Belzutifan in adults with VHL-associated central nervous system hemangioblastoma: a single-center experience.

PURPOSE: Belzutifan is a selective inhibitor of hypoxia-inducible factor 2 alpha (HIF-2a) that has emerged as a targeted therapy option for Von Hippel-Lindau (VHL) syndrome-associated tumors with recent FDA approval. There is limited real-world evidence regarding safety and efficacy in CNS hemangioblastoma. Our objective was to report on our clinical experience with belzutifan in adult patients with VHL-associated CNS hemangioblastoma. METHODS: We retrospectively reviewed our institutional experience of belzutifan in adult patients (> 18 years of age at time of therapy) with VHL and craniospinal CNS hemangioblastomas not amenable to surgical resection. The period for study review was October 2021 to March 2023. RESULTS: 4 patients (all female) with a median age of 36 years at time of belzutifan initiation were included. Median duration of therapy at last follow-up was 11 months (6-17 months). All patients had radiographic response to therapy after a median of 3 months (2-5 months), with maximal response to therapy after a median of 8 months (3-17 months). Therapy was well tolerated, with the most common adverse effect being anemia. No patients had treatment pauses or dose adjustments due to belzutifan-related toxicity. No patients experienced hypoxia. CONCLUSION: We showed that belzutifan is safe and well-tolerated with strong disease response for CNS hemangioblastoma in adults with VHL, supporting continued use of belzutifan in this patient population. Future studies should assess duration of treatment, effects of cessation after long-term use, and markers of therapeutic response.

Effects of a ketogenic and low-fat diet on the human metabolome, microbiome, and foodome in adults at risk for Alzheimer's disease.

INTRODUCTION: The ketogenic diet (KD) is an intriguing therapeutic candidate for Alzheimer's disease (AD) given its protective effects against metabolic dysregulation and seizures. Gut microbiota are essential for KD-mediated neuroprotection against seizures as well as modulation of bile acids, which play a major role in cholesterol metabolism. These relationships motivated our analysis of gut microbiota and metabolites related to cognitive status following a controlled KD intervention compared with a low-fat-diet intervention. METHODS: Prediabetic adults, either with mild cognitive impairment (MCI) or cognitively normal (CN), were placed on either a low-fat American Heart Association diet or high-fat modified Mediterranean KD (MMKD) for 6 weeks; then, after a 6-week washout period, they crossed over to the alternate diet. We collected stool samples for shotgun metagenomics and untargeted metabolomics at five time points to investigate individuals' microbiome and metabolome throughout the dietary interventions. RESULTS: Participants with MCI on the MMKD had lower levels of GABA-producing microbes Alistipes sp. CAG:514 and GABA, and higher levels of GABA-regulating microbes Akkermansia muciniphila. MCI individuals with curcumin in their diet had lower levels of bile salt hydrolase-containing microbes and an altered bile acid pool, suggesting reduced gut motility. DISCUSSION: Our results suggest that the MMKD may benefit adults with MCI through modulation of GABA levels and gut-transit time.

Panobinostat in adults with H3 K27M-mutant diffuse midline glioma: a single-center experience.

INTRODUCTION: Diffuse midline gliomas (DMG) with the H3 K27M-mutation are a well-described entity with most DMG harboring this mutation, with notable heterogeneity in adults. No therapy has been proven to improve survival in this tumor type. Panobinostat is a histone deacetylase inhibitor that may have therapeutic benefit. METHODS: We report our retrospective experience with use of panobinostat in adults (> 18 years) with H3 K27M-mutant DMG treated at Mayo Clinic (Rochester) from January 2016 to August 2020, with follow-up until October 2021. Survival was calculated using the Kaplan-Meier method. RESULTS: 4 patients with H3 K27M-mutant glioma were treated with panobinostat as compassionate use. Patients had a median age of 40 years (range 22-62 years) and 2 were female. Tumor location was midline for all patients, spinal cord (n = 2), brainstem (n = 1), and thalamus (n = 1). All tumors were IDH1/IDH2 wildtype. 3 patients received radiotherapy followed by adjuvant panobinostat. All patients had no other pharmacologic therapy utilized prior to or during panobinostat therapy aside from concurrent dexamethasone utilized in 3 patients. No patient experienced a grade 2 or higher (per CTCAE grade) adverse effect. The median overall survival was 42 months, median progression free survival of 19 months, 2 patients were alive at last follow up (both with spinal cord tumors and received radiation). The best response was stable disease in 2 patients and a partial response in 1 patient. CONCLUSIONS: This is the first report of clinical outcomes of panobinostat in adults with H3 K27M-mutant DMG. We showed that it is well-tolerated at the dosage schedule that we describe, with no serious adverse effects throughout the study period.

