Family doctor

About migraine

A migraine headache is a severe head pain, often unilateral (on one side) and frequently described as throbbing in nature. Migraine attacks may include nausea and vomiting, photophobia (intolerance to light) and phonophobia (intolerance to noise). Migraines are usually recurrent and episodes last anywhere between 4 hours and 3 days. An attack has the potential to temporarily disable a person but after it has settled, is unlikely to have any impact on the individuals day to day health. Migraine symptoms can vary between attacks.

Migraine is seen more often in women where it affects approximately one in five, compared with men where the incidence is near one in 16. It can start at any age but usually in late childhood or early adulthood. Onset of migraine over age 50 can occur but is less common and so other causes of headache must be looked for. Migraines can be inherited and thus run in families.

In some people migraine attacks have been linked with "triggers" such as sleep deprivation, alcohol (red wine), emotional stress and certain foods such as aged cheese, chocolate, yoghurt and preserved meats. Migraine can be associated with the menstrual cycle, and about 2/3 of migraines disappear at the menopause. Where possible avoiding triggers may decrease the frequency of migraine headaches. Some medications such as the combined oral contraceptive pill and nitrates (used to treat circulation problems) may also initiate migraines.

It is generally accepted that migraine symptoms are the result of changes that occur in blood vessels within and around the brain. Various neurotransmitters (chemical messengers) can cause these blood vessels to constrict (become narrower) and dilate (become wider). The chemical messenger serotonin seems to play a major role in this sequence of events.

Diagnosing migraine

Migraines are commonly divided into 2 groups:

(1) Classical Migraine or "migraine with aura". An aura is an unusual sensation that the sufferer feels prior to the headache. It may consist of a visual disturbance such as blurred vision, flashing lights, the appearance of geometrical shapes or transient loss of parts of the visual field. Transient numbness or weakness of the face or body and sometimes difficulty speaking are other types of aura. The headache usually follows the aura but not always. Migraine with aura accounts for about 15% of all migraines.

(2) Common Migraine or "migraine without aura" is the more common type of migraine and is seen in the remaining 85% of sufferers.

The diagnosis of migraine is made by listening to the patient's description of the symptoms. There is no specific feature of a clinical examination that confirms a migraine and similarly there is no blood test, x-ray or other investigation that can establish the diagnosis. A thorough clinical examination is required to exclude any threatening illnesses such as meningitis, brain haemorrhage or brain tumour. Special tests may also be ordered to help rule out these conditions.

A common form of headache often confused with migraine is tension headache. This type of headache can last from half an hour to one week and is often felt as a tightening across the forehead and temples. It is not associated with nausea or vomiting and is less severe than migraine. It is thought to be associated with muscular tension around the head and neck.

A history of long-standing headaches with symptom free intervals between headaches strongly suggests the diagnosis of migraine. A recent onset of severe headache with symptoms such as fever, drowsiness, neck stiffness, limb weakness and double vision suggest more severe causes as described above.

What is the treatment?

The first line of treatment is simple pain relief such as aspirin, paracetamol and non steroidal anti-inflammatories (eg. Ibuprofen). Nausea can be controlled with metoclopramide ('Maxolon') and it can be taken orally, or if severe vomiting occurs, in suppository form. It can also help with the absorption of the pain relief medications and should be taken half an hour prior to them. It is best to start treatment at the onset of the headache or aura. Migraines often diminish with sleep so lying down in a dark , quiet room and napping is helpful.

Specific prescription medications for migraine can be tried if the above are not successful. These include treatments that interfere with the action of serotonin such as ergotamine, sumatriptan and zolmitriptan. Sumatriptan is available as an autoinjector (6 mg dose) or as a tablet (50 or 100 mg). The sumatriptan autoinjector allows the patient to simply inject into the fat over the thigh muscle. Sumatriptan is more effective if dosing is delayed until the aura is finished. Should the migraine not respond to one dose of 100 mg orally or to the autoinjector then a second dose of sumatriptan is unlikely to help. If the migraine initially responds but then recurs, further doses may be helpful. The maximum dose you can take in 24 hours is two 6 mg autoinjectors or three 100 mg tablets. Sumitriptan is known to cause tightening of the blood vessels that supply the heart in some people. Symptoms of chest tightness may therefore occur and for this reason it should be avoided in people with angina.

Rarely, narcotic analgesics are required to control a migraine attack. This is seen as a last option where other therapies have not been effective. These medications should be avoided if at all possible due to their potential for abuse and addiction.

For less fortunate sufferers who have frequent migraine attacks that are difficult to treat, prophylactic (preventative) medications may be an option. This form of treatment requires daily use of medications in an attempt to reduce the frequency and severity of migraine. Several classes of medications have been proven to be beneficial. Beta blockers, often used to treat high blood pressure, are commonly used. Side effects may include tiredness and those with lung disease may not be able to take them. Other classes include tricyclic antidepressants and anticonvulsants.

Frequently asked questions:

Can migraine lead to threatening medical problems?

People who have migraine accompanied by aura may have an increased stroke risk according to a study published by the American Academy of Neurology in May 1999. Research suggests that almost 50 percent of these people have a condition known as patent foramen ovale (a congenital opening between two chambers in the heart). This opening is present in 30 percent of the general population, and is a risk factor for the uncommon strokes that occur in young people. Small clots that form in the veins can pass through the foramen ovale and enter the brain. Researchers state that people who have migraine with aura still have a very low risk of stroke, but it is three times greater than patients with migraine alone and eight times greater than those that do not suffer with migraine. To minimise risk, it is important for those with migraine accompanied by aura to avoid smoking and for women to avoid the combined oral contraceptive pill. The Progesterone Only Pill is a safer alternative choice of contraception.

How do I know I have not got a brain tumour?

Your doctor will take a thorough history. As discussed above symptoms such as drowsiness, neck stiffness, double vision, and limb weakness, or certain clinical signs, will require further investigation, such as a CT scan or MRI scan of the head.