Headache Fact File - Part 3 - Migraine

In the third of this five-part series, Dr David Kernick discusses the assessment and management of migraines.

Coloured SPECT scan of a brain during migraine
Coloured SPECT scan of a brain during migraine

Migraine is the main cause of high impact headache and affects 7.6 per cent of males, 18.3 per cent of females and 12 per cent of children.

Unfortunately, the majority of sufferers are reluctant to seek help and when they do the condition is less than optimally managed.

Migraine is comorbid with depression and anxiety disorders, epilepsy and asthma.

Making the diagnosis
Migraine is the most common headache presentation in primary care. Although the International Headache Society criteria (see box, right) are quite specific, from a clinical perspective they may be relaxed. Answering yes to two out of three simple questions effectively identifies migraine:

  • Has a headache limited your activities for a day or more in the past three months?
  • Are you nauseated or do you vomit when you have a headache?
  • Does light bother you when you have a headache?

The stages of migraine

  • Prodrome - sensory or psychological features that can occur up to 48 hours prior to attack. Experienced by 30-50 per cent of migraineurs. Craving for a particular food during the prodrome can be confused with a trigger.
  • Aura - a reversible sensory or motor phenomenon of the cortex, or less commonly brainstem, lasting less than 60 minutes. Auras are experienced by 30 per cent of migraineurs. Visual auras are the most common followed by paraesthesiae. Atypical auras can occur, for example vertigo or hemiplegia. Auras can occur in the absence of headache. As they are caused by a spreading cortical depression, their evolution with time distinguishes them from TIA.
  • Headache - unilateral, throbbing or pulsating. Associated with nausea or vomiting, photophobia or phonophobia. Increased skin sensation can also occur.
  • Postdrome - tiredness, elation.

Migraine triggers

  • Triggers are often inconsistent. The importance of allergy remains unproven.
  • The often unrecognised trigger is sensitivity to change (glucose, hydration, stress, estrogen, sleep patterns) so keep everything as constant as possible.

Pathogenesis

  • Pathogenesis is poorly understood. The mid-brain migraine generator activates the trigeminal system which causes dural inflammation and pain.
  • Migraine generator is close to nausea and vomiting centre. Gastric stasis and inhibition of drug absorption are major problems.
  • Migraine generator overlaps nuclei of upper cervical nerves. Neck and shoulder pain common in migraineurs and probably represents efferent signals and not primary neck problem.

The emergency call out

  • Parenteral sumatriptan is the treatment of choice.
  • IM diclofenac 50mg with IM antiemetic second line.
  • Avoid opiates as dependency develops.

Managing the acute attack

  • A useful first-line treatment that can be bought cheaply OTC, all of which should be taken together is: domperidone 10mg, paracetamol 1g, ibuprofen 400mg or aspirin 600mg. Soluble preparations act quicker. This can be taken prior to a triptan. Larger initial doses may reach therapeutic levels quicker (domperidone 20mg, paracetamol 1.5 g, ibuprofen 600 mg or aspirin 900mg) providing maximum daily doses are not exceeded.
  • With vomiting or severe nausea, use domperidone suppositories 30mg and diclofenac suppositories 100mg.
  • Triptans are the cornerstone of acute attack management. Nasal forms (sumatriptan and zolmitriptan) are useful when gastric stasis is a problem, or injectable forms (sumatriptan) for intractable cases. Wafer formulations (zolmitriptan and rizatriptan) are for convenience only and not absorbed through the oral mucosa. Sumatriptan 50mg is now available OTC. Failure of response to triptans is not a drug class effect. If one does not work, rotate choices. Treat at onset of pain; it may not be effective if taken during the aura phase. More effective if taken with an antiemetic. Vascular disease is an absolute contraindication.

Preventive treatment

  • No specific indications for using preventive treatment. The impact upon the patient is the best guide.
  • Preventive medication should be given for at least eight weeks at its maximum tolerated dose before its impact is assessed. If successful, continue for at least six months.
  • Beta-blockers are the drug of choice and propranolol, metoprolol, timolol and nadolol are licensed for use in migraine. Atenolol 25mg increasing to 100mg or the highest tolerable dose appears effective, is cheap and convenient to take. Nebivolol is useful if side-effects are problematic.
  • Amitriptyline 10mg increasing to 100mg or the highest tolerable dose is the second choice preventive medication.
  • Antiepileptic drugs form the third-line choices, particularly sodium valproate (unlicensed) and topiramate (licensed). Gabapentin and lamotrigine are sometimes used.

Alternative treatments

  • Biofeedback and cranial massage are not supported by firm evidence.
  • Positive trials on acupuncture have been criticised on methodological grounds.
  • Butterbur, feverfew, coenzyme Q10 and magnesium have a weak evidence base.

Migraine in women

  • Avoid combined oral contraception in women with aura or migraine without aura with other vascular risk factors.
  • Look for hormone-sensitive migraine. Perimenstrual mefenamic acid or naproxen from two days before to two days after menstruation; transcutaneous estrogen gel 1.5g/day from five days before to two days after menstruation; frovatriptan 2.5mg/day from two days before to four days after menstruation. Perimenopausal (low-dose HRT, not oral). All above are unlicensed for this use.
  • The majority of women have fewer migraines in pregnancy. Paracetamol and antiemetics are safe.

Dr Kernick is a GP in Exeter and RCGP headache champion

Available triptans

Group A (Higher speed onset)
Sumatriptan 100/50mg
Rizatriptan 10/5mg
Zolmitriptan 2.5mg
Eletriptan 20mg/40mg
Almotriptan 12.5mg


Group B (Lower headache recurrence, lower side-effect profile)
Naratriptan 2.5mg
Frovatriptan 2.5mg

 

Formal criteria for migraine diagnosis

International Headache Society criteria for migraine

a. At least five attacks fulfilling criteria b to d

b. Headache attacks lasting 4-72 hours (untreated or unsuccessfully treated)

c. Headache has at least two of the following characteristics:

  • unilateral location
  • pulsating quality
  • moderate or severe pain intensity
  • aggravating or causing avoidance of routine physical activity

d. During headache, at least one of the following:

  • nausea and or vomiting
  • photophobia or phonophobia

e. Not attributed to another disorder (a formal diagnosis of migraine therefore must include an examination to exclude other disorders)

 

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