SPONTANEOUS VERTEBRAL DISSECTION - CLINICAL, CONVENTIONAL ANGIOGRAPHIC, CT, AND MR FINDINGS

Objective: The purpose of this study was to determine if typical clini cal and neuroradiologic patterns exist in patients with spontaneous ve rtebral artery (VA) dissection. Materials and Methods: The medical rec ords and neuroradiologic examinations of 14 patients with spontaneous VA dissection were reviewed. The medical records were examined to excl ude patients with a history of trauma and to record evidence of a nont raumatic precipitating event (''trivial trauma'') and presence of poss ible risk factors such as hypertension. All patients underwent convent ional angiography, 13 either CT or MRI (11 both CT and MRI), and 3 MRA . Conventional arteriograms were evaluated for dissection site, eviden ce of fibromuscular dysplasia, luminal stenosis or occlusion, and pseu doaneurysm formation, CT examinations for the presence of infarction o r subarachnoid hemorrhage, MR examinations for the presence of infarct ion or arterial signal abnormality, and MR angiograms for abnormality of the arterial signal column. Results: Seven patients had precipitati ng events within 24 h of onset of symptoms that may have been causativ e of dissection and five had hypertension. At catheter angiography, tw o patients had dissections in two arteries (both VAs in one patient, V A and internal carotid artery in one patient), giving a total of 15 VA s with dissection. Dissection sites included V1 in four patients, V2 i n one patient, V3 in three patients, V4 in six patients, and both V3 a nd V4 in one patient. Luminal stenosis was present in 13 VAs, occlusio n in 2, pseudoaneurysm in 1, and evidence of fibromuscular dysplasia i n 1. Posterior circulation infarcts were found on CT or MR in five pat ients. Subarachnoid hemorrhage was found on CT in two patients and by lumbar puncture alone in two patients. Abnormal periarterial signal on MRI was seen in three patients. MRA demonstrated absent VA signal in one patient, pseudoaneurysm in one, and a false-negative examination i n one. Repeat catheter angiography of nine VAs at an interval ranging from 2 weeks to 1 year showed progression to occlusion in two arteries , unchanged appearance in 4, and angiographic resolution in three, whi ch did not closely correlate with clinical outcome. Conclusion: No pre ferred site of dissection along the course of the VA was found in this study. CT and MR examinations of the head are frequently normal in pa tients with VA dissections. No correlation between clinical outcome an d findings at repeat angiography was demonstrated.