Subarachnoid haemorrhageBMJ 2009; 339 doi: https://doi.org/10.1136/bmj.b2874 (Published 21 August 2009) Cite this as: BMJ 2009;339:b2874
- Graeme J Hankey, consultant neurologist and head of stroke unit1, clinical professor2,
- Mark R Nelson, chair of general practice3, professorial fellow4
- 1Department of Neurology, Royal Perth Hospital, Perth, WA6001, Australia
- 2School of Medicine & Pharmacology, University of Western Australia, Perth
- 3School of Medicine, University of Tasmania, Hobart, Tasmania
- 4Menzies Research Institute, University of Tasmania, Hobart, Tasmania
- Correspondence to: G J Hankey
Spontaneous (non-traumatic) subarachnoid haemorrhage accounts for about 5% of strokes and often occurs at a fairly young age. The usual cause is a ruptured intracranial aneurysm.
A 45 year old woman, well known to you as she frequently attends with migraine, has secured an appointment at the end of your Friday list. She reports her “worst migraine ever” and on specific questioning reports a sudden onset occipital headache now generalised with associated vomiting. She requests analgesia and an antiemetic so that she can “sleep it off at home” and has brought her son to drive her home.
How common is it?
The incidence of subarachnoid haemorrhage is about 7 per 100 000 person years1
On average a full time general practitioner with a list of 2000 patients will see one patient with the condition every seven years
Subarachnoid haemorrhage is missed in 20-50% of patients at first presentation2
Why is it missed?
Subarachnoid haemorrhage may be missed because the cardinal symptom—sudden, severe headache—is not present in a quarter of patients, and even when it is present the characteristic sudden onset might not be made known to the doctor (as patients tend to focus on severity) or the doctor may attribute the headache to a more common cause of headache with an atypically rapid onset (such as tension headache, sinusitis, cervicogenic headache, migraine) or to primary thunderclap headache, primary exertional headache, or sex headache. Among patients who present to general practice with sudden headache alone, subarachnoid haemorrhage is the cause in 1 in 10.2 3 Subarachnoid haemorrhage may also be missed because …