Details of a Classic Migraine

Almost everyone has at one point in their life or another experienced a headache. Migraines are a particular type of headache that is marked by certain characteristic features. It is commoner in women and can start in childhood. Studies have shown that over 30 million people in the United States suffer from migraine at some point in their life.1

In fact, it is one of the commonest forms of headache that people experience.

In this article, we will cover classic migraine in a bit more detail, covering the triggers, clinical features and management of this condition.

Cause of migraine

One of the commonest causes of migraine is a positive family history. It can form a part of other clinical syndromes such as mitochondrial disorders.

There are two primary patho-physiological explanations for migraine –

1. Vascular theory

According to the vascular theory, dilatation (expansion) and pulsation of the blood vessels results in the headache. This is why the vasodilator drugs can precipitate the symptoms of migraine. However, this theory does not explain all the symptoms of migraine.

2. Neurovascular theory

This theory connects neural hyper-excitability to vasodilatation, meaning that the enlargement of the blood vessels is related to increased activity of the nerves in the brain.

There is some belief that certain vasoactive substances are responsible for migraine attacks. These can include nitric oxide and substance P, just to name a couple. These can cause vasodilatation and can result in migraine attacks.

What triggers migraine?

There are a number of stresses and triggers of migraine. These have been listed in the table below –

 Triggers that precipitate a migraine attack

  • Foods such as cheese, vinegars, peanuts and yogurt (to name a few)
  • Stress
  • Smoking
  • Lack of sleep
  • Menstruation and pregnancy
  • Change in weather, extreme cold
  • Medications such as oral contraceptive pills and vasodilator agents

Clinical features

Headache is the primary symptom of migraine, and is typically a throbbing type of headache. It is usually unilateral and localised initially, but can become a lot more widespread in a few hours. Patients also experience nausea and vomiting with the headache. Patients may be sensitive to bright lights (photophobia) and to sounds
(phonophobia).

One of the features of classic migraine is ‘aura’. Auras usually occur a short while before the onset of migraine, and can include visual field defects, flashing lights or scintillating scotoma (fortification spectrum). Patients may also experience altered nerve sensation (parasthesias) that can involve the arms and the face.

Some patients who suffer from migraines can experience prodromal symptoms. These refer to symptoms that can present hours to days before the onset of migraine.

Symptoms can include increased thirst, anorexia, cravings for a variety of foods and even changes in mood. These can vary between individuals, though they tend to remain the same for each patient.

Investigations

Almost all cases of migraine are diagnosed from clinical history. In some cases, it is diagnosed after excluding other causes of headache such as tumors or infection. Patients who suffer from severe attacks of migraine, who have an associated fever or who develop migraine after age of 50 may require a CT scan of the head to rule out any tumors or bleeding.

One of the differential diagnoses of migraine is subarachnoid haemorrhage. Features of headache can be similar, particularly with the mechanism of onset. In such cases, a lumbar puncture may be required to rule out a bleed before treating the patient for migraine.

Treatment

The treatment of migraine is twofold – treatment of the acute attack and prevention of future attacks.

1. Treatment of acute attack

When an acute attack of migraine strikes, patients can take simple analgesics such as acetaminophen or non-steroidal anti-inflammatory drugs (NSAIDs) to help relieve the pain. However, in more severe cases, 5-hydroxytryptamine-1 (5-HT-1) agonists such as Sumatriptan are excellent treatments that help abort the attack quickly. Medication for associated nausea may be required as well.

2. Prevention of future attacks

There are a few ways this can be achieved –

  • Avoiding triggers of migraine – Patients who suffer from migraine will be fully aware of the triggers that can precipitate an attack, so should be wary and avoid these. This can include stopping certain medication and even the oral contraceptive pill if required.
  • Beta-blockers – Evidence suggests that beta blockers such as propranolol can alter the release of neurotransmitters that mediate the pain, thus helping in prevention of attacks.
  • Tricyclic antidepressants – These are also similar to beta blockers in their mechanism of action.
  • Naproxen sodium – This NSAID is helpful in preventing migraine attacks as well, with an effect as potent as beta blockers.

3. Other treatments

Treatments such as cognitive behavioural therapy and relaxation therapy have been used to manage migraine attacks and are usually used along with drug therapy. In some cases, complimentary medicine or alternative therapies such as yoga, acupuncture and acupressure may be used.

Newer approaches to migraine therapy are constantly being researched. Antagonism of calcitonin gene related polypeptide has been shown to help abort acute attacks, but studies are still in early stages.

Prognosis

Patients with migraine are always at risk of having recurrent attacks in the future. However, in most cases, as the patient gets older, the number of attacks can reduce significantly to a point where it completely disappears.

Conclusion

Classic migraine is a common clinical condition that causes headaches. There are a variety of triggers and a cluster of classic symptoms that make this a rather unique condition. Treatments are aimed at aborting acute attacks and preventing future episodes from occurring.

References

1. Lipton RB, Scher AI, Kolodner K, Liberman J, Steiner TJ, Stewart WF. Migraine in the United States: epidemiology and patterns of health care use. Neurology. Mar 26 2002;58(6):885-94.