title: Spatial relationship between cerebral microbleeds, moyamoya vessels, and hematoma in moyamoya disease.
abstract: BACKGROUND
  Adult moyamoya disease (MMD) is known to have high incidence of cerebral microbleeds (cMBs); however, the clinical significance still remains unclear. We investigated the frequency of cMBs in a large number of patients and analyzed the patterns of MB distribution in association with the location of the hematoma and moyamoya vessels.
  
  
  METHODS
  We studied 259 consecutive patients with MMD using prospectively collected database. One hundred ninety-one patients were eligible for the present study, and image analysis was performed retrospectively. The presence of cMBs and remains of hemorrhage were determined using gradient-echo T2*-weighted sequence (1.5 T). The development of moyamoya vessels was assessed on source images of time-of-flight magnetic resonance angiography. The analysis consists of descriptive assessment of the spatial relationship between cMB, remains of hemorrhage, and moyamoya vessels. Statistical analysis was performed to calculate relative risk ratio in the presence of cMBs in relation to the remains of hemorrhage (macrohematoma), age of onset, and the presence of concomitant moyamoya vessels.
  
  
  RESULTS
  Thirty MBs were observed in 20 adult MMD patients (16.9%). MBs were located predominantly in the periventricular white matter (63.3%) followed by the basal ganglia/thalami (20%). Comparing the patients with cMBs from those without, hematoma was more frequently observed in patients with cMBs (odds ratio [OR] 4.29; 95% confidence interval [CI] 1.58-11.62; P=.0062). Patients with adult onset was more likely to demonstrate cMBs (14.4%) compared with the patients with pediatric onset (4.1%) (OR 3.93; 95% CI 1.11-13.91). Moyamoya vessels appeared in the lateral part of the trigon, and the periventricular white matter was significantly associated with the presence of cMBs (lateral part of the trigon; OR 3.29 [1.59-6.82], P=.0019, periventricle of the body of lateral ventricle; OR 2.40 [1.20-4.79], P=.0214, respectively). cMBs accompanied concomitant arteries in 23 (76.7%) lesions. The subependymal-leptomeningeal artery anastomosis was the most common pattern (n=20, 66.7%).
  
  
  CONCLUSIONS
  Spatial relationship was demonstrated between the moyamoya vessels and perivascular hemosiderin deposition particularly around the subependymal-leptomeningeal anastomosis, suggesting the mechanism for the development of cMBs in MMD. Present study further supports previous findings that cMBs potentially serve as a marker for the bleeding-prone microangiopathy in MMD. The significance of the present study lies in selecting optimal surgical candidate for preventing future hemorrhage by the presence of the cMBs, whereas current surgical indication relying on the degree of ischemia frequently fails to detect patients with future hemorrhage.
authors: Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan. Electronic address: kazumata@med.hokudai.ac.jp.
authors: Ken
authors: K
authors: Kazumata
authors: Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors: Daisuke
authors: D
authors: Shinbo
authors: Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors: Masaki
authors: M
authors: Ito
authors: Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors: Hideo
authors: H
authors: Shichinohe
authors: Department of Neurosurgery, Toyama University Graduate School of Medicine, Toyama, Japan.
authors: Satoshi
authors: S
authors: Kuroda
authors: Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors: Naoki
authors: N
authors: Nakayama
authors: Department of Neurosurgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors: Kiyohiro
authors: K
authors: Houkin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000473:pathology*; D002543:Cerebral Hemorrhage / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009072:Moyamoya Disease / Q000473:pathology*; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult
keywords: Moyamoya disease; intracranial hemorrhage; intraventricular hemorrhage; medullary artery; microbleeds; subependymal artery