The Research Progress Of Risk Factors Of Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage

To examine the literature on risk factors for delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage,one of the most serious complications following aneurysmal subarachnoid hemorrhage.It is very important to understand the risk factors for its prevention and treatment.Using standard search engines,including PubMed,the medical literature on risk factors for delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage was reviewed.Severe subarachnoid hemorrhage evident on computed tomography scan was the only consistent risk factor for delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage.Effects of risk factors on delayed cerebral ischemia,including age,clinical grade,rebleeding,intraventricular or intracerebral hemorrhage on computed tomography scan,acute hydrocephalus,aneurysm site and size,leukocytosis,interleukin-6 level,and cardiac abnormalities,appeared to be associated with the severity of subarachnoid hemorrhage rather than each having a direct effect.Cigarette smoking,hypertension,and left ventricular hypertrophy on electrocardiogram were associated with delayed cerebral ischemia without any relationship to subarachnoid hemorrhage.Severe subarachnoid hemorrhage evident on computed tomography scan appears to be a definite risk factor for delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage,followed by cigarette smoking,hypertension,and left ventricular hypertrophy on electrocardiogram.However,the pathogenesis of delayed cerebral ischemia is not clear.To understand the pathogenesis of delayed cerebral ischemia,further studies,especially factors not related to the severity of aneurysmal subarachnoid hemorrhage,are necessary.