Mycotic aneurysm.

Angioinvasive fungal infections of the cerebral vasculature often lead to significant morbidity and mortality. High clinical suspicion and early antifungal therapy could improve outcomes. We describe the fatal case of a patient with a rapidly enlarging cavernous carotid aneurysm due to angioinvasive fungus. This case highlights the challenges in diagnosis and management of this condition.

A nonhuman primate model of early Alzheimer's disease pathologic change: Implications for disease pathogenesis.

INTRODUCTION: Nonhuman primates may serve as excellent models of sporadic age-associated brain ß-amyloid deposition and Alzheimer's disease pathologic changes. We examined whether a vervet nonhuman primate model recapitulated pathologic, physiologic, and behavioral features of early Alzheimer's disease. METHODS: Nine middle-aged (mean = 11.2 years) and nine aged (mean = 21.7 years) female vervet/African green monkeys underwent cerebrospinal fluid collection, gait speed measurement, and neuroimaging before neuropathologic assessment. RESULTS: ß-amyloid plaques were identified in all aged vervets and paired helical filament tau immunoreactivity was observed in all animals. Cerebrospinal fluid ß-amyloid42 and gait speed correlated negatively with age and plaque density. Greater plaque and paired helical filament tau burden predicted reduced volumes and CMRg in several brain regions. DISCUSSION: We observed a coordinated set of relationships among neuropathologic, cerebrospinal fluid, imaging, and behavioral modalities consistent with early Alzheimer's disease. Our results support future use of the vervet model to explore disease mechanisms, biomarkers, and novel therapeutic strategies.

Bihemispheric Seizure Without Generalization.

A 70-year-old male without prior psychiatric history presented with recurrent episodes (<60 seconds each, every 5-10 minutes) of left hemibody and right lower extremity jerking movements concerning for seizure with preserved awareness (Video). Examination showed left hemiparesis (leg > arm) in addition to right lower extremity weakness. Computed tomography showed a right parafalcine acute subdural hematoma (SDH). Clinical events did not recur after intravenous lorazepam (4 mg) and levetiracetam load (3500 mg), and his weakness improved. He was continued on levetiracetam and has since remained seizure free for 16 months. A 60-minute awake/sleep electroencephalogram (EEG) obtained 12 hours after administration of antiseizure medications showed low amplitude theta slowing (posterior predominant) in the range of 5-7 Hz. There was no apparent epileptiform activity or other abnormalities during the awake and sleep recording or photic stimulation. Focal seizures originate from pathologic disruption of neuronal activity within an isolated brain region, almost exclusively from a single hemisphere. Focal seizures may generalize bilaterally with associated impaired awareness. This is the first visual report demonstrating focal, bihemispheric clinical seizures, without generalization or impaired awareness. Rarely patients with generalized motor involvement from seizures have had retained consciousness and memory. The parafalcine SDH likely promoted epileptogenicity of the bilateral hemispheres. Acute and chronic SDH commonly present with seizures. Although there were no supportive electrographic findings, parasagittal epileptogenic lesions may be difficult for both clinical and electrographic localization. Post-event paresis with clinical improvement in the hours after event cessation supports clinical seizure.

Recurrent Pleomorphic Xanthoastrocytoma Presenting With Diffuse Leptomeningeal Spread.

We report a case highlighting key clinical, CSF, and imaging findings of recurrent pleomorphic xanthoastrocytoma with leptomeningeal spread.

