Diagnosing acute headache
Avoiding pitfalls in acute headache diagnosis – a guide to practice
By Sean Kavanagh, MRCP(UK)
This article uses cases dealt with by MPS to illustrate the potential pitfalls encountered in treating patients with acute headache. It is a general guide and is not exhaustive. Not all of the diagnoses discussed necessarily present acutely, but they may do so, or be time-sensitive, in terms of preventing avoidable sequelae.
Headache is a common symptom in primary and secondary care. The list of differential diagnoses is immense – numbering several hundred.1
Most are benign, but there are conditions it is imperative not to miss – see Box 1.
History
A useful template for taking a history in headache sufferers can be found at www.bash.org.uk (British Association for the Study of Headache’s website). Box 2 illustrates relevant historical and diagnostic factors, useful in differentiation of the important diagnoses in acute headache. The history needn’t be overly detailed, depending on one’s confidence in this field. It is important to establish the nature of the headache’s onset and whether or not this type of headache is novel to the patient. At a minimum, one should ascertain the standard ‘sieve’ of information relating to the nature, site, character and aggravating/relieving factors of the pain. Useful associated features to ask about include photophobia, nausea, syncope, seizures and visual symptoms – again, see Box 2. Many headache diagnoses can be reached on the basis of history alone, but examination is essential – see Box 3.
Diagnosis
The crucial thing when attempting to diagnose acute headache is to assess the overall combination of symptoms and signs and come to the most likely diagnosis, with the ‘not to miss’ causes kept high in the differential list. This is illustrated by Case 1.
Often, intuition based on experience brings the clinician to the correct cause. A good rule to follow, if you feel you lack the pertinent expertise, is to ask yourself if any of the conditions in the ‘not to miss’ list (particularly the common ones), could possibly be to blame, referring the patient to a specialist if the answer is ‘yes’.