Vertebral artery hypoplasia and vertebral artery dissection: a hospital-based cohort study.

OBJECTIVE

To test the hypotheses that vertebral artery hypoplasia (VAH) is associated with an increased risk of ipsilateral spontaneous vertebral artery dissection (sVAD) and that hypoplastic vertebral arteries (VAs) are more prone than dominant VAs to dissection.

METHODS

In this case-control study, the population comprised 112 patients with sVAD and 224 age- and sex-matched controls treated at a high-volume center between 2005 and 2013. VAH and sVAD were diagnosed by digital subtraction angiography combined with noninvasive imaging findings. Conditional logistic regression was performed to identify independent risk factors for sVAD. Relationships between sVAD and VAH and the likelihood of ipsilateral (vs contralateral) presentation were also assessed.

RESULTS

VAH was more frequent in patients with sVAD than in controls in univariate analysis (30.4% vs 17.4%; odds ratio [OR] 2.1; 95% confidence interval [CI] 1.2-3.6; p = 0.008) and in multivariate regression analysis adjusted for migraine, hyperhomocysteinemia, smoking, trivial trauma, prior infection, and associated connective tissue/vascular disorders (OR 2.0; 95% CI 1.1-3.5; p = 0.017). Migraine, current smoking, and trivial trauma were associated with sVAD in multivariate models. sVAD was more frequently detected in hypoplastic than dominant VAs (68.0% vs 32.0%; OR 4.1; 95% CI 1.7-9.7; p = 0.002).

CONCLUSIONS

sVAD is associated with ipsilateral VAH and occurs more frequently in hypoplastic VAs than in their normal counterparts.