Virtual Medical Centre

Migraine

• What is Migraine?
• Who gets Migraine?
• Predisposing Factors
• Progression
• Probable Outcomes
• How Will Migraine Affect Me?
• How is Migraine Diagnosed?
• How is Migraine treated?
• Migraine References
• Drugs/Products Associated with Migraine

What is Migraine?

Migraines are recurrent headaches which can occur in conjunction with gastrointestinal and visual symptoms.  The name is derived from the Greek word meaning 'pain in half the head', as migraines often produce a unilateral (one-sided) headache.

The headache or migraine is due to vasodilation or oedema of intra- and extra-cranial blood vessels and the subsequent stimulation of nerve endings near these blood vessels.

Types of migraine 

There are several types of migraine - the two main types are classical migraine and common migraine.

3D Animation on Migraine This animation brought to you by Blausen Medical Communications. Contact Andrew Walbank.

Classical migraines are preceded by an aura (neurological symptoms which develop before the headache). This may include visual symptoms (e.g. zig-zagging lines, flashing lights, loss of half the visual field, scotoma (loss of a small area of vision), or it may include other symptoms such as weakness, loss of sensation in the limbs or inability to talk. The aura may last from 15 minutes up to an hour and the headache then follows often beginning locally and then becoming generalised. Nausea and vomiting then follow. The migraine lasts for several hours and the patient may then fall into a deep sleep. Common migraines are not preceded by an aura. The headache lasts 4-72 hours, and is pulsating and unilateral. Nausea and vomiting, photophobia (pain from bright light) and phonophobia (pain from noise) may occur.

Who gets Migraine?

Migraine is common, affecting at least one in 10 people. It is more common in females and most frequently affects those between 20 and 50 years of age. 25% of migraines first occur in childhood.

Predisposing Factors

The exact cause of migraine is not known. However, migraine headaches are thought to result from a combination of environmental factors (such as diet or stress) interacting with biochemical factors in the brain. Around 70% of migraine sufferers have a family history of migraine, suggesting a genetic component.

There are a number of 'triggers' which seem to cause migraines in susceptible people:

• Stress or tension: and in particular the relief of tension after a stressful period (sometimes known as 'weekend migraine')
• Tiredness, physical exhaustion, oversleeping
• Alcohol (especially red wine).
• Some foods: foods high in tyramine, such as aged cheese, or high in phenylalanine, such as chocolate
• Hormonal factors: puberty, menstruation, pregnancy
• Exercise
• Some medications: vasodilators (drugs used to treat angina, high blood pressure, or erectile dysfunction), oestrogens (such as the oral contraceptive pill), MSG, or nitrites
• Strong sensory stimulation, eg. glare or bright light, strong smells, loud noise
• Head trauma

Progression

The frequency of migraine headaches varies greatly between patients. They may be more frequent around times of hormonal change, such as puberty or menopause.

Migraine headaches can be preceded by an aura (classical migraine) which may last from 15 minutes to an hour. 'Aura' refers to symptoms such as flashes of light or visual changes, thought to be caused by disturbances in the electrical activity of the brain. After the aura, the headache begins. The headache usually lasts 6-8 hours, although it can last for up to 72 hours. Nausea and vomiting may follow the onset of the headache.

Not all patients with migraines experience aura. Migraine headache without aura is known as 'common migraine'.

A migraine may occur at any time of day. Migraine headaches resolve on their own, often after sleep. However, many patients feel drained and tired and may experience muscle aches for up to a day after the headache resolves.