Science Fair Project Encyclopedia
Migraine is a form of headache, usually very intense and disabling. It is a neurologic disease of vascular origin. The word "migraine" originates from the Greek construction hemikranion (pain affecting one side of the head) .
Migraine is characterized by attacks of sharp pain involving (usually) one half of the skull and accompanied by nausea, vomiting, photophobia and occasionally visual (or other, such as smell or balance) disturbances known as aura. The symptoms and their timing vary considerably among migraine sufferers, and to a lesser extent from one migraine attack to the next. Migraine has been thought to be caused by the expansion of the blood vessels of the head and neck. Newer research, however, suggests the cause may be overactivity of nerve cells in certain areas of the brain, leading to expanded blood vessels only as a side effect. Classical migraine (migraine with aura) is forerun by a group of symptoms called aura, whereas common migraine does not have any indicator for the impending headache. Some actually get aura without migraine (amigrainous migraine ). Although comparable in severity, the symptoms of migraine differ from those of cluster headache.
The aura preceding a migraine attack usually manifests itself as a multicolored zig-zag pattern which grows from a small dot until it covers a large part of the field of vision of one eye. The aura disappears within 20-40 minutes and the onset of headache comes about half an hour after the aura has disappeared.
Migraine can accompany, in many cases, another type of headache called Tension headache. Since the treatment differs from that of migraine, it is important to recognize when tension headache is occurring. In some cases, migraine can cause seizures such as a tonic-clonic seizure. Stroke symptoms (passing or permanent) are seen in very severe subtypes.
Migraine often runs in families and starts in adolescence, although some research indicates that it can start in early childhood or even in utero. Migraine occurs more frequently in women than men, and is most common between ages 15-45, with the frequency of attacks declining with age in most cases.
Because their symptoms vary, an intense headache may be misdiagnosed as a migraine by a layperson. Where possible, see a doctor to determine if the headaches are a symptom of something else.
Conventional treatment focuses on three areas: trigger avoidance, symptomatic control, and preventive drugs.
Elimination of triggers
In a minority of patients the incidence of migraine can be reduced through diet changes to avoid certain chemicals present in such foods as cheddar cheese and chocolate, and in most alcoholic beverages. Other triggers may be situational and can be avoided through lifestyle changes.
This can happen even if they have known triggers, such as particular points in the menstrual cycle, certain weather patterns, or hunger. Avoid bright flashing lights if you notice these trigger attacks; most migraineurs are sensitive and avoid bright or flickering lights. Relaxation after stress, notably weekends and holidays is a potent trigger; wind down gradually if possible.
Symptomatic control to abort attacks
The first step is to treat symptoms in an attack. Simple pain killers (analgesics) such as paracetamol (acetaminophen), aspirin or (low doses of) codeine are sometimes effective. Anti-emetics by suppository or injection may be needed in cases where vomiting dominates the symptoms. The earlier these drugs are taken in the attack, the better their effect. Until the introduction of sumatriptan (Imitrex®/Imigran®) around 1985, ergot derivatives (see ergoline) were the primary oral drugs available to stop a migraine once it was underway. Analgesics and caffeine were used to provide some relief, though they are not effective for most sufferers. Narcotic pain medications(heroin, morphine, other opiates) provide variable relief, but their side effects and ability to cause serious drug addiction contraindicates their general use.
Ergotamine tablets (usually with caffeine), though sometimes effective, have gone out of favour. Absorption is erratic unless taken by suppository or injection. Dihydroergotamine (DHE), which must be injected or inhaled, can also be effective. These drugs can be used either as preventive or abortive therapy.
Sumatriptan (Imitrex®) and the related 5-hydroxytryptamine (serotonin) receptor agonists are now available and are the therapy of choice for severe migraine attacks . They are highly effective, reducing or abolishing all the symptoms within 30 to 90 minutes, but about 20 - 30% patients do not respond. Some patients have a rebound headache later in the day, and one such rebound only can be treated with a second dose of a triptan. They have few side effects if used in correct dosage and frequency. Some members of this family of drugs are:
- sumatriptan (Imitrex®, Imigran®)
- zolmitriptan (Zomig®)
- naratriptan (Amerge®, Naramig®)
- rizatriptan (Maxalt®)
- eletriptan (Relpax®)
- frovatriptan (Frova®)
- almotriptan (Almogran®)
Evidence is accumulating that these drugs are effective because they constrict certain blood vessels in the brain. They do this by acting at serotonin receptors on nerve endings. This action leads to a decrease in the release of a peptide known as CGRP . In a migraine attack, this peptide is released and may produce pain by dilating cerebral blood vessels.
These drugs are available only by prescription (U.S. and U.K.). Many migraine sufferers do not use them only because they have not sought treatment from a physician.
Preventive medication has to be taken on a daily basis, usually for a few weeks before the effectiveness can be determined. It is used only if attacks occur more often than every two weeks (Ref 1). Supervision by a neurologist is advisable. A large number of medications with varying modes of action can be used. Selection of a suitable medication for any particular patient is a matter of trial and error, since the effectiveness of individual medications varies widely from one patient to the next.
Beta blockers such as propranolol and atenolol are usually tried first. Antidepressants such as amitriptyline may be effective. Antispasmodic drugs are used less frequently. Sansert was effective in many cases, but has been withdrawn from the U.S. market.
Migraine sufferers usually develop their own coping mechanisms for intractable pain. A cold or hot shower directed at the head, less often a warm bath, or resting in a dark and silent room may be as helpful as medication for many patients, but both should be used when needed.
Some migraine sufferers find relief through acupuncture which is usually used to help prevent headaches from developing. Sometimes acupuncture is used to relieve the pain of an active migraine headache.
Biofeedback has been used successfully by some to control migraine symptoms through training and practice.
Supplementation of Coenzyme Q10 has been found to have a beneficial effect on the condition of some sufferers of migraines.
The plant feverfew (Tanacetum parthenium) is a traditional herbal remedy believed to reduce the frequency of migraine attacks. Clinical trials have been carried out, and appear to confirm that the effect is genuine (though it does not completely prevent attacks).
[[Diet_(nutrition)|]] and [[Visualization_(cam)|]]/Self-hypnosis are also important alternative treatment and prevention approaches.
1. Pearce JMS. Headache. Neurological Management series. J Neurology Neurosurgery & Psychiatry 1994; 57 : 134-44
- General Information
- Migraine Information from the US National Institute of Neurological Disorders and Stroke
- Migraine Headache: Clinical and Alternative Treatment
- Migraine - gives a quick overview of the phenomenon as well as some suggestions on diet (from the BBC).
- FAQ on migraine treatment (Michigan Head Pain and Neurological Institute)
- CVSA information on a potential migraine variant Cyclical Vomiting Syndrome
- Diagnostic criteria
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