Tags: Disease.
Moyamoya syndrome is a disease in which certain arteries in the brain are constricted. Blood flow is blocked by the constriction and also by blood clots (thrombosis).A collateral circulation develops around the blocked vessels to compensate for the blockage but the collateral vessels are small weak and prone to hemorrhage aneurysm and thrombosis. On X-rays these collateral vessels have the appearance of a puff of smoke (もやもや (moyamoya) in Japanese).
