Psychomotor delay, a possible rare presentation of moyamoya disease.

Moyamoya disease is a rare, chronic cerebrovascular occlusive disease of unknown etiology. It is characterized by progressive stenosis of the arteries of the circle of Willis leading to ischemic strokes in young people and cerebral hemorrhage, which is more frequent in adults. Secondarily, an abnormal network of fine collateral vessels arises at the base of the brain. The term moyamoya refers to the angiographic appearance of the cerebral vasculature. We present such a disease in an 18-month-old Iranian girl with global developmental delay, which is a very rare presentation of moyamoya disease. She was diagnosed by magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA).