgical options such as microvascular decompression (MVD), rhizotomy, or radiosurgery are considered. When comparing treatment modalities, MVD shows a high success rate and long duration of symptom relief but carries risks associated with general anesthesia and surgery. Radiofrequency rhizotomy (RFR) involves fewer risks related to anesthesia and surgery, but has a higher chance of causing sensory disturbances. Radiosurgery offers a fair treatment effect without surgical complications, but tends to have higher recurrence and sensory dysfunction rates. In our institution, MVD, RFR, and Gamma Knife Surgery (GKS) are used in the treatment of TN. In this study, we compared the outcomes of these three modalities. A total of 145 patients were included between March 2013 and September 2024, spanning approximately 12 years. Comparison factors included treatment efficacy, duration of pain relief, reduction in medication use, complications, and recurrence rates. MVD was performed in 49 patients. The most common offending vessel was the superior cerebellar artery (SCA), with some cases involving a vein or persistent trigeminal artery. A few patients had previously undergone treatments such as GKS or RFR. Treatment success was defined as achieving a Barrow Neurological Institute (BNI) pain score of 3a or lower, which was observed in 85% of cases. Complete pain relief (BNI 1) was achieved in 67% of patients, with an average duration of 43 months. Treatment failure or recurrence occurred in 14%, and complications were observed in 8%. Among the seven patients with recurrence or treatment failure, five had SCA and two had venous offenders. Reported complications included sensory changes, cerebrospinal fluid leakage, and wound problems. GKS was performed in 63 patients. A marginal dose of 42.5 Gy to the 50% isodose line was used. Some patients had received prior treatments. BNI ≤3a was achieved in approximately 70% of patients, while 23% maintained BNI 1, with an average duration of 50 months. Treatment failure or recurrence was observed in 30%, and complications occurred in 31%, all of which were facial sensory disturbances. RFR was performed in 33 patients. The cases were almost evenly divided between classical and idiopathic TN. A portion of the patients had received prior treatments. BNI ≤3a was achieved in 63% of cases, and 33% maintained BNI 1, with an average duration of 18 months. Treatment failure or recurrence occurred in 36%, while complications were observed in 45%, which included facial sensory disturbances and tinnitus. When comparing the three treatment modalities in terms of effectiveness, recurrence, and complications, MVD demonstrated superior outcomes. It showed the highest rate of symptom relief, the greatest likelihood of discontinuing medication, the lowest rates of treatment failure or recurrence, and the lowest complication rates. GKS, consistent with previous literature, showed better long-term pain control than RFR, but with lower selectivity and a 1/3 incidence of sensory complications. Review of existing literature reveals some variation across studies, but consistently shows that MVD offers longer-lasting pain relief and lower recurrence rates. Our findings are in line with prior studies, confirming that MVD is more effective and associated with lower recurrence compared to the other two modalities. This study presents a single-center analysis comparing MVD, RFR, and GKS in the treatment of trigeminal neuralgia, focusing on treatment outcomes, recurrence, and complications. The choice of treatment should be made by carefully weighing the advantages and disadvantages of each method, along with various patient-specific considerations.

Introduction: Gasser´s ganglion stimulation is a new technique for trigeminal´s refractory treatment. These patients suffer from chronic pain which is not able to improve with medication or either other kind of treatment, by this way the gasser`s ganglion stimulation can improve the quality of life in these patients/ Objectives: to show the therapeutic results that our treatment had about gasser´s ganglion stimulation in patients who suffered from refractory trigeminal neuralgia and finally to find the way to avoid that the electrode migrate./Methods: the patients are treated in the gasser´s ganglion by stimulation with an electrode. In first place it is made in a provisional treatment, so if paint rate is 50% better than the previous one, it will be implanted with the IPG. Once it has been implanted, we secure them in order to make sure it will not move to another place./ Conclusion: the result show that the success rate in our patients is high and there is not any electrode`s migration in de final stimulation. In that way our secure system seems to be really good, furthermore there is not any other kind of surgical complications

Usually, they inability to produce a clot is a severe contraindication for implanting devices that include pumps or neurostimulators, but there are patients that can benefit from such procedures that are in this category. We describe a case of a patient with severe platelet disorder and inability to produce blood clots. This patient presented with severe case of CRPS II of the left limb. This patient had a history of clotting disorder, which exhibited from early age with severe post operative bleedings after simple procedures, like tonsillectomy and metatarsal orthopaedic procedure, and also with severe menstrual bleeding. After careful consultation with our hematology department, the patient was prepared for two weeks with specific lab work and administration of desmopressin and tranexamic acid. When the lab work showed sufficient platelet count clotting ability, we performed the implantation of two epidural electrodes up to T8 connected them with rechargeable neurostimulator with the pocket being prepared at the right flank of the trunk. The procedure was an eventful and no postoperative hematoma was observed, eventhough the patient exhibited the night prior to the procedure allergy to desmopressin and the treatment there after was exclusively performed with tranexamic acid. During the procedure and for 15 days post procedural the patient continued daily treatment with tranexamic acid. After that period the treatment was discontinued and the sutures were removed. Up to six months the patient did not develop any complication of the implantation and at the same time, a successful treatment was observed with 90% of improvement in quality of life and verbal analogue pain scales. We believe that such patients can benefit from these procedures when properly prepared according to daily testing and pre procedural treatment with the instructions of the attending haematologist.