A Case of Long-Term Survival After Glioblastoma, IDH-Wild Type.

INTRODUCTION: Glioblastoma is a uniformly lethal primary central nervous system neoplasm. Despite the increased understanding of its pathophysiology and treatment advancements, median overall survival for patients with glioblastoma, IDH-wild type remains 14 to 21 months from diagnosis. CASE REPORT: We present the case of a 48-year-old female who presented with a focal seizure and was found to have a right frontal lobe mass on the brain magnetic resonance imaging. She underwent gross total resection and received a histological diagnosis of glioblastoma. She received radiotherapy and 6 cycles of carmustine (BCNU). Seventeen months later, she developed left hemiparesis. Imaging was concerning for tumor progression, and she was treated with 1 cycle of mechlorethamine, vincristine (oncovin), procarbazine, and prednisone (MOPP). Subsequent surveillance imaging demonstrated a therapeutic response. Twenty-seven years after her glioblastoma diagnosis, she developed status epilepticus and died from respiratory failure. Neuropathology on autopsy demonstrated extensive treatment-related changes but no evidence of recurrent glioblastoma. Genomic testing performed over 30 years after her original diagnosis revealed a profile diagnostic of glioblastoma, IDH-wild type per 2021 World Health Organization criteria. CONCLUSIONS: This patient is one of the longest-known survivors of glioblastoma, IDH-wild type, with pathologic confirmation of glioblastoma at the time of her resection and no evidence of residual disease 26 years after her last treatment. She presented with multiple factors associated with long-term glioblastoma survivorship, including female sex, young age, high Karnofsky score, and multimodal therapy. This case shows that long-term survival after glioblastoma diagnosis is possible and likely mediated through a combination of individual, tumor, and treatment factors.

Neurosurgical Implications of Targeting Hypoxia-Inducible Factor 2α in Hemangioblastomas with Belzutifan.

OBJECTIVE: To highlight the neurosurgical implications of the hypoxia-inducible factor-2α- targeting agent belzutifan in the management of both von-Hippel Lindau (VHL)-associated and sporadic hemangioblastomas (HBLs). METHODS: The literature was queried for VHL, HBLs, and belzutifan. A summary of recent uses of belzutifan and currently ongoing clinical trials that are investigating the use of belzutifan in the treatment of HBLs is presented. RESULTS: VHL disease occurs as a result of germline mutations in the VHL tumor suppressor gene on chromosome 3p25-p26, leading to growth of benign and malignant tumors such as HBLs. The possibility of intermittent growth in HBLs indicates that it is important to avoid hasty surgical interventions. Belzutifan is the first nonsurgical food and drug administration-approved treatment for VHL disease-related tumors that may delay or circumvent the need for surgery or radiation therapy by inhibiting HIF-2α, an important component of cellular hypoxic response. There is limited real-world experience of belzutifan in patients with HBLs as a primary indication, though there are 2 phase II clinical trials investigating the use of belzutifan in the treatment of HBLs. CONCLUSIONS: There is limited experience regarding the use of belzutifan for CNS hemangioblastoma. While its application has been limited to a small group of clinical cases, it has exhibited significant efficacy in reducing the size and consequences of HBLs. Based on the promising outcomes observed in individual patient experiences and ongoing clinical trials, we infer that further exploration and integration of belzutifan into neurosurgical treatment plans for both sporadic and VHL-associated HBLs are warranted.

Proton versus photon craniospinal irradiation for adult medulloblastoma: A dosimetric, toxicity, and exploratory cost analysis.

