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Purpose: Missense mutated von Hippel Lindau (VHL) protein (pVHL) maintains intrinsic function but undergoes proteasomal degradation and tumor initiation and/or progression in VHL disease. Vorinostat can rescue missense mutated pVHL and arrest tumor growth in preclinical models. We asked whether short-term oral vorinostat could rescue pVHL in central nervous system hemangioblastomas in patients with germline missense VHL. Patients and Methods: We administered oral vorinostat to 7 subjects (ages 46.0 ± 14.5 years) and then removed symptomatic hemangioblastomas surgically (ClinicalTrials.gov identifier NCT02108002). Results: Vorinostat was tolerated without serious adverse events by all patients. pVHL expression was elevated in neoplastic stromal cells compared with untreated hemangioblastomas from same patients. We found transcriptional suppression of downstream hypoxia-inducible factor (HIF) effectors. Mechanistically, vorinostat prevented Hsp90 recruitment to mutated pVHL in vitro. The effects of vorinostat on the Hsp90–pVHL interaction, pVHL rescue, and transcriptional repression of downstream HIF effectors was independent of the location of the missense mutation on the VHL locus. We confirmed a neoplastic stromal cell–specific effect in suppression of protumorigenic pathways with single-nucleus transcriptomic profiling. Conclusions: We found that oral vorinostat treatment in patients with germline missense VHL mutations has a potent biologic effect that warrants further clinical study. These results provide biologic evidence to support the use of proteostasis modulation for the treatment of syndromic solid tumors involving protein misfolding. Proteostasis modulation with vorinostat rescues missense mutated VHL protein. Further clinical trials are needed to demonstrate tumor growth arrest.

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Direct putaminal infusion of adeno-associated virus vector (serotype 2) (AAV2) containing the human glial cell line-derived neurotrophic factor (GDNF) transgene was studied in a phase I clinical trial of participants with advanced Parkinson's disease (PD). Convection-enhanced delivery of AAV2-GDNF with a surrogate imaging tracer (gadoteridol) was used to track infusate distribution during real-time intraoperative magnetic resonance imaging (iMRI). Pre-, intra-, and serial postoperative (up to 5 years after infusion) MRI were analyzed in 13 participants with PD treated with bilateral putaminal co-infusions (52 infusions in total) of AAV2-GDNF and gadoteridol (infusion volume, 450 mL per putamen). Real-time iMRI confirmed infusion cannula placement, anatomic quantification of volumetric perfusion within the putamen, and direct visualization of off-target leakage or cannula reflux (which permitted corresponding infusion rate/cannula adjustments). Serial post-treatment MRI assessment (n = 13) demonstrated no evidence of cerebral parenchyma toxicity in the corresponding regions of AAV2-GDNF and gadoteridol co-infusion or surrounding regions over long-term follow-up. Direct confirmation of key intraoperative safety and efficacy parameters underscores the safety and tissue targeting value of real-time imaging with co-infused gadoteridol and putative therapeutic agents (i.e., AAV2-GDNF). This delivery-imaging platform enhances safety, permits delivery personalization, improves therapeutic distribution, and facilitates assessment of efficacy and dosing effect.

Multiple sclerosis (MS) is an autoimmune inflammatory disease that results in demyelination of the central nervous system (CNS). MS affects as many as 350,000 individuals in the United States and commonly presents before the age of 45 years. Patients with MS, as the general population, are likely to encounter degenerative changes of the spine as they age, and this can pose a unique challenge to both patients with MS and physicians, as both conditions can have a great deal of symptomatic overlap despite stark differences in management. Currently there is no definitive approach that allows physicians to distinguish between the 2 conditions; however, specific clinical and radiologic findings have been identified as being useful in evaluating these patients.

Familial neoplastic syndromes commonly impact the central and peripheral nervous systems. The most common neoplastic syndromes clinically relevant to neurology and neurologic surgery, include neurofibromatosis type 1, neurofibromatosis type 2, and Von Hippel-Lindau disease. We define the epidemiology, genetics, clinical presentation, and manifestations, as well as screening recommendations and management paradigms for these syndromes and other familial neoplastic syndromes that affect the nervous system. To ensure the optimal care of patients with neoplastic syndromes requires a multi-disciplinary approach and a comprehensive knowledge of the genetics, pathophysiology, manifestations, and management.

The impact of neurosurgical resident hospital coverage system, performed via a night float (12-hour shifts overnight) or a 24-hour call, on neurological surgery resident training and patient care is unknown.Retrospective review comparing night float and 24-hour call coverage on trainee surgical experience, elective time, annual program surveys, patient outcomes, and length of stay.The Ohio State Wexner Medical Center Neurosurgery residency program, Columbus, Ohio.The neurosurgical residents from 2016 to 2019.Monthly cases performed by junior residents significantly increased after transitioning to a 24-hour call schedule (18 versus 30, p0.001). There were no differences for total cases among program graduates during this time (p = 0.7). Trainee elective time significantly increased after switching to 24-hour call coverage (18 versus 24 months after the transition; p = 0.004). Risk-adjusted mortality and length of stay indices were not different (0.5 versus 0.3, p = 0.1; 0.9 versus 0.9; p = 0.3). Program surveys had minimal change after the transition to 24-hour call.Transitioning from a night float to a 24-hour call coverage system led to improved junior resident case volume and elective time without detrimental effect on patient-related outcomes.

