The Impact of Perilesional Heatsink Structures on Ablation Volumes in Laser Interstitial Thermal Therapy for Brain Metastases.

BACKGROUND AND OBJECTIVES: Laser interstitial thermal therapy (LITT) has demonstrated promise in surgical neuro-oncology because of its effectiveness in delivering precise thermal energy to lesions. The extent of ablation (EOA) is a prognostic factor in improving patient outcomes but is often affected by perilesional heatsink structures, which can lead to asymmetric ablations. The purpose of this study was to quantitatively evaluate the impact of various perilesional heatsink structures on the EOA in LITT for brain metastases. METHODS: Twenty-seven procedures for 22 unique patients with brain metastases fit the inclusion criteria. Intracranial heatsink structures were identified: sulci, meninges, cerebrospinal fluid (CSF) spaces, and vasculature. Asymmetric ablation was determined by measuring 3 pairs of orthogonal distances from the proximal, midpoint, and distal locations along the laser catheter to the farthest edge of the ablation zone bilaterally. Distances from the same points on the laser catheter to the nearest heatsink were also recorded. The Heatsink Effect Index was created to serve as a proxy for asymmetric ablation. Pearson correlations, t-tests, and analysis of variance were the statistical analyses performed. RESULTS: From the midpoint of the catheter, the 27 heatsinks were meninges (40.7%), sulci (22.2%), vasculature (22.2%), and CSF spaces (14.8%). Across all points along the catheter track, there was a significant generalized heatsink effect on asymmetric ablations (P < .0001). There was a negative correlation observed between asymmetric ablations and EOA from the midpoint of the laser catheter (r = -0.445, P = .020). Compared with sulci, CSF spaces trended toward a greater effect on asymmetric ablation volumes (P = .069). CONCLUSION: This novel quantitative analysis shows that perilesional heatsinks contribute to asymmetric ablations. CSF spaces trended toward higher degrees of asymmetric ablations. Importantly, neurosurgeons may anticipate asymmetric ablations preoperatively if heatsinks are located within 13.3 mm of the laser probe midpoint. These preliminary results may guide surgical decision-making in LITT for metastatic brain lesions.

Alternative patterns of deep brain stimulation in neurologic and neuropsychiatric disorders.

Deep brain stimulation (DBS) is a widely used clinical therapy that modulates neuronal firing in subcortical structures, eliciting downstream network effects. Its effectiveness is determined by electrode geometry and location as well as adjustable stimulation parameters including pulse width, interstimulus interval, frequency, and amplitude. These parameters are often determined empirically during clinical or intraoperative programming and can be altered to an almost unlimited number of combinations. Conventional high-frequency stimulation uses a continuous high-frequency square-wave pulse (typically 130-160 Hz), but other stimulation patterns may prove efficacious, such as continuous or bursting theta-frequencies, variable frequencies, and coordinated reset stimulation. Here we summarize the current landscape and potential clinical applications for novel stimulation patterns.

Epidural Versus Local Anesthesia for Percutaneous Endoscopic Lumbar Discectomy: A Systematic Review and Meta-Analysis.

