Cerebral vasospasm (CVS) is an extraordinarily prolonged period of vasoconstriction following spontaneous subarachnoid hemorrhage (SAH), with gradual pathological and histological changes in the cerebral arteries over time. The annual incidence of spontaneous subarachnoid hemorrhage is approximately 6/100,000, of which approximately 65% to 80% are caused by ruptured intracranial aneurysms. The prognosis for aneurysmal subarachnoid hemorrhage is poor, with death or disability in 50% to 75% of patients. cvs is a common and high-risk complication after SAH, with an incidence of 30% to 90%. CVS can cause severe local cerebral ischemia or delayed ischemic brain damage, even leading to cerebral infarction, and is the main cause of disability and death in SAH. Meanwhile, brain edema caused by extensive ischemia and hypoxia of the brain can increase intracranial pressure. However, once the narrowed intravascular lumen is tolerant to the ischemia in the extreme phase of spasm, it can be restored to its original state after 3 to 4 weeks.CVS can also occur secondary to traumatic brain injury.