Glioblastoma multiforme is the most common primary malignant brain tumor and despite treatment with surgery, radiation, and chemotherapy, the median survival of patients with glioblastoma multiforme is ∼1 year. Glioblastoma multiforme explants and cell lines have been reported to overexpress the interleukin-13 receptor α2 subunit (IL13Rα2) relative to nonneoplastic brain. Based on this finding, a recombinant cytotoxin composed of IL13 ligand and a truncated form of Pseudomonas aeruginosa exotoxin A (IL13-PE38QQR) was developed for the targeted treatment of glioblastoma multiforme tumors. In a recently completed phase III clinical trial, however, IL13-PE38QQR was found to be no more effective than an existing therapy in prolonging survival. To determine possible explanations for this result, we analyzed the relative expression levels of IL13Rα2 in glioblastoma multiforme and nonneoplastic brain specimens using publicly available oligonucleotide microarray databases, quantitative real-time reverse transcription PCR, and immunohistochemical staining. Increased expression of the IL13Rα2 gene relative to nonneoplastic brain was observed in 36 of 81 (44%) and 8 of 17 (47%) tumor specimens by microarray and quantitative real-time reverse transcription PCR analyses, respectively. Immunohistochemical staining of tumor specimens showed highly variable expression of IL13Rα2 protein both within and across specimens. These data indicate that prescreening of subjects may be of benefit in future trials of IL13Rα2 targeting therapies. [Cancer Res 2007;67(17):7983–6]

Supplementary Figure 1 from Expression of Interleukin-13 Receptor α2 in Glioblastoma Multiforme: Implications for Targeted Therapies

Supplementary Figure 1 Legend from Expression of Interleukin-13 Receptor α2 in Glioblastoma Multiforme: Implications for Targeted Therapies

A 13-year-old male presented with a 10-day history of left eye swelling and pain. These symptoms prompted presentation to the emergency department. He had no significant past medical history and no preceding fevers or chills. He was found on examination of the eyes and the orbit to have left supraorbital erythema, edema, and pain with upward and medial gaze. Examination of the globe, fundus, and visual fields were normal. His white blood cell count was 6.2 (x1000/mm3) with an erythrocyte sedimentation rate of 4 (mm/hr). Diagnostic endoscopic biopsy was performed. Here we present this case alongside clinical reasoning and diagnostic evaluation with relevant input from respective experts. This case discussion reviews the final diagnosis, as well as the corresponding evaluation and management. Diagnostic algorithms based on literature review and clinical experience are also included.

At present there is a significant unmet need for clinically available treatments for Parkinson’s disease (PD) patients to stably restore balance to dopamine network function, leaving patients with inadequate management of symptoms as the disease progresses. Gene therapy is an attractive approach to impart a durable effect on neuronal function through introduction of genetic material to reestablish dopamine levels and/or functionally recover dopaminergic signaling by improving neuronal health. Ongoing clinical gene therapy trials in PD are focused on enzymatic enhancement of dopamine production and/or the restoration of the nigrostriatal pathway to improve dopaminergic network function. In this review, we discuss data from current gene therapy trials for PD and recent advances in study design and surgical approaches.

Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare genetic disorder characterized by deficient synthesis of dopamine and serotonin. It presents in early infancy, and causes severe developmental disability and lifelong motor, behavioral, and autonomic symptoms including oculogyric crises (OGC), sleep disorder, and mood disturbance. We investigated the safety and efficacy of delivery of a viral vector expressing AADC (AAV2-hAADC) to the midbrain in children with AADC deficiency (ClinicalTrials.gov Identifier NCT02852213). Seven (7) children, aged 4–9 years underwent convection-enhanced delivery (CED) of AAV2-hAADC to the bilateral substantia nigra (SN) and ventral tegmental area (VTA) (total infusion volume: 80 µL per hemisphere) in 2 dose cohorts: 1.3 × 1011 vg (n = 3), and 4.2 × 1011 vg (n = 4). Primary aims were to demonstrate the safety of the procedure and document biomarker evidence of restoration of brain AADC activity. Secondary aims were to assess clinical improvement in symptoms and motor function. Direct bilateral infusion of AAV2-hAADC was safe, well-tolerated and achieved target coverage of 98% and 70% of the SN and VTA, respectively. Dopamine metabolism was increased in all subjects and FDOPA uptake was enhanced within the midbrain and the striatum. OGC resolved completely in 6 of 7 subjects by Month 3 post-surgery. Twelve (12) months after surgery, 6/7 subjects gained normal head control and 4/7 could sit independently. At 18 months, 2 subjects could walk with 2-hand support. Both the primary and secondary endpoints of the study were met. Midbrain gene delivery in children with AADC deficiency is feasible and safe, and leads to clinical improvements in symptoms and motor function., Aromatic L-amino acid decarboxylase deficiency (AADC) is a rare neurodevelopmental disorder. Here the authors describe a clinical trial of MR-guided delivery of AAV2-AADC for the treatment of AADC.