STUDY DESIGNS: Systematic Review. OBJECTIVE: To examine the impact of anesthesia type on patient-reported outcomes (PROs) and complications after percutaneous endoscopic lumbar discectomy (PELD). SUMMARY OF BACKGROUND DATA: A significant advantage of PELD involves the option to use alternative sedation to general anesthesia (GA). Two options include local anesthesia (LA) and epidural anesthesia (EA). While EA is more involved, it may yield improved pain control and surgical results compared with LA. However, few studies have directly examined outcomes for PELD after LA versus EA, and it remains unknown which technique results in superior outcomes. MATERIALS AND METHODS: A systematic review and meta-analysis of the PubMed, EMBASE, and SCOPUS databases examining PELD performed with LA or EA from inception to August 16, 2021 were conducted. All studies reported greater than 6 months of follow-up in addition to PRO data. PROs, including visual analog scale (VAS)-leg/back, and Oswestry Disability Index (ODI) scores were collected. Complications, recurrent disk herniation, durotomy, and reoperation rates, as well as surgical data, were recorded. All outcomes were compared between pooled studies examining LA or EA. RESULTS: Fifty-six studies consisting of 4465 patients (366 EA, 4099 LA) were included. Overall complication rate, durotomy rate, length of stay, recurrent disk herniation, and reoperation rates were similar between groups. VAS back/leg and ODI scores were all significantly improved at the first and last follow-up appointments in the LA group. VAS leg and ODI scores were significantly improved at the first and last follow-up appointments in the EA group, but VAS back was not. CONCLUSIONS: EA can be a safe and feasible alternative to LA, potentially minimizing patient discomfort during PELD. Conclusions are limited by a high level of study bias and heterogeneity. Further investigation is necessary to determine if PELD under EA may have greater short-term PRO benefits compared with LA.

Injury-Transplantation Interval-Dependent Amelioration of Axonal Degeneration and Motor Deficit in Rats with Penetrating Traumatic Brain Injury.

Penetrating traumatic brain injury (pTBI) is increasingly survivable, but permanently disabling as adult mammalian nervous system does not regenerate. Recently, our group demonstrated transplant location-dependent neuroprotection and safety of clinical trial-grade human neural stem cell (hNSC) transplantation in a rodent model of acute pTBI. To evaluate whether longer injury-transplantation intervals marked by chronic inflammation impede engraftment, 60 male Sprague-Dawley rats were randomized to three sets. Each set was divided equally into two groups: 1) with no injury (sham) or 2) pTBI. After either 1 week (groups 1 and 2), 2 weeks (groups 3 and 4), or 4 weeks after injury (groups 5 and 6), each animal received 0.5 million hNSCs perilesionally. A seventh group of pTBI animals treated with vehicle served as the negative control. All animals were allowed to survive 12 weeks with standard chemical immunosuppression. Motor capacity was assessed pre-transplant to establish injury-induced deficit and followed by testing at 8 and 12 weeks after transplantation. Animals were euthanized, perfused, and examined for lesion size, axonal degeneration, and engraftment. Compared to vehicle, transplanted groups showed a trend for reduced lesion size and axonal injury across intervals. Remote secondary axonal injury was significantly reduced in groups 2 and 4, but not in group 6. The majority of animals showed robust engraftment independent of the injury-transplant time interval. Modest amelioration of motor deficit paralleled the axonal injury trend. In aggregate, pTBI-induced remote secondary axonal injury was resolved by early, but not delayed, hNSC transplantation.

Radical supramaximal resection for newly diagnosed left-sided eloquent glioblastoma: safety and improved survival over gross-total resection.

OBJECTIVE: Supramaximal resection (SMR) has arisen as a possible surrogate to gross-total resection (GTR) to improve survival in newly diagnosed glioblastoma (nGBM). However, SMR has traditionally been limited to noneloquent regions and its feasibility in eloquent nGBM remains unclear. The authors conducted a retrospective multivariate propensity-matched analysis comparing survival outcomes for patients with left-sided eloquent nGBM undergoing SMR versus GTR. METHODS: A retrospective review was performed of all patients at our institution who underwent SMR or GTR of a left-sided eloquent nGBM during the period from 2011 to 2020. All patients underwent some form of preoperative or intraoperative functional mapping and underwent awake or asleep craniotomy (craniotomy under general anesthesia); however, awake craniotomy was performed in the majority of patients and the focus of the study was SMR achieved via awake craniotomy and functional mapping with lesionectomy and additional peritumoral fluid attenuated inversion recovery (FLAIR) resection. Propensity scores were generated controlling for age, tumor location, and preoperative Karnofsky Performance Status (KPS) score with the nearest-neighbor algorithm. RESULTS: A total of 102 patients (48 SMR, 54 GTR) were included in this study. The median overall survival (OS) and progression-free survival (PFS) for patients receiving SMR were 22.9 and 5.1 months, respectively. Propensity matching resulted in a final cohort of 27 SMR versus 27 GTR patients. SMR conferred improved OS (21.55 vs 15.49 months, p = 0.0098) and PFS (4.51 vs 3.59 months, p = 0.041) compared to GTR. There was no significant difference in postoperative complication rates or KPS score in SMR compared with GTR patients (p = 0.236 and p = 0.736, respectively). In patients receiving SMR, improved OS and PFS showed a dose-dependent relationship with extent of FLAIR resection (EOFR) on log-rank test for trend (p < 0.001). CONCLUSIONS: SMR by means of awake craniotomy with functional mapping for left-sided eloquent nGBM is safe and confers a survival benefit compared to GTR obtained with lesionectomy alone while preserving postoperative neurological integrity. When tolerated, greater EOFR with SMR may be associated with improved survival.

