Introduction

Chronic Lumbar back pain (CLBP) is one of the most common chronic pain conditions resulting in both individual suffering and a burden to societies. For these patients there are several interventional treatment options such as surgery, blocks, radiofrequency, and spinal cord stimulation. Lately, also Dorsal Root Ganglion Stimulation (DRG-S) has been mentioned as an option, by targeting bilateral T12 dorsal ganglia. In this study we will present the outcome of 11 patients with CLBP treated with bilateral T12 DRG-S.

Method

13 patients with CLBP with and without leg pain were treated with bilateral T12 DRG-S. Three of the patients also received a third lumbar lead due to leg pain. 11 of the patients had a more than 50% pain relief during the per- or/and postoperative testing and received a fully implantable neurostimulator. Pain intensity, general health status, quality of life, pain catastrophizing, mental status, sleeping disorder, physical activity and patient satisfaction were followed using numeric rating scale (NRS), patient-reported outcomes measurement information system 29, ver. 2.1 (PROMIS-29), pain catastrophizing score (PCS), generalized anxiety disorder 7-item scale (GAD-7), patient health questionnaire depression module (PHQ-9), insomnia severity index (ISI) and patient satisfaction questionnaire at baseline before implantation, 3 months and 6 months. The results were analyzed based on 6 domains: pain relief, sleeping disorder, social ability, mental status, physical activity, and satisfaction. To be identified as a responder the patients should show a significant improvement in the pain relief domain together with at least two other domains. All responders were given the opportunity to test 4 HZ DRG-S and compare it with traditional 20 Hz stimulation.

Results

All 11 patients were identified as responders at six months. 5 of the patients had a more than 80% pain relief with an average NRS score reduction of 71 % for the whole group. Significant improvement could be observed in 3 domains for one patient, 4 domains for three patients, 5 domains for six patients and 6 domains for one patient. Seven patients chose to try 4 Hz stimulation. All seven identified 4 Hz stimulation at least as good or better than 20 Hz stimulation and chose to continue with 4 Hz stimulation.

Conclusions

Bilateral T12 DRG-S seems to be an effective treatment for chronic low back pain with significant beneficial effect not only on pain but also on quality of life, pain catastrophizing, mental status, sleeping disorder and physical activity. 4 Hz DRG-S gave comparable or better result than 20 Hz stimulation.

Introduction:

Spastic desorders are sometimes disabling and their treatment can be very challenging. The basic phenomenon underlying spasticity is hyperexcitability of the stretch reflex Excess spasticity in limb may make residual motor functions makes passive movement difficult and generates pain. When the spasticity is refractory to optimal oral medication, refractory to physical therapy, the neurosurgical procedures aims to reestablish the tonic balance between agonist and antagonist muscles by reducing the excess of spasticity.

Materials and methods :

The aim of our study was to objectify the functional effects of the tibial neurotomy in the spasticfoot .Our material included 243 patients who underwent  369 partials and selectives neurotomies of the tibial nerve (126 patients were operated bilaterally) . The age of our patients varied between 04 and 56 years. Causes of  spasticity were dominated by the cerebral palsy in 138 patients (56,79%), followed by head trauma in 76cases (31,27%). Other etiologies are found in the remaining cases.

All patients were selected by a multidisciplinary team according to a clinical evaluation and analytical assessment after a physical rehabilitation protocol well conducted.The preoperative anesthetic block tests were mandatory to select patients for surgery.

Results :

After a mean of 21 years, our results were rated "good to excellent»: 65% of cases walk and run with correct plantigrade support   .

We observed a clear improvement in confort in 25% of our patients.

Discussion:

Neurotomy of the tibial nerve was followed by orthopedic correction in 34 patients during the same surgical procedure.

All patients benefited from institutional care program in various rehabilitation centers throughout the country.

Conclusion:

When pharmacological and physical therapies are not effective in treating spastic components focalized to lower limb, selective tibial neurotomy leade to long- term satisfactory improvement in function and /or comfort with a low morbidity rate in appropriately  selected patients  suffering from severe harmful spasticity localized to the  lower limb.This procedure take place before the onset of irreversible articular disturbances and musculo tendinousre tractions which requiere  complementery orthopedic corrections .

Background:

Trigeminal schwannomas (TS) represent less than 10% of intracranial schwannomas. Complete resection can be curative, but, due to intimate relation to critical neurovascular structures, it is associated with high risk of morbidity and mortality. Stereotactic radiosurgery (SRS) is considered a valuable safe and minimally invasive therapeutic alternative for treating benign intracranial tumors, such as nonvestibular schwannomas. This single-centre study aimed to evaluate the clinical outcome of patients with TS who undervent SRS treatment using Leksell gamma knife (LGK).

Methods:

From 1994 to 2014 we enrolled 31 patients (15F), mean age 49.8 years with the diagnosis of TS. Initial symptoms were headache (19%), face pain (32%), face numbness (55%) and double vision (32%). All patients underwent radiosurgical treatment on LGK (model B, C, 4C and Perfexion). The prescription dose was 12-14Gy on 50% isodose line. We evaluated changes in clinical signs (improvement or impairment) and tumor volume on regular follow up. The mean follow up was 93.7 months (range 12-241 months).

Results:

Permanent clinical sign improvement after SRS treatment was achieved in 13 (42%) patients. The mean time to improvement was 25months (2-60months). The symptoms which improved were face pain, diplopia and face numbness. Posttreatment symptomatic brain edema was in 2 (6%) patients with successful conservative treatment. In 3 (9,5%) patients we observed permanent clinical impairment. Overall tumor control rate was 90,3% and tumor decrease rate was 68,3%. The clinical improvement was associated with tumor volume regression in 10 (77%) patients.

Conclusion:

Our results confirm that the LGK is an effective treatment modality for TS with low risk of clinical impairment and high rate of tumor control.

Case Presentation:

We present a case of a 34-year-old Polish female who was  hospitalized at the Neurosurgery Clinic of University Hospital No. 2 in Bydgoszcz due to left hemifacial pain with neuropathic features, mainly in the area of the trigeminal nerve branches V1 and V2. In 2020, the patient underwent two laryngological surgeries due to chronic sinusitis. 

Since then, the patient has reported severe facial pain-8 VAS scale.Between 2021 and 2022, the patient underwent 9 times radiofrequency rhizotomy procedures of the Gasserian ganglion and 5 blockades of the maxillary and mandibular nerve branches, with a slight short-term improvement.

The patient does not have any other chronic illnesses and the head MRI showed no intracranial pathologies. Laboratory tests were within normal range. Neurological examination at admission to the hospital revealed hypoesthesia in the area of V1 and V2 branches on the left side, with no other deviations noted.

Under general anesthesia, the electrode was percutaneously implanted into the left SPG. The electrode was connected to an external battery and tonic stimulation was initiated.

The patient was discharged home for a period of 2 weeks. After the trial stimulation period, the patient reported a resolution of pain in the V2 branch (VAS 2), but pain in the V1 branch on the forehead still persisted at a VAS score of 8.

