Involvement of the external carotid arteries in moyamoya disease: neuroradiological evaluation of 66 patients.

Abstract

Arterial stenoses and/or occlusions in moyamoya disease are mainly localized intracranially, although some instances of stenotic lesions of the extracranial arteries have been reported in some autopsy cases. We have reviewed the angiograms of 66 patients with moyamoya disease to investigate whether stenotic lesions are present in the external carotid artery and its branches. We noticed that 13 patients had stenoses in the branches of the external carotid artery, although no occlusions were recognized. This result indicates that the arterial stenoses and/or occlusions are not confined to the intracranial arteries and that systemic factors contribute to the pathogenesis of moyamoya disease. This result also suggests that studies on specimens of the superficial temporal artery, which can be obtained easily at surgery, may reveal the molecular mechanism of intimal thickening.