Sub Arachnoid Hemorrhage Most common cause : Trauma >Spontaneous rupture of Berry aneurysm Clinical features Sudden transient loss of consciousness (occurs in nearly half of the patients) Excruciating severe headache: presenting complaint in 45% of cases (worst headache of patients life) more common upon regaining consciousness when loss of consciousness is associated. Neck stiffness and vomiting are common associations Focal neurologicalal deficit : uncommon Sudden headache in the absence of Focal neurological deficit is the Hallmark of aneurysmal rupture Associated prodromal symptoms (suggest location of progressively enlarging unruptured aneurysm) Third nerve cranial nerve palsy :Aneurysm at junction of PCS and ICA Sixth nerve palsy :Aneurysm in cavernous sinus Occipital and posterior cervical pain: Inferior cerebellar aery aneurysm Pain in or behind the eye :MICA aneurysm Ref: Sabiston 20th edition Pgno :1918