OBJECTIVE While high-velocity missile injury (gunshot) is associated with kinetic and thermal injuries, non-missile penetrating head injury (NMPHI) results in primary damage along the tract of the piercing object that can be associated with significant secondary complications. Despite the unique physical properties of NMPHI, factors associated with complications, expected outcomes, and optimal management have not been defined. In this study, the authors attempted to define those factors. METHODS Consecutive adult patients with NMPHI who presented to Tygerberg Academic Hospital (Cape Town, South Africa) in the period from August 1, 2011, through July 31, 2018, were enrolled in a prospective study using a defined treatment algorithm. Clinical, imaging, and laboratory data were analyzed. RESULTS One hundred ninety-two patients (185 males [96%], 7 females [4%]) with 192 NMPHIs were included in this analysis. The mean age at injury was 26.2 ± 1.1 years (range 18–58 years). Thirty-four patients (18%) presented with the weapon in situ. Seventy-one patients (37%) presented with a Glasgow Coma Scale (GCS) score of 15. Weapons included a knife (156 patients [81%]), screwdriver (18 [9%]), nail gun (1 [0.5%]), garden fork (1 [0.5%]), barbeque fork (1 [0.5%]), and unknown (15 [8%]). The most common wound locations were temporal (74 [39%]), frontal (65 [34%]), and parietal (30 [16%]). The most common secondary complications were vascular injury (37 patients [19%]) and infection (27 patients [14%]). Vascular injury was significantly associated with imaging evidence of deep subarachnoid hemorrhage and an injury tract crossing vascular territory (p ≤ 0.05). Infection was associated with delayed referral (> 24 hours), lack of prophylactic antibiotic administration, and weapon in situ (p ≤ 0.05). A poorer outcome was associated with a stab depth > 50 mm, a weapon removed by the assailant, vascular injury, and eloquent brain involvement (p ≤ 0.05). Nineteen patients (10%) died from their injuries. The Glasgow Outcome Scale (GOS) score was linearly related to the admission GCS score (p < 0.001). One hundred forty patients (73%) had a GOS score of 4 or better at discharge. CONCLUSIONS The most common NMPHI secondary complications are vascular injury and infection, which are associated with specific NMPHI imaging and clinical features. Identifying these features and using a systematic management paradigm can effectively treat the primary injury, as well as diagnose and manage NMPHI-related complications, leading to a good outcome in the majority of patients.

BACKGROUND: Retrobulbar hemangioblastomas involving the optic apparatus in patients with von Hippel-Lindau disease (VHL) are rare, with only 25 reported cases in the literature. OBJECTIVE: To analyze the natural history of retrobulbar hemangioblastomas in a large cohort of VHL patients in order to define presentation, progression, and management. METHODS: Clinical history and imaging of 250 patients with VHL in an ongoing natural history trial and 1774 patients in a neurosurgical protocol were reviewed. The clinical course, magnetic resonance images, treatment, and outcomes were reviewed for all included patients. RESULTS: A total of 18 patients with retrobulbar hemangioblastoma on surveillance magnetic resonance imaging met the inclusion criteria for this study. Of the 17 for whom clinical information was available, 10 patients presented with symptoms related to the hemangioblastoma, and 7 were asymptomatic. The mean tumor volume was larger for symptomatic (810.6 ± 545.5 mm(3)) compared to asymptomatic patients (307.6 ± 245.5 mm(3); P

OBJECTIVEThe objective of this study was to assess the feasibility, accuracy, effectiveness, and safety of an MRI-compatible frameless stereotactic ball-joint guide array (BJGA) as a platform for cannula placement and convection-enhanced delivery (CED).METHODSThe authors analyzed the clinical and imaging data from consecutive patients with aromatic l-amino acid decarboxylase (AADC) deficiency who underwent infusion of adeno-associated virus (AAV) containing the AADC gene (AAV2-AADC).RESULTSEleven patients (7 females, 4 males) underwent bilateral MRI-guided BJGA cannula placement and CED of AAV2-AADC (22 brainstem infusions). The mean age at infusion was 10.5 ± 5.2 years (range 4–19 years). MRI allowed for accurate real-time planning, confirmed precise cannula placement after single-pass placement, and permitted on-the-fly adjustment. Overall, the mean bilateral depth to the target was 137.0 ± 5.2 mm (range 124.0–145.5 mm). The mean bilateral depth error was 0.9 ± 0.7 mm (range 0–2.2 mm), and the bilateral radial error was 0.9 ± 0.6 mm (range 0.1–2.3 mm). The bilateral absolute tip error was 1.4 ± 0.8 mm (range 0.4–3.0 mm). Target depth and absolute tip error were not correlated (Pearson product-moment correlation coefficient, r = 0.01).CONCLUSIONSUse of the BJGA is feasible, accurate, effective, and safe for cannula placement, infusion MRI monitoring, and cannula adjustment during CED. The low-profile universal applicability of the BJGA streamlines and facilitates MRI-guided CED.

Loss of nigrostriatal dopaminergic projection neurons is a key pathology in Parkinson’s disease, leading to abnormal function of basal ganglia motor circuits and the accompanying characteristic motor features. A number of intraparenchymally delivered gene therapies designed to modify underlying disease and/or improve clinical symptoms have shown promise in preclinical studies and subsequently were evaluated in clinical trials. Here we review the challenges with surgical delivery of gene therapy vectors that limited therapeutic outcomes in these trials, particularly the lack of real-time monitoring of vector administration. These challenges have recently been addressed during the evolution of novel techniques for vector delivery that include the use of intraoperative MRI. The preclinical development of these techniques are described in relation to recent clinical translation in an adeno-associated virus serotype 2-mediated human aromatic L-amino acid decarboxylase gene therapy development programme. This new paradigm allows visualisation of the accuracy and adequacy of viral vector delivery within target structures, enabling intertrial modifications in surgical approaches, cannula design, vector volumes and dosing. The rapid, data-driven evolution of these procedures is unique and has led to improved vector delivery.

