Key learning points
- First or worst headache is assumed to be a subarachnoid haemorrhage, not a migraine
- Migraine affects 10-20% of the US population
- About 400,000 sufferers in Ireland
- M:F = 1:3 (ratio reversed in children)
- The first attack often occurs in childhood
- Incidence increases in adolescence
- Migraine is probable related to Serotonin and Dopamine receptors in the brain
- Triggering factors include:
- Certain foods like chocolate, citrus fruits, cheese, Sodium Glutamate, alcohol, caffeine
- Hormonal fluctuations, emotional stress
- Physical Stresses - e.g. travel or change in shift work pattern
- External stimuli
Key Clinical Features
- Recurrent, episodic, headaches that may be unilateral or bilateral. Often throbbing.
- -/+ a prodromal aura, with neurological symptoms (particularly visual scintillations) - in 10%.
- Attacks last hours or even days with total freedom between attacks.
- Common migraine (or migraine without aura) and classical migraine (with aura) may be accompanied by nausea (80%), vomiting, diarrhoea, photophobia or phonophobia (80%), confusion and, in rare cases, temporary paralysis and loss of speech.
- Sensitivity to light, noise and strong smells is frequently reported.
- Examination should be unremarkable.
- Beware raised intracranial pressure, meningism, altered level of consciousness, localising neuro signs.
- Beware "jaw claudication" (temporal arteritis) and glaucoma, particularly in the older patient.
- Investigations only to exclude other pathology if clinically suspected.
Consider CT for patients with:
- headache and an abnormal neurological exam.
- headache worsened by Valsalva manoeuvre.
- headache causing awakening from sleep.
- consider CT for new headache in older people and progressively worsening headache.
Treatment and management
- Avoid opiates
- Metoclopramide is the drug of choice in the treatment of acute migraine in the Emergency Department Ref 1
- (± Prochlorperazine)
- NSAIDs ( Diclofenac 75mg PO or Indomethacin 50 mg PO or Naproxen 50mg PO).
- Migraine specific treatments e.g. oral Sumatriptan [Cochrane], Rizatriptan [Cochrane], Eletriptan [Cochrane] or Dihydroergotamine - though these have usually already been taken prior to presentation at the Emergency Department
- Sumatriptan is more effective than Natriptan or Rizatriptan [Bandolier]
- Frovex 2.5 mg is also effective [Bandolier] and has a long half life (particularly suited to menstrual associated migraines).
- Treat in a quiet dark room if possible.
- Anticonvulsants are effective in reducing the frequency of attacks but have side effects [Bandolier]
- Propanolol has little evidence to support its use [Bandolier]
- SSRIs are not effective at reducing attack frequency [Bandolier]
- In patients who have received successful abortive treatment for migraine, consider a single dose of IV Dexamethasone [EMJ BestBest 2013]
Red flags and pitfalls
- First or worst headache is a subarachnoid haemorrhage until proven otherwise
- A change in frequency, severity, or clinical features of the attack
- Progressive headache that persists for days
- Precipitation of headache with Valsalva manoeuvres (↑ ICP)
- Age onset > 40 years, recent trauma, papilloedema
- Repetitive / long-lasting / non-spreading aura
- Temporal artery tenderness