The patient was then qualified for the implantation of a supraorbital nerve electrode. Under general anesthesia, the lead was introduced and connected to an external battery, and the parameters for tonic stimulation were established as.........

After 5 days of observation, the facial pain in the V1 and V2 branches decreased to a VAS score of 1.

A non-rechargeable battery was implanted in the left subclavicular region of the patient.

Conclusion: In the treatment of neuropathic trigeminal neuralgia, the implantation of more than one electrode may increase the analgesic effect. Such an approach should be considered in every patient with unsatisfactory pain relief with the use of a single lead. Sphenopaltine ganglion stimulation covers pain area of V2 branch mainly.

Introduction: With the goal of identifying and fostering opportunities for early-career neurosurgeons, we conducted a survey among members and centres of the European Association of Neurosurgical Societies (EANS) to gather information about their scope of practice in pain surgery, as well as pain-related fellowships and training opportunities across neurosurgery centres across Europe.

 Methods: An online questionnaire with 26 questions was distributed to all EANS individual members and centres listed on the online EANS map of European neurosurgical departments. Responses were tabulated and analysed using descriptive statistics.

 Results: A total of 27 centres fully completed the questionnaire ascertaining details about their pain fellowship offering and expertise. Among the responding centres, 28% offer a single neurosurgical pain fellowship a year, 42% offer two fellowships a year, 14% offer four fellowships a year, and 14% offer five or more such fellowships per year. The majority of centres offer fellowships to applicants from outside the country but only 40% of responding centres offer paid fellowships. 50% of centres offer participation in research projects. A majority of responding centres (70%) were open to receiving visiting surgeons for short-term visits or observerships for educational and research purposes. Microvascular decompression (MVD) was the most common pain surgery procedure performed (62%), followed by spinal cord stimulation (SCS) (53.8%), deep brain stimulation for pain (DBS) (50%), implantation of intrathecal drug delivery pumps (50%), and balloon compression for trigeminal neuralgia (38%). The least common procedures were cordotomy (6%), mesencephalotomy (6%), cryoablation (7.7%), sphenopalatine ganglion stimulation (7.7%), and methylene blue neurolysis (0%). 

 Conclusion: Our study highlights the need for more education and training opportunities in pain-related neurosurgery. The fact that only a small number of European centres offer fellowship programmes has serious implications for the next generation of neurosurgeons, who will be responsible for treating patients with pain-related conditions. Without access to specialized training programmes at their home institutions, these young neurosurgeons may lack the knowledge and skills required to perform specific neurosurgical interventions for pain. This could have a significant impact on patient outcomes, as well as the continued advancement of the field of pain-related neurosurgery. It is therefore essential that more centres offer fellowships and training opportunities in this area, to ensure that this knowledge and these skills are kept alive and passed on to future generations of neurosurgeons.

Introduction

Hyperactive dysfunction syndrome of the cranial nerves is defined as a functional disturbance of cranial nerves caused by neurovascular compression in the posterior fossa. The pathogeny involves a direct contact with mechanical irritation of cranial nerves at the root entry zone by a blood vessel. Detailed anatomic visualization of the root entry zone is essential for the success of the surgical intervention. This study aims at evaluating the efficacy and safety of micro-inspection endoscope assisted microvascular decompression to achieve the best neurological outcome. 

Material and Methods

This is a retrospective pilot study of a series of 8 patients diagnosed with neurovascular compression syndrome (six cases with trigeminal neuralgia and two cases with hemifacial spasm) who underwent surgical treatment in our department, over the course of ten months (May 2022 to February 2023). We used high-resolution MRI with dedicated sequences like 3D-FIESTA-C (CISS) to reveal the neurovascular conflict. All patients had a history of complementary pain/spasm-relief therapies, with unsatisfying results. For all patients we used the endoscopic micro-inspection tool (Qevo^®, Kinevo 900, Zeiss) to assist the microvascular decompression procedure.

Results

The study included 8 patients, of which 5 (62.5%) were females. The mean (±SD)  age at diagnosis was 57.3 (± 9.8)  years. 6 patients (75%) underwent microvascular decompression for trigeminal neuralgia and 2 patients (25%) for hemifacial spasm. In our study, arterial involvement was noted in 7 cases (87.5%). For one case of trigeminal neuralgia, the MRI examination did not highlight any neurovascular conflict. Intraoperatively, no arterial conflict was detected; a venous neurovascular conflict was objectified, this finding being also confirmed by micro-inspection tool. In all cases, adequate microvascular decompression was achieved, assisted by the endoscopic micro-inspection tool. This tool allowed the surgeon to meticulously visualise the root entry zone of the cranial nerves, the blood vessels, or the placement of Teflon pads, aiding the surgeon to find hidden anatomical details during microsurgical intervention.  Complete remission of symptoms was registered in all cases. Postoperative neurological morbidity rate was 0%. 

Conclusions

Surgical microvascular decompression remains the treatment of choice for neurovascular compression syndromes. The endoscopic micro-inspection tool enhances the 360-degree visualization of the root entry zone of the nerve and helps to identify the neurovascular conflict when it is not readily apparent in the microscopic field. 

Objective: Teflon granuloma is a possible cause of recurrence in patients with trigeminal neuralgia who underwent successful microvascular decompression. Its incidence is variable and the pathophysiology and mechanisms for recurrence are not well defined. In this study, we aim to characterize the histological features of Teflon granulomas and to correlate its occurrence with clinical and intraoperative findings.

Methods: Clinical and histological data of patients with recurrent trigeminal neuralgia who underwent posterior fossa re-exploration over a 15-year period was collected and analyzed.

Results: Histopathological specimens were available in a total of 13/41 cases who underwent surgery for recurrent trigeminal neuralgia. In 6 cases the distribution of pain had progressed to an adjacent area, mostly from V2 to V2 and V3. The mean time for recurrence was 30,65 months after the first microvascular decompression. Intraoperatively a “piston-effect” was noted and calcification of the Teflon occurred in 7/13 cases. All samples showed scar tissue and within this scar birefringent Teflon filaments were observed, which were embedded between enlarged and collagenous fibers. The full configuration of foreign body granulomas with Teflon-adherent giant cells and discrete lymphocytic infiltrates was evident in 10/13 cases. Siderophages were found in 4/13 cases. Microcalcifications occurred in 5/13 cases. The presence of siderophages (mean of 3,50 years), macrophages (mean of 3,50 years) and microcalcifications (mean of 6,60 years) was associated with a latter period compared to the presence of macrophages (mean of 2,33 years) and lymphocytes (mean of 3,40 years).

Conclusions: The majority of Teflon granulomas manifested as foreign body granulomas, corresponding to a scar reaction embedding the Teflon material and an immunological component in the form of giant cells. Clinically, expansion of the distribution of pain during recurrence after a prior successful microvascular decompression can be observed. Our data indicates that Teflon is not an inert material when used for microvascular decompression and that alternative materials or techniques might be considered for microvascular decompression.

