A 45 years old hypeensive male presented with sudden onset severe headache, vomiting and neck stiffness. On examination he didn't have any focal neurological deficit. His CT scan showed blood in the Sylvain fissure. The probable diagnosis is

*Most unruptured intracranial aneurysms are asymptomatic. *Symptoms are usually due to rupture and resultant SAH.*At the moment of aneurysmal rupture with major SAH, the ICP suddenly rises.*This may causes sudden transient LOC, preceded by a brief moment of excruciating headache.*In 10% of cases, it causes LOC.*The patient often calls the headache "the worst headache of my life"; *The headache is usually generalized, often with neck stiffness, and vomiting is common.*Although sudden headache in the absence of focal neurologic symptoms is the hallmark of aneurysmal rupture, focal neurologic deficits may occur. *Anterior communicating aery or MCA bifurcation aneurysms may rupture into the adjacent brain or subdural space and form a hematoma large enough to produce mass effect. *The deficits that result can include hemiparesis, aphasia, and abulia.(Ref: Harrison's 18/e p3296, 17/e p1727)