A Comparative Study of the Etiology of Intracranial Vertebral Artery Dissection and Carotid Artery Dissection

BACKGROUND: Both extrinsic (trauma or violent movement) and intrinsic (structural abnormality, atherosclerosis, or hemodynamic instability) factors may result in arterial dissection. The role of these factors in the origin or progression of dissection remains unclear. This study aimed to characterize the clinical features, radiologic features, and outcomes of intracranial vertebral artery dissection compared with carotid artery dissection and to determine the major causative factors. METHODS: Consecutive patients with craniocervical dissection (n=127) were retrospectively analyzed. Patients with intracranial vertebral artery dissection (n=77) and those with carotid artery dissection (n=35) were compared with respect to patient age, sex, cerebrovascular risk factors, laboratory indices, and radiologic features. RESULTS: Intracranial vertebral artery dissection was the most common craniocervical arterial dissection in our cohort (n=77, 60.6%). Body mass index in the intracranial vertebral artery dissection group was significantly greater than that in carotid artery dissection group. Clinical manifestations of intracranial vertebral artery dissection included ischemic stroke (37.7%), dizziness or vertigo (39.0%), and headache or neck pain (44.2%). Two patients had a definite history of trauma. The frontal and lateral tortuosity ratios of the vertebral basilar artery were significantly greater while the vertex angle was smaller in the intracranial vertebral artery dissection group compared with carotid artery dissection group. A positive correlation between the tortuosity ratios and subarachnoid hemorrhage and a significant inverse correlation between the tortuosity ratios and lipid parameters (high-density lipoprotein; apolipoprotein A1) were identified. CONCLUSIONS: Intrinsic causes may play a more important role in the development of intracranial vertebral artery dissection than carotid artery dissection.