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Updated: Aug 16, 2026

Pre-Chiasmatic, Single Injection of Autologous Blood to Induce Experimental Subarachnoid Hemorrhage in a Rat Model
Published on: June 18, 2021
Sudden onset of vomiting as a presentation of perimesencephalic subarachnoid haemorrhage
Ben Caesar1, Paul M Middleton, Laurence D Watkins
1Department of Surgery, Royal Infirmary of Edinburgh, Edinburgh, Scotland.
Abstract:
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.
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