<prompt> Commonest cause of non traumatic subarachnoid hemorrhageIdiopathicBerry aneurysm ruptureHypertensionAV malformation  <response>: Ans. b Berry aneurysm ruptureRef: Bailey 26th 320 Schwartz 10th 1730 Most common cause of SAH - TRAUMA Most common cause of non traumatic subarachnoid hemorrhage - BERRY ANEURYSM RUPTURE 