Citations

Abstract General anesthesia increasingly facilitates asleep deep brain stimulation (DBS) surgery but suppresses spontaneous electrophysiological signals used to guide lead placement. Here, we investigated whether evoked resonant neural activity (ERNA), a stimulation-evoked biomarker of basal ganglia circuitry, remains informative during asleep DBS. We analyzed intraoperative recordings from a multisite cohort of 45 patients (86 hemispheres) undergoing subthalamic nucleus or globus pallidus internus DBS under awake and anesthetized conditions. Anesthesia markedly attenuated spontaneous beta and high-frequency oscillatory activity. Although ERNA amplitude was reduced at matched stimulation intensities, increasing stimulation current restored high-amplitude, spatially localized responses while preserving anatomical specificity. Across both targets, ERNA spatial distributions remained stable across awake and anesthetized states, co-localized with established motor-network biomarkers, and retrospectively identified electrode levels associated with the greatest postoperative therapeutic window. These retrospective findings position stimulation-evoked circuit interrogation as a complement to imaging for physiology-guided asleep DBS and as a candidate signal for contact prioritization. Prospective studies are warranted to determine whether ERNA-guided decisions improve placement, programming efficiency and clinical outcomes.

OBJECTIVE Magnetic resonance–guided focused ultrasound (MRgFUS) thalamotomy has become a popular tool in the neurosurgical armamentarium for managing tremor in patients with essential tremor (ET) and Parkinson’s disease (PD). METHODS Given the recent exponential growth in the use of this technology, the American Society for Stereotactic and Functional Neurosurgery, which acts as the joint section representing the field of stereotactic and functional neurosurgery on behalf of the Congress of Neurological Surgeons and the American Association of Neurological Surgeons, provides an update on treatment indications and the efficacy and safety of MRgFUS for the treatment of tremor. RESULTS In ET, the efficacy of MRgFUS thalamotomy is supported by several open-label and 1 prospective, double-blind, sham-controlled randomized clinical trial (RCT) that showed a 47% improvement in hand tremor in the short term. Follow-up studies demonstrated that the benefits of MRgFUS for ET are sustained in the long term. Studies investigating the effects of bilateral staged MRgFUS thalamotomy in patients with ET have shown that tremor improvement on the second side was as significant as that observed after the first procedure. The efficacy of MRgFUS thalamotomy for PD tremor is supported by a systematic meta-analysis that consisted predominantly of smaller, nonrandomized studies; 1 RCT; and 1 prospective cohort study. Despite a significant short-term improvement in PD tremor, the long-term effects of this therapy remain unknown. Common early adverse effects of MRgFUS thalamotomy include gait disturbance and paresthesias. These, however, tend to subside over time. Other reported side effects are dysarthria, ataxia, taste disturbance, motor deficits, and speech difficulty. CONCLUSIONS MRgFUS thalamotomy is a safe, effective, and durable intervention for refractory ET in appropriately selected patients. The procedure appears to be safe and effective for PD tremor, although the long-term durability of the technique remains a concern. Early experience with bilateral staged lesions for ET suggests the procedure to be safe and effective.

Thalamic neuromodulation for drug-resistant epilepsy has evolved from ablative thalamotomy to network-guided deep-brain stimulation (DBS) and responsive neurostimulation (RNS). Currently, the only Food and Drug Administration-approved DBS target is the anterior thalamic nucleus, which provides substantial and durable seizure reduction, particularly in limbic and temporal epilepsies. There is growing evidence that the centromedian and pulvinar nuclei are implicated in generalized, multifocal, and posterior neocortical epilepsies. Advanced imaging, probabilistic atlases, and connectomics can be used to refine targeting; however, they are limited by patient specificity, acquisition burden, and interatlas variability. Thalamic stereoelectroencephalography may clarify potential neuromodulation target selection by characterizing ictal recruitment, network dynamics, and biomarkers. Although DBS and RNS each have unique benefits, no modality has demonstrated superior. Pediatric data are heterogeneous and scarcer, but seizure reduction and safety profiles are similar to adults. Further studies are needed to optimize neuromodulation target selection and programming paradigms.

Background: Estimating operative time with low accuracy and precision leads to suboptimal scheduling of available operating rooms (ORs) and waste of healthcare resources. We aimed to develop a predictive machine learning (ML) model for operative time using our institutional data to improve the scheduling of neurosurgical ORs, minimize waste, and maximize resource utilization. Methods: We developed a predictive model using our institution’s multicenter registry, which included diverse neurosurgical cases across three tertiary hospitals. We applied multiple ML techniques, including linear regression, support vector regression, deep neural networks, and extreme gradient boosting regression (XGBR). The best model was combined with the first fit decreasing bin-packing algorithm to create a practical OR scheduling system based on prior data. Results: The XGBR model exhibited the best performance, with lower mean absolute errors (MAEs) (root mean squared error: 52.24, MAE: 37.25) and higher R2 (0.76) values than other models. Implementing this model in a simulated OR scheduling scenario using institutional data, we successfully scheduled 30 random procedures with minimal residual time, such that the model ran out of procedures for the week with 86 and 171 min remaining in the cranial and spinal ORs, respectively, demonstrating potential efficiency gains. The cranial procedures were scheduled over 4 days and spinal procedures over 6 days, optimizing available OR time. Conclusion: Integrating ML models into operative time prediction can significantly improve the accuracy and efficiency of surgical schedules. This approach minimizes wasted OR time and enhances resource allocation, potentially improving patient outcomes and satisfaction by reducing waiting times.

Abstract Objective There is a need to develop a comprehensive, formalized, and globally applicable epilepsy surgery curriculum in order to help standardize the quality of epilepsy surgery practice in the world. Methods The Epilepsy Surgery Educational Task Force of the ILAE developed a competency‐based epilepsy surgery educational curriculum comprised of four domains: Diagnosis, Counseling, Pre‐surgical Work‐up, and Surgical Techniques. To evaluate this educational curriculum, a survey questionnaire consisting of 11 items was sent out for feedback to ILAE and IESS members. The survey questionnaire asked respondents to rate the degree of importance of each competency on a five‐point scale that ranged from “extremely important” to “not at all important” and provided space for free text comments. All competencies that were rated as “slightly important” or “somewhat important” by more than 10% of responders, as well as all free text feedback comments, were fully reviewed, and the final curriculum was adjusted accordingly. Results One hundred and twenty‐two responses ( n = 122) were submitted by the ILAE and IESS communities. Seventy‐one percent (71.9%) of the responses came from neurosurgeons of varied experience and training levels. Ninety‐four percent (94.4%) of responders stated that they “support a curriculum to determine the competency of neurosurgeons participating in the care of people with epilepsy in my country,” and 94.3% confirmed that they “would be interested in taking or would recommend an ILAE course based on these competencies, that would provide an ILAE certificate of completion.” Relevant changes within the curriculum were made based on feedback. Significance The newly developed ILAE comprehensive epilepsy surgery educational curriculum has a high level of support from neurosurgeons and neurologists around the world and shows potential for broad acceptance and implementation.

BACKGROUND AND OBJECTIVES: Upper limb motor recovery is limited and affects functional outcomes in stroke survivors. Recent randomized controlled trials have assessed the role of combining vagus nerve stimulation with standard neurorehabilitation. The aim of this review was to evaluate the effectiveness of pairing implanted vagus nerve stimulation (I-VNS) with rehabilitation therapy in ischemic stroke patients and to provide a framework for its integration into standard clinical practice. METHODS: We searched PubMed, Scopus, CINAHL Plus, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews for articles published from inception to July 2024. Randomized controlled trials and follow-up studies assessing the efficacy and/or safety of I-VNS in stroke rehabilitation were included. The outcomes included upper limb motor function and adverse events related to intervention. The risk of bias was assessed using the Cochrane risk-of-bias tool, and a random-effects model was generated for the meta-analysis using the Meta package in R. RESULTS: The final analysis included 8 studies, with a cumulative sample size of n = 498 patients who underwent I-VNS–paired rehabilitation for upper extremity weakness in unilateral supratentorial stroke. The intervention group (I-VNS) included 245 patients (49.1%) whereas the control group had 252 patients (50.6%). The mean age was 59.0 ± 10.01 years in the intervention group and 61.0 ± 9.7 years in the control group. The intervention group included 155 male patients (63.2%), and the control group had 165 male patients (64.4%). The meta-analyses showed statistically significant improvement in upper limb motor function in the I-VNS–paired rehabilitation group with a mean difference of 2.73 (95% CI: 1.32-4.13; P = .04) in the Fugl-Meyer Assessment for Upper Extremity score. Only one study reported a serious adverse event. CONCLUSION: A systematic review and meta-analysis of the current literature provides high-level evidence that I-VNS–paired rehabilitation improves functional outcomes and has a favorable safety profile in patients with poststroke upper extremity weakness.

