Introduction: Deep brain stimulation (DBS) is an effective surgical procedure for the treatment of Parkinson’s disease (PD) and other movement disorders. Despite the acknowledged beneficial effects of stimulation on motor performances, immediate and delayed complications after DBS surgery have been described. Among these, peri-lead edema (PLE) is a relatively common DBS-related complication, but its etiology is still unknown. Moreover, PLE's exact frequency and long-term effects are subjects of ongoing debate. This study aims to elucidate the long-term clinical and neuropsychological outcomes of PLE and to find possible etiological correlates. Methods: We collected clinical and neuropsychological data from 51 PD patients before and one year after DBS. PLE visualized on FLAIR MRI sequence was manually segmented. Using appropriate statistical tests, continuous and categorical variables were compared between patients with and without PLE. Pearson’s correlation was used to correlate edema volume to clinical and neuropsychological variables. Finally, a multivariate regression model was employed to analyze the contribution of clinical variables to edema volume changes. Results: 68.62% of patients presented PLE at the immediate postoperative MRI. Patients with PLE were significantly older (59.34 ± 7.8 VS 47.44 ± 9.86 years, p<0.001) and had more frequent postoperative confusion episodes (9/35, 25.7% VS 0/16, 0%, p=0.025). Furthermore, more MER (microelectrode recording) tracks (3.31 ± 0.86 VS 2 ± 0.0, p<0.001) were used in patients with PLE. Multiple MER tracks were directly correlated with edema volume (r = 0.65, p<0.001) and were the only significant predictor of edema volume changes in a multivariate regression model (adjusted R2 = 0.408, p<0.001). No differences were found in other clinical and neuropsychological variables. Conclusion: PLE is a frequent post-surgical event and may cause transient postoperative confusion. It seems linked to older age and multiple MER tracks. Although it does not influence global long-term motor and neuropsychological outcomes, PLE contributes to postoperative confusion episodes. To avoid PLE sequelae, using multiple MER tracks in older patients should be discouraged.

OBJECTIVE: We aimed to evaluate whether patient-specific probabilistic tractography of the dentato-rubro-thalamic tract (DRTT) better predicts tremor improvement after MR-guided focused ultrasound (MRgFUS) thalamotomy for essential tremor (ET) compared to conventional indirect coordinate targeting. METHODS: We retrospectively analyzed 28 patients with medication-refractory ET who underwent unilateral MRgFUS thalamotomy between May 2022 and August 2024. All procedures were performed under real-time MRI thermometry monitoring. Post hoc probabilistic mapping of the DRTT was conducted using the Bayesian framework of the FMRIB Software Library (FSL; BedpostX and ProbtrackX), with manually delineated regions of interest (ROIs) placed on each patient’s native-space T1-weighted and diffusion-weighted images. To preserve anatomical fidelity, all analyses were performed in each patient’s native space without transformation to a standard template. Lesion centers on postoperative MRI were compared to traditional indirect coordinates and to tractography-based targets, specifically the peak voxels of the ipsilateral non-decussating DRTT (nd-DRTT) and contralateral decussating DRTT (d-DRTT). Tremor severity was assessed using Part B of the Clinical Rating Scale for Tremor (CRST-B), and improvement at 3 months was expressed as the percentage reduction from baseline. Correlation and multiple linear regression analyses were performed, including a subgroup analysis of patients who achieved a peak sonication temperature ≥55°C. RESULTS: Tremor improvement at 3 months, expressed as percentage reduction in CRST-B scores, showed weak negative correlations with lesion distances to the d-DRTT (r = –0.30) and nd-DRTT (r = –0.28), consistent with the notion that proximity to an effective target should yield better outcomes. Distance to the conventional indirect target showed a weak positive correlation (r = +0.22). None of these correlations reached statistical significance in the full cohort. In a subgroup analysis of 17 patients who achieved a peak sonication temperature ≥55°C, tremor improvement demonstrated stronger and statistically significant negative correlations with distances to the d-DRTT (r = –0.60) and nd-DRTT (r = –0.50). Notably, the correlation was strongest for the d-DRTT. The correlation with the indirect target remained weak (r = +0.13) and non-significant. Multiple linear regression analysis adjusting for maximum temperature in the full cohort demonstrated negative associations between tremor improvement and distances to both the d-DRTT and nd-DRTT, though these did not reach statistical significance. These findings confirm that the association between lesion proximity and tremor improvement became statistically significant in the ≥55°C subgroup, particularly for the d-DRTT, supporting the clinical relevance of patient-specific DRTT-based targeting in MRgFUS thalamotomy. CONCLUSION: Lesion proximity to the contralateral dentato-rubro-thalamic tract (d-DRTT), identified via patient-specific probabilistic tractography, was a stronger predictor of tremor improvement after MRgFUS thalamotomy than conventional indirect targeting. These findings support the potential clinical utility of individualized, tractography-guided targeting strategies in functional neurosurgery. Prospective validation is warranted.

Objective: To assess the clinical outcomes of an acute automated image-guided programming (aIGP) algorithm in patients with Parkinson’s disease (PD) implanted with a deep brain stimulation (DBS) system. Background: The effectiveness of DBS in Parkinson’s disease is highly dependent on multiple factors, including patient selection, optimal lead placement, and precise programming of stimulation parameters. Traditionally, DBS programming has been performed in a trial-and-error manner, requiring multiple patient visits to optimize therapeutic effects while minimizing side effects. Recent advancements in imaging and computational modeling offers the potential to improve DBS programming using image-guided algorithms, which may enhance efficiency, reduce patient burden, and improve clinical outcomes by systematically identifying optimal settings based on patient-specific anatomy and lead location. This report presents preliminary, first-in-human clinical results demonstrating the use of an automated image-guided programming (aIGP) algorithm in patients with idiopathic PD. Method: This is an ongoing, prospective, blinded, acute cross-over study involving 13 patients (10 male; 11 STN, 2 GPi) chronically implanted with a bilateral DBS system (minimum of 6-month post-DBS activation and on a stable standard-of-care (SoC) DBS program for at least 4 weeks). Patients present to clinic in a meds-off state and undergo programming with either SoC or aIGP before crossing to receive the alternative therapy. Blinded MDS-UPDRS III assessments in the meds-off/stim-on state is performed with both programs after which patients are restarted on medications and undergo an MDS-UPDRS III assessment in the meds-on/stim-on state with aIGP adjusted for medications. Results: Compared to meds-off/stim-off state, in the meds-off/initial aIGP suggested DBS-on state, motor symptoms significantly improved by an average of 37% (p=0.004). Similarly, in the meds-on/clinician-optimized aIGP DBS-on state, motor symptoms improved significantly by an average of 51% (p=0.00001). These improvements were not statistically different as compared to the optimized SoC DBS program in both the meds-OFF (p=0.81) and meds-ON (p=0.4) state. Conclusion: Here we present preliminary results that show an automated image-guided DBS program provides beneficial motor improvement equivalent to optimized SoC DBS programming. Further chronic evaluation of these automated programs are underway to evaluate the long-term efficacy.

