Negative Fluid-Attenuated Inversion Recovery- Based Intravenous Thrombolysis Using Recombinant Tissue Plasminogen Activator in Acute Stroke Patients with Unknown Onset Time

Approximately 25% of acute stroke patients were excluded from intravenous thrombolysis using recombinant tissue plasminogen activator (IV-tPA) because of unknown onset time. Recent studies have shown that patients with unknown onset time would be able to receive IV-tPA when showing no ischemia on fluid-attenuated inversion recovery (negative FLAIR). The present study evaluated the safety and feasibility of IV-tPA in patients with unknown onset time and negative FLAIR compared to those with standard IV-tPA.

Stroke patients with unknown onset time were prospectively enrolled. Only patients with an occlusion of the internal carotid artery (ICA) and/or middle cerebral artery (M1 and M2) with a Diffusion-Weighted Imaging-Alberta Stroke Program Early CT Score (DWI-ASPECTS) ≥5 were analyzed. IV-tPA was performed within 3 h from the 'first found abnormal time' if the patient showed negative FLAIR. Standard IV-tPA patients were extracted from our registry as controls after having been matched by age and occluded artery to the negative FLAIR (N-F) group.