Surgery Traumatic Brain Injury 6e378705 Most common cause of non traumatic subarachnoid hemorrhage - A Idiopathic B Berry aneurysm rupture C Hypertension D AV malformation High-Yield Explanation Ans. is 'b' i.e., Berry aneurysm o Excluding head trauma, most common cause of subarachnoid hemorrhage is rupture of a saccular (Berry) aneurysm.