A 26 year old man presents with a persistent, severe, throbbing occipital headache for 3 days and fever for 2 days. He was woken up by the headache. He is otherwise asymptomatic and has never experienced a similar headache before. His medical, family and drug histories are completely unremarkable. A full blood count is found to be normal.
The CT scan appears normal, with no obvious mass lesions or features suggestive of intraventricular or subarachnoid haemorrhage.
INR: 1.0 (normal) APTT: 28s (normal) TT: 12s (normal)
Appearance: uniformly blood stained Spectrophotometry: xanthrochromia noted Microscopy: Field full of RBC / hpf Protein: 42 mg/dl Glucose: 70 mg/dl (RBS: 120 mg/dl) Gram stain: negative
An intracranial aneurysm is noted in the region of the anterior communicating artery. No other abnormalities are noted.