Introduction: Neurovascular conflict (NVC) is the most common cause attributed to trigeminal neuralgia, which paved the way for the success of microvascular decompression. Although the link between severe neurovascular conflict and trigeminal neuralgia is well-established, there exists a gap in understanding other contributing aspects leading to pain, including the qualitative aspects of trigeminal nerve distortion. Utilizing advanced imaging technology, this study explores the reconstructed three-dimensional (3D) morphology of trigeminal nerves in trigeminal neuralgia patients to correlate deformities with the side and distribution of pain. Methods: Patients with trigeminal neuralgia and high-resolution magnetic resonance imaging (MRI) utilizing 3D constructive interference in steady state (CISS) were selected. Blinded evaluations of MRI scans were conducted, and trigeminal nerves were meticulously segmented using Brainlab Elements Software. The study involved 41 patients with trigeminal neuralgia, and parameters such as length, volume, and impressions in axial, sagittal, and coronal planes were blindly analyzed for each nerve. Results: The average age at the time of MRI was 58 years, with a mean pain duration of 4 years. Continuous pain was observed in 9 patients, 4 patients had concomitant multiple sclerosis, and 9 patients presented with preoperative hypaesthesia. The mean slice thickness of scans was 0.5 mm (range 0.3-0.7), deemed adequate for reconstruction of the morphology of the nerves. Painful sides exhibited severe coronal impressions in 17% of patients, moderate in 22%, and mild in 44%, while non-painful sides had 17% moderate, and 51% mild impressions. Sagittal impression was present in 56% of nerves on the painful side and in 39% of the nerves on the non-painful side. Coronal and sagittal deformities were associated with the side and distribution of pain. More deformities were associated with the side of pain. Adhesions contributed to the sagittal and axial impression of the trigeminal nerve. Conclusions: This morphological study concludes that deformities in both coronal and sagittal planes of the trigeminal nerve seem to be contributing factors to the pathogenesis of trigeminal neuralgia. Understanding the morphological features intrinsic to the trigeminal nerve could help in a better comprehension of the disorder and aid in refining individualized treatment for patients.

Introduction: Transcranial pulse stimulation (TPS) is a noninvasive neuromodulation technology that uses short pulses of focused ultrasound to modulate brain activity and can reach deep brain regions. There are currently no studies of TPS targeting deep brain areas in humans. Noninvasive neuromodulation reaching deep areas could be a predictive option for certain DBS indications. Objective: To evaluate the safety and efficacy of applying TPS in dorsal anterior cingulate cortex (dACC), in patients with severe and refractory neuropathic pain, who could be candidates for DBS in dACC Methods: Following approval by the ethics committee , 2 patients with chronic, severe, and resistant facial neuropathic pain underwent six sessions over two weeks of neuronavigation-guided TPS (Neurolith) in dACC. The sessions consisted of 3000 pulses per side at a frequency of 4 Hz, an energy of 0.25 mJ per pulse, witha total energy of 49,053 mJ per session. Patients were assessed before TPS and on the third day after the last TPS session using the following scales: Pain Catastrophizing Scale (PCS), the Hospital Anxiety and Depression Scale (HADS) and the Brief Pain Inventory (BPI) Results: Both patients showed significant improvement on the assessed scales. One of them wanted DBS in the dACC, with significant improvement at 10-month follow-up. Another patient preferred to continue with TPS sessions due to fear of surgery. She received one session weekly for the first month, and then one session every 15 days thereafter. Significant improvement was seen at 5-month follow-up. Discussion: In our experience, the dACC has been a feasible target, without adverse effects and with clinical efficacy. Although TPS can reach deep brain areas and its use is approved for stimulation of the brain surface in patients with PD and AD, the ideal parameters for accurately reaching deep areas, its efficacy and safety are unknown. Because it is a non-invasive, non-lesion, easy-to-use technique, it could be used as a predictor of DBS response, however the depth it reaches and its precision are limited and questionable. Conclussion: TPS in dACC could be a noninvasive predictor of DBS in dACC response for the treatment of the affective component in patients with neuropathic pain

