Author: Simon Rinaldi
Most patients presenting to the emergency department with acute headache have migraine. A minority have life-threatening disorders such as subarachnoid haemorrhage or bacterial meningitis. The clinical assessment (Table 15.1) enables you to place the patient in one of three groups, guiding differential diagnosis, investigation (Table 15.2) and further management.
Acute headache with any ‘red-flag’ features: fever, reduced conscious level, papilloedema, neck stiffness or focal neurological signs
Causes are given in Table 15.3.
- If the patient is febrile, or the index of suspicion for CNS infection is high, take blood cultures and start antibiotic/antiviral therapy to cover bacterial meningitis (Chapter 68) and herpes simplex encephalitis (Chapter 69). Next, obtain CSF to confirm the diagnosis, identify the pathogen, and direct further therapy. CT should always be performed before lumbar puncture (Chapter 123) with:
- Focal neurological signs
- Altered consciousness
- Papilloedema
- Immunosuppression, or
- Recent seizure (within two weeks)
- Tuberculous and cryptococcal meningitis should considered in at-risk groups (see Appendices 68.1 and 68.2). Meningism may be absent or mild in these diseases.
- Infectious diseases acquired abroad (e.g. malaria, typhoid) should be considered in patients with the relevant travel history (Chapter 33).
- When subarachnoid haemorrhage is suspected (see below and Chapter 67), CT is the initial investigation of choice and LP is likely to be more useful if delayed until 12 hours after the onset of headache.
- If the patient is febrile, or the index of suspicion for CNS infection is high, take blood cultures and start antibiotic/antiviral therapy to cover bacterial meningitis (Chapter 68) and herpes simplex encephalitis (Chapter 69). Next, obtain CSF to confirm the diagnosis, identify the pathogen, and direct further therapy. CT should always be performed before lumbar puncture (Chapter 123) with:
Headache with local signs
Causes and management are summarized in Table 15.4.
Acute headache with no abnormal signs
Causes are given in Table 15.5.
- Always consider subarachnoid haemorrhage (Chapter 67) and giant-cell arteritis (see below and Chapter 99).
- Formal criteria state that a headache cannot be diagnosed as migraine or tension-type headache until multiple episodes have occurred. While such criteria highlight the increased difficulty in diagnosing a single episode, it may still be appropriate to treat migraine-like headache as such if other more serious causes have been satisfactorily excluded.
- If the headache was abrupt in onset, reaching maximum intensity within minutes at most, subarachnoid haemorrhage must be excluded by CT, followed by examination of the CSF if the CT is normal or equivocal.
- CT is most sensitive for detection of subarachnoid haemorrhage if done within 12h of onset of headache. Examination of the CSF by spectrophotometry to detect bilirubin (a breakdown product of haemoglobin) is the most reliable method of confirming or excluding subarachnoid haemorrhage. Bilirubin is reliably present in CSF from 12h to 2 weeks after haemorrhage (occasionally longer). Lumbar puncture should therefore be delayed >12h after the onset of headache unless meningitis is a possibility.
- Further management of subarachoid haemorrhage is detailed in Chapter 67.
- Consider in any patient aged 50 or over with headache, which will usually be of days or a few weeks in duration.
- Associated symptoms include malaise, weight loss, jaw claudication, scalp tenderness and visual changes (amaurosis fugax, diplopia and partial or complete loss of vision).
- If the ESR is >50 mm/h and/or C-reactive protein raised, and/or the temporal artery is thickened or tender (feel 2cm above and 2cm forward from the external auditory meatus), start prednisolone. For patients with visual symptoms (who should be seen by an ophthalmologist the same day), give 60 mg as a one-off dose. For those without visual symptoms, give 40–60 mg daily (minimum 0.75 mg/kg). Also give aspirin 75 mg daily, if not contraindicated, and a proton pump inhibitor for gastroprotection.
- Arrange urgent review by a rheumatologist (and ophthalmologist if ophthalmic involvement is suspected).
- See Chapter 99.
- Diagnostic criteria are given in Table 15.6. The first migraine headache usually occurs between the ages of 10 and 30.
- Treatment of an acute attack is with an NSAID, triptan, dispersible aspirin or paracetamol and an antiemetic, for example metoclopramide 10 mg IM or domperidone (available in suppository form). Combination therapy with a triptan and NSAID/paracetamol may be more effective.