Background: Transcranial MRI-guided focused ultrasound (MRgFUS) thalamotomy is an established, incisionless treatment for essential tremor (ET). Precise targeting of the ventral intermediate nucleus (VIM) is critical for efficacy but remains challenging, as the VIM is not directly visible on MRI and must be inferred from anatomical landmarks. Inaccurate targeting can result in off-target lesions and long-term sensory complications such as persistent sensory and motor deficits. Objective: To compare the targeting accuracy of RebrAIn’s OptimMRI, an automated machine learning algorithm, with traditional neurosurgical methods in patients who developed persistent numbness following MRgFUS thalamotomy for essential tremor. Methods: We retrospectively analyzed 11 patients who developed persistent numbness 1 month post-operatively from a challenging MRgFUS thalamotomy. For each patient, we recorded the neurosurgeon's original target coordinates and the final lesion site on post-procedure imaging. We then retrospectively used RebrAIn’s OptimMRI to generate an AI-predicted VIM target for each case. Targeting accuracy was assessed by comparing the Y-axis (anterior-posterior) deviation between the AI-generated target and the actual lesion site. In addition, deviations in the X-axis (medial-lateral) were assessed in patients who also had persistent motor deficits. Results: Among 11 patients with persistent numbness, the mean Y-coordinate of the final lesion was 7.0 mm anterior to the posterior commissure (range: 4.74–8.7 mm), while the mean Y-coordinate of the AI-predicted target was 7.77 mm anterior (range: 6.05–8.61 mm). The mean difference in Y position was +0.78 mm (SD: 0.61), with the AI consistently predicting a more anterior target than the final lesion in 10 out of the 11 cases (91%). Of note, in 4 out of 5 patients who had motor deficits (80%), the AI predicted a more medial target. Conclusion: Automated AI targeting systematically identified more anterior VIM targets compared to the lesions created by a neurosurgeon in patients with long-term sensory side effects, which is to be expected for an ideal target given the proximity of the sensory thalamus posterior to the VIM. In addition, this algorithm also correctly identified more medial targets in patients who developed persistent motor deficits – also to be expected as the internal capsule is lateral to the VIM. Thus, AI-driven approaches like OptimMRI could complement neurosurgical planning by offering data-driven guidance to optimize outcomes and minimize complications.

Background: Complete microsurgical removal of pediatric brain tumors remains a significant prognostic factor, but it is still associated with a significant degree of morbidity and mortality. Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) has recently been proposed for tumor ablation as an alternative to microsurgery in deep or eloquent tumors. We describe our experience and outcomes of using MRgLITT to treat pediatric brain tumors and analyze its limitations and strengths. Methods: We performed a retrospective analysis of 24 consecutive pediatric patients with brain tumors who underwent MRgLITT at our center. Clinical, radiological, and surgical data were retrospectively reviewed. Results: Twenty-five LITT procedures were performed on 24 patients. The median tumor volume was 1.24 cm 3 . The cerebellum was the most common tumor location (11/24), followed by the cerebral hemisphere (7/24), thalamus (3/24), optic pathway (1/24), brainstem (1/24), and IV ventricle (1/24). Median age at diagnosis was 7.5 years (range 1.2 – 15.09). Patients were followed for a median 3.2 [1.5 – 4.78] years. Of the 17 children with low-grade tumors, 11 underwent LITT at disease progression, and 6 underwent LITT at diagnosis. The 3-year PFS since the LITT was 100%. None of the children with low-grade tumors died. Of the seven children with high-grade tumors, 6 underwent the LITT procedure at disease progression. Four patients progressed and died after the LITT procedure, with an OS curve of 22.2% at 1.7 years after LITT. Conclusions: MRgLITT is a safe and effective approach for treating pediatric brain tumors with selected indications and has significant potential for use in several brain tumor treatment algorithms.

Introduction: Pineal gland tumors often require surgical management, which remains challenging in many cases due to their deep and complex location. Interstitial laser thermotherapy (LITT), particularly when combined with robotic assistance and image guidance, is an increasingly used minimally invasive technique in neuro-oncology for lesions deemed inoperable or high-risk by conventional approaches. We present a three-case series managed at Amiens University Hospital. Methods: Three patients were treated with robot-guided LITT for pineal region tumors between 2020 and 2024. The average patient age was 46 years. Two patients initially underwent endoscopic third ventriculocisternostomy for obstructive hydrocephalus with clinical signs of increased intracranial pressure. One patient received preoperative fractionated stereotactic radiotherapy. Two patients had preoperative oculomotor disturbances. Each patient underwent robot-assisted stereotactic biopsy to establish a histopathological diagnosis: a pineocytoma with leptomeningeal spread, a Grade 3 pineal parenchymal tumor of intermediate differentiation, and a Grade 3 papillary tumor. After multidisciplinary tumor board discussion, all tumors were deemed poorly accessible via open surgery with acceptable risk; LITT was therefore selected. Ablation was performed with the ROSA® robotic system and real-time thermal control using the VISUALASE® system (Medtronic), preserving surrounding functional structures. In two cases, two laser probes were used to optimize lesion coverage. Intraoperative MRI using FLAIR, diffusion-weighted imaging, gadolinium-enhanced T1, and spectroscopy confirmed adequate ablation. Results: Mean postoperative follow-up was 2.4 years. One patient developed a transient postoperative hemiparesis, which improved within days with corticosteroid therapy. All three patients received postoperative radiotherapy; one also received chemotherapy and later died from tumor progression and hemorrhage three years after LITT. The other two patients remain clinically stable under ongoing neuro-oncology and radiotherapy follow-up. Recent imaging confirms stability of the residual tumor in both. Conclusion: This small series suggests that robot-guided LITT is a promising, minimally invasive alternative for treating pineal gland tumors when conventional surgical approaches pose high risks. When combined with adjuvant radiotherapy, it offers effective tumor control with limited morbidity. Further studies with larger cohorts and longer follow-up are needed to validate these encouraging results.

Background: Central nervous system (CNS) tumors are the most common solid malignancies after leukemia in children worldwide, including in Armenia. The current study aims to analyze epidemiological data, treatment, and outcomes of children (≤18 years) with CNS tumors in Wigmore Women’s and Children’s Hospital, Armenia during the last 2 years. Methods: We have recruited data from patients treated for tumor surgery or other surgical interventions with CNS tumor in our Hospital for the last 2 years. Here were calculated incidence by sex, age, tumor localization, histopathology results and rates of other surgical interventions. Results: We present the results of studies conducted in our clinic on 30 patients. 17 ( 56,7% ) were male and 13 ( 43,3% ) female. Range of age: 6 months to 18 years, median age at diagnosis was 8 years (0-1 y: 2; 1-6y: 7 ; 6-12y: 10 ; 12-18y: 11). Infratentorial tumors (16) and supratentorial (14). Mostly diagnosed were astrocytomas 11 (36,7%); high-grade gliomas 6 (20%); medulloblastomas and other embryonal tumors 4 (13,3%); and low-grade gliomas 9 (30%). The patients were surgically treated 48 times. 47,9% (23 surgeries) were tumor resections and biopsy. Gross total resections amounted to 65,2%, subtotal resections and biopsies 17,4% each. Ventriculo/lumbo peritoneal shunt treated in 6 and endoscopic third ventriculostomy 5 patients. And during tumor surgery external ventricular/lumbar drainage was performed in 6 cases. Also we had 1 epidural and 1 subdural hematoma removal. Common complaints presented by persent of all patients. Headache had 63,3% (19) patients with CNS tumor treated; vomiting 40% (12); strabismus, vision loss 33,3% (10); seizures 10% (3); LOC (decreased level of consciousness) 13,3% (4); gait disturbance 10% (3); other 40% (12). Outcomes for 2 years of these patients were classified by Lansky Score: 90-100 (17, 56,7); 80-90 (4, 13,3%); 70-80 (5, 16,7%); death (4, 13,3%). Conclusion: Our results confirm that surgical management remains critical in treating pediatric CNS tumors, with gross total resection significantly contributing to positive outcomes. Functional outcomes, as assessed by Lansky Score, were favorable in most cases. The majority of patients were male, with a median age of 8 years. Infratentorial tumors were slightly more common the supratentorial, and astrocytomas represented the most frequent histopathological diagnosis. The study underscores the need for larger-scale national data on pediatric CNS tumors in Armenia. Future work should integrate molecular profiling and long-term neurocognitive outcomes.

