POSTERIOR CIRCULATION IN MOYAMOYA DISEASE - ANGIOGRAPHIC STUDY

PURPOSE: To clarify the angiographic findings of the posterior circula tion in patients with moyamoya disease. MATERIALS AND METHODS: Seventy -six patients with idiopathic moyamoya disease were studied with conve ntional angiography. The angiographic findings were reviewed for steno -occlusive lesions, collateral vessels, and aneurysms and compared wit h the finding of parenchymal lesions on computed tomographic and magne tic resonance images. RESULTS: Of 152 posterior cerebral arteries (PCA s), 66 (43%) had a stenotic or occluded lesion. The frequency of PCA l esions statistically significantly increased with the extent of the in ternal carotid artery (ICA) bifurcation steno-occlusive lesion. As the severity of ICA stenosis increased, basal cerebral moyamoya vessels a nd transdural collateral vessels similarly increased in number, but le ptomeningeal collateral vessels decreased owing to the progressive dev elopment of more PCA lesions. Cerebral infarctions, ventricular dilata tion, and cerebral atrophy were found to increase in frequency in pati ents with steno-occlusive PCA lesions. CONCLUSION: Steno-occlusive les ions of the PCA increase in frequency proportionally with severity of ICA bifurcation steno-occlusive lesions, so that cerebral infarctions increase in frequency with the extent of the PCA lesions.