Epithelioid glioblastoma is a rare aggressive variant of glioblastoma (GBM) characterized by a dismal prognosis of about 6 months and frequent leptomeningeal dissemination. A recent study has revealed that 50% of epithelioid GBMs harbor three genetic alterations – BRAF V600E mutation, TERT promoter mutations, and homozygous deletions of CDKN2A/2B. Emerging evidence support the effectiveness of targeted therapies for brain tumors with BRAF V600E mutation. Here we describe a dramatic radiographical response to combined therapy with BRAF and MEK inhibitors in a patient with epithelioid GBM harboring BRAF V600E mutation, characterized by thick spinal dissemination. From relapsed tumor procured at autopsy, we established a cell line retaining the BRAF V600E mutation, TERT promoter mutation and CDKN2A/2B loss. Intracranial implantation of these cells into mice resulted in tumors closely resembling the original, characterized by epithelioid tumor cells and dissemination, and invasion into the perivascular spaces. We then confirmed the efficacy of treatment with BRAF and MEK inhibitor both in vitro and in vivo. Epithelioid GBM with BRAF V600E mutation can be considered a good treatment indication for precision medicine, and this patient-derived cell line should be useful for prediction of the tumor response and clarification of its biological characteristics.

We retrospectively reviewed the cases of three patients with infectious intracranial aneurysms (IIAs), and discuss the indications for surgical and endovascular treatments. We treated two men and one woman with a total of six aneurysms. The mean age was 43.3 years, ranging from 36 to 51 years. One patient presented initially with an intraparenchymal hemorrhage, one with mass effect, and the other one had four aneurysms (one causing subarachnoid hemorrhages and the other causing delayed intraparenchymal hemorrhages). The average size of all aneurysms was 12.2 mm (range, 2–50 mm). They were preferentially located in the distal posterior cerebral artery, and then, in the middle cerebral artery. All cases were caused by infective endocarditis. We selected endovascular treatments for five aneurysms and treated all but one within 24 h from detection. One aneurysm was treated by combined therapy with endovascular intervention and surgery. After treatment, none of the IIAs presented angiographical recurrence or re-bleeding. If feasible, endovascular treatment is probably the first choice, but a combined surgical and endovascular approach should be considered if surgery or endovascular treatment alone are not feasible. The method of treatment should be individualized. For cases with high risk of aneurysm rupture, treatment should be performed as soon as possible.

Recent studies have suggested the feasibility of detecting H3K27M mutations in the cerebrospinal fluid of diffuse midline glioma (DMG) patients. However, cerebrospinal fluid from patients in these studies were collected mainly during biopsy, ventriculo-peritoneal shunt procedures or postmortem. We assessed circulating tumor DNA (ctDNA) extracted from cerebrospinal fluid (CSF) and plasma in a series of 12 radiographically suspected and/or pathologically confirmed diffuse midline glioma patients and assessed for H3F3A K27M mutation using digital droplet PCR. In 10 patients, CSF was obtained by lumbar puncture at presentation. A definitive detection of H3F3A K27M mutation was achieved in only one case (10%); H3F3A K27M mutation was suspected in three other cases (30%). H3F3A K27M mutation was detected in two patients in CSF obtained by ventricular tap during a ventriculo-peritoneal shunt for obstructive hydrocephalus. Cases in which a definitive assessment was possible (definite H3F3A K27M or definite H3F3A wildtype) tended to be younger (median 7.5 years vs. 40.5 years; p = 0.07) and have a higher concentration of CSF protein (median 123 mg/dL vs. 27.5 mg/dL; p = 0.21) compared to nondefinite cases. Low proliferation and apoptotic rates seemed to be characteristics of DMG unfavorable for liquid biopsy. More advanced lesions with necrosis and evidence of dissemination were unlikely to be candidates for lumbar puncture due to the fear of exacerbating obstructive hydrocephalus. Methods to safely sample CSF and a more sensitive detection of ctDNA are necessary for reliable liquid biopsy of DMG at presentation.

Purpose: We aimed to evaluate the safety and feasibility of the distal transradial approach (DTRA) as a novel technique for cerebral angiography based on our institutional initial experience. Methods: We retrospectively analyzed our institutional database of consecutive diagnostic cerebral angiographies performed with DTRA from December 2018 to August 2019. Patient demographics and clinical and procedural data were recorded. Results: In total, 51 diagnostic cerebral angiographies in 51 patients (age, 15–83 years; mean age, 59.4 years, SD 13.5; 35 (69%) females) were performed or attempted with DTRA. Ultrasound evaluation showed that the mean inner distal radial artery diameter was significantly smaller than the mean inner forearm radial artery diameter (2.19 mm vs. 2.56 mm, P < 0.001). Cannulation via the distal radial artery was successful in 47 (92%) procedures. In the four procedures that failed, operators converted to the ipsilateral transradial approach without repositioning or redraping. Selective catheterization of the intended vessel was achieved in 64 (91%) of 70 vessels. In the remaining six, operators achieved the objective of the examination with angiography injecting from proximal and conversion to another approach was not required. One patient experienced temporary numbness around the puncture site after the procedure. No radial artery occlusion was identified in the patients who underwent ultrasound evaluation. Conclusion: Our results demonstrate that DTRA could become a standard approach for diagnostic cerebral angiography owing to the low complication rate and the high cannulation success rate.

Brain arteriovenous malformations (bAVMs) are anomalies forming vascular tangles connecting the arteries and veins, which cause hemorrhagic stroke in young adults. Current surgical approaches are highly invasive, and alternative therapeutic methods are warranted. Recent genetic studies identified KRAS mutations in endothelial cells of bAVMs; however, the underlying process leading to malformation in the postnatal stage remains unknown. Here we established a mouse model of bAVM developing during the early postnatal stage. Among 4 methods tested, mutant KRAS specifically introduced in brain endothelial cells by brain endothelial cell–directed adeno-associated virus (AAV) and endothelial cell–specific Cdh5 - CreERT2 mice successfully induced bAVMs in the postnatal period. Mutant KRAS led to the development of multiple vascular tangles and hemorrhage in the brain with increased MAPK/ERK signaling and growth in endothelial cells. Three-dimensional analyses in cleared tissue revealed dilated vascular networks connecting arteries and veins, similar to human bAVMs. Single-cell RNA-Seq revealed dysregulated gene expressions in endothelial cells and multiple cell types involved in the pathological process. Finally, we employed CRISPR/CasRx to knock down mutant KRAS expression, which efficiently suppressed bAVM development. The present model reveals pathological processes that lead to postnatal bAVMs and demonstrates the efficacy of therapeutic strategies with CRISPR/CasRx.