Introduction

Hypertension is the second largest risk factor for disease worldwide.¹ Up to 10% of cases are drug-refractory:² these are typified by increased sympathetic outflow.³ This has led to the investigation of sympatholytic neuromodulatory therapies. One potential approach is stimulation of the dorsal root ganglion (DRGS), an established target for chronic pain. The DRG is known to be a source of inter-ganglionic collaterals between the autonomic and somatic nervous systems, raising the possibility of autonomic neuromodulation at this site. We have previously shown that DRGS with standard analgesic frequencies (20Hz) reduces sympathetic outflow and leads to long-term reductions in blood pressure (BP).⁴ However, the optimal stimulation parameters for haemodynamic effects have not been established. Moreover, the pain relief produced by stimulation presents a significant confound to BP changes when comparing ON vs OFF conditions. In the present study, we investigated the relationship between simulation frequency and acute changes in BP. We hypothesised that maximal analgesic and haemodynamic responses to stimulation would occur at differing frequencies.  

Materials and Methods

Nine chronic pain patients with thoracolumbar DRGS participated in a single-session within-patient crossover study. All patients had been previously established on 20Hz stimulation. Six experiment conditions were tested in a random order: OFF-4Hz-10Hz-20Hz-40Hz-80Hz, at the participant’s normal therapeutic pulse width and amplitude. A 10-minute period elapsed between each setting change to limit carryover effects.⁵ For each condition, 5 minutes of continuous BP was recorded via finger plethysmography, with pain scores recorded using the visual analog scale (VAS). A linear mixed model analysis was performed, with pain and condition order as confound variables. 

Results

Compared to the OFF condition, acute 4Hz stimulation (data available for 6 of 9 participants) produced a 7.1mmHg reduction in SBP (95% CI -13.7 – -0.5 mmHg) and a 6.7 mmHg reduction in DBP (95% CI -11.0 – -2.4mmHg), when adjusted for condition order and pain. Similar mean values were observed for SBP (-7.0mmHg) and DBP (-6.6mmHg) without adjusting for confounds. All other frequencies were non-significant. However, 20Hz stimulation provided the greatest analgesic effect compared to OFF stimulation (mean change -16.7mm, 95% CI -22.2 – -12.3 mm), with several participants reporting worsened pain at higher frequencies.  Post-hoc pairwise comparisons revealed a 7.2mmHg reduction in DBP with 4Hz stimulation compared to 20Hz (95% CI -14.42 – -2.1mmHg, p=0.003, Bonferroni-corrected).  Absolute blood pressure values for all participants by frequency are shown in Figure 1, whereas changes compared to the OFF condition are shown in Figure 2 (mean ± 95% CI). N.B. Mean Arterial Pressure is derived from SBP and DBP (1/3*SBP + 2/3*DBP).

Discussion

Our study provides preliminary supporting for very-low frequency DRGS (VLF-DRGS) in autonomic neuromodulation, showing greater haemodynamic effects at 4Hz, with greater pain relief at 20Hz. More robust reductions in DBP vs SBP were observed across subjects, supporting our previous findings and suggesting a reduction in sympathetically-mediated vascular tone may underlie acute stimulation effects. In the DRGS pain literature, differential somatosensory fibre recruitment is a likely mechanism for the analgesic effects of VLF-DRGS.⁶ However, there may also be an increased effect on autonomic fibres, which supports findings in conditions such as diabetic neuropathy.⁷ There has been increasing interest in DRGS to treat sympathetic overactivity, such as ventricular arrhythmiasand hypertension. However, most experimental protocols utilise either high-frequency (1KHz) or low-frequency (~20Hz) DRGS.⁸ Our results warrant further investigation of VLF-DRGS in pre-clinical and clinical settings. Important limitations include sample size and the need to corroborate acute findings with long-term data. These are the subject of ongoing work.

Background: Nowadays, the efficacy of Dorsal root ganglion (DRG) stimulation for intractable pain which Spinal Cord Stimulation (SCS ) is ineffective has been suggested. In addition, the availability of radiofrequency lesioning (RF) and pulsed radiofrequency (PRF) has become common especially for the pain due to nerve root. This time, we report the case which has severe chest and back pain intractable for normal SCS, RF, and PRF then treated with DRG stimulation through nerve root foramen.

 Case 43 male. He suffered from severe chest and back pain located in Th4 and 5 area after operation of decompression for spinal canal stenosis from C7 to Th8. SCS was performed and it was effective in early period. However, the effect disappeared, and the devise was removed. Then, RF and PRF for nerve roots were performed. The patient felt paresthesia at painful area in his body but the pain itself was not relieved. Because he felt the paresthesia was comfortable, we thought that continuous stimulation may be effective for pain. So, leads were inserted through nerve root foramen targeting for nerve roots and DRG, and a pulse generator was also implanted. With continuous stimulation for nerve roots and DRG, he felt less pain than SCS. However, the right lead was dislocated 3 months after operation. The effect of the left side has sustained more than 4 years.

 Discussion: The mechanism of DRG stimulation has not been identified yet. However, there are some reports about priority of DRGS to SCS in the effect for pain due to nerve roots.There are some devices for DRGS, which is inserted through translaminar approach same as SCS. The method we tried this time could stimulate nerve roots and DRG more directly. Conventional RF and PRF is performed with the same procedure, and they could be used as the trial of DRGS. This procedure may be reasonable after spinal surgery because SCS is sometimes difficult due to scar of spinal canal. On the other hand, dislocation of leads is a problem of this procedure.

Conclusion: DRG stimulation through nerve root foramen may be effective for the pain due to nerve roots especially after spinal surgery.

Background Chronic entrapment of the greater occipital nerve (GON) can not only

manifest in typical stabbing pain of occipital neuralgia (ON) but also lead to continuous

ache and pressure-like pain in the occipital and temporal areas. However, the effect of

GON decompression on these symptoms has yet to be established. We report the

follow-up results of GON decompression in typical cases of ON and chronic occipital

headache due to GON entrapment (COHGONE).

Methods A 1-year follow-up study of GON decompression was conducted on 11

patients with typical ON and 39 COHGONE patients with GON entrapment. The degree

of pain reduction was analyzed using the numerical rating scale-11 (NRS-11) score and

percent pain relief before and 1 year after surgery. A success was defined by at least a

50% reduction in pain measured via NRS-11 during the 12-month follow-up. To assess

the degree of subjective satisfaction, a 10-point Likert scale was used. Postoperative

outcome was also evaluated using the Barrow Neurological Institute (BNI) pain

intensity score. The difference in GON decompression between the patients with

typical ON and those with COHGONE was studied.

Results GON decompression was successful in 43 of 50 patients (86.0%) and percent

pain relief was 72.9925.53. Subjective improvement based on a 10-point Likert scale

was 7.92.42 and the BNI grade was 2.061.04. It was effective in both the ON and

COHGONE groups, but the success rate was higher in the ON group (90.9%) than in the

COHGONE group (84.6%), showing statistically significant differences in the results

based on average NRS-11 score, percent pain relief, subjective improvement, and BNI

grades (p<0.05, independent t-test).

Conclusion GON decompression is effective in chronic occipital headache and in ON

symptoms induced by GON entrapment.