ObjectiveVagus nerve stimulation (VNS) paired with rehabilitation therapy improved motor status compared to rehabilitation alone in the phase III VNS‐REHAB stroke trial, but treatment response was variable and not associated with any clinical measures acquired at baseline, such as age or side of paresis. We hypothesized that neuroimaging measures would be associated with treatment‐related gains, examining performance of regional injury measures versus global brain health measures in parallel with clinical measures.MethodsBaseline magnetic resonance imaging (MRI) scans in the VNS‐REHAB trial were used to derive regional injury measures (extent of injury to corticospinal tract, the primary regional measure; plus extent of injury to precentral gyrus and postcentral gyrus; lesion volume; and lesion topography) and global brain health measures (degree of white matter hyperintensities, the primary global brain measure; plus volumes of cerebrospinal fluid, cortical gray matter, white matter, each thalamus, and total brain). Eight clinical measures assessed at baseline were also evaluated (treatment group, age, race, gender, paretic side, pre‐stroke dominant hand, time since stroke, and baseline Fugl‐Meyer upper extremity score). Bivariate analyses compared each measure with the primary trial end point (change in Fugl‐Meyer upper extremity score from baseline to end of 6 weeks of treatment) across all subjects, with secondary analyses examining trial groups separately.ResultsMRIs were available from 80 patients (age = 59.8 ± 9.5 years, 29 women). Across all patients, less white matter hyperintensities (r = −0.25, p = 0.028) at baseline was associated with larger Fugl‐Meyer score change. In the VNS group, less white matter hyperintensities (r = −0.37, p = 0.018) and larger ipsilesional thalamus volume (r = 0.33, p = 0.046) were each associated with larger Fugl‐Meyer score change. Analysis of covariance (ANCOVA) analyses tested the interaction that each baseline measure had with treatment group and found that the model examining white matter hyperintensities had a significant interaction term, indicating 2.3 less change in Fugl‐Meyer Upper Extremity (FM‐UE) points in the VNS group relative to the control group for each point increase in modified Fazekas scale.InterpretationNeuroimaging measures are associated with extent of gains on the primary endpoint of a phase III stroke recovery trial. Among the neuroimaging measures examined, a measure of global brain health (extent of white matter hyperintensities) was better at explaining the change in arm impairment as compared with measures of regional injury; this was true when examining all study subjects as well as only those in the VNS group and is consistent with the global mechanism of action that VNS has throughout the cerebrum. Future studies can evaluate additional measures that further predict response to VNS therapy. The current findings suggest that individual patient neuroimaging results may be useful for a personalized medicine approach to stroke recovery therapeutics. ANN NEUROL 2025;97:709–719

Abstract Up to 80% of the world's population with epilepsy lives in low and middle‐income countries. Around one‐third of these patients will have drug‐resistant epilepsy, for which epilepsy surgery is an option. Unfortunately, many of these regions, as well as some more developed nations, lack sufficient epilepsy surgery units and trained neurosurgeons. With this in mind, the International League Against Epilepsy (ILAE) formed the Epilepsy Surgery Education Taskforce to address the shortage of further educational opportunities for surgeons and neurologists and to promote the creation of more epilepsy surgery units around the world. In this article, we publish our findings from a web‐based international survey, in which we investigated the global distribution and experience of neurosurgeons who perform epilepsy surgery, their educational paths, and opinions on the further need for epilepsy surgery education, as well as the resources available to them. We report a detailed analysis of the 202 survey replies received from 35 different countries across six continents. The lack of adequate numbers of epilepsy surgery units in the Southern Hemisphere is notable, and the aim of this task force with other ILAE committees, is to improve access to epilepsy surgery for patients and to enhance training for their health care providers.

BACKGROUND AND OBJECTIVES: Stereotactic procedures are used to manage a diverse set of patients across a variety of clinical contexts. The stereotactic devices and software used in these procedures vary between surgeons, but the fundamental principles that constitute safe and accurate execution do not. The aim of this work is to describe these principles to equip readers with a generalizable knowledge base to execute and understand stereotactic procedures. METHODS: A combination of a review of the literature and empirical experience from several experienced surgeons led to the creation of this work. Thus, this work is descriptive and qualitative by nature, and the literature is used to support instead of generate the ideas of this framework. RESULTS: The principles detailed in this work are categorized based on 5 clinical domains: imaging, registration, mechanical accuracy, target planning and adjustment, and trajectory planning and adjustment. Illustrations and tables are used throughout to convey the concepts in an efficient manner. CONCLUSION: Stereotactic procedures are complex, requiring a thorough understanding of each step of the workflow. The concepts described in this work enable functional neurosurgeons with the fundamental knowledge necessary to provide optimal patient care.