Migraine
A migraine is a common form of primary headache. Migraine pain seems to run in families, and women are three times more likely than men to experience this type of headache. The onset is usually between age 10 and 46 years. 70-80% of all migraine headaches are classified as common migraines (migraines without a preceding aura, or an unusual sensation such as tingling or seeing zigzagging lights). Migraines that are preceded by an aura are known as classic migraines. Other forms of migraine include complicated migraine (with focal neurological symptoms), basilar migraine (with vertigo and occasionally loss of consciousness), and ophthalmic migraine (with eye pain and vision loss).
Causes
Migraine pain is typically associated with alternate constricting and relaxing of blood vessels in the brain. However, in recent years researchers have also focused attention on alterations in nerve pathways and imbalances in brain chemistry. The trigeminal nerve system is a major pain pathway; serotonin, a neurotransmitter or nerve chemical, regulates pain messages passing through the trigeminal nerve system. A malfunction or chemical imbalance in this system is believed to be an underlying cause of headaches, including migraines.
There are many possible triggers of migraine pain. Triggers themselves do not cause pain; instead, they activate already existing brain chemical imbalances. Triggers vary from person to person, but may include hormonal fluctuations caused by birth control pill use, hormone replacement therapy, and premenstrual syndrome. In women who have migraines, more than half occur right before, during or directly after their period. Migraines diminish in many women following menopause.
Other triggers include physical or mental stress, changes in sleep patterns, allergic reactions, smoking or exposure to secondhand smoke, bright lights, loud noises, alcohol, caffeine and missed meals. Diet is widely implicated in migraine. Possible dietary triggers include foods that contain the amino acid tyramine (including red wine, aged cheese, figs, chicken livers and smoked fish), chocolate, processed foods, food additives (such as monosodium glutamate [MSG]), meats containing nitrates (including hot dogs, bacon and salami), nuts, peanut butter, dairy products, onions and certain fruits (such as avocados and bananas).
Symptoms
Migraine headaches are characterized by throbbing pain that most commonly begins on one side of the head. Pain may remain localized or spread to both sides. It can start on either side, beginning as a dull ache that gradually worsens into disabling pain, or it can begin abruptly with severe pain from the onset. Migraine attacks occur on a sporadic basis and can last from several hours to several days. Severe pain may be accompanied by other symptoms, such as nausea, vomiting, dizziness, chills, loss of appetite, irritability, fatigue, and extreme sensitivity to light and sound.
In some cases, migraine pain is preceded by fatigue, depression or an aura. An aura may consist of dreamlike perceptions or visual disturbances. Possible preliminary or prodromal symptoms of migraine pain include tingling or numbness, strange tastes or odors, restlessness, confusion, eye pain, blurred vision, intolerance of bright light, zigzagging lights, flashing lights and other visual hallucinations.
Diagnosis
Diagnosis of a migraine is based on the nature of the pain, its frequency and duration, location, severity, and accompanying symptoms. In some cases, a migraine is a warning sign of a potentially serious problem. Tests such as CT (computed tomography) scanning, MRI (magnetic resonance imaging), electroencephalogram (EEG), and blood studies may be performed to rule out serious underlying causes of symptoms, such as a ruptured aneurysm, brain tumor, stroke, transient ischemic attack or meningitis. Doctors recommend immediate medical evaluation for those who experience migraines accompanied by a loss in consciousness; sudden, violent head pain; head pain that worsens over time and is accompanied by symptoms such as nausea, vomiting, fever and a stiff neck; and head pain that is associated with abnormal neurological functions (including changes in speech, vision, balance, movement and sensation).
Treatment
The management of migraine pain has improved dramatically during the last 10 years. Today doctors treat migraines with two categories of medications: abortive (to relieve pain and other symptoms) and prophylactic (to prevent migraines from developing). Abortive medications include triptans (such as sumatriptan and zolmitriptan), vasoconstrictors (such ergotamine tartrate), lidocaine nasal drops, muscle relaxants, narcotic analgesics, and aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs). Prophylactic medications include tricyclic antidepressants, serotonin antagonists, cardiovascular drugs (beta blockers and calcium channel blockers), antiseizure drugs (such as valproic acid), vitamin B2 (riboflavin), and magnesium. Preventive medication is usually recommended for people who have more than two migraine attacks a month and for people in whom pain is so severe that it prevents normal activity. Doctors advise people who experience typical warning symptoms (such as auras) to take medication at the first sign of an impending attack.
The mainstay of home care is rest in a dark, quiet room. Because poor lifestyle habits can contribute to migraines, many people benefit from regular sleep, exercise, a healthy diet, and avoidance of smoking, alcohol and caffeine. Doctors also recommend strategies such as relaxation therapy and biofeedback. Whenever possible, it is important to identify and avoid the triggers of migraines (such as problem foods). Keeping a headache diary is a helpful way to do this. This entails maintaining a calendar record of headaches, associated symptoms, and environmental factors, such as diet, menstrual cycles and sleep patterns.
© Copyright 2003 American Medical Association
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