Migraine Headache

What is a migraine headache?

A migraine headache is a form of vascular headache. Migraine headache is caused by a combination of vasodilatation (enlargement of blood vessels) and the release of chemicals from nerve fibers that coil around the blood vessels. During a migraine attack, the temporal artery enlarges. (The temporal artery is an artery that lies on the outside of the skull just under the skin of the temple.) Enlargement of the temporal artery stretches the nerves that coil around the artery and causes the nerves to release chemicals. The chemicals cause inflammation, pain, and further enlargement of the artery. The increasing enlargement of the artery magnifies the pain.

Migraine attacks commonly activate the sympathetic nervous system in the body. The sympathetic nervous system is often thought of as the part of the nervous system that controls primitive responses to stress and pain, the so-called "fight or flight" response. The increased sympathetic nervous activity in the intestine causes nausea, vomiting, and diarrhea. Sympathetic activity also delays emptying of the stomach into the small intestine and thereby prevents oral medications from entering the intestine and being absorbed. The impaired absorption of oral medications is a common reason for the ineffectiveness of medications taken to treat migraine headaches. The increased sympathetic activity also decreases the circulation of blood, and this leads to pallor of the skin as well as cold hands and feet. The increased sympathetic activity also contributes to the sensitivity to light and sound sensitivity as well as blurred vision.

What are the symptoms of migraine headaches?

Migraine is a chronic condition of recurrent attacks. Most (but not all) migraine attacks are associated with headaches. Migraine headaches usually are described as an intense, throbbing or pounding pain that involves one temple. (Sometimes the pain can be located in the forehead, around the eye, or the back of the head). The pain usually is unilateral (on one side of the head), although about a third of the time the pain is bilateral. The unilateral headaches typically change sides from one attack to the next. (In fact, unilateral headaches that always occur on the same side should alert the doctor to consider a secondary headache, for example, one caused by a brain tumor). A migraine headache usually is aggravated by daily activities like walking upstairs. Nausea, vomiting, diarrhea, facial pallor, cold hands, cold feet, and sensitivity to light and sound commonly accompany migraine headaches. As a result of this sensitivity to light and sound, migraine sufferers usually prefer to lie in a quiet, dark room during an attack. A typical attack lasts between 4 and 72 hours.

An estimated 40%-60% of migraine attacks are preceded by premonitory (warning) symptoms lasting hours to days. The symptoms may include sleepiness, irritability, fatigue, depression or euphoria, yawning, and cravings for sweet or salty foods. Patients and their family members usually know that when they observe these warning symptoms that a migraine attack is beginning.

An estimated 20% of migraine headaches are associated with an aura. Usually, the aura precedes the headache, although occasionally it may occur simultaneously with the headache. The most common auras are 1) flashing, brightly colored lights in a zigzag pattern (fortification spectra), usually starting in the middle of the visual field and progressing outward and 2) a hole (scotoma) in the visual field, also known as a blind spot. Some elderly migraine sufferers may experience only the visual aura without the headache. A less common aura consists of pins-and-needles sensations in the hand and the arm on one side or pins-and-needles sensations around the mouth and the nose on the same side. Other auras include auditory (hearing) hallucinations and abnormal tastes and smells.

Complicated migraines are migraines that are accompanied by neurological dysfunction. The part of the body that is affected by the dysfunction is determined by the part of the brain that is responsible for the headache. Vertebrobasilar migraines are characterized by dysfunction of the brainstem (the lower part of the brain that is responsible for automatic activities like consciousness and balance). The symptoms of vertebrobasilar migraines include fainting as an aura, vertigo (dizziness in which the environment seems to be spinning) and double vision. Hemiplegic migraines are characterized by paralysis or weakness of one side of the body, mimicking a stroke. The paralysis or weakness is usually temporary, but sometimes it can last for days.

For approximately 24 hours after a migraine attack, the migraine sufferer may feel drained of energy and may experience a low-grade headache along with sensitivity to light and sound. Unfortunately, some sufferers may have recurrences of the headache during this period.

How are migraine headaches treated?

Treatment is can include non-medication and medication approaches.

Non-medication therapies for migraine

Therapy that does not involve medications can provide symptomatic and preventative therapy. Using ice, biofeedback, and relaxation techniques may be helpful at stopping an attack once it has started. If possible, sleep is the best medicine. Preventing migraine takes motivation for the patient to make some life changes. Patients are educated as to triggering factors that can be avoided. These include smoking cessation, avoiding certain foods especially those high in tyramine (sharp cheeses) or those containing sulphites (wines) or nitrates (nuts, pressed meats). Generally, leading a healthy life style with good nutrition, adequate water intake, sufficient sleep and exercise may be useful. Acupuncture has been suggested to be a useful non-medication therapy.

