Mouse genetic background is associated with variation in secondary complications after subarachnoid hemorrhage

Spontaneous subarachnoid hemorrhage (SAH) is a form of hemorrhagic stroke that accounts for approximately 7 % of all strokes worldwide and is associated with mortality in approximately 35 % of cases and morbidity in many of the survivors. Studies have suggested that genetic variations may affect the pathophysiology of SAH. The goal of this study was to investigate the effect of mouse genetic background on brain injury and large artery vasospasm after SAH. SAH was induced in seven inbred strains of mice, and the degree of large artery vasospasm and brain injury was assessed. After 48 h, SAH mice showed a significant reduction in middle cerebral artery diameter and increased neuronal injury in the cerebral cortex compared with sham-operated controls. Mouse strains also demonstrated variable degrees of vasospasm and brain injury. This data suggests that different genetic factors influence how much brain injury and vasospasm occur after SAH. Future investigations may provide insight into the causes of these differences between strains and into which genetic contributors may be responsible for vasospasm and brain injury after SAH.