Cerebral collaterals and stroke in patients with isolated carotid artery dissections.

To investigate potential association between collateral arterial supply and stroke in patients with isolated internal carotid artery dissection (iCeAD). We hypothesized a lower risk of stroke in patients with more robust collateral supply. This is a single-center, retrospective review of iCeAD patients between 1994 and 2018. iCeAD patients with sufficient neuroimaging data were included. Patients were categorized based on cerebral infarction (stroke) on neuroimaging. The collaterals score, ranging from 0 to 8 with higher scores indicating more robust collaterals, was assessed based on contributions from leptomeningeal arteries (0-2 points), anterior communicating artery (0-2 points) and anterior cerebral artery A1 segment (0-2 points), and posterior communicating artery (0-2 points). The study included 62 iCeAD patients, comprising 33 and 29 patients in the stroke and no stroke groups, respectively. Neurological motor deficit (p < 0.001) and internal carotid artery occlusion (p = 0.033) were independent predictors of stroke. More robust collaterals was associated with lower stroke risk (p = 0.032) in univariable analysis, but not after adjustment for baseline differences. The collaterals score performed poorly in receiver-operating characteristics (ROC) curve analysis, with area under the ROC (AUROC) curve of 0.640. A collaterals score of >4 had a sensitivity and specificity of 89.7% and 36.4% for no stroke, respectively. The covariate-adjusted AUROC curve was 0.514. Collateral circulation appeared to be a poor predictor of cerebral infarction in patients with isolated iCeAD. Future studies in larger, independent cohorts are needed to better understand the interaction of collaterals with stroke in cervical artery dissection.