Introduction: Depression significantly reduces quality of life, with up to 30% of patients classified as treatment-resistant. For these individuals, deep brain stimulation (DBS) of the superolateral medial forebrain bundle (slMFB in humans, mfb in rodents) has emerged as an experimental treatment, demonstrating rapid antidepressant effects in clinical and preclinical studies. However, the underlying mechanisms remain elusive. Gamma oscillations (30–100 Hz), driven by synchronized activity of GABAergic interneurons, have been linked to states of depression. Recent research found that mfb DBS increased low gamma activity in the medial prefrontal cortex (mPFC) of Flinders Sensitive Line (FSL) rats, a rodent model of depression, suggesting GABAergic interneurons may play a contributory role in the mechanism of action of DBS. Methods: In this study, we explored how an acute stimulation protocol, featuring three sessions of bilateral 130Hz mfb DBS lasting 30 minutes each, affects neuronal oscillations and gene expression related to GABAergic and glutamatergic activity. Using FSL rats (Stim n = 11, Sham n = 11) as a depression model and Sprague-Dawley (SD) rats (Stim n = 12, Sham n = 11) as controls, we recorded local field potentials under ketamine–xylazine anesthesia in the mPFC, nucleus accumbens (NAc), and ventral tegmental area (VTA), key regions of the reward circuitry. After recordings, brain tissues were collected for molecular analysis. Results: mfb DBS induced significant increases in high beta (21–30Hz) and more pronounced, low gamma (30–48Hz) oscillations in the VTA and NAc of FSL rats compared to SDs. In the mPFC, increases were non-significant due to high inter-animal variability within the FSL group, possibly due to biological differences affecting treatment response. We observed a progressive decrease in low gamma power across all regions over the three DBS sessions, indicating a rapid habituation effect. Additionally, we discovered baseline spectral power differences between FSLs and SDs, notably in the beta and gamma bands, which may reflect trait-like electrophysiological markers of the depression model. Preliminary qPCR results showed downregulation of parvalbumin gene expression in the mPFC of stimulated FSL rats, suggesting a complex effect of DBS on gamma involving alternative GABAergic or network-level mechanisms, with more genes and regions under investigation. Conclusion: Our findings indicate that acute repetitive mfb DBS modulates gamma oscillations in brain regions implicated in the pathophysiology of depression. These effects may involve underlying GABAergic mechanisms and highlight the potential role of gamma oscillations as a physiological marker of stimulation response.

Background Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by deficits in social communication and repetitive behaviors. While behavioral and pharmacological interventions remain the standard approach, some individuals with ASD and severe self-injurious behaviors (SIB) are refractory to conventional treatments. Neurosurgical interventions, including anterior capsulotomy and deep brain stimulation (DBS) targeting the posterior nucleus of the hypothalamus, have been explored as potential therapeutic strategies for such cases. Aim This study evaluates the clinical effects of anterior capsulotomy combined with DBS targeting the posterior nucleus of the hypothalamus in a treatment-resistant ASD case. The goal is to determine the efficacy of this approach in reducing self-injurious behaviors and improving behavioral stability. Methods This case study presents an 11-year-old boy with ASD and severe SIB who underwent anterior capsulotomy combined with posterior hypothalamic DBS. The patient exhibited extreme aggression and self-harm behaviors that failed to respond to multiple pharmacological treatments, including antipsychotics, mood stabilizers, and opioid antagonists. Preoperative imaging and neurophysiological assessments guided precise electrode placement. The surgical procedure included bilateral radiofrequency lesioning of the anterior limb of the internal capsule and implantation of DBS electrodes in the posterior hypothalamic nucleus. Results Post-surgical outcomes demonstrated a dramatic reduction in SIB immediately after DBS activation. The patient exhibited sustained improvements in aggression control and behavioral stability at follow-ups conducted at 2 weeks, 3 months, 6 months, 12 months, and 24 months post-surgery. His ability to engage in daily activities improved significantly, supporting the hypothesis that neurosurgical intervention may be beneficial in treatment-resistant cases of ASD with severe behavioral dysregulation. Conclusion The combined approach of anterior capsulotomy and posterior hypothalamic DBS represents a promising intervention for individuals with ASD who exhibit refractory self-injurious behaviors. This case underscores the need for individualized treatment strategies and further research to establish neurosurgical procedures as viable therapeutic options for ASD management. Future studies should explore long-term effects, optimal targeting strategies, and broader clinical applications of neurosurgical techniques in ASD populations.

