) Puff of smoke appearance on cerebral angiography is seen in Moyamoya disease. Fig. 32: Puff of smoke appearance on cerebral angiography is seen in Moyamoya disease Moyamoya disease Moyamoya disease is a progressive, occlusive disease of the cerebral vasculature with particular involvement of the circle of Willis and the arteries that feed it. Steno- occlusive areas are usually bilateral The term moyamoya (Japanese for "puff of smoke") refers to the appearance on angiography of abnormal vascular collateral networks that develop adjacent to the stenotic vessels. Pathology: Characterized by intimal thickening in the walls of the terminal portions of the internal carotid vessels bilaterally. The proliferating intima may contain lipid deposits. The anterior, middle and posterior cerebral arteries that emanate from the circle of Willis may show varying degrees of stenosis or occlusion. Associated with fibrocellular thickening of the intima. waving of the internal elastic lamina, and thinning of the media. Clinical Features: Ranging from being asymptomatic to manifesting as transient events to causing severe neurologic deficits. Adults experience hemorrhage more commonly Cerebral ischemic events are more common in children. Diagnosis Cerebral angiography is the criterion standard for the diagnosis of moyamoya disease. Angiographic sign: "Puff of smoke" or "Hazy foggy appearance Prognosis: Death from with moyamoya disease is usually from hemorrhage. The outcome depends on the severity and nature of the hemorrhage Prognosis depends on recurrent attacks">