[Moyamoya disease presenting initially with mental disturbance].

Moyamoya disease usually presents itself in children as recurrent episodes of transient cerebral ischemia, such as acute motor and sensory deficits, speech disturbance, headache and seizures. Its initial symptoms rarely include mental disturbance. We experienced a nine-year-old girl with Moyamoya disease who showed choreic involuntary movements of the left upper and lower limbs. In spite of mental disturbance which began around the age of four, she had never visited hospital. CT and MRI detected multiple ischemic lesions in the frontal, parietal and occipital areas. SPECT demonstrated low perfusion of these regions as well as of the right corpora striata, which appeared to be normal in MRI. She underwent right and left superficial temporal artery-middle cerebral artery (STA-MCA) anastomoses with an interval of three months. The choreic movement completely disappeared but her intelligence showed no improvement. The cerebral blood flow increased, but there was no change in the infarction area. Moyamoya disease should be considered in the differential diagnosis of mental disturbance in young children.