Abstract
A 17-year-old boy with known moyamoya disease developed an acute subdural hematoma after a mild head trauma. He had been confined to a wheelchair with contracture in the upper and lower extremities due to juvenile rheumatoid arthritis since age 1 year. He had undergone encephalo-duro-arteriosynangiosis (EDAS) on the right and encephalo-myo-synangiosis (EMS) on the left at 13 years of age. He was admitted with headache, nausea, and vomiting after a fall from his wheelchair at age 17. Computed tomography on admission showed a large acute subdural hematoma in the right frontotemporal region but no bleeding at the EDAS or EMS sites. Cerebral angiography 12 weeks after the head trauma revealed a remarkable reduction in the spontaneous transdural external-internal carotid anastomoses in the right frontal region. The acute subdural hematoma was probably caused by rupture of the spontaneous transdural anastomoses.
