Dissecting basilar artery aneurysm in Marfan syndrome: case report.

A 35-year-old man with Marfan syndrome presented to the emergency room with a severe occipital headache of several hours duration . The headache differed from his usual migraine headaches both in quality and in unresponsiveness to Cafergot. The patient's medical history included repair of an ascending aortic aneurysm and replacement of a bicuspid aortic valve 2112 years previously. The patient was receiving chronic anticoagulant therapy. A noncontrast enhanced CT of the brain obtained on admission was unremarkable. Concurrent lumbar puncture yielded CSF with 628 RBCjmm , 2 WBCjmm , and subsequently negative Gram stain and cultures . Although a traumatic lumbar puncture was a consideration, a cerebral arteriogram was performed because of clinical suspicion of a vascular lesion. The arteriogram showed a fusiform aneurysm of the basilar artery extending into the left superior cerebellar artery and the left posterior cerebral artery (Figs. 1 A and 1 B). The patient became briefly unresponsive the day after admission. A repeat lumbar puncture revealed grossly bloody CSF with 2,730,000 RBCjmm and 10,700 WBCjmm . Anticoagulant therapy was discontinued. The subsequent unenhanced CT scan of the brain demonstrated subarachnoid blood in the basal cisterns . The patient died on the 14th day of hospitalization. Postmortem examination of the brain confirmed a basilar artery and contiguous vessel aneurysm. Subarachnoid hemorrhage was present around the brainstem and rostral spinal cord . Histologic sections showed an intimal tear in the basilar artery with dissection and transmural rupture . Most of the dissection plane was within the media of the basilar artery (Fig . 1 C). Sections of the basilar (Fig . 1 D) and systemic arteries showed multiple foci of cystic medial necrosis, consistent with Marfan syndrome.