Differences and Similarities Between Spontaneous Dissections of the Internal Carotid Artery and the Vertebral Artery

Background and Purpose-To compare potential risk factors, clinical symptoms, diagnostic delay, and 3-month outcome between spontaneous internal carotid artery dissection (sICAD) and spontaneous vertebral artery dissection (sVAD). Methods-We compared patients with sICAD (n=668) and sVAD (n=302) treated in 3 university hospitals. Results-Patients with sICAD were older (46.3 +/- 9.6 versus 42.0 +/- 10.2 years; P<0.001), more often men (62.7% versus 53.0%; P=0.004), and presented more frequently with tinnitus (10.9% versus 3.4%; P<0.001) and more severe ischemic strokes (median National Institutes of Health Stroke Scale, 10 +/- 7.1 versus 5 +/- 5.9; P<0.001). Patients with sVAD had more often bilateral dissections (15.2% versus 7.6%; P<0.001) and were more often smokers (36.0% versus 28.7%; P=0.007). Thunderclap headache (9.2% versus 3.6%; P=0.001) and neck pain were more common (65.8% versus 33.5%; P<0.001) in sVAD. Subarachnoid hemorrhage (6.0% versus 0.6%; P<0.001) and ischemic stroke (69.5% versus 52.2%; P<0.001) were more frequent in sVAD. After multivariate analysis, sex difference lost its significance (P=0.21), and all other variables remained significant. Time to diagnosis was similar in sICAD and sVAD and improved between 2001 and 2012 compared with the previous 10-year period (8.0 +/- 10.5 days versus 10.7 +/- 13.2 days; P=0.004). In sVAD, favorable outcome 3 months after ischemic stroke (modified Rankin Scale, 0-2: 88.8% versus 58.4%; P<0.001), recurrent transient ischemic attack (4.8% versus 1.1%; P=0.001), and recurrent ischemic stroke (2.8% versus 0.7%; P=0.02) within 3 months were more frequent. Conclusions-sICAD and sVAD patients differ in many aspects. Future studies should perform separate analyses of these 2 entities.