Ruptured berry aneurysm of the anterior ethmoidal artery associated with bilateral spontaneous internal carotid artery occlusion in the neck. Case report.

A unique case is described of subarachnoid hemorrhage from a ruptured berry aneurysm of the right anterior ethmoidal artery, and its pathogenesis is discussed. The literature suggests an increased incidence of posterior circulation aneurysms in moyamoya disease, of contralateral anterior circulation aneurysms in agenesis of the carotid artery, and of aneurysms at various sites in spontaneous and iatrogenically acquired obstructions of the internal carotid artery. In addition to congenital anomalies of the vessel wall and systemic hypertension, increased regional blood flow should be regarded as an important factor in the generation of berry aneurysms.