Medication therapies for migraine

Individuals with occasional mild migraine headaches that do not interfere with daily activities usually medicate themselves with over-the-counter (OTC, non-prescription) pain relievers (analgesics). Many OTC analgesics are available. OTC analgesics have been shown to be safe and effective for short-term relief of headache (as well as muscle aches, pains, menstrual cramps , and fever) when used according to the instructions on their labels.

There are two major classes of OTC analgesics: acetaminophen (Tylenol) and non-steroidal anti-inflammatory drugs (NSAIDs). The two types of NSAIDs are aspirin and non-aspirin. Examples of non-aspirin NSAIDs are ibuprofen (Advil, Nuprin, Motrin IB, and Medipren) and naproxen (Aleve). Some NSAIDs are available by prescription only. Prescription NSAIDs are usually prescribed to treat arthritis and other inflammatory conditions such as bursitis, tendonitis, etc. The difference between OTC and prescription NSAIDs may only be the amount of the active ingredient contained in each pill. For example, OTC naproxen (Aleve) contains 220 mg of naproxen per pill, whereas prescription naproxen (Naprosyn) contains 375 or 500 mg of naproxen per pill.

Acetaminophen reduces pain and fever by acting on pain centers in the brain. Acetaminophen is well tolerated and generally is considered easier on the stomach than NSAIDs. However, acetaminophen can cause severe liver damage in high (toxic) doses or if used on a regular basis over extended periods of time. In individuals who regularly consume moderate or large amounts of alcohol, acetaminophen can cause serious damage to the liver in lower doses that usually are not toxic. Acetaminophen also can damage the kidneys when taken in large doses. Therefore, acetaminophen should not be taken more frequently or in larger doses than recommended on the label. For information, please read the Acetaminophen and Liver Damage article.

NSAIDs relieve pain by reducing the inflammation that causes the pain (They are called non-steroidal anti-inflammatory drugs or NSAIDs because they are different from corticosteroids such as prednisone, prednisolone, and cortisone which also reduce inflammation). Corticosteroids, though valuable in reducing inflammation, have predictable and potentially serious side effects, especially when used long-term. NSAIDs do not have the same side effects that corticosteroids have.

Aspirin, Aleve, Motrin, and Advil all are NSAIDs and are similarly effective in relieving pain and fever. The main difference between aspirin and non-aspirin NSAIDs is their effect on platelets. Platelets are small particles in the blood that cause blood clots to form. Aspirin prevents the platelets from forming blood clots. Therefore, aspirin can increase bleeding by preventing blood from clotting though it also can be used therapeutically to prevent clots from causing heart attacks and strokes. The non-aspirin NSAIDs also have anti-platelet effects, but their anti-platelet action does not last as long as aspirin.

Aspirin, acetaminophen, and caffeine also are available combined in OTC analgesics for the treatment of headaches. Examples of such combination analgesics are Pain-aid, Excedrin, Fioricet, and Fiorinal.

Finding an effective analgesic or analgesic combination often is a process of trial and error because individuals respond differently to different analgesics. In general, a person should use the analgesic that has worked in the past. This will increase the likelihood that an analgesic will be effective and decrease the risk of side effects.

What are migraine triggers?

A migraine trigger is any factor that causes a headache in individuals who are prone to develop headaches. Only a small proportion of migraine sufferers, however, clearly can identify triggers. Examples of triggers include stress, sleep disturbances, fasting, hormones, bright or flickering lights, odors, cigarette smoke, alcohol, aged cheeses, chocolate, monosodium glutamate, nitrites, aspartame, and caffeine. For some women, the decline in the blood level of estrogen during the onset of menstruation is a trigger for migraine headaches. The interval between exposure to a trigger and the onset of headache varies from hours to two days. Exposure to a trigger does not always lead to a headache. Conversely, avoidance of triggers cannot completely prevent headaches. Different migraine sufferers respond to different triggers, and any one trigger will not induce a headache in every person who has migraine headaches.

Sleep and migraine

Disturbances such as sleep deprivation, too much sleep, poor quality of sleep, and frequent awakening at night are associated with both migraine and tension headaches, whereas improved sleep habits have been shown to reduce the frequency of migraine headaches. Sleep also has been reported to shorten the duration of migraine headaches.

