Clinical Course And Radiological Outcome Of Mild Stroke Patients Treated And Not Treated With Thrombolysis

Background: Around 30% of patients with acute stroke are excluded from thrombolysis because of mild or improving symptoms, but some of these patients don’t achieve a good recovery. We compared the clinical and radiological course in a cohort of 239 patients with mild stroke treated and not treated with thrombolysis in the same institution. Methods: We studied all patients with ischemic stroke admitted within 6 hours of symptom-onset with previous mRS≤1 and mild symptoms (NIHSS≤5) at arrival or during initial evaluation. We compared the baseline characteristics, clinical course (NIHSS), radiological outcome (final DWI lesion volume), incidence of symptomatic intracranial hemorrhage (sICH) and favourable 3-month outcome (mRS≤1) of patients treated with thrombolysis (123 tPA only and 9 endovascular interventions) or not treated (n=107). Results: Treated patients had greater clinical severity at presentation and after imaging and arrived to the hospital faster than not treated patients. In a general linear model of repeated measures, their course was significantly different (p=0.03) and thrombolised patients improved more during hospitalization. Patients with significant neurological improvement (NIHSS score>1) had more severe strokes at presentation but similar outcome, and were more often treated with tPA (p<0.001). Infarct volume was significantly correlated with NIHSS score especially at day 1. Despite the differences in the initial clinical severity, final infarct volume was similar in treated and not treated patients. The rate of sICH was similar in both groups. Outcome at 3-months was associated to past history of stroke, glucose levels and deterioration during hospital stay. On multivariate analysis, thrombolysis remained associated to neurological improvement (OR 4.34;p<0.001) and was non-significantly associated to greater chances of good functional outcome at 3-months (OR 2.38;p=0.099). Conclusions: In patients with mild stroke thrombolysis was safe and was associated to better neurological course. Overall, these results suggest that patients presenting with mild symptoms do benefit from thrombolysis.