Background: This study aimed to determine whether proton craniospinal irradiation (CSI) decreased the dose to normal tissue and resulted in less toxicity than photon CSI for adult patients. Methods: This single-institution retrospective analyzed differences in radiation doses, acute toxicity, and cost between proton and CSI for adult medulloblastoma patients. Results: Of 39 total patients, 20 were treated with photon CSI prior to 2015, and 19 were treated with proton CSI thereafter. Median age was 28 years (range 18-66). The molecular subtype was most commonly sonic hedgehog (68%). Patients most commonly received 36 Gy CSI in 20 fractions with a boost to 54-55.8 Gy (92%). Proton CSI delivered significantly lower mean doses to cochleae, lacrimal glands, lens, parotid glands, pharyngeal constrictors, esophagus, lungs, liver, and skin (all P < .001). Patients receiving proton CSI had significantly lower rates of acute dysphagia of any grade (5% versus 35%, P = .044) and decreased median weight loss during radiation (+1.0 versus -2.8 kg, P = .011). Weight loss was associated with acute hospitalization (P = .009). Median follow-up was 2.9 and 12.9 years for proton and photon patients, respectively, limiting late toxicity and outcome comparisons. At the last follow-up, 5 photon patients had died (2 of progressive disease, 3 without recurrence ages 41-63) and 21% had experienced major cardiovascular events. At 10 years, 89% were alive and 82% were recurrence free. Conclusions: This study demonstrates dosimetric improvements with proton CSI, potentially leading to decreased acute toxicity including dysphagia and weight loss during treatment.

Serum and CSF metabolomics analysis shows Mediterranean Ketogenic Diet mitigates risk factors of Alzheimer's disease.

Alzheimer's disease (AD) is influenced by a variety of modifiable risk factors, including a person's dietary habits. While the ketogenic diet (KD) holds promise in reducing metabolic risks and potentially affecting AD progression, only a few studies have explored KD's metabolic impact, especially on blood and cerebrospinal fluid (CSF). Our study involved participants at risk for AD, either cognitively normal or with mild cognitive impairment. The participants consumed both a modified Mediterranean Ketogenic Diet (MMKD) and the American Heart Association diet (AHAD) for 6 weeks each, separated by a 6-week washout period. We employed nuclear magnetic resonance (NMR)-based metabolomics to profile serum and CSF and metagenomics profiling on fecal samples. While the AHAD induced no notable metabolic changes, MMKD led to significant alterations in both serum and CSF. These changes included improved modifiable risk factors, like increased HDL-C and reduced BMI, reversed serum metabolic disturbances linked to AD such as a microbiome-mediated increase in valine levels, and a reduction in systemic inflammation. Additionally, the MMKD was linked to increased amino acid levels in the CSF, a breakdown of branched-chain amino acids (BCAAs), and decreased valine levels. Importantly, we observed a strong correlation between metabolic changes in the CSF and serum, suggesting a systemic regulation of metabolism. Our findings highlight that MMKD can improve AD-related risk factors, reverse some metabolic disturbances associated with AD, and align metabolic changes across the blood-CSF barrier.

Proton Craniospinal Irradiation with Immunotherapy in Two Patients with Leptomeningeal Disease from Melanoma.

Introduction: Proton craniospinal irradiation (pCSI) is a treatment option for leptomeningeal disease (LMD), which permits whole neuroaxis treatment while minimizing toxicity. Despite this, patients inevitably experience progression. Adding systemic therapy to pCSI may improve outcomes. Methods: In this single-institution retrospective case series, we present the feasibility of treatment with pCSI (30Gy, 10 fractions) and an immune checkpoint inhibitor (ICI) in two sequential patients with LMD from melanoma. Results: The first patient developed LMD related to BRAF V600E-mutant melanoma after prior ICI and BRAF-targeted therapy. After pCSI with concurrent nivolumab, the addition of relatlimab, and BRAF-targeted therapy, he remained alive 7 months after LMD diagnosis despite central nervous system progression. The second patient developed LMD related to BRAF-wildtype melanoma after up-front ICI. He received pCSI with concurrent ipilimumab and nivolumab, then nivolumab maintenance. Though therapy was held for ICI hepatitis, the patient remained progression-free 5 months after LMD diagnosis. Conclusion: Adding an ICI to pCSI is feasible for patients with LMD and demonstrates a tolerable toxicity profile. While prospective evaluation is ultimately warranted, pCSI with ICI may confer survival benefits, even after prior ICI.