Introduction. Vector-based intracerebral gene therapies are being used to treat specific neurodegenerative conditions such as Parkinson’s Disease (PD). This review presents a basis for central nervous system (CNS) gene therapy treatments of neurodegenerative diseases such as PD, as well as the need for novel skill sets and health delivery strategies within the clinical neurosciences (neurology and neurosurgery) to meet future demand for such therapies. State of the art. Preclinical vector-based gene therapy approaches have been translated into clinical trials for PD and other neurodegenerative conditions. Unfortunately, such trials, and parallel efforts using other therapeutics, have yet to provide a breakthrough. Image-guided convection enhanced delivery (CED) optimises the parenchymal distribution of gene therapies applied within the CNS, and may ultimately provide such a breakthrough. Clinical implications. Currently, image-guided CED and gene therapy are not part of training programmes for most neurosurgeons and neurologists. As a result, few medical centres and hospitals have sufficiently experienced teams to participate in gene transfer clinical trials for PD or other neurological conditions. If CNS gene therapies prove to be efficacious for PD and/or other conditions, the demand for such treatments will overwhelm the available number of experienced clinical neuroscience teams and treatment centres. Future directions. Expanded indications and demand for CNS gene therapies will require a worldwide educational effort to supplement the training of clinical neuroscience practitioners. Initially, a limited number of Centres of Excellence will need to establish relevant educational training requirements and best practice for such therapeutic approaches. Advanced technologies, including robotics and artificial intelligence, are especially germane in this regard, and will expand the treatment team’s capabilities while assisting in the safe and timely care of those afflicted.

Background Gamma knife (GK) and linear accelerator (LINAC)-based stereotactic radiosurgery (SRS) both offer excellent local control in the management of multiple brain metastases. The efficacy and toxicity of LINAC and GK SRS have not been directly compared in the modern era. We studied outcomes in patients treated with LINAC SRS and GK at two separate institutions. Methods We identified patients treated with either LINAC or GK who were treated to ≥2 lesions and had available follow up. LINAC patients were treated using single-isocenter multitarget technique. We used Cox regression, Fine and Gray competing risks regression, and nearest neighbor propensity score matching to account for confounders and imbalance between cohorts. Kaplan–Meier curves were used to estimate overall survival and rates of radionecrosis. Results We identified 391 patients who were treated in 537 courses to a total 2699 lesions (LINAC: 1014, GK: 1685). After propensity score matching, GK was associated with similar overall survival (HR = 0.86; 95% CI 0.59–1.24; p = 0.41) and higher rate of radionecrosis (HR = 3.83; 95% CI 1.66–8.84; p = 0.002) compared to LINAC. In a secondary propensity score matched analysis comparing radionecrosis in single-fraction LINAC and GK, GK remained associated with higher incidence of radionecrosis (HR = 4.42; 95% CI 1.28–15.29; p = 0.019). Conclusions In this multi-institutional study, we found similar overall survival with lower incidence of radionecrosis in patients treated with LINAC compared to GK SRS. These findings are hypothesis generating and should be validated in an independent cohort.

Background Tumor-specific metabolic processes essential for cell survival are promising targets to potentially circumvent intratumoral heterogeneity, a major resistance factor in gliomas. Tumor cells preferentially using nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in the salvage pathway for synthesis of NAD, a critical cofactor for diverse biological processes including cellular redox reactions, energy metabolism, and biosynthesis. NAMPT is overexpressed in most malignancies, including gliomas, and can serve as a tumor-specific target. Methods Effects of pharmacological inhibition of NAMPT on cellular oxygen consumption rate, extracellular acidification, mitochondrial respiration, cell proliferation, invasion, and survival were assessed through in vitro and ex vivo studies on genetically heterogeneous glioma cell lines, glioma stem-like cells (GSCs), and mouse and human ex vivo organotypic glioma slice culture models. Results Pharmacological inhibition of the NAD salvage biosynthesis pathway using a highly specific inhibitor, KPT-9274, resulted in the reduction of NAD levels and related downstream metabolites, inhibited proliferation, and induced apoptosis in vitro in cell lines and ex vivo in human glioma tissue. These effects were mediated by mitochondrial dysfunction, DNA damage, and increased oxidative stress leading to apoptosis in GSCs independent of genotype, IDH status, or MGMT promoter methylation status. Conversely, NAMPT inhibition had minimal in vitro effects on normal human astrocytes (NHA) and no apparent in vivo toxicity in non-tumor-bearing mice. Conclusions Pharmacological NAMPT inhibition by KPT9274 potently targeted genetically heterogeneous gliomas by activating mitochondrial dysfunction. Our preclinical results provide a rationale for targeting the NAMPT-dependent alternative NAD biosynthesis pathway as a novel clinical strategy against gliomas.

Von Hippel-Lindau (VHL) disease is a multisystem disease cause by germline mutations of the VHL tumor suppressor gene. Hemangioblastomas are the most common manifestation of VHL disease and can occur in the central nervous system in up to 90% of these patients. By contrast, we found only one true case of a peripheral nervous system (PNS) hemangioblastoma in the setting of VHL. We explore the possible reasons behind the lack of PNS hemangioblastomas in VHL disease.

Diffuse midline glioma with histone H3 lysine27-to-methionine mutation (H3 K27M mutation) is a rare, aggressive tumor that is designated as World Health Organization (WHO) grade IV regardless of histologic features. Preoperative diagnosis remains challenging due to limited evidence regarding distinctive clinical and imaging characteristics. We describe the case of a young woman who presented with progressively worsening headaches due to communicating hydrocephalus. MR imaging with contrast of the cervical and thoracic spine revealed diffuse leptomeningeal enhancement with focal areas of intramedullary and subarachnoid T2 hyperintensity and enhancement, suggestive of a potential infectious process. Intraoperatively, no epidural pathology was identified, and with the differential diagnosis remaining broad, a second procedure was conducted involving intradural exploration and biopsy of a lesion. This was then identified as a diffuse midline glioma with H3 K27M mutation. The nonfocal clinical presentation in the setting of communicating hydrocephalus as well as the significant exophytic tumor growth and imaging findings made the initial diagnosis unique and challenging. This case, therefore, emphasizes the rare presentation of this tumor, and the need for further understanding of the clinical and imaging characteristics of this disease as well as the need for effective therapeutics.