General vs Local Anesthesia for Percutaneous Endoscopic Lumbar Discectomy (PELD): A Systematic Review and Meta-Analysis.

STUDY DESIGN: Systematic review. OBJECTIVES: It remains unknown whether general anesthesia (GA) or local ± epidural anesthesia (LA) results in superior outcomes with percutaneous endoscopic lumbar discectomy (PELD). The present study sought to examine the impact of anesthesia type on patient-reported outcomes (PROs) and complications with PELD. METHODS: Systematic review and meta-analysis examining PELD performed under GA or LA was conducted. Patient-reported outcomes including Visual Analog Scale (VAS)-leg/back, and Oswestry Disability Index (ODI) scores were collected. Complication, recurrent disc herniation, durotomy, and reoperation rates as well as surgical data were recorded. All outcomes were compared between pooled studies examining GA or LA. RESULTS: Sixty-eight studies consisting of 5269 patients (724 GA, 4465 LA) were included in the meta-analysis. Overall complication rate was significantly higher in the GA group (9% vs 4%, P = .003). Durotomy rates, length of stay, recurrent disc herniation and reoperation rates were similar between groups. At the first follow-up timepoint, the LA group demonstrated significant improvements in VAS back and ODI scores (P < .05) while the GA group did not (P > .05). At the final follow-up (> 6 months), the percent of patients achieving an excellent McNab score was significantly higher in the GA vs LA group (P < .001). CONCLUSIONS: Percutaneous endoscopic lumbar discectomy with LA may be associated with greater short-term improvement in VAS back pain and ODI scores. General anesthesia may be associated with more durable pain relief but a higher complication rate. Further systematic investigation is necessary to determine what short and long term benefits are associated with PELD performed under LA and GA.

Endoscopic Endonasal Resection of Rathke Cleft Cyst with Xanthogranulomatous Change: Two-Dimensional Operative Video.

Objective Sellar xanthogranulomas (XGAs) are a rare pathological subtype of hypophysitis reflecting a degenerative process of Rathke's cleft cyst with predilection in young adults. While the histological features have been described, there is limited discussion on the technical expectations in surgical management. We present the clinical, radiographic, and surgical features of the third literature-reported XGA in the pediatric population. Setting The patient was a 17-year-old boy who first identified by ophthalmologically confirmed peripheral vision loss. Subsequent endocrine workup identified delayed-onset puberty and hypopituitarism. Magnetic resonance imaging (MRI) showed a nonenhancing 2.6-cm T1 and T2 sellar-based hyperintense mass with suprasellar extension and mass effect on the optic chiasm. A small T1 hypointense encased nodule was also seen ( Fig. 1 ). Consent for resection was obtained. Results Intraoperatively the tumor was firm and adherent, requiring piecemeal removal. Radiofrequency ablation enabled ergonomic debulking and minimize thermal injury ( Fig. 2 ). 1 We used initial settings of 25 W, equivalent to 55 W. A cystic component with motor oil-like fluid was encountered and decompressed. The tumor was notably very adherent to the optic nerve and infiltrated the stalk, requiring its truncation. Closure was achieved by fat graft dead space plugging, fascia lata underlay, Medpor gasket seal, and nasoseptal flap. Conclusion Pathology confirmed dense fibrous tissue with features of chronic inflammation, cholesterol clefts, hemosiderin pigment, multinucleate giant cells, and foamy macrophages. Additional cyst wall sampling identified squamous and ciliated epithelial lining, collectively consistent with Rathke's cleft cyst and xanthogranulomatous reaction. These lesions can undergo surgical cure with resection, most commonly by transsphenoidal approach. The link to the video can be found at: https://youtu.be/S2n5iQ3aFgc .

