Subarachnoid haemorrhage--can we do better?

Patients with subarachnoid haemorrhage often have warning symptoms which are unrecognized. Specific neurological signs such as cranial nerve palsies due to aneurysm expansion may occur. Sudden and severe 'out-of-the-blue' headache following minor haemorrhage may be misinterpreted as migraine. Focal neurological signs from secondary ischaemia may be misinterpreted as thromboembolic events. Computed tomography (CT) head scans can be misleading especially if performed too late.