The treatment of World Health Organization (WHO) grades 2 and 3 meningiomas remains difficult and controversial. The pathogenesis of high-grade meningiomas was expected to be elucidated to improve treatment strategies. The molecular biology of meningiomas has been clarified in recent years. High-grade meningiomas have been linked to NF2 mutations and 22q deletion. CDKN2A/B homozygous deletion and TERT promoter mutations are independent prognostic factors for WHO grade 3 meningiomas. In addition to 22q loss, 1p, 14p, and 9q loss have been linked to high-grade meningiomas. Meningiomas enriched in copy number alterations may be biologically invasive. Furthermore, several new comprehensive classifications of meningiomas have been proposed based on these molecular biological features, including DNA methylation status. The new classifications may have implications for treatment strategies for refractory aggressive meningiomas because they provide a more accurate prognosis compared to the conventional WHO classification. Although several systemic therapies, including molecular targeted therapies, may be effective in treating refractory aggressive meningiomas, these drugs are being tested. Systemic drug therapy for meningioma is expected to be developed in the future. Thus, this review aims to discuss the distinct genomic alterations observed in WHO grade 2 and 3 meningiomas, as well as their diagnostic and therapeutic implications and systemic drug therapies for high-grade meningiomas.

The use of robot-assisted frameless stereotactic electroencephalography (SEEG) is becoming more common. Among available robotic arms, Stealth Autoguide (SA) (Medtronic, Minneapolis, MN, USA) functions as an optional instrument of the neuronavigation system. The aims of this study were to present our primary experiences with SEEG using SA and to compare the accuracy of implantation between SA and navigation-guided manual adjustment (MA). Seventeen electrodes from two patients who underwent SEEG with SA and 18 electrodes from four patients with MA were retrospectively reviewed. We measured the distance between the planned location and the actual location at entry (De) and the target (Dt) in each electrode. The length of the trajectory did not show a strong correlation with Dt in SA (Pearson's correlation coefficient [r] = 0.099, p = 0.706) or MA (r = 0.233, p = 0.351). De and Dt in SA were shorter than those in MA (1.99 ± 0.90 vs 4.29 ± 1.92 mm, p = 0.0002; 3.59 ± 2.22 vs 5.12 ± 1.40 mm, p = 0.0065, respectively). SA offered higher accuracy than MA both at entry and target. Surgical times per electrode were 38.9 and 32 min in the two patients with SA and ranged from 51.6 to 88.5 min in the four patients with MA. During the implantation period of 10.3 ± 3.6 days, no patients experienced any complications.

This study aimed to measure the impact of the COVID-19 pandemic on the volumes of annual stroke admissions compared with those before the pandemic in Japan. We conducted an observational, retrospective nationwide survey across 542 primary stroke centers in Japan. The annual admission volumes for acute stroke within 7 days from onset between 2019 as the pre-pandemic period and 2020 as the pandemic period were compared as a whole and separately by months during which the epidemic was serious and prefectures of high numbers of infected persons. The number of stroke patients declined from 182,660 in 2019 to 178,083 in 2020, with a reduction rate of 2.51% (95% confidence interval [CI], 2.58%-2.44%). The reduction rates were 1.92% (95% CI, 1.85%-2.00%; 127,979-125,522) for ischemic stroke, 3.88% (95% CI, 3.70%-4.07%, 41,906-40,278) for intracerebral hemorrhage, and 4.58% (95% CI, 4.23%-4.95%; 13,020-12,424) for subarachnoid hemorrhage. The admission volume declined by 5.60% (95% CI, 5.46%-5.74%) during the 7 months of 2020 when the epidemic was serious, whereas it increased in the remaining 5 months (2.01%; 95% CI, 1.91%-2.11%). The annual decline in the admission volume was predominant in the five prefectures with the largest numbers of infected people per million population (4.72%; 95% CI, 4.53%-4.92%). In conclusion, the acute stroke admission volume declined by 2.51% in 2020 relative to 2019 in Japan, especially during the months of high infection, and in highly infected prefectures. Overwhelmed healthcare systems and infection control practices may have been associated with the decline in the stroke admission volume during the COVID-19 pandemic.

The rate of recanalization after coil embolization for unruptured intracranial aneurysms (UIAs) is reported to occur around 11.3%-49%. This study aims to investigate the factors that influence the recanalization after coil embolization for UIAs in our institution. We retrospectively investigated 307 UIAs in 296 patients treated at our institution between April 2004 and December 2016. The stent-used cases were excluded. Cerebral angiography and 3D time-of-flight magnetic resonance angiography (TOF MRA) were used for evaluation of the postoperative occlusion status. Volume embolization ratio (VER), aneurysmal size, neck width, and aspect ratio (AR) were compared between the recanalized and non-recanalized groups. The mean follow-up period ranged from 6 to 172 months (mean: 79.0 ± 39.8 months). Recanalization was noted in 78 (25.4%) aneurysms, and 19 (6.2%) aneurysms required retreatment. There was no aneurysmal rupture during the follow-up period. Univariate analysis showed that the aneurysm size (p < 0.001), neck width (p < 0.001), AR (p = 0.003), and VER (p = 0.012) were associated with recanalization. Multivariate logistic regression analysis showed that the AR (p =0.004) and VER (p =0.015) were significant predictors of recanalization. To summarize, a higher AR and a lower VER could lead to recanalization after coil embolization of UIAs. Careful follow-up is required for coiled aneurysms with these features.

Distal transradial approach (dTRA) for neuroendovascular procedures has received much attention in recent years as a newer and less invasive alternative to the conventional transfemoral or transradial approaches. We present the case of an 89-year-old woman with a basilar artery aneurysm requiring simultaneous catheterization of the bilateral vertebral arteries who was successfully embolized using bilateral dTRA. The aneurysm was accessed from the right vertebral artery using the right dTRA. Control angiograms during the procedure were performed from the left vertebral artery via the left dTRA. The operator's posture was ergonomically comfortable, and the catheters were easy to handle during the procedure. To the best of our knowledge, this is the first case of a bilateral dTRA used for neuroendovascular procedures. Bilateral dTRA is a safe and minimally invasive method for patients and ergonomically comfortable for operators.