Subarachnoid Haemorrhage

Around 8% of patients presenting to the Emergency Department have a headache?

Around 25% of patients with a subarachnoid haemorrhage will die within the first 24 hours?

Atraumatic subarachnoid haemorrhage is due to an aneurysm in 20% of cases?

Perry found that a plain CT head within 6 hours of onset of headache, in neurologically normal patients, had a sensitivity of 100% for subarachnoid haemorrhage?