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Migraine Headaches: A Patient Handout
Migraine headaches are usually characterized by severe pain on one or both sides of the head, an upset stomach, and at times disturbed vision. Sensitivity to light is a standard symptom of the two most prevalent types of migraine-caused headache: classic and common.
The major difference between the two types is the appearance of neurological symptoms 10-30 minutes before a classic migraine attack. These symptoms are called an aura. The person may see flashing lights or zigzag lines, or may temporarily lose vision. Other classic symptoms include speech difficulty, weakness of an arm or leg, tingling of the face or hands, and confusion.
The pain of a classic migraine headache may be described as intense, throbbing, or pounding and is felt in the forehead, temple, ear, jaw, or around the eye. Classic migraine starts on one side of the head but may eventually spread to the other side. An attack lasts 1-2 days.
Common migraine—a term that reflects the disorder's greater occurrence in the general population—is not preceded by an aura. But some people experience a variety of vague symptoms beforehand, including mental fuzziness, mood changes, fatigue, and unusual retention of fluids. During the headache phase of a common migraine, a person may have diarrhea and increased urination, as well as nausea and vomiting. Common migraine pain can last 3-4 days.
Both classic and common migraine can strike as often as several times a week, or as rarely as once every few years. Both types can occur at any time. Some people, however, experience migraines at predictable times—for example, near the days of menstruation or every Saturday morning after a stressful week of work.
The migraine process. Research scientists are unclear about the precise cause of migraine headaches. There seems to be general agreement, however, that a key element is blood flow changes in the brain. People who get migraine headaches appear to have blood vessels that overreact to various triggers.
Scientists have devised one theory of migraine which explains these blood flow changes and also certain biochemical changes that may be involved in the headache process. According to this theory, the nervous system responds to a trigger such as stress by causing a spasm of the nerve-rich arteries at the base of the brain. The spasm closes down or constricts several arteries supplying blood to the brain, including the scalp artery and the carotid or neck arteries. As these arteries constrict, the flow of blood to the brain is reduced. At the same time, blood-clotting particles called platelets clump together—a process which is believed to release a chemical called serotonin. Serotonin acts as a powerful constrictor of arteries, further reducing the blood supply to the brain.
Reduced blood flow decreases the brain's supply of oxygen. Symptoms signaling a headache, such as distorted vision or speech, may then result, similar to symptoms of stroke. Reacting to the reduced oxygen supply, certain arteries within the brain open wider to meet the brain's energy needs. This widening or dilation spreads, finally affecting the neck and scalp arteries. The dilation of these arteries triggers the release of pain-producing substances called prostaglandins from various tissues and blood cells. Chemicals that cause swelling and inflammation, and substances that increase sensitivity to pain, are also released. The circulation of these chemicals and the dilation of the scalp arteries stimulate the pain-sensitive nociceptors. The result, according to this theory: a throbbing pain in the head.
Women and migraine. Although both males and females seem to be equally affected by migraine, the condition is more common in adult women.
The relationship between female hormones and migraine is still unclear. Women may have "menstrual migraine"—headaches around the time of their menstrual period—which may disappear during pregnancy. Other women develop migraine for the first time when they are pregnant. Some are first affected after menopause.
The effect of oral contraceptives on headaches is perplexing. Some women with migraine who take birth control pills experience more frequent and severe attacks. However, a small percentage of women have fewer and less severe migraine headaches while taking birth control pills. And women who do not suffer from headaches may develop migraines as a side effect when they use oral contraceptives.
Triggers of headache. Although many sufferers have a family history of migraine, the exact hereditary nature of this condition is still unknown. People who get migraines are thought to have an inherited abnormality in the regulation of blood vessels.
Migraine triggers include stress and other normal emotions, as well as biological and environmental conditions. Fatigue, glaring or flickering lights, changes in the weather, and certain foods can set off migraine. Some scientists believe that foods such as yogurt, nuts, and lima beans (and several others) contain chemical substances, such as tyramine, that constrict arteries—the first step of the migraine process. Other scientists believe that foods cause headaches by setting off an allergic reaction in susceptible people.
How Is Migraine Headache Treated?
Drug therapy, biofeedback training, stress reduction, and elimination of certain foods from the diet are the most common methods of preventing and controlling migraine and other vascular headaches.
Regular exercise, such as swimming or vigorous walking, can also reduce the frequency and severity of migraine headaches.
During a migraine headache, temporary relief can sometimes be obtained by applying cold packs to the head or by pressing on the bulging artery found in front of the ear on the painful side of the head.
Biofeedback and relaxation training. Drug therapy for migraine is often combined with biofeedback and relaxation training. Biofeedback refers to a technique that can give people better control over such body function indicators as blood pressure, heart rate, temperature, muscle tension, and brain waves. Thermal biofeedback allows a patient to consciously raise hand temperature. Some patients who are able to increase hand temperature can reduce the number and intensity of migraines.
A patient learning thermal biofeedback wears a device that transmits the temperature of an index finger or hand to a monitor. While the patient tries to warm his hands, the monitor provides feedback either on a gauge that shows the temperature reading or by emitting a sound that increases in intensity as the temperature increases. The patient is not told how to raise hand temperature, but is given suggestions such as "imagine your hands feel very warm and heavy."
In another type of biofeedback called electromyographic (EMG) training, the patient learns to control muscle tension in the face, neck, and shoulders.
Although biofeedback can be practiced at home with a portable monitor, the ultimate goal is to wean the patient from the machine. The patient can then use biofeedback anywhere at the first sign of a headache.
The antimigraine diet. Scientists estimate that a small percentage of migraine sufferers will benefit from a treatment program focused solely on eliminating headache-provoking foods and beverages.
Other migraine patients may be helped by a diet to prevent low blood sugar. Low blood sugar, or hypoglycemia, can cause headache. This condition can occur after a period without food: overnight, for example, or when a meal is skipped. People who wake up in the morning with a headache may be reacting to the low blood sugar caused by the lack of food overnight.
Treatment for headaches caused by low blood sugar consists of scheduling smaller, more frequent meals. A special diet designed to stabilize the body's sugar-regulating system is sometimes recommended.
Reprinted from: National Institute of Neurological Disorders and Stroke. Available at: www.ninds.nih.gov/disorders/headache/detail_headache.htm. Accessed May 15, 2007.