The common cause of subarachnoid hemorrhage Is
*Subarachnoid hemorrhage commonly,but exclusively results from rupture of congenital berry aneurysms in the interpeduncular cistern . Subarachnoid haemorrhage, a medical emergency, is usually from a bulging blood vessel that bursts in the brain (aneurysm). It may lead to permanent brain damage or death if not treated promptly Ref Harrison20th edition pg 2567
Aerio-venous malformation
Cavernous angioma
Aneurysm
Hypeension
C.N.S