Objective Endolymphatic sac tumors (ELSTs) are a frequent cause of hearing loss and other audiovestibular dysfunction in patients with von Hippel-Lindau disease (VHL). Unified screening recommendations for VHL patients have not been established. To develop consensus guidelines, the VHL Alliance formed an expert committee to define evidence-based clinical screening recommendations. Patients and Methods Recommendations were formulated by using the Grading of Recommendations, Assessment, Development, and Evaluation framework after a comprehensive literature review. Results Diagnosis of ELSTs in VHL requires a combination of clinical evaluation and imaging and audiometric findings. Audiovestibular signs/symptoms are often an early feature of small ELSTs, including those that are not visible on imaging. Diagnostic audiograms have the greatest sensitivity for the detection of ELST-associated sensorineural hearing loss and can help confirm clinically relevant lesions, including those that may not be radiographically evident. Magnetic resonance imaging (MRI) can be a more specific test for ELSTs in VHL particularly when supplemented with computed tomography imaging for the identification of small tumors. VHL patients between the ages 10 and 60 years carry high preponderance for ELST presentation. Conclusion We recommend that clinical evaluation (yearly) and diagnostic audiograms (every other year) be the primary screening tools for ELSTs in VHL. We suggest that screening be performed between the ages 11 and 65 years or with the onset of audiovestibular signs/symptoms for synchronicity with other testing regimens in VHL. We recommend that baseline imaging (MRI of the internal auditory canals) can be performed between the ages of 15 and 20 years or after positive screening.

Purpose Multiple studies have reported favorable outcomes for stereotactic radiosurgery (SRS) in the treatment of limited brain metastases. An obstacle of SRS in the management of numerous metastases is the longer treatment time using traditional radiosurgery. Single-isocenter multitarget (SIMT) SRS is a novel technique that permits rapid therapy delivery to multiple metastases. There is a lack of clinical evidence regarding its efficacy and safety. We report the outcomes of patients treated with this technique. Methods and Materials We reviewed the records of patients with intact or resected brain metastases treated with SRS in 1 to 5 fractions using SIMT technique at our institution, with at least 1 available follow-up brain magnetic resonance imaging. Survival, disease control, and toxicity were evaluated using Cox regression, logistic regression, and Kaplan-Meier analysis. Results We identified 173 patients with 1014 brain metastases. Median follow up was 12.7 months. Median beam-on time was 4.1 minutes. The median dose to the brain was 219.4 cGy. Median overall survival and freedom from intracranial progression were 13.2 and 6.3 months, respectively. Overall survival did not differ between patients treated with greater than or less than 4 lesions (hazard ratio, 1.03; 95% confidence interval 0.66-1.61; P = .91). Actuarial 1- and 2-year local control were 99.0% and 95.1%, respectively. Rates of grade 2 and grade 3 or higher radionecrosis were 1.4% and 0.9%, respectively. Conclusions SIMT radiosurgery delivered in 1 to 5 fractions offers excellent local control and acceptable toxicity in the treatment of multiple intact and postoperative brain metastases. This technique should be evaluated prospectively.

OBJECTIVE To investigate the safety and tolerability of convection-enhanced delivery of an adeno-associated virus, serotype-2 vector carrying glial cell line-derived neurotrophic factor into the bilateral putamina of PD patients. METHODS Thirteen adult patients with advanced PD underwent adeno-associated virus, serotype-2 vector carrying glial cell line-derived neurotrophic factor and gadoteridol (surrogate MRI tracer) coinfusion (450 μL/hemisphere) at escalating doses: 9 × 1010 vg (n = 6); 3 × 1011 vg (n = 6); and 9 × 1011 vg (n = 1). Intraoperative MRI monitored infusion distribution. Patients underwent UPDRS assessment and [18 F]FDOPA-PET scanning preoperatively and 6 and 18 months postoperatively. RESULTS Adeno-associated virus, serotype-2 vector carrying glial cell line-derived neurotrophic factor was tolerated without clinical or radiographic toxicity. Average putaminal coverage was 26%. UPDRS scores remained stable. Ten of thirteen and 12 of 13 patients had increased [18 F]FDOPA Kis at 6 and 18 months postinfusion (increase range: 5-274% and 8-130%; median, 36% and 54%), respectively. Ki differences between baseline and 6- and 18-month follow-up were statistically significant (P

In MRI-negative cases Cushing’s disease (CD), surgeons perform a more extensive exploration of the pituitary gland, with fewer instances of hormonal remission. 18F-fluoro-deoxy-glucose (18F-FDG) positron emission tomography (PET) has a limited role in detecting adenomas that cause CD (corticotropinomas). Our previous work demonstrated corticotropin-releasing hormone (CRH) stimulation leads to delayed, selective glucose uptake in corticotropinomas. Here, we prospectively evaluated the utility of CRH stimulation in improving 18F-FDG-PET detection of adenomas in CD. Subjects with a likely diagnosis of CD (n = 27, 20 females) each underwent two 18F-FDG-PET studies [without and with ovine-CRH (oCRH) stimulation] on a high-resolution PET platform. Standardized-uptake-values (SUV) in the sella were calculated. Two blinded neuroradiologists independently read 18F-FDG-PET images qualitatively. Adenomas were histopathologically confirmed, analyzed for mutations in the USP8 gene and for glycolytic pathway proteins. The mean-SUV of adenomas was significantly increased from baseline (3.6 ± 1.5) with oCRH administration (3.9 ± 1.7; one-tailed p = 0.003). Neuroradiologists agreed that adenomas were visible on 21 scans, not visible on 26 scans (disagreed about 7, kappa = 0.7). oCRH-stimulation led to the detection of additional adenomas (n = 6) not visible on baseline-PET study. Of the MRI-negative adenomas (n = 5), two were detected on PET imaging (one only after oCRH-stimulation). USP8 mutations or glycolytic pathway proteins were not associated with SUV in corticotropinomas. The results of the current study suggest that oCRH-stimulation may lead to increased 18F-FDG uptake, and increased rate of detection of corticotropinomas in CD. These results also suggest that some MRI invisible adenomas may be detectable by oCRH-stimulated FDG-PET imaging. 18F-FDG-PET imaging with and without CRH stimulation was performed under the clinical trial NIH ID 12-N-0007 (clinicaltrials.gov identifier NCT01459237). The transsphenoidal surgeries and post-operative care was performed under the clinical trial NIH ID 03-N-0164 (clinicaltrials.gov identifier NCT00060541).