Microendoscopic lumbar discectomy with general versus local anesthesia: A systematic review and meta-analysis.

Background: While general anesthesia (GA) is the most commonly used anesthetic method during lumbar microendoscopic discectomy (MED), local ± epidural anesthesia (LA) has been gaining popularity as an alternate method. Theoretical advantages of LA include reduced morbidity of anesthesia and improved surgeon-patient communication facilitating less nerve root manipulation and yielding improved surgical outcomes. The objective of this systematic review is to examine the impact of anesthesia type on patient reported outcomes (PROs) and complications with MED. Methods: A systematic review and meta-analysis of the available literature examining MED performed under GA or LA was performed. The PubMed, EMBASE and SCOPUS databases were searched from inception to August 16, 2021, utilizing strict inclusion and exclusion criteria with all studies reporting greater than 6 months of follow-up and PRO data. PROs including Visual Analog Scale (VAS)-leg/back, Oswestry Disability Index (ODI), Japanese Orthopedic Association (JOA) and/or 36-Item Short Form (SF-36) physical component scores were collected. Complication, recurrent disc herniation, durotomy and reoperation rates as well as surgical factors were collected. All outcomes were compared between pooled studies examining GA or LA. Risk of bias was assessed with the Newcastle-Ottawa Scale. Results: A total of 23 studies consisting of 2,868 patients (1,335 GA, 1,533 LA) were included in the meta-analysis. There were no significant differences between GA and LA groups in regard to overall complication rate, durotomy rate, recurrent disc herniation rate, reoperation rate, blood loss, or surgical time (p > 0.05). Both groups demonstrated significant improvements in ODI and JOA (p<0.0004), however leg and back VAS was only improved in GA (p<0.0025) and not in LA (p>0.058), and SF-36 only in LA (p=0.003). Conclusions: Patients undergoing MED under both anesthetic techniques demonstrated significant improvements in ODI and JOA, with no significant differences in complication or reoperation rates. However, patients undergoing GA demonstrated significant improvement in VAS leg and back pain at last follow-up while LA did not. LA may be offered to carefully selected patients and prior studies have demonstrated reduced costs and risks with LA. Conclusions are limited by a high level of study bias and heterogeneity. Further investigation is needed to assess the true effects of GA and LA on outcomes after MED.

Morphological characteristics of symptomatic and asymptomatic carotid webs.

