Intravenous Thrombolysis Increases the Rate of Dramatic Recovery in Patients with Acute Stroke with an Unknown Onset Time and Negative FLAIR MRI.

BACKGROUND AND PURPOSE: The safety and feasibility of intravenous thrombolysis using recombinant tissue plasminogen activator (IV-tPA) were retrospectively compared between patients with unknown onset time and no ischemia on fluid-attenuated inversion recovery (negative FLAIR) and patients receiving standard therapy.

METHODS: Acute stroke patients with unknown onset times were treated using IV-tPA if they had: negative FLAIR; internal carotid artery and/or middle cerebral artery occlusion; and a diffusion-weighted imaging (DWI)-Alberta Stroke Programme Early CT Score ≥5. All patients had abnormal DWI scans indicating an acute stroke. IV-tPA therapy was performed within 3-4.5 h of first found abnormal time (FAT). Patients who were admitted within 3-4.5 h of FAT and did not receive IV-tPA therapy despite the same imaging findings were extracted from our registry as controls.

RESULTS: There were 24 patients in the IV-tPA group and 28 in the control group. None of the IV-tPA group and 1 (4%) of the control group patients experienced symptomatic intracerebral hemorrhage (P = 1.000). The rate of dramatic recovery at day 7 (≥10-point reduction in the total National Institutes of Health Stroke Scale [NIHSS] score or NIHSS score of 0-1) was 46% in the IV-tPA group and 18% in the control group (P = .038). Multivariate regression analysis revealed that IV-tPA was an independent predictor of dramatic recovery at day 7 (odds ratio 13.74; 95% confidence interval, 1.95-96.92; P = .009).

CONCLUSIONS: IV-tPA may safely increase the rate of dramatic recovery in acute stroke patients with unknown onset times and negative FLAIR.