[Clinical features and outcomes of 10 asymptomatic adult patients with moyamoya disease].

Recent development of non-invasive diagnostic technology, such as magnetic resonance imaging (MRI) and angiography (MRA), is believed to have made possible on increase in the diagnoses of asymptomatic moyamoya disease. However, no criteria have been established for the management of such cases. The present study aimed to clarify the natural history of asymptomatic moyamoya disease retrospectively. Ten patients were included in this study. None of them had experienced any episode due to moyamoya disease and were only incidentally diagnosed as having moyamoya disease. There were 4 males and 6 females. Their ages ranged from 30 to 67 years, with the mean age of 46.2. Cerebral angiography showed there was the tendency of disease progression in elder patients. MRI detected cerebral infarction in 3 of 10 patients (30%). Hemodynamic ischemia, such as impaired reactivity to acetazolamide and/or elevated oxygen extraction fraction, was observed in 4 of 10 patients. Only one patient underwent surgical revascularization. Antiplatelet or anticonvulsant medication was administered in 5 of 10 patients. The mean follow-up period was 4.1 years, ranging from 0.5 to 13 years. During follow-up periods, the moyamoya lesion markedly progressed and caused cerebral infarction in one patient. However, neither ischemic nor hemorrhagic stroke occurred in the other 9 patients. Multi-center nation-wide study should be planned to clarify the natural course of asymptomatic moyamoya disease and establish the management guidelines for patients with asymptomatic moyamoya disease.