Stroke thrombolysis at 5.5 hours based on computed tomography perfusion

A young man was admitted with sudden onset of right-sided weakness. He was assessed in the emergency department, and an immediate computed tomography (CT) perfusion study of the brain was arranged, which showed a left middle cerebral artery territory infarct with occlusion of the M1 segment. There was a significant penumbra measuring approximately 50% of the arterial territory. By the time his assessment was completed, it was 5.5 hours from the onset of symptoms. He was nonetheless administered intravenous recombinant tissue plasminogen activator (rtPA) based on the significant penumbra. He was discharged from the hospital after one week with significant residual deficit. At 2 months clinic follow-up, he showed almost complete recovery with a Modified Rankin Score of 1. We hope to demonstrate that a significant penumbra is an important determinant for good neurological recovery and outcome following stroke thrombolysis, even when patients present outside the 4.5 hours onset-to-treatment time window.