OBJECTIVE: Carotid webs (CWs) are an increasingly recognized source of recurrent stroke among young patients without conventional vascular risk factors. There have been no previous studies demonstrating that specific web morphological characteristics correlate with a higher stroke risk. The authors aim to report distinct morphological features of symptomatic and asymptomatic CWs. METHODS: The authors performed a cross-sectional study of patients with CWs detected on CT angiography (CTA) of the neck. Patients were categorized based on whether or not they presented with stroke ipsilaterally and if it was likely to be attributable to their web. The following CW morphological variables were recorded and compared based on CTA: length, thickness, angle, and the proportion of carotid bulb lumen occupied by the web (web-to-bulb ratio [WBR]). RESULTS: A total of 86 CWs were identified, 14 of which presented with stroke (16.3%). Patients presenting with stroke had webs that were significantly longer (4.18 mm vs 2.20 mm, p = 0.001) and were situated at more acute angles relative to the carotid wall (73.2° vs 94.9°, p = 0.004). Additionally, patients presenting with stroke had higher WBRs compared to the asymptomatic cohort (0.50 vs 0.36, p = 0.008). The optimal threshold associated with stroke was web length ≥ 3.1 mm (OR 15.2, 95% CI 3.73-61.8; p < 0.001), web angle ≤ 90.1° (OR 5.00, 95% CI 1.42-17.6; p = 0.012), and WBR ≥ 0.50 (OR 30.0, 95% CI 5.94-151; p < 0.001). CONCLUSIONS: Patients with CWs that occupy more than half of the diameter of the carotid bulb lumen and are situated at acute angles relative to the carotid wall are more likely to present with acute ischemic stroke. Additional studies are needed to determine the long-term outcomes of these lesions.

Interstitial laser anterior capsulotomy for obsessive-compulsive disorder: lesion size and tractography correlate with outcome.

BACKGROUND: Anterior capsulotomy is a well-established treatment for refractory obsessive-compulsive disorder (OCD). MRI-guided laser interstitial thermal therapy (LITT) allows creation of large, sharply demarcated lesions with the safeguard of real-time imaging. OBJECTIVE: To characterise the outcomes of laser anterior capsulotomy, including radiographical predictors of improvement. METHODS: Patients with severe OCD refractory to pharmacotherapy and cognitive-behavioural therapy underwent bilateral anterior capsulotomy via LITT. The primary outcome was per cent reduction in Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) score over time. Lesion size was measured on postablation MRI. Disconnection of the anterior limb of the internal capsule (ALIC) was assessed via individual and normative tractography. RESULTS: Eighteen patients underwent laser anterior capsulotomy. Median follow-up was 6 months (range 3-51 months). Time occupied by obsessions improved immediately (median Y-BOCS item 1 score 4-1, p=0.002). Mean (±SD) decrease in Y-BOCS score at last follow-up was 46%±32% (16±11 points, p<0.0001). Sixty-one per cent of patients were responders. Seven patients (39%) exhibited transient postoperative apathy. One patient had an asymptomatic intracerebral haemorrhage. Reduction in Y-BOCS score was positively associated with ablation volume (p=0.006). Individual tractography demonstrated durable ALIC disconnection. Normative tractography revealed a dorsal-ventral gradient, with disconnection of orbitofrontal streamlines most strongly associated with a positive response (p<0.0001). CONCLUSIONS: Laser anterior capsulotomy resulted in immediate, marked improvement in OCD symptom severity. Larger lesions permit greater disconnection of prefrontal-subcortical pathways involved in OCD. The importance of greater disconnection is presumably related to variation in ALIC structure and the complex role of the PFC in OCD.

Ventriculostomy supply cart decreases time-to-external ventricular drain placement in the emergency department.

BACKGROUND: Minimizing time-to-external ventricular drain (EVD) placement in the emergency department (ED) is critical. We sought to understand factors affecting time-to-EVD placement through a quality improvement initiative. METHODS: The use of process mapping, root cause analyses, and interviews with staff revealed decentralized supply storage as a major contributor to delays in EVD placement. We developed an EVD "crash cart" as a potential solution to this problem. Time-to-EVD placement was tracked prospectively using time stamps in the electronic medical record (EMR); precart control patients were reviewed retrospectively. RESULTS: The final cohorts consisted of 33 precart and 18 postcart cases. The mean time-to-EVD in the precart group was 99.09 min compared to 71.88 min in the postcart group (two-tailed t-test, P = 0.023). Median time-to-EVD was 92 min in the precart group compared to 64 min in the postcart group (rank sum test, P = 0.0165). Postcart patients trended toward improved outcomes with lower modified Rankin score scores at 1 year, but this did not reach statistical significance (two-tailed t-test, P = 0.177). CONCLUSION: An EVD "crash cart" is a simple intervention that can significantly reduce time-to-EVD placement and may improve outcomes in patients requiring an EVD.