Objectives: Medial forebrain bundle deep brain stimulation (mfb-DBS) evokes monoamine release like dopamine and noradrenaline, which are essential for affect regulation. Integrating fiber photometry and DBS in a rodent model, the study aimed to: (1) investigate the in vivo signaling of major depression disorder related receptors (α2A-adrenoreceptor and D2-receptor) at PFC and NAC during burst (iTBS) and continuous high-frequency stimulation (HFS, 130Hz); (2) explore cumulative effect or desensitization during intermittent stimulation; (3) compare monoamine signaling across ipsilateral, contralateral, and bilateral conditions; (4) examine monoamine signaling during chronic continuous stimulation; and (5) correlate affective behavior with monoamine activity. Methods: Fifteen male Sprague Dawley rats received either AAV9-hsyn-NE2m or AAV9-hsyn-DA2m injections and optic fiber implantation at the left PFC or NAC. DBS was implanted at bilateral mfb. Pseudorandomized intermittent stimulation (5s bursts for 20 repetitions) with iTBS/50 µs/100 µs DBS in ipsilateral/contralateral/bilateral conditions and sham were delivered in each consecutive day. After a 1-week washout, continuous stimulation (2 x 10 mins) was applied. The monoamine signaling and ultrasonic vocalization were recorded spontaneously during the stimulation via fiber photometry and two microphones, respectively. Ultrasonic vocalizations in the positive affect band were recorded and correlated with monoamine signaling. (Figure 1a) Results: High-energy HFS (100 µs) elicited the strongest monoamine signaling, followed by low-energy (50 µs) HFS and iTBS (Figure 1b, c, d, e). More monoamine signaling was observed in NAC compared to PFC. iTBS failed to evoke monoamine action in PFC. No desensitization or cumulative effect occurred after twenty 5s stimulations with 50s intervals. No significant difference was observed in ipsilateral, contralateral, and bilateral conditions. Five seconds of acute stimulation caused a peak of signaling, followed by a sustained decline after cessation of stimulation. The acute peaking of α2A-adrenoreceptor signaling in PFC started at 0.16 ± 0.1 s by ipsilateral stimulation until 0.65 ± 0.1 s and 0.26 s by contralateral stimulation until 0.83 ± 0.06 s. In NAC, it started at 0.31 ± 0.06 s by ipsilateral stimulation until 0.6 ± 0.06s and 0.34 ± 0.05s by contralateral stimulation until 0.55 ± 0.08s. The acute peaking of D2-recepter signaling at PFC started at 0.26 ± 0.17 s by ipsilateral stimulation until 0.94 s and 0.36 s by contralateral stimulation until 0.94 s. In NAC, it started at 0.24 ± 0.04 s by ipsilateral stimulation until 0.53 ± 0.07s and 0.3 ± 0.05 by contralateral stimulation until 0.55 ± 0.13s. For the chronic stimulation paradigm, an acute peak was followed by sustained signaling, with a noticeable rebound peak after cessation of the stimulation. Continuous stimulation induced more positive affect vocalizations than intermittent stimulation. The noradrenalin signaling in PFC showed positive correlation (r = 0.71) with positive affective vocalization (P = 0.02). Conclusion: Medial forebrain bundle DBS induced bilateral α2A-adrenoreceptor and D2-receptor signaling in the PFC and NAC, with levels dependent on stimulation energy. The delayed latency suggests indirect activation, likely via large myelinated fibers before reaching monoaminergic targets. Chronic continuous stimulation maintained receptor signaling and increased positive affective vocalizations.

Background: Thymic carcinoma is a rare, aggressive neoplasm that frequently metastasizes to the lungs, liver, and bones, but rarely to the central nervous system. Less than 50 cases of brain metastases from thymic carcinoma have been documented in the literature, and no consensus exists regarding their optimal management and follow-up. Case Description: Here, we report the case of a 54-year-old male who developed a solitary metastasis in the right temporoparietal region nearly four years after the diagnosis of metastatic thymic carcinoma. The lesion was discovered incidentally on follow-up PET-CT scan. He was treated with hypofractionated stereotactic radiosurgery (hSRS) using the Leksell Gamma Knife Icon (Elekta AB, Stockholm, Sweden), receiving a total dose of 25 Gy in 5-Gy daily fractions. No surgical intervention or whole brain radiotherapy (WBRT) was performed. Results: MRI showed near-complete regression of the lesion and cavity collapse at the first month, and complete remission was achieved at 4th months. The patient remains alive and recurrence-free at 17 months of follow-up. Review of Literature: To date, only five cases have been reported in which stereotactic radiosurgery (SRS) was used as part of a multimodal approach, typically in combination with surgical resection, to achieve intracranial disease control. Notably, hSRS was employed in only two of these cases, both alongside surgery; however, neither achieved progression-free survival. Conclusion: This case demonstrates that Gamma Knife-based hSRS may achieve durable control of solitary brain metastases from thymic carcinoma without the need for surgery or WBRT. It also emphasizes the importance of long-term neuroimaging surveillance in patients with thymic carcinoma due to the potential for delayed central nervous system dissemination.

Objectives Stereotactic radiosurgery combined with pharmacological treatment is currently one of the most acceptable alternatives for the treatment of trigeminal neuralgia (TN). The aim of this work is to report the pain response after CyberKnife® radiosurgery (CK-SRS) at 1 month (n=23), 1 year (n=20) and 2 years (n=10) in patients with refractory TN, as well as possible complications. Methods This study analyzed 23 patients with refractory TN treated with CK-SRS at our clinic. These patients received a single dose of 90 Gy with CK, except for one case of re-irradiation at 75 Gy. Clinical and demographic characteristics were obtained from medical records. Facial pain before radiosurgery and at 7, 15 and 30 days, as well as 1 to 2 years post-treatment was recorded with the Visual Analog Scale (VAS), while the Barrow Neurological Institute (BNI) Pain Intensity Score was obtained before treatment and at latest follow-up. The change in pain intensity was assessed with Friedman's test, using Conover's comparison to differentiate between each post-treatment control. The response in patients who opted for radiosurgery as first option and those who received previous non-pharmacological treatment was evaluated with the Mann-Whitney test. Pain-free survival was estimated with the Kaplan-Meier method. Results The mean follow-up of this cohort was 18 months. The change in BNI was toward pain reduction in 21 of the 23 patients (91.3%), from BNI I to II with fewer cases toward IIIa or IIIb, while one remained the same (IV) and one worsened (IV to V). Before radiosurgery patients reported severe pain with a mean VAS score of 10 (range 8-10). Early responses after SRS (7-30 days) showed a significant reduction in pain (p<0.001), as most patients' scores dropped to 4-6. At one year, these results were sustained (p=0.065). Patients with 2 years of follow-up maintained pain reduction from year 1 (p=0.337), with scores predominantly 0-1, except for patients 1 and 2. The most common side effect was non-bothersome facial hypoesthesia, emerging early and persisting in 13 patients (56.5%). Pain-free survival rate showed at 6 months 87% of patients were pain-free (BNI I-II), and the estimates at 12 and 24 months were 68% and 60%, respectively. Conclusions CyberKnife® radiosurgery proved to be a minimally invasive and effective treatment alternative with relatively rapid pain relief for patients with trigeminal neuralgia, as evidenced by significant early reduction in VAS scores and sustained outcomes at 1 and 2 years.

