Impact of isolated basal ganglia infarction at pretreatment DWI on outcomes after endovascular thrombectomy in acute anterior circulation stroke.

PURPOSE: Acute infarction confined to the basal ganglia (BG) is occasionally observed on baseline imaging before endovascular thrombectomy. This study aimed to investigate the impact of isolated BG infarction revealed on pretreatment DWI in a large cohort of patients with acute anterior circulation stroke who underwent thrombectomy. METHODS: We retrospectively analyzed clinical and DWI data from 328 patients who underwent thrombectomy for emergent occlusions of the intracranial internal carotid artery or the middle cerebral artery. Characteristics and treatment outcomes were compared between patients with isolated BG infarction and those with non-isolated BG infarction. Binary logistic regression analyses were performed to identify independent predictors of good outcome (90-day mRS 0-2). RESULTS: Isolated BG infarction was found in 57 patients (17.4%). Patients with isolated BG infarction had a higher incidence of underlying severe intracranial atherosclerotic stenosis (21.1% vs. 10.7%, P = 0.032) than those with non-isolated BG infarction. Successful reperfusion occurred more frequently in patients with isolated BG infarction than those with non-isolated BG infarction (93% vs. 79%, odds ratio 3.529, 95% confidence interval 1.226-10.161, P = 0.014). On multivariate logistic regression analysis, independent predictors of good outcome were age, DWI-ASPECTS, and admission NIHSS score. There was no significant difference in the rate of good outcome between the two groups (54.4% vs. 42.8%, P = 0.110). CONCLUSION: Isolated BG infarction on pretreatment DWI may predict successful reperfusion after endovascular thrombectomy in patients with acute anterior circulation stroke. In addition, our study suggested a novel finding that isolated BG infarction was more frequently associated with underlying severe ICAS than non-isolated BG infarction.