Immunovirotherapy for the Treatment of Glioblastoma and Other Malignant Gliomas.

Glioblastoma multiforme (GBM) represents one of the most challenging malignancies due to many factors including invasiveness, heterogeneity, and an immunosuppressive microenvironment. Current treatment modalities have resulted in only modest effect on outcomes. The development of viral vectors for oncolytic immunovirotherapy and targeted drug delivery represents a promising therapeutic prospect for GBM and other brain tumors. A host of genetically engineered viruses, herpes simplex virus, poliovirus, measles, and others, have been described and are at various stages of clinical development. Herein we provide a review of the advances and current state of oncolytic virotherapy for the targeted treatment of GBM and malignant gliomas.

Targeting Microglial Polarization to Improve TBI Outcomes.

Traumatic Brain Injury (TBI) is still the worldwide leading cause of mortality and morbidity in young adults. Improved safety measures and advances in critical care have increased chances of surviving a TBI, however, numerous secondary mechanisms contribute to the injury in the weeks and months that follow TBI. The past 4 decades of research have addressed many of the metabolic impairments sufficient to mitigate mortality, however, an enduring secondary mechanism, i.e. neuroinflammation, has been intractable to current therapy. Neuroinflammation is particularly difficult to target with pharmacological agents due to lack of specificity, the blood brain barrier, and an incomplete understanding of the protective and pathologic influences of inflammation in TBI. Recent insights into TBI pathophysiology have established microglial activation as a hallmark of all types of TBI. The inflammatory response to injury is necessary and beneficial while the death of activated microglial is not. This review presents new insights on the therapeutic and maladaptive features of the immune response after TBI with an emphasis on microglial polarization, followed by a discussion of potential targets for pharmacologic and non-pharmacologic treatments. In aggregate, this review presents a rationale for guiding TBI inflammation towards neural repair and regeneration rather than secondary injury and degeneration, which we posit could improve outcomes and reduce lifelong disease burden in TBI survivors.

Rathke's cleft cyst with xanthogranulomatous change: A case report and review of the literature.

BACKGROUND: Rathke's cleft cysts (RCCs) are benign, typically asymptomatic sellar lesions found incidentally in adults, with a dramatically lower incidence in pediatric patients (<18 years). We present a case of RCC with xanthogranulomatous change (XGC) - an even less common subtype of RCC - treated by endoscopic endonasal surgical resection. This is the second reported instance of an RCC with XGC occurring in a pediatric patient. CASE DESCRIPTION: The patient is a 17-year-old male with delayed puberty who presented with bitemporal hemianopsia and was found to have a 2.6 cm lesion, initially thought to be a craniopharyngioma. He subsequently underwent uncomplicated transsphenoidal endoscopic endonasal resection. Histology confirmed the diagnosis of RCC and demonstrated marked degenerative XGCs with squamous metaplasia. The patient tolerated the procedure well with improvement in visual symptoms. CONCLUSION: RCC with XGC is a very rare pathology, particularly in the pediatric population. These lesions, while benign, can manifest clinically with significant symptoms. While treatment paradigms are not fully established with a small cohort of cases, endoscopic endonasal approaches have made surgical resection of these lesions a safe and effective treatment strategy, even in the pediatric population.

Survival benefit of lobectomy for glioblastoma: moving towards radical supramaximal resection.