Background Laser-interstitial thermal therapy (LITT) has been supported by some authors as an ablative treatment of glioblastoma multiforme (GBM). Although the effects of LITT have been modeled in vivo, the histologic effects in a clinical circumstance have not been described. We analyzed tissue from a patient who underwent LITT as primary treatment for GBM. Case presentation A 62-year-old male was diagnosed with a left temporal GBM and underwent LITT at an outside institution. Despite corticosteroid therapy, the patient was referred with increasing headache and acalculia associated with progressive peritumoral edema two weeks after LITT procedure. En bloc resection of the enhancing lesion and adjacent temporal lobe was performed with steroid-independent symptom resolution (follow-up, > 2 years). Histologic analysis revealed three distinct histologic zones concentrically radiating from the center of the treatment site. An acellular central region of necrosis (Zone 1) was surrounded by a rim of granulation tissue with macrophages (CD68) (Zone 2; mean thickness, 1.3 ± 0.3 mm [±S.D.]). Viable tumor cells (identified by Ki-67, p53 and Olig2 immunohistochemistry) were found (Zone 3) immediately adjacent to granulation tissue. The histologic volume of thermal tissue ablation/granulation was consistent with preoperative (pre-resection) magnetic resonance (MR)-imaging. Conclusion These findings are the first in vivo in humans to reveal that LITT causes a defined pattern of tissue necrosis, concentric destruction of tumor and tissue with viable tumor cells just beyond the zones of central necrosis and granulation. Furthermore, MR-imaging appears to be an accurate surrogate of tissue/tumor ablation in the early period (2 weeks) post-LITT treatment. Surgery is an effective strategy for patients with post-LITT swelling which does not respond to steroids.

Creeping flows govern many important physiological phenomena such as elevated interstitial fluid flows in tumors, glymphatic flows in the brain, among other applications. However, few methods exist to measure such slow flows non-invasively in optically opaque biological tissues in vivo. Phase-contrast MRI is a velocimetry technique routinely used in the clinic to measure fast flows in biological tissues, such as blood and cerebrospinal fluid (CSF), in the order of cm/s. Use of this technique to encode slower flows is hampered by diffusion weighting and phase error introduced by gradient hardware imperfections. In this study, a new PC-MRI technique is developed using stimulated echo preparation to overcome these challenges. Flows as slow as 1 μm/s are measured and validated using controlled water flow through a pipe at 4.7 T. The error in measured flow rate obtained by integrating the measured velocity over the cross-sectional area of the pipe is less than 10%. The developed method was also able to capture slow natural convection flows appearing in liquids placed inside a horizontal bore magnet. Monitoring the 4D velocity vector field revealed that the natural convection flows decay exponentially with time. This method could be applied in future to study creeping flows, e.g. in tissue.

PURPOSE/OBJECTIVE(S) The standard of care for elderly glioblastoma patients (GBM) is 40 Gy in 15 fractions with temozolomide (TMZ). However, this regimen has a lower biologic equivalent dose (BED) compared to the Stupp regimen of 60 Gy in 30 fractions. We hypothesize that dose escalated hypofractionated radiation of 52.5 Gy in 15 fractions (BED equivalent to Stupp) will have superior survival compared to 40 Gy in 15 fractions. MATERIALS/METHODS Elderly patients (> 60 yo) who received hypofractionated radiation with TMZ were included in this analysis. Overall survival (OS) and progression free survival (PFS) were defined as the time elapsed between surgery/biopsy and death from any cause or progression. Baseline characteristics were compared with pairwise tests. Univariate and multivariate analyses were performed. RESULTS 66 newly-diagnosed patients were eligible for this analysis. 39 patients were treated with 40 Gy in 15 fractions, and 27 patients were treated with 52.5 Gy in 15 fractions. The median follow up for this cohort was 8.8 months. Patients were well balanced with no significant differences in age, sex, MGMT, extent of resection, or KPS. The median OS was 7.9 months in the 40 Gy arm and 13.1 months in the 52.5 Gy arm (P = 0.035). For unmethylated patients, the median OS was 6.7 months in the 40 Gy arm and 11.3 months in the 52.5 Gy arm (P = 0.012). Increasing planning treatment volume (P = 0.007) was associated with decreased OS. On multivariate analysis, MGMT methylation (HR 0.45 [0.23-0.87] P = 0.018) and dose escalation (HR 0.45 [0.21-0.96] 0.04) remained independent prognostic factors for OS. In a multivariate model for PFS, only dose-escalation was significant (HR 0.49 [0.25-0.98] P = 0.045). No significant differences in toxicity were observed between treatment groups. CONCLUSION Dose-escalation to 52.5 Gy in 15 fractions was associated with superior OS and PFS compared to standard of care 40 Gy in 15 fractions. This treatment regimen gives the elderly population an alternative to Stupp that is not de-escalating therapy. These hypothesis generating data support dose-escalated hypofractionation in future prospective trials. AUTHOR DISCLOSURE H.K. Perlow: None. M. Yang: None. B. Klamer: None. R. Raval: None. D.M. Blakaj: None. A.L. Arnett: None. S. Beyer: None. J.C. Grecula: None. M. Ammirati: None. J.B. Elder: None. R.R. Lonser: None. D. Hardesty: None. S.S. Ong: None. P. Giglio: None. C. Pillainayagam: None. J. Goranovich: None. A. Chakravarti: None. V. Gondi: Partner; Radiation Oncology Consultants, Ltd. Honoraria; UpToDate, RaySearch. Partnership; Radiation Oncology Consultants, Ltd. Co-Principal Investigator; NRG Oncology. P.D. Brown: None. J.D. Palmer: Research Grant; Varian Medical Systems, The Kroger Company. Consultant; Huron Consulting. Speaker's Bureau; Varian Medical Systems, Depuy Synthes. Advisory Board; Novocure. Member of panel; NCCN.

