Relevance of transient ischemic attack to early neurological recovery after nonlacunar ischemic stroke

Background: We hypothesized that previous transient ischemic attack (TIA) had a favorable effect on early outcome after acute nonlacunar ischemic stroke. Methods: Data of 1,753 consecutive patients with ischemic stroke collected from a prospective hospital-based stroke registry were studied. A comparison was made of the groups with and without previous TIA. Favorable outcome included spontaneous neurological recovery or grades 0 - 2 of the modified Rankin scale at hospital discharge. Results: Previous TIA occurred in 55 (11.5%) of 484 patients with lacunar stroke and in 166 (13.1%) of 1,269 patients with nonlacunar stroke. The percentage of nonlacunar ischemic stroke patients with favorable outcome was 21.7% in those with a history of TIA compared to 15% without TIA (p < 0.03). In the lacunar stroke group, differences were not significant. In the multivariate analysis, TIA was an independent predictor of spontaneous inhospital recovery. Conclusions: Prior TIA was associated with a favorable outcome in nonlacunar ischemic stroke, suggesting a neuroprotective effect of TIA possibly by inducing a phenomenon of ischemic tolerance allowing better recovery from a subsequent ischemic stroke. Copyright (C) 2004 S. Karger AG, Basel.