Migraine

Key learning points

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

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

Recurrent,episodic, headaches that may be unilateral or bilateral. Often throbbing.
-/+ a prodrome (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
- headache causing awakening from sleep
- Consider CT in new headache in older people and progressively worsening headache

Avoid opiates
Metoclopramide 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 Naproxin 50m PO).
Migraine specific treatments eg 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]

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
Repteative / long-lasting / non-spreading aura
Temporal artery tenderness