Objectives: To investigate the long-term changes in thecal sac compression following T9 paddle lead spinal cord stimulation (SCS) using three-dimensional myelographic computed tomography (CT).

Materials and Methods (Table 1): Seventeen patients with five-column paddle lead SCS at T9 underwent three-dimensional myelographic CT scans preoperatively, immediately after surgery, and after an average of 11 months. The cross-sectional areas of thecal sac and spinal cord and the widths of anterior and posterior cerebrospinal fluid (CSF) spaces were repeatedly measured and compared. The contact angle of the lead with long-term pain relief was assessed.

Results (Table 5): The cross-sectional areas of thecal sac and spinal cord decreased significantly after lead placement (30.47 ± 9.21% and 4.71 ± 9.84%, respectively). Even after 11 months, a significant reduction was found with the preoperative values (17.97 ± 12.32% and 2.88 ± 7.09%). The widths of anterior and posterior CSF spaces decreased significantly after surgery (43.53 ± 13.17% and 57.13 ± 13.17%, respectively) and the severe decrease persisted long-term (29.13 ± 21.54% and 50.99 ± 16.07%). The average pain relief was 42.27 ± 17.50% with no correlation between the rate of reduction in cross-sectional areas of thecal sac and the widths of CSF spaces.

Conclusions: Significant early reduction and late partial restoration occurred in the thecal sac and spinal cord and the width of the anterior and posterior CSF spaces in the T9 5-column paddle lead SCS. Thecal sac compromise was expected to some extent after paddle lead implantation, but the degree is significant, and the cross-sectional area of the spinal cord as well as the thecal sac is affected. Fortunately, these anatomical changes did not cause any clinical problems except for intercostal root irritation. The shape and flat contours of the five-column paddle leads clearly affected the results.

Introduction: Radiosurgical treatment of trigeminal autonomic cephalalgias (Sluder's neuralgia and cluster headache) using irradiation of the pterygopalatine ganglion has been described. However, this experience is not well-known in the treatment of migraines. Here, we present a small sample of patients suffering from migraine headaches.

Patients and method: We treated 7 patients  (F:M=5:2, age range 43-66 yrs, median 49 yrs, follow-up 12 -163 months, median 54 months) suffering from chronic migraine with gamma knife radiosurgery (GKS).Two of them suffered from bilateral migraine.  All patients had received conservative treatment in specialized clinics for headache prior to radiation. The radiation was targeted to the area of the pterygopalatine fossa at  the level of the canal for the great petrosal nerve. Two shots (4 mm /weight 1/ and 8 mm /weight 0.5/) with identical coordinates were used for radiation application. The maximum dose was 90 Gy. In the patients with bilateral migraine the both pterygopalatine ganglions were irradiated.  In total, 9 pterygopalatine ganglions was irradiated  in 7 patients. Pain relief was evaluated by patients in terms of the percentage of residual pain and also using the BNI score. A residual pain of up to 50%, BNI score III, and sustained relief for at least 1 year have been considered successful treatment outcomes.

Results: Successful treatment was achieved in 6 patients: 4 patients with unilateral migraine on the corresponding side of the head, 1 patient with bilateral migraine on both sides of the head, and 1 patient with bilateral migraine on only one side of the head. In 1 patient we were unsuccessful - the relief lasted only 8 months. Overall, a favorable response to GKS irradiation was observed in 7 out of 9 pterygopalatine ganglions. Five patients were headache free.  The treatment effect occurred within 1 week - 3 months, median 3 months. Recurrence occurred in 3 patients after 12,24 and 108 months. We repeated the radiation with the same dose for pain relief in 1 patient again with good effect.  We did not observe any side effects of the treatment.

Conclusion: Patients with migraine responded well to gamma knife treatment. We achieved pain relief in 7 cases (6 patients). We have not observed any side effects. GKS in migraine targeting the pterygopalatine ganglion is another treatment option for these difficulties with minimal risk. In case of failure, GKS does not exclude other types of treatment such as biological treatment or neuromodulation.                                                                                                                                                                                                                                                                                  This study was supported by the  Ministry of Health, Czech Republic – conceptual development of research organization (NHH, 00023884, IG221201).

Introduction. Spinal cord stimulation (SCS) is effective in the treatment of chronic pain and intractable angina pectoris. Recently, animal studies have showed that SCS can also suppress atrial fibrillation (AF). Our study aimed to test the safety and efficacy of temporary SCS to prevent the occurrence of AF in the early postoperative period in patients undergoing elective coronary artery bypass grafting (CABG).

Methods and Materials. Fifty-two patients with indications for CABG and history of paroxysmal AF were randomized to 2 groups: CABG plus standard medical therapy (MED) with beta-blockers (n=26, Control group) and CABG plus MED plus the percutaneous lead placement for temporary SCS (n=26, SCS group). In the SCS group under local anesthesia and with fluoroscopic guidance, temporary leads were placed at C7-T4 level according to the patient’s sense of paresthesia and connected to a trial stimulator. Temporary SCS was begun 3 days before elective CABG, deactivated during surgery, reactivated in the intensive care unit after CABG, and continued for 7 days at which time the leads were removed. Continuous external ECG monitoring was performed for 30 days after CABG in all patients. These primary objectives were tested over the 30-day postoperative period: 1) occurrence of adverse events, including death, stroke or TIA, myocardial infarction and kidney injury; and 2) occurrence of AF or any atrial tachyarrhythmia lasting over 30 seconds.

Results. Percutaneous lead placement for temporary SCS was successfully performed in all 26 patients before CABG with no complications. There were no adverse events related to temporary SCS in any patient throughout the follow-up. There were no significant differences in CKMB and creatinine levels between groups (p=0.1 and 0.2, respectively) as well as other typical CABG-related complications (p>0.05). Postoperative AF occurred in 8 (30.7%) of 26 patients in the Control group versus only 1 (3.8%) of 26 patients in the SCS group (p=0.012, log-rank test).

Discussion. Though SCS is a minimally invasive procedure, it could have complications, but in our study, we avoid them. We use conventional SCS in these patients with paresthesia feelings in the chest; hence, the effect of SCS with other types of stimulation (burst or high frequency/density) is the other direction of exploration in this question.

Conclusions. Temporary SCS was effective in suppressing postoperative AF after CABG, with no adverse events in this study. Further studies of SCS with larger samples are indicated to test its clinical value as a perioperative intervention.

In comparison to the enormous effect of basal ganglia circuit neuromodulation in movement disorders proves neuromodulation against neuropathic pain being almost ineffective. I started 15 years ago with implantation of two electrodes per cerebral hemisphere. The posterior limp of the internal capsule and the sensory thalamic region were my target structure. Our goal was to alleviate the severe burning pain including allodynia, dysesthesia, hyperpathia associated by sensory deficits following damage of the nervous system by stimulating of the sensory thalamic nuclei and the posterior limp of the internal capsule.

