Moyamoya disease in twins.

Tc-99m HMPAO SPECT was used to evaluate regional blood flow in one monozygotic twin who had angiographically proven moyamoya disease. Focal and global reduced regional cerebral perfusion were observed in both patients with Tc-99m HMPAO SPECT studies. There was good correlation between the localization and degree of regional cerebral blood flow abnormalities and the severity and stage of clinical symptoms on angiography. These results suggest that Tc-99m HMPAO SPECT is a useful method in the detection of hemodynamic abnormalities in moyamoya disease.