PURPOSE: Extent of resection remains a paramount prognostic factor for long-term outcomes for glioblastoma. As such, supramaximal resection or anatomic lobectomy have been offered for non-eloquent glioblastoma in an attempt to improve overall survival. Here, we conduct a propensity-matched analysis of patients with non-eloquent glioblastoma who underwent either lobectomy or gross total resection of lesion to investigate the efficacy of supramaximal resection of glioblastoma. METHODS: Patients who underwent initial surgery for gross total resection or lobectomy for non-eloquent glioblastoma at our tertiary care referral center from 2010 to 2019 were included for this propensity-matched survival analysis. Propensity scores were generated with the following covariates: age, location, preoperative KPS, product of perpendicular maximal tumor diameters, and product of perpendicular FLAIR signal diameters. Inverse probability of treatment weighting (IPTW) with generated propensity scores was used to compare progression-free survival and overall survival. RESULTS: Sixty-nine patients were identified who underwent initial resection of glioblastoma for non-eloquent glioblastoma from 2010 to 2019 (GTR = 37, lobectomy = 32). Using IPTW, overall survival (30.7 vs. 14.1 months) and progression-free survival (17.2 vs. 8.1 months were significantly higher in the lobectomy cohort compared to the GTR group (p < 0.001). There was no significant difference in pre-op or post-op KPS or complication rates between the two groups. CONCLUSION: Our propensity-matched study suggests that lobectomy for non-eloquent glioblastoma confers an added survival benefit compared to GTR alone. For patients with non-eloquent glioblastoma, a supramaximal resection by means of an anatomic lobectomy should be considered as a primary surgical treatment in select patients if feasible.

Supratentorial intraventricular rosette-forming glioneuronal tumors - Case report and review of treatment paradigms.

BACKGROUND: Rosette-forming glioneuronal tumors (RGNT) are slow-growing WHO Grade I tumors that are characterized by mixed histology and rosette formation. Although typically located in the posterior fossa, these tumors can rarely originate elsewhere. Here, we describe the fourth case in literature where an RGNT was localized to the lateral ventricles and detail the treatment approach. CASE DESCRIPTION: A 41-year-old male presented with a 10 day history of gradually worsening headaches and mild gait difficulty. Computed tomography and magnetic resonance imaging (MRI) identified a heterogeneously enhancing 6.0 cm left lateral ventricular cystic mass with hydrocephalus. An interhemispheric transcallosal approach was performed for tumor debulking. The mass was emanating from the roof of the left lateral ventricle. Sub-total resection (STR) was achieved. Pathology showed a glioneuronal neoplasm with vague neurocytic rosettes and loose perivascular pseudorosettes. Tumor vessels were thickly hyalinized and contained eosinophilic granular bodies and Rosenthal fibers. Tumor stained positive for GFAP, S-100, OLIG2, and SOX10, and patchy positive for epithelial membrane antigen (EMA), D2-40, CD99, and p16. Neurocytic rosettes and perivascular structures stained positive for synaptophysin. The patient was discharged home uneventfully and remained intact at his 6-month follow-up visit. Long-term care included MRI surveillance with repeat surgery being considered in case of progression. CONCLUSION: In this report, we describe the fourth case of an RGNT being isolated to the lateral ventricles and the first where it stained positive for EMA and D2-40. Our patient's uneventful recovery after STR indicates that surgery alone continues to be a viable initial treatment option.

Individualized Anatomy-Based Targeting for VIM-cZI DBS in Essential Tremor.

BACKGROUND: Deep brain stimulation of the ventral intermediate nucleus (VIM) or caudal zona incerta (cZI) is effective for refractory essential tremor (ET). To refine stereotactic planning for lead placement, we developed a unique individualized anatomy-based planning protocol that targets both the VIM and the cZI in patients with ET. METHODS: 33 patients with ET underwent VIM-cZI lead implantation with targeting based on our protocol. Indirect targeting was adjusted based on anatomic landmarks as reference lines bisecting the red nuclei and ipsilateral subthalamus. Outcomes were evaluated through the follow-up of 31.1 ± 18.4 months. Active contact coordinates were obtained from reconstructed electrodes in the Montreal Neurological Institute space using the MATLAB Lead-DBS toolbox. RESULTS: Mean tremor improvement was 79.7% ± 22.4% and remained stable throughout the follow-up period. Active contacts at last postoperative visit had mean Montreal Neurological Institute coordinates of 15.5 ± 1.6 mm lateral to the intercommissural line, 15.3 ± 1.8 mm posterior to the anterior commissure, and 1.4 ± 2.9 mm below the intercommissural plane. No hemorrhagic complications were observed in the analyzed group. CONCLUSIONS: Individualized anatomy-based VIM-cZI targeting is feasible and safe and is associated with favorable tremor outcomes.

