The annual population incidence of a brain tumour is 0.01%. The incidence of a tumour diagnosed one year after a GP consultation for headache is 0.09%.
Here is a guide for those red flag symptoms that need urgent investigation even in the midst of a COVID-19 pandemic and which symptoms have a lower threshold for investigation but require careful monitoring.
Red flag symptoms requiring urgent investigation with the risk of tumour likely to be greater than 1% (two week referral):
- focal neurology
- significant alterations in consciousness, memory
- epileptic seizure
- history of cancer elsewhere, particularly breast, prostate or lung.
Orange flags require careful monitoring but with a lower threshold for investigation with the risk of tumour likely to be between 0.1 and 1% (discuss with neurology or order imaging if directly available and not resolving):
- new headache where a diagnostic pattern has not emerged after eight weeks from presentation. The majority of headaches presenting to general practice will be migraine.
- headache aggravated by exertion or Valsalva’s manoeuvre
- headaches that have been present for some time but have changed significantly (here interpretation may be difficult)
- new headache in a patient over 50 years of age (exclude temporal arteritis)
- headaches that wake from sleep (but migraine and cluster headache invariably wake from sleep)
- subtle personality change (history from partner).
Orange flags need regular fundoscopy as a minimum examination, blood tests are unhelpful. Discuss problems of incidental abnormalities with imaging with the patient as can cause significant anxieties and can be as high as 10%. MRI is the investigation of choice but it could be argued that if a tumour is of sufficient size to give headache it will be visible on CT.
Dr David Kernick is a GP with special interest in headache based in Exeter