Background: The relationship between tumor-to-corticospinal tract (CST) distance and the subcortical motor evoked potential (scMEP) threshold remains unclear. This study examines how contrast-enhancement charecteristics influence this correlation. Methods: We retrospectively analyzed preoperative imaging and intraoperative electrophysiological data from 323 patients who underwent resection of intra-axial tumors adjacent to the CST. We recorded the shortest distance from the tumor margin to the CST (as defined by DTI-based tractography) and the lowest stimulation current required to elicit an scMEP. To ensure the lowest threshold corresponded the minimal tumor-to-CST distance, only patient underwent gross total resection were included. Correlation between tumor-to-CST distance and scMEP threshold were analyzed, stratified by contrast enhancement status. Results: Of the 203 patients meeting inclusion criteria, 158 had contrast-enhancing tumors. The mean preoperative tumor-to-CST distance was 9 ± 7.4 mm (range: 0–20 mm) for enhancing tumors and 7.2 ± 5.4 mm (range: 0.9–20 mm) for non-enhancing tumors. The mean lowest scMEP threshold was 7.9 ± 4.7 mA (range: 1–25 mA) for enhancing tumors and 6.5 ± 4.5 mA (range: 1–20 mA) for non-enhancing tumors. A strong correlation was observed between tumor-to-CST distance and scMEP threshold in non-enhancing tumors (r = 0.73; 95% CI: 0.54–0.85; P < .0001), whereas the correlation was weaker in enhancing tumors (r = 0.37; 95% CI: 0.21–0.51; P < .0001). Conclusions: In non-enhancing tumors, preoperative tumor-to-CST distance reliably predicts the minimal current required to elicit an scMEP. However, in contrast-enhancing tumors, intraoperative scMEP mapping offers superior functional guidance, underscoring its critical role in surgical planning and decision-making.

Background: Deep brain stimulation (DBS) is an effective treatment for medication-refractory essential tremor (ET). Targets include the ventral intermediate nucleus (VIM) of the thalamus, the posterior subthalamic area (PSA), and the dentato-rubro-thalamic tract (DRTT). However, DBS can cause side effects like ataxia, dysarthria, and gait disturbance in approximately one-third of patients. The occurrence of habituation to DBS has also been linked to DBS-induced ataxia. DBS-induced ataxia may arise from unintentional stimulation of nearby white matter tracts or from activating the same fibers responsible for tremor reduction, making it challenging to determine the optimal DBS settings. This study aims to delineate the specific stimulation areas associated with gait impairment to optimize DBS function. Methods: Retrospective clinical assessments pre- and post-DBS were conducted using the Fahn-Tolosa-Marin (FTM) tremor rating scale for tremor improvement and the first item of the Scale for Assessment and Rating of Ataxia (SARA) for gait impairment. For 41 patients, stimulation volumes for 82 hemispheres were calculated using the Lead DBS pipeline. Significant voxels associated with either tremor improvement or gait impairment were identified through Spearman-rank correlation. Furthermore, a multivariate regression analysis assessed the influence covariates (active contact point coordinates, total electrical energy delivered (TEED), disease duration, sex, age, hemisphere or baseline SARA score) on the difference in SARA scores. Results: Analysis of the volume of tissue activated (VTA) of 41 patients revealed two overlapping regions of stimulation linked to both tremor reduction and gait disturbances (p<0.05, FDR corrected). These regions include VIM, PSA and DRT. No specific region or “sour spot” was identified as being uniquely responsible for gait impairment. Further post-hoc analysis showed that active contacts positioned more anteriorly were significantly associated with gait issues (p<0.01, uncorrected). Additionally, patients with higher baseline levels of gait ataxia experienced less progression of gait disturbances following stimulation (p<0.05, uncorrected). Conlusions: Our findings indicate that overlapping regions within the DRTT are involved in both improving tremor and contributing to gait problems. This paradox suggests that stimulation may affect multiple fiber pathways simultaneously, potentially leading to both therapeutic and adverse effects. However, within the DRTT, more anterior positioned fibers are associated with gait impairment. Previous studies suggest a somatotopic distribution within the DRTT and VIM. Further investigations using functional and structural connectivity are needed to further disentangle specific fibers involved in tremor improvement and DBS-induced ataxia, to be able to optimize DBS for tremor patients.

Deep Brain Stimulation (DBS) is a well-established treatment for symptoms of movement and psychiatric disorders. Its clinical efficacy relies on the positioning of the DBS electrodes in millimeter-sized anatomical targets. However, for many conditions, the optimal stimulation sites are still under discussion. In addition, few studies have highlighted the benefits of an asymmetrical placement of the electrodes between the first and second implanted hemispheres. Thus, this study aims at identifying optimal and sub-optimal stimulation positions for tremor alleviation in Essential Tremor (ET) and compare them between hemispheres. 497 (277 left, 220 right hemisphere) intra-operative stimulation tests of 23 ET patients yielding tremor improvement were analyzed. During the tests, tremor improvement was classified as: “null” (0%), “poor” (25%), “fair” (50%), “good” (75%), “excellent” (100%). Stimulation positions were marked on the patients’ electrode trajectories and transformed to a common anatomical space for cumulative analysis. The positions were labelled with 4 improvement categories: “low” (0

The aim of this work was to evaluate and compare measures of daily activity and quality of life in patients with Parkinson's disease (PD) during subthalamic nucleus neurostimulation (DBS STN) and after destructive interventions on subcortical brain structures. Methods A group of 80 patients divided into two groups was analyzed. A group of patients who underwent DBS STN on both sides (n = 40). And 40 patients with PD after stereotactic destruction of subcortical ganglia: VL - thalamotomy (n = 20) and pallidotomy (n = 20). Daily activity was assessed using UPDRS (part II) and Schwab and England scales. The dynamics of quality of life indicators was performed by the PDQ-39 quality of life questionnaire. Results In the DBS STN group after surgical intervention, there was an improvement in the Schwab and England and UPDRS (II part) scale scores of daily activities of daily living in the off and on-periods at all main follow-up stages. After 3, 6, and 12 months, the Schwab and England Scale of Activities of Daily Living scores doubled in the off-period; in the on-period, the improvement was 15%. After 24 months, the percentage of improvement in the off- and on-periods further increased slightly. On UPDRS Part II after 3, 6, and 12 months, there was 62% improvement in the off-period and 17% improvement in the on-period. There was a 12.5 % improvement in daily activities of daily living in the off-period and a 20 % improvement in the on-period after 24 months. In the group of unilateral stereotactic destruction the maximum improvement of daily activity was noted 3 months after the surgical intervention. According to the Schwab and England scale, in the off-period after 3 months the indices of daily activity increased by 58 %, in the on-period by 9 %; according to the UPDRS part II in the off-period - by 38 %, in the on-period - by 14 %. After 6, 12, and 24 months, a gradual deterioration of daily activities of daily living was noted. However, the Schwab and England scale at 24 months showed a 37% improvement in activities of daily living above preoperative levels. In the off-period and by 3% in the on-period. The UPDRS part II activity was 5% higher in the off-period and 14% higher in the on-period. When analyzing the dynamics of daily activity according to the II part of the UPDRS scale and the Schwaband England scale, statistically significant differences (p < 0.05) were found between the groups in off- and on-periods at all stages of follow-up. Analysis of the results of PDQ-39 questionnaire showed statistically significant improvement in the quality of life in patients of both groups 24 months after surgical treatment. In the STN NS group the improvement of the quality of life amounted to 31 %, in the stereotactic destruction group - 6 %. Changes occurred in increased mobility, communication, emotional well-being, and enjoyment of favorite activities. Conclusions After surgical treatment there is an improvement in the indices of daily activity and quality of life of PD patients, but the level of improvement is higher on the background of DBS of the subthalamic nucleus than after destructive interventions on the subcortical structures of the brain.

