Which of the following is the most common cause of late neurological detrioration in case of cerebrovascular accident?

Vasospasm: Narrowing of the aeries at the base of the brain following SAH occurs regularly This vasospasm causes symptomatic ischemia and infarction in approximately 30% patients and is the major cause of delayed morbidity or death Signs of ischemia appear 4-14 days after the hemorrhage, most frequently at about 7 days. Ref: Harrisons 19th edition Pgno: 1785