Background: Thyroid cancer brain metastasis is rare and usually associated with a poor prognosis. Gamma Knife radiosurgery (GKRS) is an effective treatment modality for the treatment of brain metastases; however, there is limited evidence defining its efficacy in the treatment of thyroid cancer brain metastasis, due to the low incidence of thyroid cancer brain metastasis. This study aimed to evaluate the clinical outcomes of patients with thyroid cancer brain metastasis treated with GKRS. Methods: A retrospective analysis was conducted on 10 patients with a total of 40 brain metastases from thyroid cancer, among all brain metastasis cases who underwent GKRS between 2005 and 2025 at two institutions. The median patient age was 67 years. Patient demographics, tumor characteristics, treatment parameters and follow-up data were reviewed. Radiological and clinical outcomes were evaluated both on a per-patient and per-tumor basis. Results: Among 3834 patients treated with GKRS for brain metastases, only 0.26% had primary thyroid cancer. The majority had papillary thyroid carcinoma (57.1%) and presented with multiple lesions (60%), metastases most frequently localized to the frontal lobe (47.5%). The median interval from primary thyroid cancer diagnosis to brain metastasis detection was 22 months. The median prescribed dose was 23 Gy. Local control was achieved in 95% of treated metastases, with progression observed in only two metastases (5%). In one case, radiation necrosis occurred but resolved without clinical effects. Distant intracranial metastases were developed in two patients during the follow-up period. The median follow-up period was 8 months and 80% of patients had died, with one death associated with brain metastasis while the remaining deaths were related to progression of the primary disease. Conclusion: GKRS provides favorable local control rates and a low complication profile in the management of brain metastases from thyroid cancer. Although the study is limited by a small sample size, these findings support the use of GKRS as an effective treatment option in selected thyroid cancer brain metastasis patients.

Comparison of accuracy and safety between frame-based and frameless DBS implantation Authors: MD Magočová Veronika PhD. (first author, presenter), MD Ján Bánoci PhD., Prof. MD Matej Škorvánek PhD., Asoc. Prof. MD Kaťuch Vladimír PhD., MD Kollová Aurélia PhD., MD Vladimír Haň PhD., MD Knorovský Kamil Institution: Pavol Jozef Šafárik University in Košice, Louis Pasteur University Hospital in Košice Keywords: Deep brain stimulation, stereotactic accuracy, frameless stereotaxy Introduction Deep brain stimulation (DBS) electrode implantation is traditionally performed using a frame-based technique; however, frameless DBS has gained increasing popularity. This study compares the accuracy, safety, and operative time of both techniques. Methods A retrospective analysis was conducted on 113 patients (76 frame-based DBS, 37 frameless DBS). We evaluated implantation accuracy (central electrode position vs. deviation), operative time, and occurrence of complications. Matlab-based calculations were used to provide an objective and reproducible method for assessing electrode accuracy. Results • Implantation Accuracy: The frameless method showed higher accuracy (94.6% vs. 73.7% correctly placed electrodes). • Operative Time: The average duration of frame-based DBS was 7 hours, while frameless DBS was 3.5 hours. • Complications: Fewer complications were observed with frameless DBS (2 infections) compared to frame-based (1 bleeding, 4 infections, 6 dislocations). Conclusion Frameless stereotaxy for DBS is faster, more accurate, and associated with a lower complication rate compared to the frame-based method. These findings support the broader adoption of frameless technology in clinical practice.

Background Subacute sclerosing panencephalitis (SSPE) is a chronic progressive disease affecting the central nervous system (CNS) as a consequence of persistent measles virus (MeV) infection. The disease is characterized by a pair of symptoms with variable progression from gradual cognitive and motor decline to coma, vegetative state and even death, over a period of 3–4 years from clinical onset. Its incidence is inversely proportional to vaccination coverage and its pathogenesis is still not well defined. The main risk factor is the measles virus and any conditions that may predispose the host to infection, such as a lack of group immunity or immunosuppression’s state. Furthermore, the earlier the age of measles infection is the greater the risk of developing SSPE.. Among the various treatment available the intraventricular interferon alpha administration demonstrated greater effectiveness. Method We described the step-by-step surgical technique of the positioning of an intraventricular catheter connected to a rechargeable subcutaneous pump. The main surgical steps and the pump settings are illustrated . Conclusion This surgical management guarantees a continuous drug release improving the therapeutic effect in terms of clinical and neuroradiological outcome and reducing the toxicity profile.