Background: MR Guided Focused Ultrasound (MRgFUS) is an incisionless and efficacious treatment for medication resistant ET and tremor dominant PD. Initial pre-operative targeting of the ViM often relies on generalized stereotactic coordinates, resulting in the need for significant awake testing during sonication to find the optimal targeting location. Despite the attention paid to targeting, gait disturbance remains a complication in a significant number of patients, most of which is transient. Although the occurrence of this complication is not solely related to the location of the lesion, several centers have shown that a deep lesion correlates with a higher frequency of gait disorder. While studies have previously described using DTI imaging for better preoperative targeting, no standard algorithm exists to create patient-specific targets. We present here the ReBrain AI algorithm that allows accurate prediction of the lesion target in MRgFUS patients and its correlation with imbalance. Objective: To demonstrate the efficacy of the ReBrain AI algorithm in predicting ViM lesion sites in patients with significant tremor improvement following MRgFUS sonication and its interest to correlate with gait disturbances. Methods: A retrospective analysis was performed of 161 ET and tremor dominant PD patients treated at a single center in the past 5 years with MRgFUS of the ViM. Patients were excluded that were missing pre or post-op tremor scores or gait analysis. Following chart review, anonymized MRI images of 50 patients were analyzed using a targeting algorithm. Two studies were carried out: a Z-axis correlation between the location of the RebrAIn prediction and the lower pole of the lesion, followed by a multi-direction analysis of the relationship between lesion position and the occurrence of gait disorders. Results: Analysis of the correlation between the distance from the RebrAIn target to the inferior pole of the lesion on the Z axis and the occurrence of a gait disorder shows that the deeper the lesion, the greater the risk, with a correlation coefficient of 0.36 (Figure 1). Multiaxis analysis of the directions shows that the deeper and more lateral the lesion, the greater the risk of gait disturbance (Figure 2). The maximal correlation value is 0.36 and it is achieved at direction (0.45 , 0 , -0.89). Conclusion: The Rebrain algorithm is effective in correlating the occurrence of gait disturbance after MRgFUS of the VIM in tremor. This study confirms that an inferior and lateral location of the lesion generates an increased risk of gait disturbance.

Phantom limb pain (PLP), a debilitating condition affecting up to 80% of amputees, remains a significant clinical challenge. Traditional management strategies, including neuromodulation, nerve blocks, and analgesics, frequently provide only transient relief, underscoring the need for innovative approaches. Targeted Muscle Reinnervation (TMR), a surgical technique initially developed to improve prosthetic control, has emerged as a promising intervention for preventing and treating PLP. By redirecting severed peripheral nerves into nearby denervated muscle tissue, TMR aims to restore physiological nerve signaling, mitigate disorganized axonal sprouting, and reduce the formation of symptomatic neuromas—a common source of neuropathic pain post-amputation. Despite its growing adoption, the clinical application of TMR, particularly in patients with chronic PLP lasting years, remains inadequately understood. Current evidence, largely derived from observational studies and small case series, suggests that TMR significantly reduces pain intensity and improves patient-reported outcomes. For instance, systematic reviews (Yuan et al., 2022) report statistically meaningful decreases in PLP incidence and severity, with postoperative Visual Analog Scale (VAS) scores often halved compared to standard care. However, the majority of these studies focus on primary TMR performed during initial amputation, leaving uncertainties about its efficacy in secondary procedures or in patients with long-standing pain. The pathophysiological rationale for TMR lies in its ability to provide a "biological target" for regenerating nerves, thereby preventing neuroma formation and aberrant nerve signaling. While this mechanism aligns with reduced pain reports in short-term follow-ups, the durability of these benefits and their applicability to chronic PLP populations remain unclear. Patients with prolonged pain may exhibit central sensitization or structural neural changes, potentially diminishing the effectiveness of peripheral nerve interventions like TMR. Furthermore, technical variations in surgical execution (e.g., nerve selection, muscle graft placement) and postoperative rehabilitation protocols complicate comparative analyses. Objectiveю.To evaluate the efficacy of Targeted Muscle Reinnervation (TMR) in reducing the intensity of phantom limb pain (PLP) in patients with limb amputations and chronic pain lasting ≥1 year. Materials and Methods. This is a prospective study of patients with chronic pharmacoresistant pain phantom syndrome, taking place at the Federal Center of Neurosurgery in Novosibirsk, Russia. This study will include participants with lower limb amputations and PLP duration more than 1 year. Our results will be evaluated by VAS, PainDETECT scale and SF-36 scale preoperatively, 6and 12 months postoperatively. At this moment 3 patients (aged 45–60 years) with limb amputations and PLP duration ≥2 years was included in the study. Initial results: Mean preoperative VAS score: 7.0 (range: 6–8). Mean postoperative VAS score at 6 months: 2.3 (range: 2–3). All patients achieved ≥50% pain reduction, with no reported complications. The most significant improvement was observed in a patient with a baseline score of 8 (reduced to 2). Conclusions: 1. TMR demonstrated high efficacy in alleviating PLP in patients with long-term pain (≥3 years), consistent with findings from systematic reviews (Yuan et al., 2022). 2. Results support TMR as a promising approach for preventing and managing chronic neuropathic pain post-amputation. 3. Further studies with larger cohorts and extended follow-up (≥12 months) are required to validate long-term outcomes. Perspectives. Integrating TMR into standard amputation protocols may reduce complications and enhance patients’ quality of life.

Introduction: Refractory facial pain (RFP) is a complex clinical entity often resistant to standard pharmacological and surgical treatments. Due to its multifactorial etiology and overlapping symptomatology with dental, neurological, ENT, and musculoskeletal disorders, accurate diagnosis and effective treatment remain challenging. To address this, we implemented a structured multidisciplinary team (MDT) approach aimed at improving diagnostic accuracy and optimizing therapeutic outcomes. Methods: A comprehensive MDT protocol was developed and implemented at Dubrava University Hospital. The MDT includes experts from neurosurgery, neurology, psychiatry, otorhinolaryngology, maxillofacial and oral surgery, anesthesiology, radiology, and physical medicine. The protocol is organized into three escalating treatment lines: (1) Diagnostic clarification and pharmacological therapy, (2) Interventional pain management, and (3) Advanced neuromodulatory and surgical options. Patients are referred via a centralized MDT email system and undergo coordinated assessment and individualized treatment planning. Regular follow-ups are conducted to evaluate clinical response and determine progression through therapeutic lines. Results: To date, a number of patients with refractory facial pain have completed the MDT evaluation and treatment process. Diagnostic precision was significantly improved, enabling the exclusion of secondary causes and appropriate patient stratification. Several patients progressed to the third treatment line and were treated with motor cortex stimulation (MCS). These patients demonstrated marked reduction in pain intensity and significant improvements in quality of life, with minimal adverse effects. Clinical success was most evident in cases with confirmed neuropathic pain phenotypes. Conclusion: The structured MDT approach offers a systematic and effective framework for managing refractory facial pain. It facilitates accurate diagnosis, reduces unnecessary diagnostics, and enables timely initiation of advanced treatments, such as MCS, for carefully selected patients. Our early clinical experience supports the continued development and potential expansion of this protocol as a model for comprehensive facial pain management.

