Background and purposeThe aim of the study was to evaluate whether leukoaraiosis (LA) severity is associated with earlier neurological outcome in acute stroke patients undergoing mechanical thrombectomy. Materials and methodsIn this retrospective multicenter study, we evaluated 273 acute stroke patients treated with mechanical thrombectomy. LA severity was graded as 0–2 (absent-to-moderate) versus 3–4 (severe) according to the van Swieten scale. The main clinical outcome was the proportion of early neurological improvement and early neurological deterioration. Early neurological improvement was defined as a decrease of≥4 points on the NIHSS, or an NIHSS score of zero 24hours after baseline assessment. Early neurological deterioration was defined as an increase of≥4 points on the NIHSS 24hours after baseline assessment. ResultsThere was a significantly lower early neurological improvement rate (17.1% versus 39.2%; P=0.006) and non-significantly higher early neurological deterioration rate (29.3% versus 17.7%; P=0.084) in patients with severe LA (sLA) compared with patients with absent-to-moderate LA. In multivariable analysis, sLA was inversely associated with early neurological improvement (OR, 0.31; 95% CI, 0.13–0.78; P=0.012). There was no significant association of sLA with early neurological deterioration. However, in patients without symptomatic intracranial hemorrhage, sLA was an independent predictor of early neurological deterioration (OR, 2.65; 95% CI, 1.09–6.45; P=0.032). ConclusionssLA is a significant negative predictor of early neurological improvement and is an independent predictor of early neurological deterioration in patients without symptomatic intracranial hemorrhage.