Natural History and Risk Factor of Recurrent Hemorrhage in Hemorrhagic Adult Moyamoya Disease

BACKGROUND: Recurrent hemorrhage is a serious neurosurgical problem in adult moyamoya disease (MMD) patients. OBJECTIVE: To find the natural history and risk factors of recurrent hemorrhage in cases of adult hemorrhagic MMD. METHODS: One hundred seventy-six adult MMD patients presenting with hemorrhage were enrolled. Patients' medical records and radiological images were retrospectively reviewed. Clinical and radiological features of recurrent hemorrhage, and related risk factors were analyzed. Poor neurological outcome was defined as a score on the modified Rankin Scale of 4 to 6. The hemisphere in which the initial hemorrhage occurred was considered as the affected one. The mean follow-up duration was 83 months. RESULTS: The overall estimated rate of recurrent hemorrhage was 16.9%/person (95% confidence interval, 11.3%-24.8%) at 5 years and 26.3%/person (95% confidence interval, 18.5%-36.4%) at 10 years after the initial episode of hemorrhage. The affected hemisphere showed a higher recurrent hemorrhagic rate (11.7% vs 8.3%/hemisphere at 5 years, P = .09) after conservative treatment. As a result of recurrent hemorrhages, the number of patients with poor neurological outcome increased (first episode: 13.8%, second: 37.5%, third: 40.0%, fourth: 100%). The presence of intraventricular hemorrhage ( P = .05, hazard ratio = 3.32) and bilateral MMD ( P = .05, hazard ratio = 4.15) had a marginal significance for recurrent hemorrhage. Eight ischemic strokes (4.5%) including 4 postoperative infarctions were identified, and all ischemic strokes were minor stroke. CONCLUSION: During the follow-up period, recurrent hemorrhagic events continued to increase and deteriorated the patients' neurological conditions. The presence of intraventricular hemorrhage was a significant risk factor of recurrent hemorrhage.