Background and purpose
Smoking and hypertension are risk factors for aneurysmal subarachnoid hemorrhage (aSAH), whilst excessive alcohol consumption is less consistently linked with aSAH. Perimesencephalic hemorrhage (PMH) is a benign subset of non-aneurysmal subarachnoid hemorrhage. The exact cause of PMH is unknown, and its risk factor profile may help to elucidate the pathogenesis. The influence of smoking, hypertension and excessive alcohol consumption on the occurrence of PMH was studied.