Literature Review of Aneurysmal Subarachnoid Hemorrhage from Incidence to Treatment Options

Introduction. Aneurysmal subarachnoid haemorrhage (SAH) is associated with high mortality and morbidity. Rebleeding, cerebral vasospasm (VS) with delayed cerebral ischemia (DCI) are major complications after SAH associated with poor neurological outcome. Aim of the study. To summarize the existing research data on the SAH from incidence, risk factors and clinical presentation to diagnostic, monitoring and treatment options after SAH. Materials and Methods. Literature review was carried out to identify factors associated with SAH using specific keywords (aneurysmal subarachnoid haemorrhage, rebleeding, cerebral vasospasm, delayed cerebral ischemia) in the PUBMED database. In the time period from 2000 to 2019, 34 full articles were reviewed. Results. According to the literature, the key risk factors for cerebral aneurysms and the SAH are hypertension, smoking, chronic alcohol abuse, family history of intracranial aneurysms in first-degree relatives and female sex. The key risk factor for early complication - rebleeding after SAH - is hypertension. The factors responsible for late complications - cerebral VS and DCI after SAH - are initially lower Glasgow coma scale and higher grades of Fisher scale, where grade IV and III predict cerebral VS in 31-37%. Furthermore, hyperglycaemic state, hyponatremia, hypotension and cerebral hypoperfusion, increased level of Troponin correlate with the incidence of cerebral VS and DCI. Although the golden standard to detect cerebral VS is digital subtraction angiography, CT angiography has become a routine examination. Transcranial doppler sonography is recommended and regional cerebral oximetry also seems to be promising. To avoid rebleeding for wide-necked, gigantic aneurysms or when SAH is combined with intraparenchymal hematoma, surgical clipping is preferred. For posterior circulation aneurisms, poor grade SAH and patients with age >70 years superior is endovascular treatment. To avoid late complications, the pharmacological method is used with Nimodipine. Conclusions. SAH is still associated with poor clinical outcome due to the development of early and late complications. The highest risk patients are those with low Glasgow coma scale and high grades of Fisher scale. Timely performed obliteration methods of the ruptured aneurysm are crucial and Nimodipine is the main agent to prevent cerebral VS and DCI.