Classification and pathogenesis of cerebral hemorrhages after thrombolysis in ischemic stroke

Background and Purpose - Brain hemorrhage after ischemic stroke is a serious complication of treatment; however, its pathology is poorly understood. A classification based on brain imaging may help to better understand and avoid causal factors. Methods - Review of the results of controlled randomized trials and the available literature. Results - Hemorrhagic infarctions have no impact on clinical outcome and are probably not associated with the thrombolytic itself and the type of reperfusion strategy. They are associated with the extent of ischemic damage and most probably to an ischemic vasculopathy. Parenchymal hematomas are often clinically relevant. Their incidence is affected by the thrombolytic itself, the type, and probably the time point of reperfusion strategy. The loss of hemostatic control seems important in their pathogenesis. Extraischemic hematomas (remote from the infarct), unique or multiple, suggest pre-existing brain pathology, especially cerebral amyloid angiopathy. Conclusions - The radiological description of 3 different types of brain hemorrhage is useful to better understand the specific pathology and the impact on clinical outcome. It may help to avoid clinically relevant brain hemorrhages.