Sudden onset of vomiting as a presentation of perimesencephalic subarachnoid haemorrhage.

Subarachnoid haemorrhage (SAH) makes up 1% of all attendances for acute severe headache to emergency departments, but other less common presentations may be seen. A 28-year-old man presented to the ED complaining of a 24-h history of nausea and vomiting of sudden onset, but without headache. The patient also described mild photophobia and neck stiffness. A computed tomography scan revealed perimesencephalic blood, and a subsequent angiogram was negative. This appearance is seen in cases of non-aneurysmal SAH, which often occur in younger, male, normotensive patients, and give rise to few warning symptoms. A high index of suspicion should be maintained for SAH, even in the absence of headache.