Introduction: Spinal cord injury (SCI) remains a devastating condition with limited options for functional recovery and chronic pain management. Traditionally, spinal cord stimulation (SCS) has been reserved for refractory neuropathic pain; however, emerging evidence suggests its potential in promoting motor recovery and autonomic function in SCI patients. This report presents two illustrative cases exploring both conventional and novel indications for SCS. Methods: We describe two patients with SCI who underwent SCS implantation. The first, a middle-aged male with post-traumatic SCI due to a gunshot wound, presented with intractable neuropathic pain. The second, a young adult female with complete paraplegia following a motor vehicle accident, was selected for neuromodulation targeting motor and sensory improvement. Both patients underwent comprehensive clinical evaluation, imaging, psychological assessment, and intraoperative neuromodulation testing. Outcomes were assessed using pain scales, spasticity grading, and functional mobility indices. Results: The first patient experienced a significant reduction in pain intensity (VAS from 9 to 3) and decreased reliance on opioids within the first three months post-SCS. The second patient, despite complete motor paraplegia (AIS A), demonstrated unexpected early gains in trunk control, reduced spasticity, and subjective improvement within three months of stimulation onset. No device-related complications were observed. Conclusion: These two cases underscore the expanding therapeutic potential of SCS in SCI. While pain relief remains a well-established indication, neuromodulation may potentially offer functional benefits even in complete SCI. These observations advocate for broader research into the neuroplastic and rehabilitative effects of SCS and encourage reconsideration of candidacy criteria in the SCI population.

Introduction: Deep Brain Stimulation (DBS) of the subthalamic nucleus (STN) is a well-established treatment for advanced Parkinson’s disease (PD), offering significant symptomatic relief. Although DBS is generally considered safe, it carries risks, including the potential for delayed complications such as intracerebral hemorrhage (ICH). Case Presentation: We present a rare case of a 67-year-old male with PD who developed delayed ICH after undergoing bilateral STN DBS. Initially, the patient showed no neurological deficits postoperatively, with imaging confirming correct lead placement and no signs of hemorrhage. However, on the second postoperative day, the patient developed sudden right-sided hemiparesis. A CT scan revealed ICH alongside the left lead. The hemorrhage was managed conservatively, and the patient underwent extensive physical therapy, leading to significant improvement. Over the next two weeks, the patient’s condition improved, and follow-up CT scans showed complete resolution of the ICH. At this point, the left lead stimulation was initiated, further improving the patient’s PD symptoms. This case illustrates the potential for delayed ICH following STN DBS, emphasizing the need for ongoing monitoring and individualized treatment strategies. Conclusion: This case underscores the importance of vigilant postoperative monitoring and individualized management strategies in STN DBS patients. Early detection and appropriate management of complications such as ICH are crucial for minimizing risks and ensuring optimal patient outcomes. The potential for delayed complications highlights the need for continuous follow-up, even in the absence of immediate postoperative issues.

Introduction Subthalamic stimulation (STN-DBS) effectively ameliorates tremor in Parkinson’s disease according to clinical studies; however, objective outcome measurement is lacking. We aimed to explore how this therapy influences the kinematic parameters of the resting and postural tremor. Methods Thirty-one patients with tremor-dominant Parkinson’s disease treated with bilateral STN-DBS were recruited. Resting and postural tremor of the more affected hand were measured for 15 minutes with a three-dimensional gyroscope in the preoperative phase and a minimum of 6 months after STN-DBS implantation. After the Fourier transformation, the peak amplitude frequency, the peak amplitude, and the rhythm as the coefficient of variation were calculated. The MDS UPDRS motor scores and tremor scores were collected. Active contact distances from the center of the dorsolateral STN were measured. Results The mean age (±SD) of the patients was 63.2±7.67 years, there were 11 females and 20 males. Disease duration at the time of surgery was 8.1±4.37 years. Postoperative evaluation was performed 3.4±2.66 years after surgery. The MDS UPDRS III. (MED ON) scores improved from 15.8±10.85 points to 8.3±7.07 points (STIM ON - MED ON) after the operation. Resting tremor scores in the conditions mentioned above improved from 1.9±1.16 points to 0.26±0.51 points, while postural tremor scores decreased from 1.3±1.14 points to 0.2±0.42 points. The peak frequency of the tremor raised (resting: from 4.8±0.6 Hz to 7.2±1.91 Hz; postural: from 5.3±0.55 Hz to 8.0±1.3 Hz). Peak amplitude decreased significantly (resting tremor: 53.7%, postural tremor: 99.9% improvement). The rhythmicity of the resting tremor decreased by 55% and that of the postural tremor by 42%. The active contacts are located 2.6±0.97 mm from the center of the subthalamic nucleus contralateral from the more affected hand. Conclusion Subthalamic stimulation significantly improves tremor amplitude, reduces rhythmicity, and raises frequency more efficiently on postural than resting tremor in Parkinson’s disease. Disclosure The authors declare nothing to disclose.

Background: Deep brain stimulation (DBS) of the caudal zona incerta (cZI) has emerged as an effective treatment for tremor, potentially offering advantages over traditional targeting of the ventral intermediate nucleus (VIM). Given the role of the dentatorubrothalamic tract (DRTT) in tremor pathophysiology, proximity of stimulation to this tract may influence clinical outcomes. This study evaluated the association between the distance from active DBS contacts within the cZI to the DRTT and therapeutic efficacy. Methods: In this retrospective study, 12 patients with tremor who underwent cZI-targeted DBS were included. Preoperative diffusion tensor imaging (DTI) was used to reconstruct the DRTT via probabilistic tractography. Postoperative computed tomography was co-registered with MRI to localize active electrode contacts. The shortest Euclidean distance between each contact and the ipsilateral DRTT was calculated. These distances were correlated with clinical improvement in tremor severity. Results: Reduced distance between active contacts and the DRTT was associated with greater clinical improvement. Patients with contacts closest to the DRTT exhibited superior tremor suppression, suggesting that DRTT proximity is a key determinant of DBS efficacy in the cZI region. Conclusions: These findings support the integration of tractography-based targeting in cZI DBS for tremor. Closer proximity of stimulation to the DRTT may enhance clinical outcomes and should be considered in surgical planning to optimize therapeutic benefit.

Introduction: Deep brain stimulation (DBS) has become an established neurosurgical treatment for movement disorders such as Parkinson’s disease, offering significant improvements in motor symptoms and quality of life. In recent years, increasing attention has been directed toward peri-lead edema (PLE), a radiological finding observed postoperatively in some DBS patients. While often asymptomatic and self-limiting, PLE may occasionally present with clinical symptoms and has raised concerns regarding its etiology, impact, and optimal management. The underlying pathomechanism remains unclear. This study aimed to investigate potential factors associated with the development of PLE. Methods: A retrospective analysis was conducted of 119 patients with Parkinson’s disease who underwent bilateral DBS of the subthalamic nucleus with stereotactic planning and intraoperative computed tomography (iCT) between 2017 and 2025. Parameters collected included age, sex, type of stereotactic frame, anesthesia type (awake/asleep), presence and timing of PLE detection, and whether PLE was unilateral or bilateral. Statistical analysis was performed using JAMOVI version 2.6.26.0. Results: The median patient age was 64 years; 83 (70%) were male and 36 (30%) female. 56 (47%) patients were operated on using the Leksell Vantage frame and 63 (53%) with the Zamorano–Duchovny (ZD) frame. 91 (76%) underwent awake surgery and 28 (24%) under general anesthesia. A total of 112 patients had postoperative CT scans; 24 were symptom-triggered and the remainder were routine. 36 patients received CT within 21 days postoperatively, and 19 between days 21 and 91. In 18 of the 112 scans, PLE was detected, with a mean detection time of 17 days post-op. Of these, 11 (8.6%) were symptomatic and 7 (6.9%) asymptomatic. PLE was bilateral in 10 cases (56%) and unilateral in 8 (44%). In the univariable analysis, a trend toward an association between anesthesia type and PLE occurrence was observed, with higher rates following general anesthesia (p = 0.025). No significant associations were found for age (p = 0.789), sex (p = 0.764), or frame type (p = 0.148). Discussion: Literature suggests PLE typically develops within 21 days and resolves over several weeks. Some studies report correlations between asleep surgery, greater count of microelectrode recording (MER) usage, and PLE. Our data reports a correlation with asleep surgery. These findings support systematic early postoperative imaging in DBS patients while considering radiation exposure. Prospective studies are warranted.