Material and Methodes: From 2008 until 2023 we treated more than 70 patients by stereotactic DBS against neuropathic pain. Out of these 12 Patients suffered from atypical facial pain (4 x analgesia dolorosa), 9 cluster headache, 3 patients had a complete paraplegia, 7 patients had more than 2 cervical root avulsions, 10 times ischemic thalamic post stroke pain, 17 times hemorrhagic thalamic post stroke pain, 4 times peripheral nerve injury following surgery are the pathologic specimen. The average age of the patient at the time for surgery was 51.9 years with a range from 38 to 68 years. 34 patients were female. The average pain disease time was 116.6 months until surgery (10 months – 336 months). As target for stimulation we choose our modified approach in combination of sensory thalamic and posterior limp of the internal capsule. Beside of quantitative sensory testing we utilized in all patients a questionnaire consisting of EQ-5D-German Version, Oswestry Questionaire – German Version, Mc.Gill Pain Questionaire short form German Version, SF-36 Standard German Version 1.0, Eisner VAS Body Region Questionaire.

Results: A combined stimulation of the sensory thalamic region and the posterior limp of the internal capsule revealed a stable pain reduction of more than 60% in all our patients with exception of our posthaemorrhagic central stroke patients and the complete paraplegic patients. Allodynia, dysesthesia and hyperpathia were reduced dramatically in our patients with more than 80 % pain reduction proofen by quantitative sensory testing.

Discussion: A modified approach and the combination of two electrodes per hemisphere is revealing better results in deep brain stimulation against the most severe pain syndromes in humans since 15 years in comparison to the international literature.

Background: Cordotomy, the selective disconnection of the nociceptive fibers in the spinothalamic tract (STT), is used to provide pain palliation to oncological patients suffering from intractable cancer-related pain. Cordotomies are commonly performed using a cervical (C1-2) percutaneous approach under imaging guidance and require patients’ cooperation to functionally localize the STT. This, can be challenging in patients suffering from extreme pain. It has recently been demonstrated that intraoperative neurophysiology monitoring by electromyography may aid in safe lesion positioning.

Objective: The aim of this study is to evaluate the role of compound muscle action potential (CMAP) in deeply sedated patients undergoing percutaneous cervical cordotomy (PCC).  

Methods: A multi-center, retrospective analysis was conducted of all patients who underwent percutaneous cordotomy while deeply sedated between January 2019 and November 2022. The operative report, neuromonitoring logs, and clinical medical records were evaluated.

Results: 11 patients underwent PCC under deep sedation. In all patients, the final motor assessment prior to ablation was done using the electrophysiological criterion alone. The median threshold for evoking CMAP activity at the lesion site was 0.9V ranging between 0.5 and 1.5V (average 1V ± 0.34V SD). An immediate, substantial decrease in pain was observed in 9 patients. Median pain scores (NRS) decreased from 10 preoperatively (range 8-10) to a median 0 (range 0-10) immediately following surgery. None of our patients developed motor deficits.

Conclusion: CMAP-guided PCC may be feasible in deeply sedated patients without added risk to postoperative motor function. This technique should be considered in a group of patients who are not able to undergo awake PCC.

Introduction

The role of stimulation parameters in dorsal root ganglion stimulation (DRG-S), especially of stimulation frequency, is not well understood. Previous studies documented higher effectiveness for frequencies as low as 20 Hz, but there is evidence that even lower values could lead to better outcomes. In this study, we investigate the influence of low-frequency DRG-S.

Methods

We report on the results of a randomized double-blind clinical trial with crossover design. Patients with an already implanted DRG-S system were included and randomly tested with 4 Hz, 20 Hz, 60 Hz and sham stimulation. Amplitude was adjusted to subthreshold values for each frequency. Each frequency was tested for 5 days, followed by a 2-day wash-out period. Patients were assessed using VAS, McGill Pain Questionnaire, EQ-5D-5L and Beck Depression Inventory.

Results 

17 patients were included. Time between inclusion in this study and primary implant was 32.8 months. Baseline stimulation frequency was 20 Hz in all patients. Mean baseline pain intensity was VAS 3.2 (SD 2.2). With 4 Hz stimulation, VAS was 3.8 (SD 1.9), with 20 Hz VAS 4.2 (SD 2.0) and with 60 Hz VAS 4.6 (SD 2.7). Worst pain control was seen with sham stimulation with a VAS of 5.3 (SD 3.0). Stimulation with 4 Hz achieved lower VAS scores, but this was only statistically significant when compared to sham (p = 0.001). A similar trend favoring 4 Hz stimulation was seen using the Beck Depression Inventory, but in this case no statistical significance was found. Outcomes of McGill Pain Questionnaire and EQ-5D-5L favored 20 Hz stimulation, but again without statistical significance.

Conclusions

Low-frequency stimulation might be most effective in dorsal root ganglion stimulation for chronic neuropathic pain. Longer wash-out and observational periods might be necessary to show clear differences in frequency response.

Background: The electromagnetic tracking (EMT) technique is an effective method for neuronavigation as it allows for real-time wireless guidance of tools without requiring a line of sight. EMT systems are used for shunt insertions [1], or to guide the placement of depth electrodes such as deep brain stimulation (DBS) electrodes [2], in combination with a frameless stereotactic system. However, EMT systems available on the market are not compatible with the standard procedure of DBS based on a stereotactic system. This incompatibility is caused by the distortions induced by the stereotactic system in the tracking volume [3], which can lead to significant degradation of tracking performance [4]. Most distortions are the result of the alternating magnetic field of the EMT system itself. This alternating field is required to localize the sensing units, which are inductive sensors called micro-coils. To address this issue, we developed a new EMT system, ManaDBS, based on on-chip magnetometers which are non-inductive sensors capable of measuring the quasi-static magnetic fields applied for our tracking. In this work, we compare the tracking performance degradation of our system to the market device, NDI Aurora®, in the presence of a stereotactic system.                

Methods: The two navigation systems, NDI Aurora® and ManaDBS, consist both of a magnetic field generator of 20 cm x 20 cm x 7 cm and a flexible tube of 1.4 mm diameter, functionalized with a sensor at the tip. The sensor was placed at 25 cm from the generator. The frame and arc of the Leksell® Vantage™ Stereotactic System and Leksell® Stereotactic G system were investigated. Each object was inserted between the generator and the sensor. The sensor's localization was carried out twice; initially without the object, and subsequently with the object placed at a distance ranging from 60 mm to 5 mm from the sensor. The position error was calculated as the Euclidean distance between the positions obtained without the object and with the object at varying distances. For the orientation, the Sum of Squared Errors (SSE) was also calculated as both systems have 6 degrees of freedom.

Results: The NDI Aurora® exhibits errors (Euclidian distance) up to 0.4 mm, 2.5 mm, 5.8 mm, 5.9 mm for the Vantage frame, G-frame, Vantage arc, and G-arc respectively (Fig. 1) with a mean error of 0.4 mm, 1.9 mm, 3.8 mm, 4.8 mm. The ManaDBS exhibits a maximal error of 0.4 mm and a mean error of 0.1 mm over all the different objects. The mean SSE for the orientation is 0.9° and 1.4° for the NDI Aurora® and the ManaDBS respectively over all the different objects.

