Table 1. Differential diagnosis in SAH related to aneurysmal rupture or RCVS.

	Aneurysmal SAH	SAH associated with RCVS
Onset	Hyperacute	Hyperacute
Mean age	55 years	45 years
Female/male ratio	1.5/1	3–4/1
Hunt and Hess Grade	I–V	Usually I
Location of SAH	Basilar cisterns	Convexity of brain surface
Vasospasm	Common	Uncommon
Non communicating hydrocephalus	Likely	Unlikely
Neurovascular diagnostic imaging	CTA-MRA or cerebral angiogram	Cerebral angiogram