Fasting and migraine

Fasting possibly may precipitate migraine headaches by causing the release of stress-related hormones and lowering blood sugar. Therefore, migraine sufferers should avoid prolonged fasting.

Bright lights and migraine

Bright lights and other high intensity visual stimuli can cause headaches in healthy subjects as well as patients with migraine headaches, but migraine patients seem to have a lower than normal threshold for light-induced pain. Sunlight, television, and flashing lights all have been reported to precipitate migraine headaches.

Caffeine and migraine

Caffeine is contained in many food products (cola, tea, chocolates, coffee) and OTC analgesics. Caffeine in low doses can increase alertness and energy, but caffeine in high doses can cause insomnia, irritability, anxiety, and headaches. The over-use of caffeine-containing analgesics causes rebound headaches. Furthermore, individuals who consume high levels of caffeine regularly are more prone to develop withdrawal headaches when caffeine is stopped abruptly.

Chocolate, wine, tyramine, MSG, nitrites, aspartame and migraine

Chocolate has been reported to cause migraine headaches, but scientific studies have not consistently demonstrated an association between chocolate consumption and headaches. Red wine has been shown to cause migraine headaches in some migraine sufferers, but it is not clear whether white wine also will cause migraine headaches. Tyramine (a chemical found in cheese, wine, beer, dry sausage, and sauerkraut) can precipitate migraine headaches, but there is no evidence that consuming a low-tyramine diet can reduce migraine frequency. Monosodium glutamate (MSG) has been reported to cause headaches, facial flushing, sweating, and palpitations when consumed in high doses on an empty stomach. This phenomenon has been called Chinese restaurant syndrome. Nitrates and nitrites (chemicals found in hotdogs, ham, frankfurters, bacon and sausages) have been reported to cause migraine headaches. Aspartame, a sugar-substitute sweetener found in diet drinks and snacks, has been reported to trigger headaches when used in high doses for prolonged periods.

Female hormones and migraine

Some women who suffer from migraine headaches experience more headaches around the time of their menstrual periods. Other women experience migraine headaches only during the menstrual period. The term "menstrual migraine" is used mainly to describe migraines that occur in women who have almost all of their headaches from two days before to one day after their menstrual periods. Declining levels of estrogen at the onset of menses is likely to be the cause of menstrual migraines. Decreasing levels of estrogen also may be the cause of migraine headaches that develop among users of birth control pills during the week that estrogens are not taken.

What should migraine sufferers do?

Individuals with mild and infrequent migraine headaches that do not cause disability may require only OTC analgesics. Individuals who experience several moderate or severe migraine headaches per month or whose headaches do not respond readily to medications should avoid triggers and consider modifications of their life-style. Life-style modifications for migraine sufferers include:

• Go to sleep and waking up at the same time each day.

• Exercise regularly (daily if possible). Make a commitment to exercise even when traveling or during busy periods at work. Exercise can improve the quality of sleep and reduce the frequency and severity of migraine headaches. Build up your exercise level gradually. Over-exertion, especially for someone who is out of shape, can lead to migraine headaches.

• Do not skip meals, and avoiding prolonged fasting.

• Limit stress through regular exercise and relaxation techniques.

• Limit caffeine consumption to less than two caffeine-containing beverages a day.

• Avoid bright or flashing lights and wearing sunglasses if sunlight is a trigger.

• Identify and avoid foods that trigger headaches by keeping a headache and food diary. Review the diary with your doctor. It is impractical to adopt a diet that avoids all known migraine triggers, however, it is reasonable to avoid foods that consistently trigger migraine headaches.

What are prophylactic medications for migraine headaches?

Prophylactic medications are medications taken daily to reduce the frequency and duration of migraine headaches. They are not taken once a headache has begun. There are several classes of prophylactic medications: beta blockers, calcium-channel blockers, tricyclic antidepressants, antiserotonin agents and anticonvulsants. Medications with the longest history of use are propranolol (Inderal), a beta blocker, and amitriptyline (Elavil), an antidepressant. When choosing a prophylactic medication for a patient the doctor must take into account the drug side effects, drug-drug interactions, and co-existing conditions such as diabetes, heart disease, and high blood pressure.

Beta blockers

Beta-blockers are a class of drugs that block the effects of beta-adrenergic substances such as adrenaline (epinephrine). By blocking the effects of adrenaline, beta-blockers relieve stress on the heart by slowing the rate at which the heart beats. Beta-blockers have been used to treat high blood pressure, angina, certain types or tremors, stage fright, and abnormally fast heart beats (palpitations). They also have become important drugs for improving survival after heart attacks. Beta-blockers have been used for many years to prevent migraine headaches.

