The cornerstone of
acute ischemic stroke treatment relies on rapid clearance of an offending
thrombus in the cerebrovascular system. There are various drugs and different methods of assessment to select patients more likely to respond to treatment. Current clinical guidelines recommend the administration of intravenous
alteplase (following a brain noncontract CT to exclude
hemorrhage) within 4.5 hours of
stroke onset. Because of the short therapeutic time window, the risk of
hemorrhage, and relatively limited efficacy of
alteplase for large clot burden, research is ongoing to find more effective and safer reperfusion
therapy, as well as focussing on refinement of patient selection for acute reperfusion treatment. Studies using advanced imaging (incorporating perfusion CT or diffusion/perfusion MRI) may allow us to use thrombolytics, or possibly endovascular
therapy, in an extended time window. Recent clinical trials have suggested that
Tenecteplase, used in conjunction with advanced imaging selection, resulted in more effective reperfusion than
alteplase, which translated into increased clinical benefit. Studies using
Desmoteplase have suggested its potential benefit in a sub-group of patients with large artery occlusion and salveageable tissue, in an extended time window. Other ways to improve acute reperfusion approaches are being actively explored, including endovascular
therapy, and the enhancement of thrombolysis by ultrasound insonation of the clot (sono-thrombolysis).