Non-aneurysmal subarachnoid hemorrhage in two patients with systemic lupus erythematosus: Case reports and literature review.

We describe two cases of non-aneurysmal subarachnoid hemorrhage (SAH) and multifocal stenosis of the intracranial arteries. The patients' histories together with magnetic resonance angiography, vessel wall imaging and transcranial Doppler (TCD) indicated that the SAH was due to vasculitis or reversible cerebral vasoconstriction syndrome (RCVS). Differential diagnosis of vasculitis and RCVS is important because the treatment strategies are different: immunosuppressants in vasculitis and calcium channel blockers in RCVS. Vessel wall magnetic resonance imaging and TCD can be helpful in differentiating them.