Conclusion: Metallic parts from the stereotactic system such as both arcs and the G-frame respectively induced a degradation in the performance of the NDI Aurora®. As the Vantage frame is made from resin that doesn’t distort the magnetic field, both navigation systems exhibit unchanged performances.  The variability of the error on the orientation tends to suggest that the error is not strongly correlated to the presence of the stereotactic parts but mainly related to the intrinsic performance of each system. The ManaDBS shows robustness to the presence of the stereotactic system in the tracking volume in comparison to the market device. By embedding the on-chip magnetometer at the tip of a DBS electrode, this system should provide a new approach to intra-operative verification of the localization. Further work is required to validate its robustness in a surgical environment.

References:

[1] Jung, N., & Kim, D. (2013). Effect of Electromagnetic Navigated Ventriculoperitoneal Shunt Placement on Failure Rates. Journal of Korean Neurosurgical Society, 53(3), 150. doi:10.3340/jkns.2013.53.3.150
[2] Burchiel, K. J., Kinsman, M., Mansfield, K., & Mitchell, A. (2020). Verification of the Deep Brain Stimulation Electrode Position Using Intraoperative Electromagnetic Localization. Stereotactic and Functional Neurosurgery, 98(1), 37–42. doi:10.1159/000505494

[3] Franz, A. M., Haidegger, T., Birkfellner, W., Cleary, K., Peters, T. M., & Maier-Hein, L. (2014). Electromagnetic Tracking in Medicine—A Review of Technology, Validation, and Applications. IEEE Transactions on Medical Imaging, 33(8), 1702–1725. doi:10.1109/TMI.2014.2321777

[4] Nafis, C., Jensen, V., Beauregard, L., & Anderson, P. (2006). Method for estimating dynamic EM tracking accuracy of surgical navigation tools (K. R. Cleary & R. L. Galloway, Jr., Eds.; p. 61410K). doi:10.1117/12.653448

Objective: To determine if an image-guided programming (IGP) tool can enable shorter initial Deep Brain Stimulation (DBS) programming sessions and evaluate continued chronic use of recommended stimulation settings in Parkinson’s disease (PD) patients.

Background: Historically, optimization of DBS programming consists of a lengthy trial-and-error process potentially leading to extended programming sessions and frequent clinical visits. An IGP-based platform to visualize lead location relative to patient anatomy may be capable of reducing programming times and aiding active contact(s) selection through direct visualization and targeting of Stimulation Field Models(SFMs).

Methods: Novel IGP software (GUIDE XT, Boston Scientific) was evaluated as part of an ongoing prospective, multicenter, registry (NCT02071134)in which pre-operative MRI and post-operative CT scans were provided in order to localize the DBS lead relative to each patient’s anatomy and to select of programming parameters which are aligned with SFMs. Time to reach effective DBS settings during the initial programming session was collected, along with device aided suggested stimulation settings. DBS stimulation settings were also collected at follow-up visits.

Results: To date, 59-patients (mean age 62.9-years, 75% male) with 10.5-years of disease have been enrolled. Initial programming of bilateral directional leads, where IGP software was utilized, occurred at a mean of 35.6 ± 4.3 minutes, and 62% completed these sessions in ≤30minutes (70% GPi, 61% STN). A smaller cohort of eighteen patients (with 36 leads) completed study visits up to 12-months following this visit and had programming information available. A 20-point improvement (n = 14) in motor function was noted at 6-months and sustained up to 1-year (n = 8) as assessed by MDS-UPDRS III scores in the medication off stimulation on condition. Fifty percent (18 of 36) of the programs provided at the initial device activation were still being utilized at 6- and and 12-month visits.

Conclusions: Preliminary results suggest the use of IGP software reduced time required to achieve optimal therapeutic settings for bilateral STN DBS devices in daily clinical practice. Shorter, more efficient programming sessions will be potentially useful to clinicians as long as stable and efficacious DBS settings can be shown as clear outcomes. This real-world database will address these challenges.

Objective: The objective of this study is to assess and report real-world outcomes of dystonia patients implanted with Multiple Independent Current Control (MICC)-based directional Deep Brain Stimulation (DBS) systems.

Background: Management of dystonia using Deep Brain Stimulation (DBS) is a well-established therapeutic approach. However, optimal DBS target sites in patients with cervical (focal) versus generalized dystonia are thought to diverge and be specific for particular connections. DBS devices equipped with capabilities such as directionality and Multiple Independent Current Control (MICC) offer potential for improved neurostimulative precision. Here, we report a sub-analysis of patients with cervical dystonia only or dystonia with cervical involvement from an on-going, multicenter registry.

Methods: This is a sub-analysis of patients with focal (cervical) dystonia only or cervical dystonia in the context of segmental or generalized dystonia assessed within a prospective, multicenter, international dystonia registry (NCT02686125). All patients receive an MICC-based, directional DBS system (Vercise, Boston Scientific). Patients are followed up to 3-years (post-implant). Several study assessments are being collected to evaluate their dystonia symptoms (e.g., TWSTRS), quality of life and overall satisfaction. Adverse Events are also collected.

Results: A total of 43-patients (mean age 56.9-years, 58% females) with focal (cervical) dystonia only and 83 patients (mean 41.95-years, 61% females) with cervical dystonia in context of segmental or generalized dystonia have been evaluated. Both groups reported significant improvement in overall TWSTRS scores – however the extent varied. In the cervical only cohort, a 19.9-point improvement was noted at 6-months (n=25) and sustained up to 1-year (23.2-point improvement, n=20). In those with cervical dystonia within frame of segmental or generalized dystonia, a 9.7-point and 7.3-point improvement in overall TWSTRS scores was noted at 6- (n=50) and 12-months (n=38), respectively.

Conclusions: This registry represents the first comprehensive, large-scale collection of real-world outcomes associated with dystonia patients implantedwith a directional DBS system capable of MICC. Preliminary results demonstrate significant improvement in patients with cervical dystonia (alone or in context of segmental or generalized dystonia) following DBS.

Objective: In this report, preliminary data will be presented from a prospective, multicenter, international Essential Tremor (ET) outcomes study in which patients received a multiple independent constant current (MICC) Directional DBS system for treatment of their ET symptoms.

Background: DBS has been demonstrated to be safe and effective in the treatment of several movement disorders including Parkinson's disease, Essential Tremor, and Dystonia. DBS of ventral intermediate nucleus (Vim) is currently recommended as a therapeutic option for appropriate subjects with ET. Large, multi-center patient registries have the potential to provide insight on the use of DBS in the treatment of ET as used per routine clinical practice.

Methods: In this prospective, on-label, multi-center, international DBS registry, enrolled patients are implanted with a directional MICC-based DBSsystem (Vercise, Boston Scientific). Patients are followed up to 3-years and overall improvement in quality of life and ET symptoms areevaluated. Clinical endpoints evaluated at baseline and during study follow-up timepoints include Quality of Life in Essential Tremor Questionnaire (QUEST), Fahn-Tolosa-Marin Rating Scale (FTMTRS), and Global Impression of change. Adverse events are also being collected.

