For migraines that occur three or more times a month, preventive treatment is usually recommended. Drugs used to prevent classic and common migraine include methysergide maleate, which counteracts blood vessel constriction; propranolol hydrochloride, which stops blood vessel dilation; amitriptyline, an antidepressant; valproic acid, an anticonvulsant; and verapamil, a calcium channel blocker.

Antidepressants called MAO inhibitors also prevent migraine. These drugs block an enzyme called monoamine oxidase which normally helps nerve cells absorb the artery-constricting brain chemical, serotonin. MAO inhibitors can have potentially serious side effects - particularly if taken while ingesting foods or beverages that contain tyramine, a substance that constricts arteries.

Many antimigraine drugs can have adverse side effects. But like most medicines they are relatively safe when used carefully and under a physician's supervision. To avoid long-term side effects of preventive medications, headache specialists advise patients to reduce the dosage of these drugs and then stop taking them as soon as possible. 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. The mechanisms underlying these self-regulation treatments are being studied by research scientists."To succeed in biofeedback," says a headache specialist, "you must be able to concentrate and you must be motivated to get well."A patient learning thermal biofeedback wears a device which 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 or beep 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.""I have a good imagination," says one migraine sufferer who traded in her medication for thermal biofeedback. The technique decreased the number and severity of headaches she experienced.

In another type of biofeedback called electromyographic or EMG training, the patient learns to control muscle tension in the face, neck, and shoulders.Either kind of biofeedback may be combined with relaxation training, during which patients learn to relax the mind and body.Biofeedback can be practiced at home with a portable monitor. But the ultimate goal of treatment 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 migraines. 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 migraine may be reacting to the low blood sugar caused by the lack of food overnight.

Treatment for a migraine caused by low blood sugar consists of scheduling smaller, more frequent meals for the patient. A special diet designed to stabilize the body's sugar-regulating system is sometimes recommended.For the same reason, many specialists also recommend that how to treat migraine patients is to avoid oversleeping on weekends. Sleeping late can change the body's normal blood sugar level and lead to a migraine.