Impacts of Cigarette Smoking and Basilar Artery Flow on 1-year Recovery in 3-Month survivors of Intracranial Vertebrobasilar Artery Dissection-related Ischemic Stroke.

OBJECTIVE Intracranial vertebrobasilar artery dissection (iVBD) is an important etiology for posterior circulation ischemic stroke (PCS); however, its long-term functional outcome has been seldom reported. The present study aimed to elucidate the functional outcomes and the predictors of poor functional recovery at 1-year after iVBD-caused PCS. METHODS Patients with iVBD-caused PCS who had been recruited in the Stroke Registry of Taipei Veterans General Hospital between January 1, 2012 to February 28, 2014 were included. Multivariate analysis was used to detect predictors for poor 1-year functional recovery [modified Rankin Scale (mRS) ≥ 4]. RESULTS Sixty patients [age: 66.3±15.1 years; 45(75%) men] were included. At 1-year after stroke, 61.7% of patients had good functional status (mRS 0-1); however, 21.6% of patients were disabled (mRS≥4). Multivariate analyses showed that older age, cigarette-smoking history and low basilar-artery (BA) flow velocity were significantly associated with poor functional recovery independent of stroke severity at admission. The results also revealed a synergistic effect of cigarette-smoking and low BA flow on poor 1-year functional recovery: patients with both, a history of cigarette-smoking and low BA flow (≤24cm/s) had an odds ratio of 276.1 (p=0.007) leading to poor 1-year functional recovery, versus patients with neither cigarette-smoking history nor low BA flow. CONCLUSIONS Our results suggest that adequate blood flow may be key to functional recovery after iVBDcaused PCS. Methods to improve blood flow and tissue perfusion after iVBD-caused PCS should be considered in the future clinical studies with the purpose to improve functional recovery in these patients.