Management and Long-Term Outcomes of Patients With Recurrent Stroke-Like Episodes After Cranial Radiotherapy.

BACKGROUND: Recurrent Stroke-Like Episodes of transient negative neurologic symptoms are a long-term consequence of cranial radiation therapy (RT) that may lead to significant functional impairment and worsen quality of life. We assessed management patterns and clinical course at our institution to assess optimal management strategy and understand long-term outcomes. METHODS: We conducted a retrospective review of all patients with recurrent negative neurologic symptoms after cranial RT who were treated at Mayo Clinic (Rochester), with follow-up extending through October 2021 with a goal of assessing for clinical change in the setting of medical management. Descriptive statistics and Fisher exact tests were performed for group comparisons. RESULTS: Twenty-five patients were included. Median age at diagnosis was 28.7 years (range: 3.0 to 65.8). Median time from RT to symptom onset was 14.6 years (range: 3.3 to 30.5). The most common presentations included hemiparesis (56%), visual field (33%) and hemisensory (22%) loss, and aphasia (22%). Therapeutics used specifically for management of recurrent episodes included antiseizure medications (92%), antiplatelets (68%), verapamil (52%), statins (48%), glucocorticoids (24%), antivirals (20%), and angiotensin converting enzyme inhibitor/ Angiotensin receptor blockers (16%). Antivirals were less commonly used in patients with cessation (Fisher exact, P =0.0235). Progressive encephalopathy was more commonly seen in those without cessation (Fisher exact, P =0.0072), and in all patients who died at last follow-up. CONCLUSIONS: Although retrospective experience from a single institution, our cohort represents one of the largest with management data reported for this complex clinical scenario. We hope that our findings may be used as a reference for clinicians in the management of this challenging clinical scenario.

The Current Status, Challenges, and Future Potential of Therapeutic Vaccination in Glioblastoma.

Glioblastoma (GBM) is the most common malignant primary brain tumor and confers a dismal prognosis. With only two FDA-approved therapeutics showing modest survival gains since 2005, there is a great need for the development of other disease-targeted therapies. Due, in part, to the profound immunosuppressive microenvironment seen in GBMs, there has been a broad interest in immunotherapy. In both GBMs and other cancers, therapeutic vaccines have generally yielded limited efficacy, despite their theoretical basis. However, recent results from the DCVax-L trial provide some promise for vaccine therapy in GBMs. There is also the potential that future combination therapies with vaccines and adjuvant immunomodulating agents may greatly enhance antitumor immune responses. Clinicians must remain open to novel therapeutic strategies, such as vaccinations, and carefully await the results of ongoing and future trials. In this review of GBM management, the promise and challenges of immunotherapy with a focus on therapeutic vaccinations are discussed. Additionally, adjuvant therapies, logistical considerations, and future directions are discussed.

Improving Neurology Inpatient Fall Rate: Effect of a Collaborative Interdisciplinary Quality Improvement Initiative.

Objective: To reduce unwitnessed inpatient falls on the neurology services floor at an academic medical center by 20% over 15 months. Patients and Methods: A 9-item preintervention survey was administered to neurology nurses, resident physicians, and support staff. Based on survey data, interventions targeting fall prevention were implemented. Providers were educated during monthly in-person training sessions regarding the use of patient bed/chair alarms. Safety checklists were posted inside each patient's room reminding staff to ensure that bed/chair alarms were on, call lights and personal items were within reach, and patients' restroom needs were addressed. Preimplementation (January 1, 2020, to March 31, 2021) and postimplementation (April 1, 2021, to June 31, 2022) rates of falls in the neurology inpatient unit were recorded. Adult patients hospitalized in 4 other medical inpatient units not receiving the intervention served as a control group. Results: Rates of falls, unwitnessed falls, and falls with injury all decreased after intervention in the neurology unit, with rates of unwitnessed falls decreasing by 44% (2.74 unwitnessed falls per 1000 patient-days before intervention to 1.53 unwitnessed falls per 1000 patient-days after intervention; P=.04). Preintervention survey data revealed a need for education and reminders on inpatient fall prevention best practices given a lack of knowledge on how to operate fall prevention devices, driving the implemented intervention. All staff reported significant improvement in operating patient bed/chair alarms after intervention (P<.001). Conclusion: A collaborative, multidisciplinary approach focusing on provider fall prevention education and staff checklists is a potential technique to reduce neurology inpatient fall rates.

