Animal models of SAH and their translation to clinical SAH

Animal models of stroke may be useful for elucidating mechanisms of disease, but they have arguably not been particularly successful at predicting what treatments will be successful for ischemic stroke in humans. Animal models of subarachnoid hemorrhage also have been developed in rodents, dogs, and nonhuman primates. These models mimic angiographic vasospasm and some aspects of subarachnoid hemorrhage such as the transient global ischemia that sometimes occurs at the time of rupture of an aneurysm. Since the detailed acute and delayed pathologic effects of subarachnoid hemorrhage on human brain are not well delineated, how the animal models replicate this is unknown. Nevertheless, meta-analysis of the literature suggests that clinical trials of drugs for angiographic vasospasm in humans have been effective, and that some animal models accurately reflect what the effects of drugs are in humans. Analysis of animal models and comparison of drug effects on angiographic vasospasm in humans and animals suggest injection of autologous blood into the basal cisterns; assessment of vasospasm more than 3 days after the injection and intrathecal delivery of drugs may be better ways to study drugs in animals, in terms of translation to success in humans.