[A case of chorea gravidarum with moyamoya disease].

A 16-year-old girl developed acute left choreic movements during her fourth week of pregnancy. She had sometimes had transient ischemic attacks since she was 10 years old. During the eighth week of pregnancy, a brain MRI showed old ischemic lesions deep in the right frontal white matter. Her angiograph revealed a complete obstruction of the terminal portion of the right internal carotid artery with a developed moyamoya net work. After her abortion, all involuntary movements completely subsided. The choreic movements might have been caused not only by ischemia, but also by enhanced dopaminergic sensitivity mediated by elevations in female sex hormones due to pregnancy.