Migraine

The two commonest categories are migraine without aura and migraine with aura. A further category, often leading to a neurological referral, is chronic migraine. More than one category of migraine may occur in the same patient.

Epidemiology

• Very common and affects over 10% of people in the western world.
  
• Prevalence: Females (18%) > males (6%). It may commence at any age but most commonly the initial attack occurs during teens and a first episode of migraine is rare after the age of 40.
  
• Migraine beginning for the first time in older people requires investigation for alternative explanations.
  
• Tends to recur at variable frequency throughout life and attacks often become less severe and less frequent with age.

Aetiology

• Approximately 90% have a family history.
  
• Modern neuroimaging techniques suggest a primary neural basis for migraine and pathophysiology may involve a neurovascular mechanism.

History

Migraine without aura: Diagnosis requires at least five lifetime attacks, lasting 4–72 h with two of four pain features and at least one of two sets of associated symptoms.

• At least two of the following headache characteristics: Unilateral new location, pulsating quality, moderate or severe pain intensity, aggravated or causing avoidance of routine physical activity (e.g. walking or climbing stairs).
  
• At least one of the following associated features: Nausea and/or vomiting, photophobia and/or phonophobia.

Migraine with aura: Typically migraine aura produces focal neurological symptoms which precede the headache but may occur without a following headache. Auras usually develop over 5 min and last no longer than an hour. Visual auras are by far the commonest. Sensory symptoms occur in approximately a third of patients with migraine with aura. Dysphasia and motor weakness, as well as decreased levels of consciousness may be seen but are far less common. The most frequent story in patients with migraine with aura is that the aura is followed by a headache with the features listed in the above section.

Investigations

A diagnosis of migraine is based on the history along with normal brain imaging. Patients should be reassured.

Management

• Reassurance regarding benign nature of migraine with no underlying sinister cause (such as a brain tumour) is important.
  
• General recommendations: Avoid triggers and reduce caffeinated drinks and alcohol intake, perform regular exercise with avoidance of prolonged fasts, have sufficient sleep and remove medications contributing to headaches.
  
• Pharmacotherapy can be divided into two groups. Therapies that provide symptomatic relief during an acute episode and therapies that are taken for their prophylactic effects if migraine frequency and duration are sufficient to warrant this. Typically, prophylactic regimens are considered if attacks occur more than several times each month.
  
• Symptomatic treatment: This is most effective if taken as early as possible during the attack. Simple analgesics such as Aspirin, Ibuprofen or Paracetamol may be all i.e. required with an antiemetic if necessary. If simple analgesics are not sufficient, selective 5-HT1 agonists (Triptans) may be used. Treat at least two different attacks before deciding a drug is ineffective. If there is no benefit from the drug, it may be necessary to change formulation or root of administration or add an adjunctive therapy. Non-drug treatments including lying in a darkened room or sleeping for a period are often effective towards shortening an attack.

• Prophylactic treatment: Relatively few preventative medications for migraine have proven to be effective in large randomised controlled clinical trials; therapies commonly tried in the United Kingdom include Amitriptyline, Propranolol, Sodium Valproate and Topiramate. Note that if the prophylactic drugs are used, administer it at a sufficient dose for a sufficient period of time (typically several months) before deeming them to be ineffective and moving to the next therapy.

Tension-type Headache