Background and Purpose—: Recently, we reported a common genetic variant, ring finger protein 213 ( RNF213 ) c.14576G>A variant, a susceptibility gene for moyamoya disease (MMD), among patients with intracranial major artery stenosis/occlusion (ICASO) in a selected Japanese population. The aim of this 2-center–based case–control study was to confirm our previous finding in a larger population. Methods—: Study participants were recruited from The University of Tokyo Hospital and Kanto Neurosurgical Hospital. The occurrence rate of c.14576G>A variant was investigated in 323 patients, 22 with definite MMD, 8 with unilateral MMD, 84 with ICASO in the absence of MMD (non-MMD ICASO), 34 with extracranial carotid atherosclerosis, 44 with cerebral aneurysm, 21 with intracerebral hemorrhage, and 110 control subjects. Results—: RNF213 c.14576G>A variant was found in 1.8% (2/110) of the normal control group and had significant associations with definite MMD ( P <0.0001; odds ratio, 144.0; 95% confidence interval, 26.7–775.9), unilateral MMD ( P =0.0001; odds ratio, 54.0; 95% confidence interval, 7.5–386.8), and non-MMD ICASO ( P A, indicating that RNF213 c.14576G>A variant is a high-risk allele for ICASO.

Background and Purpose—: The c.14576G>A variant in ring finger protein 213 (RNF213) was recently identified as a susceptibility gene variant for moyamoya disease (MMD). The occurrence of c.14576G>A variant was evaluated in patients with intracranial major artery stenosis/occlusion (ICASO) without signs of MMD (non-MMD ICASO), as well as in patients with MMD and other cerebrovascular diseases as controls. Methods—: This single-hospital–based case-control study was completed in 7 months (from October 2011–April 2012) at Department of Neurosurgery, The University of Tokyo Hospital. The occurrence of c.14576G>A variant was analyzed in 41 patients with non-MMD ICASO, in 48 with MMD, in 21 with cervical disease, in 61 with cerebral aneurysm, and in 25 normal subjects. Results—: Nine of 41 patients (21.9%) with non-MMD ICASO and 41 of 48 (85.4%) with MMD had the c.14576G>A variant. One of 61 patients (1.6%) with cerebral aneurysm and no patients with cervical disease or normal subjects had the variant. Comparison of each phenotype group with the normal subjects showed that presence of c.14576G>A variant had significant associations with MMD (odds ratio [OR], 292.8; 95% confidence interval [CI], 15.4–5153.0; PA variant in RNF213.

Moyamoya disease is characterized by severe stenosis at the ends of the bilateral internal carotid arteries and the development of collateral circulation. The disease is very diverse in terms of age at onset, onset patterns, radiological findings, and genetic phenotypes. The pattern of onset is mainly divided into ischemic and hemorrhagic onsets. Recently, the opportunity to identify asymptomatic moyamoya disease, which sometimes manifests as nonspecific symptoms such as headache and dizziness, through screening with magnetic resonance imaging has been increasing. Various recent reports have investigated the associations between the clinical features of different onset patterns of moyamoya disease and the corresponding imaging characteristics. In this article, we have reviewed the natural history, clinical features, and imaging features of each onset pattern of moyamoya disease.

Intracranial atherosclerosis (ICAS) involves diverse histologies and several remodeling patterns. Ring finger protein 213 (RNF213) c.14576G>A variant (rs112735431), recently reported to be associated with ICAS, may be linked with negative remodeling (outer diameter - reducing morphological alteration) of intracranial arteries. This study investigated the outer diameter of atherosclerotic middle cerebral artery (MCA). Patients with unilateral atherosclerotic MCA stenosis/occlusion were enrolled in this single-hospital-based case-control study at The University of Tokyo Hospital. The patients were divided into two groups by the presence of RNF213 c.14576G>A (variant group and wild-type group) and the outer diameter of the MCA was measured with high-resolution magnetic resonance imaging. Twenty-eight patients with the wild type and 19 patients with the variant type were included. The outer diameter of the stenotic side MCA was smaller in the variant group than in the wild-type group (P = 8.3 × 10-6). The outer diameter of the normal side MCA was also smaller in the variant group than in the wild-type group (P = 5.2 × 10-3). The ratio of stenotic side to normal side was also smaller in the variant group than in the wild-type group (P = 1.5 × 10-5). This study indicates that RNF213 c.14576G>A is associated with negative remodeling of ICAS.

Background and purpose: The initial steps in the cascade leading to cell death are still unknown because of the limitations of the existing methodology, strategy, and modalities used. Methods: Imaging mass spectrometry (IMS) was used to measure dynamic molecular changes of phosphatidylcholine (PC) species in the rat hippocampus after transient global ischemia (TGI) for 6 min. Fresh frozen sections were obtained after euthanizing the rats on Days 1, 2, 4, 7, 10, 14, and 21. Histopathology and IMS of adjacent sections compared morphological and molecular changes, respectively. Results: Histopathological changes were absent immediately after TGI (at Day 1, superacute phase). At Days 2–21 after TGI (from subacute to chronic phases), histopathology revealed neuronal death associated with gliosis, inflammation, and accumulation of activated microglia in CA1. IMS detected significant molecular changes after TGI in the same CA1 domain: increase of PC (diacyl-16:0/22:6) in the superacute phase and increase of PC (diacyl-16:0/18:1) in the subacute to chronic phases. Conclusions: Histopathology and IMS can provide comprehensive and complementary information on cell death mechanisms in the hippocampal CA1 after global ischemia. IMS provided novel data on molecular changes in phospholipids immediately after TGI. Increased level of PC (diacyl-16:0/22:6) in the pyramidal cell layer of hippocampal CA1 prior to the histopathological change may represent an early step in delayed neuronal death mechanisms.

De novo aneurysm formation after intracranial anastomotic surgery is a relatively rare complication with fewer than 20 reported cases, and the mechanism is still unclear. A 63-year-old male treated for symptomatic internal carotid artery occlusion developed de novo aneurysms twice after anastomoses first of the superficial temporal artery-middle cerebral artery and second of the external carotid artery-radial artery-middle cerebral artery over a 10-year period. The first de novo aneurysm was successfully resected with pathological diagnosis of true aneurysm. The second de novo aneurysm thrombosed naturally after gradual growth. Genetic testing of the patient revealed the c.14576G>A (p.R4859K) variant in ring finger protein 213, which is a susceptibility gene for moyamoya disease. This genetic variant was probably involved in the repeated de novo aneurysm formation, and this case represents a rare phenotype of the genetic variant.