A patient presents with sudden headache and vomiting and unconsciousness. The diagnosis is

• MC 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 neurological 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 cranial nerve palsy: Aneurysm at junction of PCA and ICA −− Sixth nerve palsy: Aneurysm in cavernous sinus −− Occipital and posterior cervical pain: Inferior cerebellar artery aneurysm −− Pain in or behind the eye: MCA aneurysm Diagnosis • Non contrast CT scan: Investigation of choice (Lumbar puncture is not indicated prior to an imaging procedure) • CSF picture: Hallmark of aneurysmal rupture is blood in CSF (Xanthochromic spinal fluid)