Late neurological improvement during hospitalization is a predicative factor for acute ischemic stroke.

Purpose: This study aimed to investigate whether late neurological improvement (LNI) during hospitalization serves as a favorable prognostic indicator in patients with acute ischemic stroke (AIS) and to identify the predictors of LNI.

Methods: We retrospectively analyzed data from the Safe Implementation of Treatments in Stroke (SITS) registry at two stroke centers in Egypt. LNI was defined as the lack of early neurological improvement (ENI) within 24 h after admission, accompanied by neurological improvement within 7 days of hospitalization. Multivariate logistic regression was employed to analyze the factors influencing favorable prognosis (modified Rankin Scale score 0-2) and LNI.

Results: A total of 834 patients with AIS were included in this study, of which 130 (15.6%) exhibited LNI. Among these, 99 (76.2%) achieved favorable outcomes. Both ENI (OR = 6.756, 95% CI 3.355-13.603, P < 0.001) and LNI (OR = 5.760, 95% CI 3.146-10.545, P < 0.001) were independently associated with favorable prognosis after adjustment. Predictors of LNI in multivariable-adjusted logistic regression included younger age (OR = 0.973, 95% CI 0.957-0.990, P = 0.001), higher baseline National Institutes of Health Scale (NIHSS) score (OR = 1.196, 95% CI 1.146-1.248, P < 0.001), and rt-PA treatment (OR = 1.953, 95% CI 1.206-3.163, P = 0.006).

Conclusions: Approximately three-quarters of patients with LNI are expected to achieve good outcome. LNI was a favorable prognostic indicator in patients with AIS and younger age, higher baseline NIHSS score and rt-PA treatment predicted LNI.