Results: Preliminary results from this ongoing, prospective, multicenter, international outcomes study demonstrate significant improvement in ET related symptoms and quality of life up to 12-month follow-up. A total of 41 subjects (22 males, mean age = 65.5 years, mean disease duration = 19.9 years) received DBS. A mean 7.7-hour reduction in tremor was noted (self-reported, QUEST) compared with Baseline (14.4-hours at Baseline, 6.3-hours at 12-months) in a typical day. A clinically significant improvement in quality of life (Δ = 18.8-point in QUEST SI score, n = 18) at 12-months post-DBS was reported (MCID >4.47 points). According to clinicians, 18 out of 19 (94.7%) of the subjects demonstrated improvement at 12-months, while 1 (5.3%) subject reported no change. No lead breakages/fractures were reported.

Conclusions: Results from this ongoing real-world study demonstrates significant reduction in tremor and improvement in quality of life in Essential Tremor patients with the use of a Directional DBS systems capable of multiple independent current control (MICC).

Objective: In this report, we compared real-world outcomes of Parkinson's disease (PD) patients using Deep Brain Stimulation (DBS) Systems based on patients being awake or asleep during lead placement procedures.

Background: During the past several years, conducting DBS procedures with patients asleep (i.e., under general anesthesia) has becoming increasingly popular due to patient preference, programming flexibility with directional leads, and advances in imaging technology. Previous work assessing those undergoing awake versus asleep DBS procedures has demonstrated no difference in cognition, mood,and/or behavioral adverse effects (Holewijn RA, et al. JAMA Neurol, 2021). 

Methods: This is a prospective, on-label, multi-center, international real-world where subjects received multiple-source, constant-current directional DBS systems (Boston Scientific) for the treatment of PD. Based on sites’ standard-of-care and preferred technique, DBS procedures were performed with subjects awake or asleep during lead placement. Subjects were followed up to 3-years post-implantation and quality-of-life and PD motor symptoms was evaluated. Clinical endpoints evaluated at baseline and during study follow-up included Unified Parkinson's Disease Rating Scale (UPDRS), MDS-UPDRS III (converted), Parkinson's disease Questionnaire (PDQ-39), and Global Impression of Change.

Results: A total of 633 implanted patients in the study were analyzed based on being awake or asleep during lead placement procedures. Of these, 173 patients (mean age = 61.4 ± 8.3 years, 68% male) were asleep during lead placement and 460 (mean age= 60.6 ± 8.5 years, 66% male) were awake. Improvement in quality-of-life as assessed by PDQ-39 was noted in both groups with the asleep group reporting a 5.3-point improvement (n = 111) and awake group reporting a 4.2-point improvement (n = 356) at 1-year. Similarly, a 19.1- and 21.5-point improvement in converted MDS-UPDRS III scores (meds off) was noted in the asleep and awake groups, respectively.

Conclusions: Preliminary results show that motor function related, and quality of life outcomes show little to no difference between groups who received leads during DBS procedures whether awake versus asleep (i.e., under general anesthesia). Asleep DBS procedures can shorten the total time taken for DBS procedures (Holewijn RA, et al. JAMA Neurol, 2021). However, RCTs comparing asleep versus awake techniques are needed.

Objective:

The purpose of this multicenter, real-world outcomes study is to evaluate the impact of Deep Brain Stimulation (DBS) on the treatment of Parkinson’s Disease (PD) when DBS is utilized per routine clinical care.

Background:

Patient data, which is acquired on the basis of real-world, standard of care may facilitate new insights regarding the clinical use and outcomes of DBS. Here, we present preliminary outcomes from an ongoing prospective, multicenter study for the management of PD levodopa-responsive motor symptoms. The study was conducted in the United States on patients with directional DBS Systems capable of multiple independent current control (MICC).

Methods:

Study participants are all implanted with the Vercise DBS system (Boston Scientific), a multiple-source, constant- current system, and are assessed to 3-years post-implantation. Quality of life and PD motor symptoms are the measures emphasized in this study. Measures are recorded at baseline and during study follow-up and include: Unified Parkinson's disease Rating Scale (UPDRS), MDS-UPDRS, Parkinson's disease Questionnaire (PDQ-39), Global Impression of Change and Non-Motor Symptom Assessment Scale (NMSS) and adverse events.

Results:

A total of 111-patients (mean age: 64.1±8.7 years, 73% male, disease duration 9.7±5.3 years, n = 108) were enrolled, and 93/111 subjects have undergone device activation. A 56.4% improvement (28.2-points, p<0.0001) in motor function was noted at 6 months as assessed by MDS-UPDRS III in the meds off condition. Quality-of-life (QoL) was improved by 8.4-points on the PDQ-39 Summary Index (p<0.0001). This value exceeded the minimal clinically important difference (MCID) for PDQ-39 is of MCID >4.7-points (Horvath K., et al. 2017). Ninety-eight percent of patients and 95% of clinicians reported a categorical improvement at 6-months (GIC). No lead breakage or unanticipated adverse events were reported.

Conclusions: 

Real-world outcomes from a large, prospective, multi-center outcomes study demonstrated improvement in quality of life and motor function following DBS. There was also a subjective satisfaction among both patients and clinicians. Data from this study will be used to provide insights into the application of the MICC-based directional DBS Systems in clinical practice.

Introduction: Stereoelectroencephalography (SEEG) is a safe and effective technique for identifying the epileptogenic zone in pharmacoresistant epilepsy patients. While traditionally performed with stereotactic frames, robotic systems promise higher operative efficiency. Recently, a table-mounted robotic platform (Cirq®, Brainlab AG, Germany) with no OR footprint, which is already widely utilized for spinal procedures and cranial biopsies, received CE mark for SEEG. We aimed to compare its accuracy and performance for implanting depth electrodes to a Leksell Coordinate Frame G (Elekta, Sweden) in a phantom setting.

Methods: 3 realistic SEEG cases (one bilateral, two unilateral) with 10 trajectories each were planned on publicly available MRIs from the IXI database using Brainlab Elements. 6 skull models (Sawbones, Sweden) were coated with epoxide gel to mimic compact and spongy bone for drilling and filled with 1.6% agar. Two identical sets of 10 anchor bolts plus 10 SEEG electrodes (Ad-Tech Medical, USA) were implanted.

To compare the accuracy and efficiency of Cirq and the Leksell frame, P.R. implanted each SEEG case twice in identical phantoms fixated in a Leksell head ring and positioned laterally. Cone-beam computed tomography (CBCT, Loop-X Mobile Imaging Robot, Brainlab) was used for Automatic Image Registration (AIR, Brainlab) with the robotic arm, stereotactic localization of the frame and for post-op electrode localization in both workflows. 

For all 60 electrodes, DICOM coordinates of planned and executed entry and target points were used to calculate various error metrics, as illustrated in Figure 1. Implantation time per electrode was measured for both workflows.

Results: The mean radial entry error was 0.62 ± 0.40 mm in the robotic workflow and 0.77 ± 0.50 mm in the frame workflow. The mean Euclidean, radial and absolute depth target point errors with the robotic system were 1.60 ± 0.94 mm, 1.03 ± 0.53 mm and 1.03 ± 1.02 mm respectively, and with the frame 1.04 ± 0.34 mm, 0.59 ± 0.32 mm and 0.74 ± 0.45 mm. Mean implantation time per electrode using the robotic system was shorter than with the frame, at 5.5 ± 1.3min vs. 8.0 ± 1.9min.