Glioma Metabolic Feedback In Situ: A First-In-Human Pharmacodynamic Trial of Difluoromethylornithine + AMXT-1501 Through High-Molecular Weight Microdialysis.

BACKGROUND AND OBJECTIVES: No new drug has improved survival for glioblastoma since temozolomide in 2005, due in part to the relative inaccessibility of each patient's individualized tumor biology and its response to therapy. We have identified a conserved extracellular metabolic signature of enhancing high-grade gliomas enriched for guanidinoacetate (GAA). GAA is coproduced with ornithine, the precursor to protumorigenic polyamines through ornithine decarboxylase (ODC). AMXT-1501 is a polyamine transporter inhibitor that can overcome tumoral resistance to the ODC inhibitor, difluoromethylornithine (DFMO). We will use DFMO with or without AMXT-1501 to identify candidate pharmacodynamic biomarkers of polyamine depletion in patients with high-grade gliomas in situ . We aim to determine (1) how blocking polyamine production affects intratumoral extracellular guanidinoacetate abundance and (2) the impact of polyamine depletion on the global extracellular metabolome within live human gliomas in situ. METHODS: DFMO, with or without AMXT-1501, will be administered postoperatively in 15 patients after clinically indicated subtotal resection for high-grade glioma. High-molecular weight microdialysis catheters implanted into residual tumor and adjacent brain will be used for postoperative monitoring of extracellular GAA and polyamines throughout therapeutic intervention from postoperative day (POD) 1 to POD5. Catheters will be removed on POD5 before discharge. EXPECTED OUTCOMES: We anticipate that GAA will be elevated in tumor relative to adjacent brain although it will decrease within 24 hours of ODC inhibition with DFMO. If AMXT-1501 effectively increases the cytotoxic impact of ODC inhibition, we expect an increase in biomarkers of cytotoxicity including glutamate with DFMO + AMXT-1501 treatment when compared with DFMO alone. DISCUSSION: Limited mechanistic feedback from individual patients' gliomas hampers clinical translation of novel therapies. This pilot Phase 0 study will provide in situ feedback during DFMO + AMXT-1501 treatment to determine how high-grade gliomas respond to polyamine depletion.

Plasma exchange as a tool for removal of bevacizumab: Highlighting application for urgent surgery.

Background: Bevacizumab is commonly used to manage cerebral edema associated with brain tumors. However, its long half-life poses challenges for patients requiring urgent surgery due to wound complications. We present a case of utilizing therapeutic plasma exchange (TPE) to remove bevacizumab in a patient with recurrent glioblastoma requiring urgent surgery. Methods: A 58-year-old male with recurrent glioblastoma, IDH-wildtype, presented with clinical and radiographic concern for ventriculitis requiring urgent wound washout only 4 days after his last bevacizumab infusion. TPE was performed for 3 sessions after surgery using a centrifugation-based cell separator. Replacement fluids included normal serum albumin, normal saline, and fresh frozen plasma. Bevacizumab levels were quantified using an enzyme-linked immunoabsorbent assay before and after each TPE session. Results: TPE effectively removed bevacizumab, enabling safe surgery without new complications. Plasma bevacizumab levels decreased from 1087.63 to 145.35 ng/mL (13.4% of original) by the end of the last TPE session. This decline is consistent with nearly 3 half-lives, which compares favorably to the expected timeline of natural decline given the 21-day half-life. Conclusions: We report a complex clinical scenario of a patient requiring urgent wound washout 4 days after last bevacizumab infusion for CNS infection. Surgery was successfully performed without new complications with use of TPE to remove bevacizumab immediately following surgery. This case highlights the feasibility of this approach, which may be utilized effectively in patients requiring surgery after having recently received bevacizumab.