It is not known how beta-blockers prevent migraine headaches. It may be by decreasing prostaglandin production, though it also may be through their effect on serotonin or a direct effect on arteries. The beta-blockers used in preventing migraine headaches include propranolol (Inderal), atenolol (Tenormin), metoprolol (Lopressor, Lopressor LA, Toprol XL), nadolol (Corgard), and timolol (Blocadren).

Beta-blockers generally are well-tolerated. They can aggravate breathing difficulties in patients with asthma, chronic bronchitis, or emphysema. In patients who already have slow heart rates (bradycardias) and heart block (defects in electrical conduction within the heart), beta-blockers can cause dangerously slow heartbeats. Beta-blockers can aggravate symptoms of heart failure. Other side effects include drowsiness, diarrhea, constipation, fatigue, decrease in endurance, insomnia, nausea, depression, dreaming, memory loss, impotence.

Tricyclic antidepressants

Tricyclic antidepressants (TCAs) prevent migraine headaches by altering the neurotransmitters, norepinephrine and serotonin, that the nerves of the brain use to communicate with one another. The tricyclic antidepressants that have been used in preventing migraine headaches include amitriptyline (Elavil), nortriptyline (Pamelor, Aventyl), doxepin (Sinequan), imipramine (Tofranil), and protriptyline.

The most commonly encountered side effects associated with TCAs are fast heart rate, blurred vision, difficulty urinating, dry mouth, constipation, weight gain or loss, and low blood pressure when standing.

TCAs should not be used with drugs that inhibit monoamine oxidase such as isocarboxazid (Marplan), phenelzine (Nardil), tranylcypromine (Parnate), and procarbazine (Matulane), since high fever, convulsions and even death may occur. TCAs are used with caution in patients with seizures, since they can increase the risk of seizures. TCAs also are used with caution in patients with enlargement of the prostate because they can make urination difficult. TCAs can cause elevated pressure in the eyes of some patients with glaucoma. TCAs can cause excessive sedation when used with other medications that slow the brain's processes, such as alcohol, barbiturates, narcotics, and benzodiazepines, e.g. lorazepam (Ativan), diazepam (Valium), temazepam (Restoril), oxazepam (Serax), clonazepam (Klonopin), zolpidem (Ambien). Epinephrine should not be used with amitriptyline, since the combination can cause severe high blood pressure

Antiserotonin medications

Methysergide (Sansert) prevents migraine headaches by constricting blood vessels and reducing inflammation of the blood vessels. Methylergonovine is related chemically to methysergide and has a similar mechanism of action. They are not widely used because of their side effects. The most serious side effect of methysergide is retroperitoneal fibrosis (scarring of tissue around the ureters that carry urine from the kidneys to the bladder). Retroperitoneal fibrosis, though rare, can block the ureters and cause backup of urine into the kidneys. Backup of urine into the kidneys can cause back and flank (the side of the body between the ribs and hips) pain and ultimately can lead to kidney failure. Methysergide also has been reported to cause scarring around the lungs that can lead to chest pain, and shortness of breath.

Calcium channel blockers

Calcium channel blockers (CCBs) are a class of drugs that block the entry of calcium into the muscle cells of the heart and the arteries. By blocking the entry of calcium, CCBs reduce contraction of the heart muscle, decrease heart rate, and lower blood pressure. CCBs are used for treating high blood pressure, angina, and abnormal heart rhythms (e.g., atrial fibrillation). CCBs also appear to block a chemical within nerves, called serotonin, and have been used occasionally to prevent migraine headaches. The CCBs used in preventing migraine headaches are diltiazem (Cardizem, Dilacor, Tiazac), verapamil (Calan, Verelan, Isoptin), and nimodipine.

The most common side effects of CCBs are constipation, nausea, headache, rash, edema (swelling of the legs with fluid), low blood pressure, drowsiness, and dizziness. When diltiazem or verapamil are given to individuals with heart failure, symptoms of heart failure may worsen because these drugs reduce the ability of the heart to pump blood. Verapamil and diltiazem may reduce the elimination and increase the blood levels of carbamazepine (Tegretol), simvastatin (Zocor), atorvastatin (Lipitor), and lovastatin (Mevacor). This can lead to toxicity from these drugs.

Anticonvulsants

Anticonvulsants (antiseizure medications) also have been used to prevent migraine headaches. Examples of anticonvulsants that have been used are valproic acid, phenobarbital, gabapentin, and topiramate. It is not known how anticonvulsants work to prevent migraine headaches.