Background. Drug-resistant epilepsy (DRE) secondary to hypothalamic hamartoma (HH) often requires surgical resection or stereotactic radiosurgery, which frequently fail to provide satisfactory outcomes and are associated with severe side efects. Magnetic resonance-guided focused ultrasound (MRgFUS) may represent a minimally invasive surgical approach to HH by ofering precise thermal ablation of sub-millimetric brain targets while sparing surrounding structures. Methods. We present the case of a 19-year-old man with HH-associated DRE, who was successfully treated with MRgFUS. The procedure resulted in efective ablation of the hypothalamic interface of the HH, disconnecting the epileptogenic lesion from the surrounding brain tissue. We also reviewed the literature on MRgFUS for DRE. Results. The patient experienced a complete resolution of seizures and signifcant improvements in social and occupational functioning over an 18-month follow-up period. No neurological, cognitive, or endocrinological adverse efects were observed. Conclusion. Our case report and literature review suggest that MRgFUS may achieve adequate seizure control in DRE associated with HH without adverse efects. While MRgFUS shows promise for other forms of DRE, data remain preliminary, and some safety concerns persist. Further studies with long-term follow-up are warranted to better support the use of MRgFUS in DRE.

Background: Drug-resistant epilepsy (DRE) may affect about 30% of patients suffering from epilepsy. Deep brain stimulation of the anterior nucleus of the thalamus (ANT DBS) is a proven neuromodulation therapy for patients with refractory focal seizures evolving into bilateral tonic-clonic seizures. The aim of the present study was to describe our long-term results regarding the efficacy and safety of ANT DBS in 16 consecutive patients with DRE. Methods: We prospectively analyzed the clinical data for patients with DRE who underwent ANT DBS. Moreover, we meticulously confirmed the location of implanted DBS leads within the ANT. Results: Sixteen patients with a mean age of 36.9 years (range, 23 - 48 years) at ANT DBS surgery (mean duration of DRE 25.8 years, range 5 - 41 years) were included in this prospective study. The median seizure monthly count in three months period preceding surgery (baseline seizure count) was 47.25 (range, 4-150). ANT DBS caused seizure frequency reduction at last follow-up (mean 27,3 months, range 3-57 months) by 66.4 %. Patients with temporal and frontal lobe epilepsy had a remarkable reduction of seizure frequency. No patient suffered transient or permanent neurological deficits. Over the follow-up period, 4 patients experienced abrupt reemergence of seizures due to depletion of implantable pulse generators. Replacements with rechargeable IPGs were associated with high impedance in 3 patients and problems with charging the pulse generator in 1 patient. Conclusions: ANT DBS is a safe and efficacious treatment for DRE. Clinical efficacy of ANT DBS may support more widespread utilization of this neuromodulation technique. Taking into account the relatively young age of the patients and long-term treatment, the use of rechargeable IPGs is recommended at the initial surgery.

Background: Intractable epilepsy originating from the isthmus of the cingulate gyrus is exceedingly rare and sparsely described in the literature. Most reported cases involve cortical dysplasia of the retrosplenial cortex, often presenting with temporal or motor-like seizure semiology. We present two cases of medically intractable epilepsy caused by tumorous lesions in the isthmus of the cingulate gyrus, both demonstrating non-localizing preoperative evaluations and favorable surgical outcomes. Case Presentations: The first patient, a 20-year-old female, experienced episodic unresponsiveness. Scalp EEG showed temporal spikes, and PET imaging revealed right temporal hypometabolism. However, MRI revealed a distinct tumor in the right isthmus of the cingulate gyrus. She underwent lesionectomy without invasive monitoring. Histopathological analysis confirmed a pilocytic astrocytoma. She remains seizure-free 19 years postoperatively, with normal follow-up EEG. The second patient, a 19-year-old male, presented with similar symptoms. Scalp EEG and PET suggested a left temporal epileptogenic focus, while MRI revealed a tumor in the right isthmus of the cingulate gyrus. Invasive monitoring with depth electrodes in the left hippocampus and right isthmus localized seizure onset to the isthmic lesion. Surgical resection was performed, and pathology revealed a low-grade epilepsy-associated neuroepithelial tumor (LEAT). Although he developed a postoperative abscess, which was managed with stereotactic drainage, he has had only one seizure during seven years of follow-up while maintained on a reduced dose of antiepileptic medication. Conclusion: These cases highlight the importance of recognizing tumors in the isthmus of the cingulate gyrus as a potential source of intractable epilepsy, even when non-invasive evaluations suggest misleading lateralization. Accurate lesion identification on MRI and targeted surgical resection, with or without invasive monitoring, can yield excellent long-term seizure control—even in deep, functionally complex regions such as the cingulate isthmus.

Background: Surgical resection remains the gold standard for treating medically intractable focal epilepsy. When non-invasive studies fail to adequately localize the seizure onset zone, intracranial EEG (iEEG) monitoring becomes essential. The two primary modalities—subdural EEG (SDE) and stereotactic EEG (SEEG)—offer complementary advantages. SDE provides high-resolution cortical surface mapping, while SEEG enables sampling of deeper brain structures with less invasiveness. A comparative effectiveness study has shown that SDE is more likely than SEEG to lead to surgical resection but is associated with a higher complication rate and lower probability of long-term seizure freedom. Given their distinct perspectives, there are instances when combined use of SDE and SEEG is required for optimal localization. However, dual implantation can increase surgical complexity and potential risk. Objective: To describe our technique and experience using endoscope-assisted SEEG implantation in patients already undergoing subdural electrode (ECoG) placement, with the goal of minimizing complications while achieving accurate electrode localization. Materials and Methods: Eight consecutive patients underwent combined SDE and SEEG implantation, using a minimally invasive, endoscope-assisted technique. A small craniotomy window (2.5 cm in diameter) was used for SDE electrode placement. A 4 mm rigid endoscope was then inserted through a planned cranial bolt site to visualize and assist in the implantation of SEEG electrodes under direct endoscopic guidance. The average time required to insert each SEEG electrode was 8 minutes. Results: There were no postoperative hemorrhages or neurological complications in any of the patients. Electrode placements were accurate and well-tolerated. The endoscopic approach provided real-time visualization, helping to avoid vascular injury and misplacement. Conclusion: When both SEEG and SDE electrodes are required, endoscope-assisted SEEG implantation represents a safe and efficient option to enhance visualization, improve accuracy, and potentially reduce complications. This technique may be particularly valuable in complex cases requiring multimodal intracranial monitoring.