We received so many biographies of women neurosurgery leaders for this issue that only a selection could be condensed here. In all of them, the essence of a leader shines through. Many are included as “first” of their country or color or other achievement. All of them are included as outstanding—in clinical, academic, and organized neurosurgery. Two defining features are tenacity and service. When faced with shocking discrimination, or numbing indifference, they ignored it or fought valiantly. When choosing their life’s work, they chose service, often of the most neglected—those with pain, trauma, and disability. These women inspire and point the way to a time when the term “women leaders” as an exception is unnecessary.—Katharine J. Drummond, MD, on behalf of this month’s topic editors

OBJECTIVE The Neurosurgery Research and Education Foundation (NREF) provides research support for in-training and early career neurosurgeon-scientists. To define the impact of this funding, the authors assessed the success of NREF awardees in obtaining subsequent National Institutes of Health (NIH) funding. METHODS NREF in-training (Research Fellowship [RF] for residents) and early career awards/awardees (Van Wagenen Fellowship [VW] and Young Clinician Investigator [YCI] award for neurosurgery faculty) were analyzed. NIH funding was defined by individual awardees using the NIH Research Portfolio Online Reporting tool (1985–2014). RESULTS Between 1985 and 2014, 207 unique awardees were supported by 218 NREF awards ($9.84 million [M] in funding), including 117 RF ($6.02 M), 32 VW ($1.68 M), and 69 YCI ($2.65 M) awards. Subspecialty funding included neuro-oncology (79 awards; 36% of RF, VW, and YCI awards), functional (53 awards; 24%), vascular (37 awards; 17%), spine (22 awards; 10%), pediatrics (18 awards; 8%), trauma/critical care (5 awards; 2%), and peripheral nerve (4 awards; 2%). These awardees went on to receive $353.90 M in NIH funding that resulted in an overall NREF/NIH funding ratio of 36.0:1 (in dollars). YCI awardees most frequently obtained later NIH funding (65%; $287.27 M), followed by VW (56%; $41.10 M) and RF (31%; $106.59 M) awardees. YCI awardees had the highest NREF/NIH funding ratio (108.6:1), followed by VW (24.4:1) and RF (17.7:1) awardees. Subspecialty awardees who went on to obtain NIH funding included vascular (19 awardees; 51% of vascular NREF awards), neuro-oncology (40 awardees; 51%), pediatrics (9 awardees; 50%), functional (25 awardees; 47%), peripheral nerve (1 awardees; 25%), trauma/critical care (2 awardees; 20%), and spine (2 awardees; 9%) awardees. Subspecialty NREF/NIH funding ratios were 56.2:1 for vascular, 53.0:1 for neuro-oncology, 47.6:1 for pediatrics, 34.1:1 for functional, 22.2:1 for trauma/critical care, 9.5:1 for peripheral nerve, and 0.4:1 for spine. Individuals with 2 NREF awards achieved a higher NREF/NIH funding ratio (83.3:1) compared to those with 1 award (29.1:1). CONCLUSIONS In-training and early career NREF grant awardees are an excellent investment, as a significant portion of these awardees go on to obtain NIH funding. Moreover, there is a potent multiplicative impact of NREF funding converted to NIH funding that is related to award type and subspecialty.

Meningiomas arising with inherited genetic syndromes occur nearly exclusively in the context of neurofibromatosis type 2 (NF2). NF2 is an autosomal dominant familial neoplasia syndrome that results from a mutation in the NF2 tumor suppressor gene located on the long arm of chromosome 22. The NF2 gene encodes for the protein merlin (moesin-ezrin-radixin-like protein), which has tumor suppressive effects that are reduced/inactivated in NF2-associated tumors. NF2-associated neoplasms affect the nervous system (schwannomas, meningiomas, ependymomas, astrocytomas, and neurofibromas) and skin. Other NF2 findings include ophthalmological lesions and peripheral neuropathy. Meningiomas are the second most frequent NF2-associated tumors (occurring in approximately half of all NF2 patients). They are often multiple and have unpredictable growth patterns. NF2-associated meningiomas can cause significant morbidity and mortality due to their location and a mass effect. Because of the multiplicity, frequent development of new tumors, and their protean nature, defined treatment strategies with serial surveillance is critical for optimal management of NF2-associated meningiomas. While surgical resection is the primary treatment for NF2-associated meningiomas, radiation plays an important adjunctive role in the management of recurrent and inoperable meningiomas.