Akash Mishra1,2, Elizabeth Espinal1,3, Max Nentwich1, Serdar Akkol1, Gelana Tostaeva2, Sarah Johnson2, Ashesh D Mehta1,2, Stephan Bickel1,2,4 1 The Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, USA 2 Departments of Neurosurgery and Neurology, Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA 3Drexel University, Philadelphia, PA, USA 4Center for Biomedical Imaging and Neuromodulation, Nathan Kline Institute, Orangeburg, NY, USA How the brain integrates information across distributed cortical and subcortical regions is still unknown. High-frequency oscillations (HFOs) may serve as a mechanism for synchronizing neural activity across these brain regions. We investigated the potential role of HFOs during visual and memory processing using intracranial electroencephalography in human participants performing a visual perception task, a list learning task, and naturalistic narrative viewing with free recall. In a passive visual localizer task single-trial features of HFOs across widespread cortical regions were sufficient to classify image from six visual object categories to an accuracy of 85%. In the list learning task, hippocampal HFOs (hHFOs) increased during both encoding and retrieval phases, with these increases correlating with memory performance. During retrieval, hHFOs activated semantic processing regions that had been active during encoding, characterized by broadband high-frequency activity (HFA) and cortical HFOs. Cortical HFOs in key semantic hubs, particularly the anterior temporal lobe, co-occurred with hHFOs, especially during retrieval. These coincident hippocampal-cortical HFOs (co-HFOs) were associated with greater cortical HFA. In naturalistic narrative processing (movie watching), hHFOs increased following event boundaries, with co-HFOs appearing in cortical regions known to support event segmentation (inferior parietal, precuneus, lateral occipital, and inferior frontal cortices). Importantly, event-specific patterns of co-HFOs observed during event viewing re-occurred following subsequent event boundaries in a decaying fashion and during later recall, consistent with replay-based models of memory consolidation. These findings suggest that HFOs may subserve coordinating activity across distributed brain areas in multiple functions from perception, to memory encoding, and recall.

It is common that patients that have been hospitalized, especially for a long period of time, are colonized by various nosocomial pathogens. Typical microbes include MRSA, proteus, various types of pseudomonas, e.coli, clostridium difficile and also various types of candida or similar fungus. So far there are no cohort studies to provide data about the management of such patients when they require implantation of specific devices like intrathecal pumps and neurostimulators. Although the tendency is to avoid implantations to these patients, there are cases that the use of invasive neuromodulatory devices is essential for these patients. We present our pre-implantation protocol of preparing these patients that we have applied to 12 patients with resistant or otherwise "difficult to deal with" nosocomial pathogens. 15 days before the procedure skin, blood, urinary, rectal and nasal cultures are taken and general blood work, including CRP and ESR are examined. After getting the results form the cultures, we proceed with 10 days of daily shower with Betadine and chlorexidine after initial soap shower and shaving of the implant-to-be area and rest of the trunk. During the procedure, the skinis prepared again with Betadine and chlorexidine or other alcoholic agent. In the pocket, powder of Vancomycin is also applied. Post procedural antibiotics or antifungal drugs are used for at least five days intravenous according to the cultures, taking also into account previous cultures from their medical history. We report 12 patients, 8 men and 4 women, presenting 6 with severe spasticity, 2 with intractable chronic and 4 with cancer pain, who were treated with this protocol that have been successfully implanted with pumps (8) or neurostimulator’s (2) or both (2), and did not develop any infection until one year post procedural. It is our opinion that when there is need for implantation, these procedures can be carried out with proper pre-, during and post- procedural management. Large cohort need to verify the safety of these protocols.

Background: Functional neurosurgery is rapidly advancing, emphasizing the need to evaluate contributions from emerging countries like Greece. This study offers a scientometric analysis of Greek publications, mapping the research landscape and impact in this field. Methods: A Scopus search was conducted using functional neurosurgery keywords, limited to Greek affiliations. Results: This search identified 3,198 publications. After screening, 276 were found to be in the field of functional neurosurgery and by authors affiliated with a Greek institution. All were written in English, apart from 1 in French and 3 in Greek. The majority (86.5%) were published after 2008, Most publications were articles (54.3%) or reviews (22.1%). The most common journals were Acta Neurochirurgica and Stereotactic and Functional Neurosurgery, with deep brain stimulation and epilepsy being the most frequent topics. First and corresponding authors were most frequently Greek-affiliated males. International collaboration was present in 55.2% of the publications, with no difference in citation counts compared to national-only collaborations. Only 27 publications were single-authored; most commonly by authors affiliated with institutions in Athens. The 50 top-cited publications had a median of 46 citations and 96% were either articles or reviews. More citations and higher Altmetric scores were found in publications that were longer, had more authors, were published in higher-impact-factor journals, and whose first author was not affiliated with a Greek institution. Conclusion: This is the first scientometric analysis of functional neurosurgery in Greece, providing a foundation for future research planning and policy-making in this growing field.

