[Diagnostic challenges in a man with subarachnoidal haemorrhage].

A 39-year-old man with multiple sclerosis was admitted to the Neurological department because of sudden and intense headache, photophobia, nausea and vomiting. A subarachnoidal haemorrhage was suspected and cerebral CT scanning showed small amounts of subarachnoidal blood distributed symmetrically over both cerebral hemispheres - an unusual location for aneurismal bleeding. Liquor analysis revealed erythrocytes, positive bilirubin and slightly elevated protein. Subsequent cerebral MRI showed no signs of aneurysm, vascular malformation, venous sinus thrombosis or infarction. An intraarterial cerebral angiography was then performed and showed bilateral widespread segmental vasoconstriction in the anterior, middle and posterior cerebral arteries. A diagnostic workup on systemic vasculitis was negative. The patient's good general condition in spite of extensive angiographic findings rendered the diagnosis cerebral vasculitis unlikely. A state of reversible cerebral segmental vasoconstriction was suspected and the patient was treated with the calcium antagonist nifedipine and observed for four weeks. Cerebral angiography was then repeated and found to be normal. This case report highlights a less recognized and probably underdiagnosed cause of subarachnoidal bleeding.