The American Board of Neurological Surgery (ABNS) was incorporated in 1940 in recognition of the need for detailed training in and special qualifications for the practice of neurological surgery and for self-regulation of quality and safety in the field. The ABNS believes it is the duty of neurosurgeons to place a patient’s welfare and rights above all other considerations and to provide care with compassion, respect for human dignity, honesty, and integrity. At its inception, the ABNS was the 13th member board of the American Board of Medical Specialties (ABMS), which itself was founded in 1933. Today, the ABNS is one of the 24 member boards of the ABMS.To better serve public health and safety in a rapidly changing healthcare environment, the ABNS continues to evolve in order to elevate standards for the practice of neurological surgery. In connection with its activities, including initial certification, recognition of focused practice, and continuous certification, the ABNS actively seeks and incorporates input from the public and the physicians it serves. The ABNS board certification processes are designed to evaluate both real-life subspecialty neurosurgical practice and overall neurosurgical knowledge, since most neurosurgeons provide call coverage for hospitals and thus must be competent to care for the full spectrum of neurosurgery.The purpose of this report is to describe the history, current state, and anticipated future direction of ABNS certification in the US.

Gene therapy is a rapidly evolving technology that has predominantly utilized viral vectors to effectively deliver genetic material inside neurons to modulate the expression of one or more particular genes. Several gene therapy clinical trials have been conducted in Parkinson's disease (PD) by exploring strategies to either restore dopamine synthesis, enhance the production of trophic factors, enhance lysosomal function, or modify the interaction between different functional nodes of the basal ganglia.In this review, the authors sought to discuss contemporary practice, emerging concepts, and unmet needs for the future of gene therapy in PD.While safety has been demonstrated, clinical trials on gene therapy for PD highlight the need for higher than anticipated volumes of infusion in order to optimize dose and vector coverage. Neurosurgical delivery techniques for gene therapy have rapidly evolved from the use of multiple trans-frontal trajectories to a single parietooccipital shape-conforming infusion. The employment of convection-enhanced delivery with reflux-resistant cannulas has further improved the vector diffusion into the target structures. Future technological developments will reduce the invasiveness and duration of surgery, improve specificity and transduction capacity with novel capsid designs, and implement strategies to control transgene expression.

Background Spine surgery is indicated for select patients with mechanical instability, pain, and/or malignant epidural spinal cord compression, with or without neurological compromise. Stereotactic body radiotherapy (SBRT) is an option for durable local control (LC) for metastatic spine disease. Objective To determine factors associated with LC and progression-free survival (PFS) for patients receiving postoperative stereotactic spine radiosurgery. Methods We analyzed consecutive patients from 2013 to 2019 treated with surgical intervention followed by SBRT. Surgical interventions included laminectomy and vertebrectomy. SBRT included patients treated with 1 to 5 fractions of radiosurgery. We analyzed LC, PFS, overall survival (OS), and toxicity. Univariate and multivariate analyses were performed. Results A total of 63 patients were treated with a median follow-up of 12.5 mo. Approximately 75% of patients underwent vertebrectomy and 25% underwent laminectomy. One-year cumulative incidence of local failure was 19%. LC was significantly improved for patients receiving radiosurgery ≤40 d from surgery compared to that for patients receiving radiosurgery ≥40 d from surgery, 94% vs 75%, respectively, at 1 yr (P = .03). Patients who received preoperative embolization had improved LC with 1-yr LC of 88% vs 76% for those who did not receive preoperative embolization (P = .037). Significant predictors for LC on multivariate analysis were time from surgery to radiosurgery, higher radiotherapy dose, and preoperative embolization. The 1-yr PFS and OS was 56% and 60%, respectively. Conclusion Postoperative radiosurgery has excellent and durable LC for spine metastasis. An important consideration when planning postoperative radiosurgery is minimizing delay from surgery to radiosurgery. Preoperative embolization and higher radiotherapy dose were associated with improved LC warranting further study.

OBJECTIVE To increase the number of independent National Institutes of Health (NIH)–funded neurosurgeons and to enhance neurosurgery research, the National Institute of Neurological Disorders and Stroke (NINDS) developed two national comprehensive programs (R25 [established 2009] for residents/fellows and K12 [2013] for early-career neurosurgical faculty) in consultation with neurosurgical leaders and academic departments to support in-training and early-career neurosurgeons. The authors assessed the effectiveness of these NINDS-initiated programs to increase the number of independent NIH-funded neurosurgeon-scientists and grow NIH neurosurgery research funding. METHODS NIH funding data for faculty and clinical department funding were derived from the NIH, academic departments, and Blue Ridge Institute of Medical Research databases from 2006 to 2019. RESULTS Between 2009 and 2019, the NINDS R25 funded 87 neurosurgical residents. Fifty-three (61%) have completed the award and training, and 39 (74%) are in academic practice. Compared to neurosurgeons who did not receive R25 funding, R25 awardees were twice as successful (64% vs 31%) in obtaining K-series awards and received the K-series award in a significantly shorter period of time after training (25.2 ± 10.1 months vs 53.9 ± 23.0 months; p < 0.004). Between 2013 and 2019, the NINDS K12 has supported 19 neurosurgeons. Thirteen (68%) have finished their K12 support and all (100%) have applied for federal funding. Eleven (85%) have obtained major individual NIH grant support. Since the establishment of these two programs, the number of unique neurosurgeons supported by either individual (R01 or DP-series) or collaborative (U- or P-series) NIH grants increased from 36 to 82 (a 2.3-fold increase). Overall, NIH funding to clinical neurological surgery departments between 2006 and 2019 increased from $66.9 million to $157.3 million (a 2.2-fold increase). CONCLUSIONS Targeted research education and career development programs initiated by the NINDS led to a rapid and dramatic increase in the number of NIH-funded neurosurgeon-scientists and total NIH neurosurgery department funding.