Moyamoya Disease

Definition

Moyamoya disease is a rare, progressive cerebrovascular disorder associated with blocked arteries in the circle of Willis at the base of the brain. “Moyamoya” is a Japanese term that means “puff of smoke,” which describes the appearance of the mass of small vessels that compensate for the vascular obstruction.

Current Knowledge

Although Moyamoya disease was first described in Japan in the 1960s, it has since been found in the USA, Europe, Australia, and Africa. The disease primarily affects children, among whom the first presentation is often ischemic stroke or recurrent transient ischemic attacks (TIAs), frequently accompanied by hemiplegia or hemiparesis and seizures. It also occurs in adults, who most often experience a hemorrhagic stroke. This cause altered consciousness, aphasia and other speech deficits, cognitive impairments, sensory loss, involuntary movements, and vision changes, typically of sudden onset. Ventricular hemorrhage is common. A fatal outcome is usually...