Introduction: Parkinson's disease (PD) is among the most prevalent neurodegenerative diseases, with its prevalence increasing with age. Despite the absence of a known cure for the disease, recent clinical findings have demonstrated that its symptoms can be effectively managed through the administration of suitable treatment. Speech is a biomarker that has been the focus of a great deal of research and could potentially aid in the early detection of the disease. However, the effective detection of the disease may be affected by other disorders, such as depression, which is a common feature of more advanced Parkinson's disease. Furthermore, deep brain stimulation surgery is limited by the severity of depression, which can be challenging to assess alongside other illnesses. Methods: The present study utilized speech recordings from patients diagnosed with depression and healthy individuals. All participants gave consent to record their voice sample for research purposes. The determination of descriptive features was conducted using an x-vector model that had been pre-trained on an English language database. Subsequently, these features were employed to train and test a Support Vector Machine (SVM), which estimated the severity of depression given the Beck Depression Inventory (BDI). Then we conducted a comparative analysis of the estimated severity values obtained from the patient diagnosed with Parkinson's disease and their original BDI. BDI scores were given by a questionnaire that was filled out by the subject. Results: The findings indicate that the model's estimates of BDI exhibit a greater margin of error (Mean Absolute Error and Root Mean Square Error) for patients diagnosed with PD compared to those diagnosed with depression and not PD. When the estimated severity values are projected to classification, it is evident that the number of samples that are falsely estimated as depressed is significantly higher in the case of PD. In contrast, the detection is more uniformly distributed in the classification of depression. Conclusion: A primary diagnosis, such as PD, has been demonstrated to influence the classifier's estimate of depression severity. The effect of this phenomenon is to shift the model output towards a false positive class. One potential explanation for this phenomenon is that PD may exert an influence on specific parameters of speech in a manner analogous to that of depression. Additionally, PD is more prevalent among the elderly population, while the depression dataset includes individuals of middle age. This age discrepancy can introduce a bias in the model.

Background The main purpose of this article is to report on the life, work and achievements of functional neurosurgeons, neurologists, psychiatrists and neuroanatomists located in Freiburg in the era of the newly founded Federal Republic of Germany along with the depiction of their long-lasting impact for functional stereotactic neurosurgery in Germany and abroad. Methods Review of available literature (Pubmed, Scopus, University Archiv of Freiburg, University Archiv Würzburg) and personal records (e.g. communications, biographical reports) was assessed and summarized providing an overview of the Freiburg School of Stereotaxy including the main protagonists Traugott Riechert (1905-1983), Rolf Hassler (1914-1984), Fritz Mundinger (1924-2012) along with Kurt Beringer (1893-1949) and Richard Jung (1911-1986) covering the years around 1950. Results The rise of stereotactic functional neurosurgery after World War II in Germany was inaugurated mainly by the Department of Neurosurgery in Freiburg through an interplay across neuro-associated disciplines. Close working relationships between the diciplines of neurosurgery (Traugott Riechert, Fritz Mundinger), neurology/psychiatry/neurophysiology (Kurt Beringer, Richard Jung) and neuroanatomy (Rolf Hassler) enabled the foundation, implementation and further development of stereotactic techniques targeting movement disorders, psychiatric indications, pain, epilepsy and brain tumors. Furthermore, educational efforts were undertaken to provide state of the art stereotactic neurosurgery, which led to the spread of the so-called Freiburg School of Stereotaxy throughout Germany and beyond (Gert Dieckmann 1925-2007; Fritz Roeder 1906-1988 / Hans Orthner 1914-2000; Konrad Nittner 1921-1994; Wilhelm Umbach 1915-1976, and others). Conclusion The work and fate presented herein underlines the eminent role of the protagonists and the Freiburg School of Stereotaxy for the development and maintenance of functional stereotactic neurosurgery in Germany. This accounts for the broad range of treated neurological disorders along with the passion to steadily strive for innovations and education displayed by the dissemination of stereotactic functional neurosurgeons across German universities ultimately leading to an increased number of stand-alone functional units and/or departments over the coming decades of the past century.

Meniere’s disease is a disorder characterized by episodic vertigo, tinnitus, and sensorineural hearing loss. These symptoms are often resistant to pharmacotherapy, and surgical treatment is required in many cases for achieving symptom control. Typically unrelated to Meniere’s disease, hemifacial spasm is caused by vascular compression of the facial nerve root exit zone, and microvascular decompression is known to be an effective treatment option. We report a case of a 50-year-old woman who was diagnosed with left-sided Meniere’s disease with accompanying ipsilateral hemifacial spasm and treated with a simultaneous vestibular neurectomy and microvascular decompression of the facial nerve using the retrosigmoid approach. The patient experienced alleviation of recurrent vertigo and hemifacial spasm over a 2-year follow-up period.