Introduction: Deep brain Stimulation of the subthalamic nucleus (STN) is a proven treatment for advanced Parkinson’s disease (PD). Activation of the hyperdirect pathway (HDP) is thought to contribute to the therapeutic effects, while stimulation of the corticospinal tract (CST) is associated with capsular side effects. This study aims to investigate pathway-specific activation patterns—focusing on the HDP pathway and CST and to identify the optimal stimulation contact using computational models. Method: This retrospective study included analysis of 16 randomly selected PD-patients who underwent bilateral STN deep brain stimulation (DBS). For each patient, individualized probabilistic whole-brain tractography was performed, and target pathways were extracted using predefined patient-specific anatomical masks. A computational model was applied to simulate stimulation at all contacts in 0.5 mA increments with a constant pulse with (60us) and frequency (130Hz). The resulting pathway recruitments were visualized and analyzed. Contact ranking was performed using a mathematical function that prioritized two factors: maximal distinction between HDP and CST activation, and greater activation of the HDP across contacts. Result: Three different types of models were implemented: homogeneous, heterogeneous, and anisotropic. The homo- and heterogeneous models produced consistent results, identifying the same optimal stimulation contact. In contrast, the anisotropic model yielded lower activation levels across patients. A statistically significant difference was observed between the activation of the hyperdirect pathway and the corticospinal tract, as determined by a paired t-test (p = .0001). The clinically selected contact was ranked among the top three model-predicted contacts in 11 out of 24 leads, corresponding to an overall accuracy of 45.83% in identifying the clinically used contact. On average, HDP activation increased from 0.3653 at the clinical contact to 0.4840 at the model-predicted contact (+0.1187), while CST activation decreased from 0.0850 to 0.0516 (−0.0334), suggesting greater pathway selectivity in the model-recommended settings. *** The observed accuracy aligns with findings reported in previous studies. Discussion: Our model identifies the optimal stimulation contact, while the amplitude can subsequently be fine-tuned by the clinician. This could lead to a significant reduction in programming time. Notably, in this retrospective study, some patients were not stimulated on the contact identified as optimal by the model, which may have contributed to the limited observed accuracy. It is possible that patient fatigue during lengthy programming sessions prevented the selection of the overall most effective contact. Prospective clinical studies are needed to validate the model’s predictions under optimized conditions, potentially improving the efficiency and outcomes of DBS programming.

Background: Evoked Compound Action Potentials (ECAPs) represent a promising biomarker for closed-loop spinal cord stimulation (SCS) optimization. However, reliable ECAP detection remains challenging with significant inter-patient variability. This study investigates the relationship between temporal impedance changes and ECAP detectability following SCS implantation. Methods: We recruited 14 patients with surgically implanted SCS systems. Using a Blackrock Neuroport system, we performed parallel ECAP recordings across all 16 channels with various ground and reference montages. Impedance measurements were collected systematically across multiple post-operative timepoints. We analyzed the correlation between impedance patterns (both absolute values and inter-electrode variations) and ECAP detectability. Results: ECAP detectability showed marked inter-patient variability, with clear signals in some patients while remaining undetectable in others despite identical recording parameters. Analysis revealed a significant correlation between overall impedance levels and ECAP detectability. Patients with consistently detectable ECAPs demonstrated lower mean impedance values (417±152Ω) compared to those without detectable ECAPs (662Ω±332Ω). Notably, we observed distinct temporal patterns in impedance evolution post-surgery. Clear up- or down-trends as well as highly variable day-to-day measurement were indicative of ECAP detectability. Inter-electrode impedance variability also proved predictive: patients with homogeneous impedance patterns across electrodes demonstrated significantly better ECAP detectability compared to those with heterogeneous patterns. Conclusions: Our findings establish a relationship between impedance patterns and ECAP detectability in SCS systems. The temporal evolution of impedance following implantation appears to be a critical factor influencing ECAP recording success. These results suggest that: 1) impedance monitoring could predict optimal timing for ECAP-based SCS optimization, 2) electrode-tissue interface maturation follows predictable patterns that impact neural recording quality, and 3) impedance heterogeneity may indicate suboptimal electrode positioning (i.e. partial contacts burrowed in fat) or tissue response. This understanding could guide clinical decision-making regarding the timing of ECAP-based SCS programming and potentially improve closed-loop neuromodulation outcomes. Future studies should investigate whether active impedance management strategies could enhance ECAP detectability in challenging cases.

Background: Magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy has emerged as a compelling non-invasive alternative to deep brain stimulation (DBS) for treating essential tremor (ET) and tremor-dominant Parkinson’s disease (tdPD). Optimal clinical outcomes depend on precise targeting of the ventral intermediate nucleus (VIM) of the thalamus. However, direct visualization of the VIM on conventional MRI is limited, often necessitating indirect targeting based on anatomical landmarks. RebrAIn’s OptimMRI is a novel machine learning–based tool trained on a large database of ET and tdPD patients successfully treated with radiosurgical thalamotomy and then designed to predict an optimal thalamic target. Objective: To compare the target location predicted by RebrAIn’s OptimMRI algorithm with the actual lesion centroid created using standard neurosurgical targeting in MRgFUS thalamotomy. Methods: A retrospective analysis was conducted on 64 patients treated with MRgFUS thalamotomy at a single center. For each patient, coordinates for neurosurgeon-defined targets, ranging from one to three targets per patient (T1, T2, and T3), were recorded relative to the anterior commissure–posterior commissure (AC-PC) plane and compared to the “optimal” target coordinates predicited by RebrAIn. Additionally, post-procedural T2-weighted MR images were used to determine the lesion centroid (L1) coordinates which were also compared to the “optimal” target coordinates predicted by RebrAIn. Results: On average, neurosurgeon targets were within 1.5 to 2 mm of the RebrAIn-predicted target, with a tendency toward being more medial and inferior. When multiple targets were planned, usually to improve tremor control, the mean coordinates for the targets moved closer to the RebrAIn target. For 2-target cases (n = 38), the mean distance decreased from 1.8 mm for T1 to 1.4 mm for the mean of T1 and T2, with 97% of cases (37/38) showing such a reduction. For 3-target cases (n = 18), the distance decreased from 1.9 mm for T1 to 1.7 mm for the mean of T1 and T2, and further to 1.5 mm for the mean of T1–T3, with 83% (15/18) following this trend. In terms of the lesion itself, the mean lesion diameter was 4.5 mm. In 80% of patients, the lesion centroid was within 2.3 mm of the RebrAIn-predicted target, with a mean radial distance of 1.7 mm. In terms of x, y, and z planes, the greatest difference between the centroid and RebrAIn targets was in the x-plane. Conclusion: RebrAIn-predicted targets differ from traditional neurosurgical targets as well as the subsequent lesions created by an average of 1.5–2 mm—a margin that, in DBS procedures, might prompt electrode adjustment. Whether such differences are clinically meaningful in MRgFUS remains to be determined and is an area we are actively investigating. However, it is notable that in cases where multiple targets were selected to improve tremor control, the averaged coordinates aligned more closely with RebrAIn’s prediction. These findings provide preliminary evidence that the RebrAIn target may represent an optimal location for tremor suppression, highlighting its potential value in refining initial VIM targeting for MRgFUS and future use as a clinical tool.

Background Post-stroke movement disorders consisting of complex involuntary movement patterns with parkinsonism, dystonia, hemiballismus / hemichorea and tremor represent a therapeutical challenge. Deep brain stimulation has been considered an effective treatment option, although it remains unclear which DBS targets should be approached. Methods An individual participant data meta-analysis was conducted analyzing the efficacy (Burke Fahn Marsden Dystonia Rating Scale (BFM)-motor / -disability and the Fahn-Tolosa-Marín scale for tremor (FTMTRS)) of pallidal (GPi) deep brain stimulation vs thalamic (VIM) vs GPi+VIM. PubMed, Embase, Cochrane Library, Ovid Medline and Scopus were searched from 2000 - 2025. Additionally, correlation/ regression analyses (age, duration of disease, stimulation parameters) were performed. Results 16 studies including 32 patients (34.4% male; 65.6% female) were enrolled targeting the GPi (63.2%) vs VIM (23.6%) vs GPi/VIM-DBS (13.2%). Dystonia with tremor was found in 53%, dystonia with hemichorea / choreoathesosis in 50% (age at disease onset: 10 ± 18 years, age at DBS surgery: 37 ± 15 years, disease duration: 28 ± 19 years. GPi-DBS improved dystonia ((BFM-motor; 12-months; p < 0.005) and >12-month (BFM-disability scores ≤12-month; p = 0.038) with no significant changes for VIM vs GPi/VIM. No correlations were determined between DBS outcome and stimulation protocol and demographic characteristics. Adverse events occurred in 19 %. Conclusion DBS is effective for treating post-stroke movement disorders. Given the heterogeneity, selection and reporting bias, the published data is limited in providing high-quality evidence. Hence, the authors advocate a multifocal DBS approach along with trial stimulation determined under a rigorous study protocol.

