Acute primary cerebral angiitis mimicking basilar artery dissection.

Two patients presented with acute severe occipital headache, neck pain, nausea, vomiting and blurred vision. In both patients angiograms of the posterior circulation showed focal narrowing of the basilar artery, thus basilar artery dissection was considered. Urgent magnetic resonance imaging (MRI) was unavailable. On the basis of additional angiography of the anterior circulation and control angiograms after 4 and 6 weeks, primary cerebral angiitis was the most probable diagnosis. Treatment with corticosteroids resulted in rapid clinical and angiographic improvement. We conclude that, when MR techniques are unavailable or inconclusive, presumption of basilar dissection on the base of clinical features, Doppler studies, Duplex scanning and angiography of the vertebro-basilar system should be confirmed by additional carotid angiography in order to exclude diffuse cerebral angiitis.