Brain arteriovenous malformations (bAVMs) are complex, heterogeneous, and uncommon intracranial lesions. They can be treated by one or a combination of the following treatment modalities, namely embolization, radiosurgery, or microsurgical resection. In Spetzler-Martin Grade 4 and 5 arteriovenous malformations (AVMs), conservative management may be the best option. A group of experts in the management of AVMs of different disciplines gathered in January 2019 in Hanoi to compile the "Expert Consensus on the Management of Brain Arteriovenous Malformations".

Cell transplantation therapy offers great potential to improve impairments after stroke. However, the importance of donor age on therapeutic efficacy is unclear. We investigated the regenerative capacity of transplanted cells focusing on donor age (young vs. old) for ischaemic stroke. The quantities of human mesenchymal stem cell (hMSC) secreted brain-derived neurotrophic factor in vitro and of monocyte chemotactic protein-1 at day 7 in vivo were both significantly higher for young hMSC compared with old hMSC. Male Sprague-Dawley rats subjected to transient middle cerebral artery occlusion that received young hMSC (trans-arterially at 24 h after stroke) showed better behavioural recovery with prevention of brain atrophy compared with rats that received old hMSC. Histological analysis of the peri-infarct cortex showed that rats treated with young hMSC had significantly fewer microglia and more vessels covered with pericytes. Interestingly, migration of neural stem/progenitor cells expressing Musashi-1 positively correlated with astrocyte process alignment, which was more pronounced for young hMSC. Aging of hMSC may be a critical factor that affects cell therapy outcomes, and transplantation of young hMSC appears to provide better functional recovery through anti-inflammatory effects, vessel maturation, and neurogenesis potentially by the dominance of trophic factor secretion.

Identifying plaque components such as intraplaque hemorrhage, lipid rich necrosis, and calcification is important to evaluate vulnerability of carotid atherosclerotic plaque; however, conventional vessel wall MR imaging may fail to discriminate plaque components. We aimed to evaluate the components of plaques using quantitative susceptibility mapping (QSM), a newly developed post-processing technique to provide voxel-based quantitative susceptibilities. Methods: Seven patients scheduled for carotid endarterectomy were enrolled. Magnitude and phase images of five-echo 3D fast low angle shot (FLASH) were obtained using a 3T MRI, and QSM was calculated from the phase images. Conventional carotid vessel wall images (black-blood T 1-weighted images [T 1 WI], T 2-weighted images [T 2 WI], proton-density weighted images [PDWI], and time-of-flight images [TOF]) were also obtained. Pathological findings including intraplaque hemorrhage, calcification, and lipid rich necrosis at the thickest plaque section were correlated with relative susceptibility values with respect to the sternocleidomastoid muscle on QSM. On conventional vessel wall images, the contrast-noise ratio (CNR) between the three components and sternocleidomastoid muscle was measured respectively. Wilcoxon signed-rank test analyses were performed to assess the relative susceptibility values and CNR. Results: Pathologically, lipid rich necrosis was proved in all of seven cases, and intraplaque hemorrhage in five of seven cases. Mean relative susceptibility value of hemorrhage was higher than lipid rich necrosis unexceptionally (P = 0.0313). There were no significant differences between CNR of hemorrhage and lipid rich necrosis on all sequences. In all six cases with plaque calcification, susceptibility value of calcification was significantly lower than lipid rich necrosis unexceptionally (P = 0.0156). There were significant differences between CNRs of lipid rich necrosis and calcification on T 1 WI, PDWI, TOF (P < 0.05). Conclusion: QSM of carotid plaque would provide a novel quantitative MRI contrast that enables reliable differentiation among intraplaque hemorrhage, lipid rich necrosis, and calcification, and be useful to identify vulnerable plaques.

Objectives -Moyamoya disease (MMD) is a unique occlusive disease of the bilateral internal carotid arteries with moyamoya vessels. A inherited or acquired disorders and conditions may present in conjunction with MMD. This condition is known as quasi-moyamoya disease. To identify the clinical features of quasi-MMD in Japan, nationwide survey was conducted.Patients and Methods-The questionnaire was directly mailed to 241 departments, which answered treating quasi-MMD patients in the primary survey. We ascertained the sex, age, family history, clinical manifestation, radiological findings, treatments, course of the disease, and daily activity of the patients.Results-A total of 114 departments replied to the questionnaire. The data of 108 patients (66 female and 42 male; female to male ratio 1.57) were registered and analyzed. Mean age was 30.6 years old with a peak of the child. Seven patients (7%) exhibited familial MMD. The initial clinical manifestation was motor weakness, followed by transient ischemic attack, headache. Their imaging study type included ischemic type in 64 patients (63.4%), bleeding type in 7 (6.9%), and normal in 27 (26.7%). Stenoocclusive lesion was seen in internal carotid artery in more than half of the patients. Development of moyamoya vessels was mild in approximately 40% of the patients. Almost all cases were accompanied with cerebral hypoperfusion. About half of them were unilateral lesion. Vascular reconstruction was employed for the approximately 60% patients. The prognosis did not changed significantly. 2Conclusion-Clinical feature of quasi-MMD were revealed in the nationwide study. In quasi-MMD, unilateral lesion is dominant, and the development of moyamoya vessels and intracranial hemorrhage are less.Full title: Nationwide survey on quasi-moyamoya disease in Japan Running title: Nationwide survey on quasi-moyamoya disease

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