Migraine



Key learning points

  • First or worst headache is assumed to be a subarachnoid haemorrhage, not a migraine

Incidence

  • Migraine affects 10-20% of the US population

Prevalence

  • 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

Causes

  • 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

  • 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


Content by Dr Íomhar O' Sullivan 11/01/2005, reviewed 26/02/2007. Last review Dr Chris Luke, Dr Í16/09/19Date -->