Objectives: In refractory epilepsy, stereoelectroencephalography (SEEG) is one of the invasive methods that allows the delineation of the seizure onset zone as a target for surgical treatment. However, up to 40% of patients are not offered surgery afterwards, as no focal epileptogenic zone (EZ) can be identified. The 5-SENSE score combines 5 parameters: magnetic resonance imaging, semiology, neuropsychological assessment, ictal and interictal electroencephalogram. This score is used to predict whether a focal EZ is likely to be identified by SEEG, potentially reducing unnecessary invasive diagnostic procedures. We intend to apply this score to patients undergoing SEEG at our institution and analyze its validity as a clinical decision tool. Methods: Single-center retrospective observational study with selection of patients with refractory epilepsy who underwent SEEG between 2020 and 2025. Patients were grouped as focal or non-focal for the localization of the EZ, based on the SEEG result. For the application of the 5-SENSE score, data from the clinical processes were collected. We used a value of 37.6 as a cut-off to decide the score result and calculated the sensitivity and specificity in the sample. Results: 11 patients were analyzed (7 with focal EZ, 3 non-focal and 1 inconclusive, the latter being excluded). The specificity of the score was 33.3% (95% CI, 0.84-90.57) and the sensitivity was 100% (95% CI, 59.04-100). Conclusion: Although the authors of the 5-SENSE score have validated it with a high specificity (76.0%), the application of this score in our patients reveals a result that falls short of the intended objective of this tool. This result, however, has inconclusive statistical significance due to the small sample size. We suggest the addition of more cases and we discuss the integration of other diagnostic data such as positron emission tomography in the decision to perform SEEG.

Rhythmic stimulation-induced discharges, known as after-discharges (AD), have long been correlated with epileptogenic processes. Nevertheless, the latent neuronal processes are still poorly understood. Our goal was to delineate cortical domain-specific characteristics of polyspike burst type ADs derived from intracranial macro- and microelectrode recordings. Our study examines the data of 7 drug-resistant epileptic patients undergoing presurgical evaluation with subdural grid electrodes, presenting ADs after 50 Hz stimulation. Simultaneously, laminar multielectrode arrays (LME) were implanted in the hypothesized epileptogenic zone. Recordings were evaluated during stimulation (n = 6) and ADs (n = 5). We examined 989 stimulation events along with 50 AD-series with overall 797 AD events. Stimulation elicited either increased (81/989), decreased (430/989) or no change (189/989) in multi-unit activity (MUA), depending on the localization of stimulated site relative to the LME. More pronounced change in MUA predicted AD appearance. Additionally, non AD-generating events showed higher MUA when stimulating an otherwise AD-producing site compared to regions where no ADs emerged. ADs proved to be very localized, detectable changes were found on LME in 17/50 series. The initial AD spikes, associated with infragranular sinks and prominent MUA, were followed by an upper-middle layer wave gradually extending to deep layers. In sum, stimulation induces excitation in cortical neurons, accompanied by pronounced surround inhibition. The magnitude of this effect is related to the cortical susceptibility to generate ADs. ADs engage cortical layers in a specific sequence. A better understanding of stimulation-dependent neural dynamics may shed light to epileptogenic process within the cortex. This study was supported by the EKÖP-2024-205 New National Excellence Program of the Ministry for Culture and Innovation from the source of the National Research, Development and Innovation Fund.

Introduction: Deep brain stimulation (DBS) has become an established therapy for otherwise treatment-refractory obsessive-compulsive disorder (OCD). Although several studies and meta-analyses have demonstrated its efficacy, the results thus far have not been analyzed with the novel tool of an umbrella review. Here, we aim to provide an umbrella review and an updated meta-analysis of all previously published data concerning the outcomes of DBS for OCD. Methods: In adherence to PRISMA guidelines, an umbrella review and meta-analysis was conducted, systematically searching PubMed, Medline, Embase, and Web of Science for meta-analyses on the treatment of OCD with DBS. Individual studies within the included meta-analyses, along with new studies, were meticulously reviewed, and duplications were removed. The results were collected and pooled to generate forest plots. The primary outcome was the relative change in Y-BOCS, HAM-A, HAM-D and Global Assessment of Functioning (GAF) scores at the last available follow-up after DBS. Results: This umbrella review encompassed seven meta-analyses evaluating the outcomes of DBS in patients with OCD published between 2014 and 2022. The current updated meta-analysis, including 29 studies, revealed significant overall improvement in OCD symptoms following DBS, as measured by Y-BOCS (mean difference (MD=14.12 95%CI=12.43, 15.82, p<0.00001, I²=73%), HAM-A (MD=10.71, 95%CI=8.55, 12.88, p<0.00001, I²=63%), HAM-D (MD=11.14, 95%CI=9.39, 12.89, p<0.00001, I²=0%), and GAF scales (MD=5.20, 95%CI=4.51, 5.89, p<0.00001, I²=99%). Conclusion: Our advanced analysis confirms that DBS is an effective therapy for OCD and its associated co-morbidities. Further research is essential to better understand and assess treatment efficacy and its underlying mechanisms.

Tourette syndrome (TS) is a chronic neurodevelopmental disorder with onset before age 18, marked by motor and vocal tics. It is frequently comorbid attention-deficit and hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD) or emotional dysregulation. Although global cognitive impairment is uncommon, specific neuropsychological deficits may occur. Deep brain stimulation (DBS) is applied in severe, treatment-refractory cases, with several targets demonstrating similar efficacy in reducing tics. While most studies report no significant cognitive decline, evidence remains limited due to small cohorts and short-term follow-up. Materials and methods. This study reports the outcomes of ten patients with treatment-resistant TS who underwent neurosurgical treatment. Pronounced comorbid OCD was diagnosed in seven cases. Eight patients were randomized between three DBS targets: the centromedian-parafascicular thalamic complex (CM-Spv-Voi, n=3), the posteroventral globus pallidus internus (pvGPi, n=3), and the anteromedial GPi (amGPi, n=2). One patient, presenting with severe treatment-resistant OCD and absence of tics in adulthood, underwent DBS targeting the pvGPi, and another received Gamma Knife bilateral capsulotomy for the same indication. The follow-up period ranged from 6 to 24 months. All patients underwent neurological, psychiatric, and neuropsychological evaluations using standardized rating scales. The assessed cognitive domains included attention, auditory-verbal and visual memory, executive functions, visuospatial abilities, and verbal fluency. Results. Executive control, cognitive flexibility, and memory performance were the most commonly affected domains. Overall, patients demonstrated mild to moderate cognitive deficits, with a mean Mini-Mental State Examination (MMSE) score of 28.2 ± 2.49 and a mean Frontal Assessment Battery (FAB) score of 15.2 ± 2.77. One patient with prominent emotional dysregulation, behavioral impulsivity, and self-injurious behavior also demonstrated pronounced executive dysfunction and was excluded from the study after 5 months due to neurostimulator damage, likely associated with self-harm. In the remaining patients, tic severity (YGTSS) improved by 37.2–50%, and OCD symptoms (Y-BOCS) decreased by 48.2–60% across the observation period. Eight patients showed no significant postoperative cognitive decline. One patient from the DBS-pvGPi group with comorbid OCD demonstrated a 20% reduction in general cognitive performance at 12 months, with partial recovery by 24 months. The most affected domains were executive functioning, auditory-verbal memory, and attention. Conclusion. DBS is an effective and cognitively safe therapeutic option for treatment-resistant TS. Nevertheless, its influence on cognitive function and psychiatric comorbidities requires further investigation. Preoperative neuropsychological assessment may be useful in selecting surgical candidates, as moderate to severe impairment may negatively impact postoperative outcomes.