Salvage craniotomy for treatment-refractory symptomatic cerebral radiation necrosis.

BACKGROUND: The incidence of symptomatic radiation necrosis (RN) has risen as radiotherapy is increasingly used to control brain tumor progression. Traditionally managed with steroids, symptomatic RN can remain refractory to medical treatment, requiring surgical intervention for control. The purpose of our study was to assess a single institution's experience with craniotomy for steroid-refractory pure RN. METHODS: The medical records of all tumor patients who underwent craniotomies at our institution from 2011 to 2016 were retrospectively reviewed for a history of preoperative radiotherapy or radiosurgery. RN was confirmed histopathologically and patients with active tumor were excluded. Preoperative, intraoperative, and outcome information was collected. Primary outcomes measured were postoperative KPS and time to steroid freedom. RESULTS: Twenty-four patients with symptomatic RN were identified. Gross total resection was achieved for all patients. Patients with metastases experienced an increase in KPS (80 vs 100, P < .001) and required a shortened course of dexamethasone vs patients with high-grade gliomas (3.4 vs 22.2 weeks, P = .003). RN control and neurological improvement at 13.3 months' follow-up were 100% and 66.7%, respectively. Adrenal insufficiency after rapidly tapering dexamethasone was the only morbidity (n = 1). Overall survival was 93.3% (14/15) at 1 year. CONCLUSION: In cases of treatment-refractory symptomatic RN, resection can lead to an overall improvement in postoperative health status and neurological outcomes with minimal RN recurrence. Craniotomy for surgically accessible RN can safely manage symptomatic patients, and future studies assessing the efficacy of resection vs bevacizumab may be warranted.

Central Neurocytoma Treatment Modalities: A Systematic Review Assessing the Outcomes of Combined Maximal Safe Resection and Radiotherapy with Gross Total Resection.

BACKGROUND: Central neurocytomas (CNCs) are rare intraventricular lesions comprising <1% of primary brain tumors. Their surgical and adjuvant management is unclear. OBJECTIVE: Our goal was to update Rades et al.'s 2006 systematic review to assess the outcome differences among 3 fundamental therapies for CNC: gross total resection with and without radiation therapy (RT) versus maximal safe resection with adjuvant RT. METHODS: Articles indexed on PubMed and Google Scholar and published between January 1, 2006 and December 31, 2019 were selected using the PRISMA criteria. Studies were excluded if they had fewer than 3 cases, did not categorize extent of resection, or were duplicate studies, technical reports, case reports, or studies without follow-up. Complication rates, recurrence rates, overall survival and progression-free survival were extracted where possible. χ2 proportionality tests were used for comparison (P values >0.05 suggested significance). RESULTS: On aggregation, 615 patients from 13 studies including ours were assessed. Although overall survival was not significantly different (χ2 = 1.56; P = 0.46), the recurrence rate differed significantly between GTR + RT (6.9%, 92.11 months), GTR-RT (23.9%, 96.8 months), and MSR + RT (16.8%, 85 months) (χ2 = 10.94; P = 0.004). Pooled complication rates for GTR and MSR + RT were 31.2% and 24% (P = 0.049), respectively. CONCLUSIONS: RT remains an important adjuvant treatment that can improve patient survival in the presence of MSR to levels comparable to those of GTR or GTR + RT. Where total resection carries too much risk, MSR + RT can be considered as the next best alternative for tumor control.