Cerebral vasospasm is one of the complications caused by<unk> . It usually happens from the third day after the aneurysm event, and reaches its peak on 5th to 7th day. There are several mechanisms proposed for this complication. Blood products released from<unk>  stimulates the tyrosine kinase pathway causing the release of calcium ions from intracellular storage, resulting in smooth muscle contraction of cerebral arteries. Oxyhaemoglobin in cerebrospinal fluid (CSF) causes vasoconstriction by increasing free radicals, endothelin-1, prostaglandin and reducing the level of nitric oxide and prostacyclin. Besides, the disturbances of autonomic nervous system innervating cerebral arteries is also thought to cause vasospasm.
Subarachnoid hemorrhage
Migraine
Subdural hematoma
Meningitis
Cerebral venous sinus thrombosis
Migraine 
ROSAH syndrome
Epidural hematoma