Progressive cerebral occlusive disease after radiation therapy.

BACKGROUND: A case of progressive irradiation-induced cerebral vasculopathy with abnormal netlike vessels and transdural anastomoses (moyamoya syndrome) is presented. Radiological findings in an additional 40 cases reported in the literature are analyzed, and their clinical relevance is discussed. CASE DESCRIPTION: A 19-year-old woman presented with recurrent ischemic brain lesions after radiation therapy for treatment of a craniopharyngioma during childhood. Cerebral angiography 6 and 12 years after completion of radiation therapy revealed progressive cerebral arterial occlusive disease involving the internal carotid artery on either side of the circle of Willis, with abnormal netlike vessels and transdural anastomoses (moyamoya syndrome).
CONCLUSIONS: Extensive similarities between irradiation-induced cerebral vasculopathy and primary moyamoya syndrome (Nishimoto's disease) support the notion that both disorders share common pathophysiological mechanisms. The occurrence of moyamoya-like vascular changes may not depend on specific trigger mechanisms but may rather represent a nonspecific response of the developing vascular system to a number of various noxious events.