A CASE OF DISSECTION OF INTRACRANIAL CEREBRAL-ARTERIES WITH SEGMENTALMEDIOLYTIC ARTERITIS

The intravital diagnosis of intracranial arterial dissection is not al ways possible due to atypic and non-specific clinical and radiological presentations. The postmortem pathological examination of cerebral bl ood vessels is therefore necessary to establish or confirm the presenc e of a dissecting aneurysm of intracranial arteries. Most of the descr ibed cases showed no significant underlying vascular pathology. Here w e present the case of a 24-year-old women who died 5 days after admiss ion to the hospital for a rapidly developing right-sided hemisyndrome. Neuroradiological examination had revealed ill-defined bifrontal hypo dense lesions and angiographic findings were compatible with a dissect ion of the left extracranial internal carotid artery with embolic subo cclusion of both anterior cerebral arteries. The pathological evaluati on ruled out a thromboembolic occlusion of cerebral arteries and an ex tracranial internal carotid artery dissection but showed an extended d issecting process of variable age in the anterior circulation of the c ircle of Willis. The dissected vessels showed pathological changes cha racteristic of segmental mediolytic ''arteritis'' [Slavin and Gonzalez -Vitale 1976]. To our knowledge this is the first report on intracrani al arteries being affected by this pathologic entity. Our case illustr ates the importance of a postmortem examination of dissecting aneurysm s of intracranial arteries. Careful serial section studies of dissecte d intracranial arteries in young subjects should be performed and may allow for a better understanding of the vascular pathology underlying the dissection processus.