Cortical SAH (cSAH) appears as SAH over the convexity. Trauma is the most common cause.

Etiologies of nontraumatic:

● pial AVMs

● dural AV fistulas

● cerebrovascular arterial dissection

● dural or cortical venous thrombosis

● vasculitis

● reversible cerebral vasoconstriction syndrome (RCVS), AKA Call-Fleming syndrome, a group of
disorders sharing the cardinal clinical and angiographic features of reversible segmental multifocal
cerebral vasoconstriction with severe headaches, focal ischemia, and/or seizures. May present
as a hemorrhage restricted to a cortical sulcus

● PRES 

● [[cerebral amyloid angiopathy]] (CAA)

● coagulopathies

● brain tumors (primary or metastatic)