Cortical blindness as a manifestation of basilar artery occlusion

Three patients with cortical blindness resulting from simultaneous ischemia of both occipital lobes are presented. In all cases there was clinical and/or angiographic evidence of basilar artery occlusion. Visual agnosia was present in all three patients. The cortical blindness was completely transient in one case, partially transient in the second, and permanent in the third. The pathogenesis of the simultaneous loss of both visual half-fields in basilar artery occlusion is discussed and compared with the bilateral homonymous hemianopia resulting from successive, bilateral occlusions within the internal carotid arterial systems.