Migraine

Key learning points

First or worst headache is assumed to be a subarachnoid haemorrhage, not a migraine
Please image all "first" migraine cases presenting to ED (particularly if an "aura" [focal neurological symptoms])

May be related to Serotonin & Dopamine receptors
Triggering factors include:
- Certain foods like chocolate, citrus fruits, cheese, Sodium Glutamate, alcohol, caffeine
- Hormonal fluctuations, emotional stress
- Physical Stresses - e.g. travel / shift work
- External stimuli

Recurrent, episodic, headaches that may be unilateral or bilateral. Often throbbing
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
± prodromal aura, with neurological symptoms (particularly visual scintillations) - in 10%

3 Criteria:

Headache lasting 4-72 hrs
Have x2 of:
- Unilateral
- Pulsating
- Moderate/severe intensity
- Aggrevating factors (below) causing interference with usual activity
During headache, have at at least one of:
- Nausea / vomiting
- Photophobia / phonophobia

Attacks last hours or even days with total freedom between attacks
Sensitivity to light, noise and strong smells is frequent
Examination should be unremarkable
Beware ⇑ICP, meningism, Δ level of consciousness, localising neuro signs
Beware "jaw claudication" (temporal arteritis) and glaucoma (red eye, fixed pupil), particularly in the older patient

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

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]
IV MgSO₄ (1-2g slow infusion) may be considered in refractory migraine

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