Discussion: In this phantom study, robot-assisted SEEG with Cirq in combination with Loop-X was easier and faster than with the Leksell frame, while providing clinically acceptable accuracy. It was also less prone to human error associated with setting frame coordinates, and has potential for wider clinical availability due to the variety of supported procedures. Further studies with patients are warranted.

Introduction

The development of different waveforms and various spinal cord stimulation (SCS) systems increases the options for patients with chronic neuropathic pain. However, the choice for the used stimulation system is commonly made on an arbitrary basis. We therefore prospectively explored the influence of different providers during the temporary trial phase of SCS in a randomized clinical trial.

Methods

30 Patients with the indication for an SCS trial were included in the study. After implantation of a test lead, subjects were tested in a randomized order with two external pulse generators (EPG) of two different device manufacturers (A and B). Test leads from company A, the connection with the EPG from company B was made with an adapter. Tonic stimulation was used for two days with the first EPG. After that, stimulation was switched to burst stimulation for the following five days. There was a washout period of two days and then the second EPG was tested with burst stimulation only for another five days. After the trial, the test lead was removed and, if medically indicated, the entire system of the provider whose stimulator produced the best pain relief is implanted. A prospective data collection of these patients takes place in the following 6 months. During the different study phases, pain intensity and perception of pain were assed with visual analog scale (VAS), PainDETECT and Pain Castastrophizing Scale (PCS).

Results

Persistent spinal pain syndrome (type II) was the most frequent pain etiology, all the subjects had PainDETECT scores over 12 indicating neuropathic pain. Mean pain intensity at the baseline was 6.6 and achieved 6.4 after five days with burst stimulation from company B and 5.4 after burst stimulation from company A. Reduction in PCS was similar between the two groups – from 31.9 to 24.3 points with company B and to 23.3 points with company A. The tonic stimulation phase, which was done with the system of a single company for each patient, elicited 4.8% pain relief with B and 16.0% with A.

Conclusion

The choice of stimulator shows to have no influence over pain reduction (non-inferior). Both types of Burst stimulation were superior in terms of pain relief, however no difference was found among companies A and B.

Introduction. Renishaw 3D neurolocate module is a frameless patient registration module that is designed for use with the Renishaw neuromate stereotactic robot. When noninvasive modalities fail to adequately localize the seizure onset zone (SOZ) in children with medically refractory epilepsy, invasive interrogation with stereo-electroencephalography (SEEG) may be required. The recent introduction of robotic trajectory guidance systems has been suggested to provide a more accurate method of implantation, but supporting evidence is very limited. This study aims to provide a review of targeting accuracy of SEEG electrode implantation, in a single centre, comparing the use of standard frame-based techniques versus the Renishaw 3D neurolocate module.

Methods. Thirteen (13) patients underwent implantation of SEEG electrodes under general anaesthesia during the period August 2019 through December 2022 at our center. All patients underwent robotic-assisted stereotactic implantation of the SEEG electrodes with intraoperative 3D scanner confirmation of the final electrode position. These coordinates were compared to the planned entry and target; with attention to depth, radial, directional and absolute errors, in addition to Euclidean distance.

Results. Of the 175 electrode implantations undertaken, 85 employed Renishaw 3D neurolocate technology. The mean age was 12.1 ± 4.35 years (range 8-17 years). The mean number of SEEGs implanted for each patient was 13.2 ± 2.04 (range 9-17 electrodes). The median absolute errors in x-,y-,z- axes were 0.5 mm,  0.7 mm and 0.8  mm respectively with use of the Renishaw 3D neurolocate versus 0. 7 mm, 1.1 mm and 0.7 mm with standard techniques. The median Euclidean distance from the planned target to the actual electrode position with Renishaw 3D neurolocate module was 1.57  mm vs standard frame-based techniques at .1.92 mm.  The median RE was 1.49 (IQR 1.25 IQR) for pre-neurolocate patients, whereas 1.08 (1.26 IQR) for post-neurolocate patients. Two sample wilcoxon test showed a statistical significance for the Radial Error (p=0,04*) attesting better accuracy with the use of Renishaw 3D neurolocate system. Based on the trajectory angle we subdivided the electrodes in oblique and orthogonal for each patients group to evaluate if trajectory could have a relevant impact on accuracy regardless of the system used. Pre-neurolocate patients accounted 44,9 % (40) oblique electrodes and 55% (49) were considered orthogonal, whereas post-neurolocate patients comprised 54,2% (45) oblique electrodes and 45,7 % (38) orthogonal. We compared the accuracy in terms of absolute errors, radial errors and euclidean distance between oblique and orthogonal trajectories in the two subgroups. No major perioperative complications occurred.  The mean follow-up time was 14.0 ± 9.3 months. 

Conclusion. Stereo-electroencephalography (SEEG) depth electrode implantation with the Renishaw 3D neurolocate module is safe for use in the pediatric population with good surgical accuracy. Our results suggest orthogonal trajectories may be more accurate compared to oblique trajectories. The Renishaw 3D neurolocate module for robotic epilepsy surgery allows compatibility with the intraoperative 3D scanner and has the potential to improve surgical targeting accuracy and patient comfort.

Introduction

With the recent advances in deep brain stimulation technology it is important to apply and analyse utility of new advances in real world clinical practice. Medtronic Percept introduced sensing capability and recording or local field potentials(LFP). In this study we have introduced the sensing technology into our practice and recorded correlations between the LFP recordings and improvements in clinical outcomes for patients.

Methods

Prospective study looking at 4 patients with deep brain stimulation of the subthalamic nucleus for Parkinsons disease. We use LFP recordings to help with programming and record if the time taken to gain optimum stimulation is reduced. We also used Beta sensing survey and record fluctuation in the beta waves over a week period, prior to programming and 1 week of sensing at each session of programming as well as at 3months at 6 months. The unique feature of this study is the use of Parkinsons kinetograph(PKG) concurrently along side the beta sensing survey. This allows us to record UPDRS at each stage of programming as well as  using the objective PKG recordings, and compare to the Beta sensing survey to see if reduction in beta fluctuations truly correlate with clinical outcomes.

Results

3 male and 1 female patient had the Medtronic Percept implant and PKG device recordings. Initial UPDRS III off were between 29 and 47. LFP recordings on initial survey predicted the best contact for stimulation in all 4 patients. The median post op UPDRS III off meds was 15. Importantly the Beta sensing survey timeline was analysed and correlated with the PKG readings showing a direct objective relationship between Beta variations in LFPs and clinical symptomology.

Conclusion

This is the first study to show objective data showing correlations between beta fluctuations in LFP and clinical symptoms. Percept technology has also shown to help identify contact for stimulation reducing time needed to reach optimum programming. Understanding the direct relationshp between LFP and symptoms will help with adaptive closed loop stimulation in the future.