Clinical Features of Moyamoya Disease in the United States

Abstract

Background and Purpose-We report the clinical features and longitudinal outcome of the largest cohort of patients with moyamoya disease described from a single institution in the western hemisphere. Moyamoya disease in Asia usually presents with ischemic stroke in children and intracranial hemorrhage in adults. Methods-Our study population included all patients with moyamoya disease evaluated at a university hospital in Houston,Texas from 1985 through 1995 (nϭ35). We used Kaplan-Meier methods to estimate individual and hemispheric stroke risk by treatment status (medical versus surgical). Predictors of neurological outcome were assessed. Results-The ethnic background of our patients was representative of the general population in Texas. The mean age at diagnosis was 32 years (range, 6 to 59 years). Ischemic stroke or transient ischemic attack was the predominant initial symptom in both adults and children. Of the 6 patients with intracranial hemorrhage, 5 had an intraventricular site of hemorrhage. The crude stroke recurrence rate was 10.3% per year in 116 patient-years of follow-up. Twenty patients underwent surgical revascularization, the most common procedure being encephaloduroarteriosynangiosis. The 5-year risk of ipsilateral stroke after synangiosis was 15%, compared with 20% for medical treatment and 22% overall for surgery. Conclusions-Our observations indicate that moyamoya disease may have a different clinical expression in the UnitedStates than in Asia, and may demonstrate a trend toward a lower stroke recurrence rate and better functional outcome after synangiosis. (Stroke. 1998;29:1347-1351.)

Epidemiological Features of Moyamoya Disease in Japan

“…In an analysis of 35 patients at a university hospital in Houston, Texas from 1985 to 1995, the female-to-male ratio was 2.5, the mean age at diagnosis was 32 years, ischemic stroke and TIA were predominant initial symptoms, and no peak incidence in childhood was observed. 2) The other report from the United States includes only 22 patients with bilateral moyamoya disease. 4) The female-tomale ratio was 6.3, ischemic stroke and TIA were the predominant initial symptoms, and again, no peak incidence in childhood was observed.…”

Moyamoya disease in pediatric patients: outcomes of neurosurgical interventions

“…Whereas some authors have reported similar presentation characteristics in North American patients, 45 others have noted distinct differences from Asian populations. 1,2,57 In children, the most common presentation is cerebral ischemia. In the Scott and colleagues' 45 study of 143 pediatric patients with MMD in North America, nearly all of the patients presented with symptoms of either stroke or TIA; similar findings were revealed in European studies.…”

Optimal surgical treatment for moyamoya disease in adults: direct versus indirect bypass

“…11,13,22,25,26 Many case series have demonstrated a decrease in ischemic symptoms and/or the maintenance of cognitive abilities in patients treated with direct bypass, but these series have been composed chiefly of children and often have included patients treated with indirect bypass or a combination of direct and indirect bypasses. 4,11,13,25,34,37,43 Thus far, no study has documented overall long-term rates of ischemic events in adult patients treated solely with direct bypass. …”

“…35,39 A number of studies have provided evidence that moyamoya disease outside of Asia can represent a different phenomenon. 4,7,21,36,38 Patient ethnicities are in proportion to the ethnicities of the people in the region of diagnosis, and adult patients present with ischemic symptoms rather than intracranial hemorrhage.…”