Introduction: Neurovascular compression of Vagus Nerve (VN) is rare. Common symptoms associated with VN compression include hiccups, cough, and symptoms of laryngeal contraction such as stridor. To our knowledge, isolated symptoms of swallowing induced hemi-pharyngeal spasm (HPS) have not yet been reported in relation to VN compression. Here, we present a case report of a rare case of dual compression of Vagus and Facial nerves resulting in hemi-pharyngeal and hemi-facial spasm, respectively. Methods: A patient with unilateral contractions in the neck/throat and face is reviewed. Results: A 65yr old female was initially diagnosed with hemifacial spasm (HFS) 5 years ago. She received multiple Botox injections in her face without significant long-lasting improvement in her symptoms. 2 years ago, she developed unilateral contractions in her neck/throat with swallowing. These were ipsilateral to her HFS. These symptoms progressively worsened. These were only triggered by swallowing and lasted a few minutes. There was no associated sharp pain, stridor or dysphonia. She remained asymptomatic in between her episodes. These symptoms were ignored by treating physicians while the focus of treatment remained on HFS. She was eventually referred to our clinic for further evaluation. After carefully reviewing her symptoms and detailed imaging, a loop of posterior inferior cerebellar artery (PICA) was identified compressing the lower cranial nerves and the apex of the loop touching the exit zone of facial nerve. Vocal cord analysis did not demonstrate any abnormalities. A retro-sigmoid approach was planned for microvascular decompression (MVD) for dual decompression of Vagus and Facial nerves. Intra-operative neuro-physiological monitoring prior to incision decompression increased electromyographic (EMG) activity in VN distribution. Once the VN was decompressed, the EMG normalized. Immediately post-op, she had complete resolution of her symptoms of both HPS and HFS. She remains symptomatic. Conclusions: Hemi-pharyngeal spasm should be recognized as a neuro-vascular compression syndrome which responds to microvascular decompression. Careful attention to symptoms and imaging is critical.

Background: Studies assessing the effectiveness of selective tibial neurotomy (STN) assume that the procedure combined with a rehabilitation program, reduces foot spasticity and allows the achievement of personal goals. However, few studies reported impact on the patient quality of life (QoL). Objectives: To prospectively assess the impact of STN on health-related QoL. Methods: Forty adult subjects with spastic foot, irrespective of the etiology, who underwent STN followed by rehabilitation program were prospectively included. Patient filled the SF-36 Questionnaire in the pre-operative period (T0), and 1 year (T1) follow-up. Each domain of the SF-36 is a multi-item questionnaire assessing physical Function (10 items), role limitations due to physical health problems (4 items), bodily pain (2 items), general health (5 items), vitality (4 items), social functioning (2 items), role limitations due to emotional problems (3 items) and emotional well-being (5 items). These eight scales can be aggregated into two summary measures: the Physical (PCS) and Mental (MCS) Component Summary scores. Results: At T1, the mean ± SD PCS was significantly higher (PCS = 40.0 ± 9.5) than at T0 (PCS = 33.8 ± 8.5, p = 0.0004 ). This improvement reflects a better perception of physical health, although the average PCS remained below the normative value of 50, indicating persistent physical limitations. In contrast, the Mental Component Summary (MCS) score did not significantly change over time, rising from 43.7 ± 10.3 at T0 to 47.0 ± 11.6 at T1 (p = 0.2), suggesting that mental well-being remained stable after the intervention. Conclusion: Selective tibial neurotomy followed by a rehabilitation program significantly improves the physical health perception of patients with spastic foot, as reflected by an increase in the PCS of the SF-36 one year after surgery. These findings highlight the importance of considering physical functioning as a measurable outcome of STN and support its role in improving health-related quality of life from a physical perspective.

Objective The study aimed to investigate the factors influencing local prognosis in patients with Chiari malformation type I undergoing modified posterior fossa decompression surgery. Methods A retrospective cohort study design was utilized to screen patients with Chiari malformation type I admitted to Chongqing Tongliang District People’s Hospital from October 2022 to September 2024. Patients who underwent modified posterior fossa decompression surgery were assigned to the study group (n=61), while those who received traditional posterior fossa decompression surgery were assigned to the control group (n=77). Compared the clinical characteristics and univariate logistic regression analysis was conducted to identify the risk factors affecting local stability at the cranio-cervical junction.Results The length of hospital stay, surgical duration, and CCOS and KPS scores at 3 months post-operatively for the two groups were (6.5±1.2) days vs (8.7±1.5) days, (180.4±25.3) min vs (210.3±30.1) min, 17.5±2.8 vs 15.8±2.2 and 85.2±8.1 vs 78.3±7.5 respectively, with significant differences (P<0.05). Univariate logistic regression analysis indicated that modified posterior fossa decompression surgery [OR=0.75 (95% CI, 0.63-0.91), P=0.02] was an independent risk factor affecting local stability of the condition at the cranio-cervical junction. Conclusion Modified posterior fossa decompression surgery effectively shortened the length of hospital stay and surgical duration while improving CCOS and KPS scores, and it was found to be beneficial for the local stability of the condition at the cranio-cervical junction.