DESCRIPTION

Headache pain occurs in the tissues covering the brain, the attaching structures at the base of the brain, and the muscles and blood vessels around the scalp, face, and neck. The brain itself is insensitive to pain. Headache is defined as primary or secondary. Headache is considered primary when a disease or other medical condition does not cause it.

The three most common primary headaches are tension or muscle contraction, migraine, and cluster. It is not uncommon for someone to experience a combination of these headaches. In fact, some experts believe that all headaches are derived from the same mechanisms that cause migraine, and they are simply variations on a single biologic theme. Secondary headaches are caused by other medical conditions, such as sinusitis infection, neck injuries or abnormalities, and stroke.

Tension Headache

Tension headache is often experienced in the forehead, in the back of the head and neck, or in both regions; it is described as a tight feeling, as if the head were in a vise. Soreness in the shoulders or neck is common. These headaches can last from minutes to days and may occur daily in some sufferers. Tension headaches do not cause nausea or limit activities as migraine headaches do, although depression, anxiety, and sleeping problems may accompany persistent headaches. They sometimes evolve in people who initially experience migraines, and, in such cases, can become chronic and difficult to treat.

Migraine Headache

The word migraine is derived from the Greek word hemikrania, meaning "half of the head". In general, there are several phases to a migraine.

Vague premonitory symptoms, called the prodrome phase, may precede a migraine attack by several hours, or even a day or two. Such prodrome symptoms can include sensitivity to light or sound, changes in appetite, fatigue, malaise, and mood changes.

About 20% of migraine sufferers have pre-headache sensory disturbances called auras. Migraine headaches with auras are termed classic migraines; migraines without auras are called common migraines. A person may experience one or the other at different times. Typical auras include visual disturbances such as the appearance of zigzag lines, stars or shimmering areas, blind spots, and tunnel vision (inability to see to the side). Speech disturbances, tingling or numbness, weakness in an arm or leg, perceptual disturbances such as space or size distortions, and confusion may also occur, though these symptoms are less common. Migraine auras last between 15 and 45 minutes. A type of migraine, known as ocular migraine, is painless and produces only auras or other visual symptoms.

The pain of a classic migraine headache is 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 to 2 pain-wracked days.

The 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 or 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 -near the days of menstruation or every Saturday morning after a stressful week of work.

After a migraine attack, there is usually a postdrome phase, in which patients may feel exhausted and mentally foggy for a while.

Although half of women with migraines report they are related to menstruation, experts believe that true menstrual migraines are less common than thought. Such migraines are without auras and defined as those that regularly occur during the first three days of menstruation, but not during ovulation or right before a period. The study found no association between menstruation and migraines with auras.

Children may have a form of migraine known as a migraine equivalent or abdominal migraine, which does not cause a headache at all. Instead children experience periodic bouts of nausea and vomiting (called cyclic vomiting syndrome) or other secondary symptoms found in adult migraine, such as a reaction against light or sound.

Cluster Headache

Cluster headaches cause very severe, stabbing pain centered in one eye. People often awaken with them a few hours after they go to bed. Associated symptoms include excessive tearing, a drooping eyelid, and one stuffy or runny nostril, all on the same side as the pain. Feelings of intense restlessness are common, unlike migraine attacks, during which the tendency is to sleep. People in the throes of a cluster headache may pace the floor or may even bang their heads against the wall in an attempt to cope with the pain. Attacks are usually brief, lasting between 30 and 90 minutes, although they can persist for up to 3 hours. During an active period, sufferers can experience one or more bouts a day, or as few as one every other day. Patients typically experience recurrent cluster attacks over 4 to 12 weeks, with headache-free periods lasting several months or even years. In a rare form of cluster headache, known as chronic paroxysmal hemicrania, as many as six attacks per day can occur.

Headaches Secondary to Other Medical Disorders

About 90% of the people seeking help for headaches have one of the primary headache disorders discussed above. In secondary headaches, there is an underlying disorder that produces the headache as a symptom. Many conditions produce headache; some of the most common are listed below.

Headache Due to Neck Problems. Some headaches may be caused by abnormalities of the neck muscles resulting from prolonged bad posture (such as sitting in front of a computer keyboard or daily driving for long periods), arthritis, injuries of the upper spine, or abnormalities in the cervical spine (the spinal bones in the neck). Nerves in the neck converge in the trigeminal nerve in the face and can generate pain signals that the brain may interpret as headache. Pain is usually on one side; even if it affects both sides of the head it is usually more severe on one side. The quality of the headache may be similar to an aching tension headache or a mild migraine without auras.

Sinus Headache. Fever, runny nose, congestion, and general debilitation accompany headaches produced by sinus infection. Sinus headaches are usually around the eyes, across the cheeks, or over the forehead. They are usually mild in the morning and increase during the day. Many primary headaches are misdiagnosed as sinus headache when, in fact, there is no infection; a true sinus headache lasts until the infection is treated.

Temporomandibular Joint Dysfunction (TMJ). TMJ is caused by clenching the jaws or grinding the teeth (usually during sleep), or by abnormalities in the jaw joints themselves. The diagnosis is easy if chewing produces pain or if jaw motion is restricted or noisy. TMJ pain can occur in the ear, the cheek, temples, or neck and shoulders.

Glaucoma. Acute glaucoma is caused by increased pressure in the eye and requires immediate medical attention. Throbbing pain may be felt around or behind the eyes or in the forehead. Patients have redness in the eye and may see halos or rings around lights. Pain may be referred to other areas.

Brain Tumor. Fear of brain tumor is common among people with headaches, but headache is almost never the first or only sign of a tumor. Changes in personality and mental functioning, vomiting, seizures, and other symptoms are more likely to appear first. When the headache does develop, it is often worse early in the morning or may awaken sufferers during the night.

Hypertension. Although many people attribute headaches to high blood pressure, the two are rarely associated. An exception is malignant hypertension, an uncommon medical emergency, in which the blood pressure abruptly rises to extreme levels, causing damage to blood vessels in the brain, heart, and kidneys.

Strokes Caused by Blood Clots or Hemorrhages. A blood clot or hemorrhage in the brain leading to a stroke can cause a severe headache, sometimes referred to as a thunderclap headache when it is very sudden and severe. The onset of such a headache, particularly if it is associated with confusion, stupor, or other neurologic symptoms, mandates prompt medical attention. It is important to determine if a clot or bleeding is causing the stroke, since treatments are very different.

Head Injuries. It is obvious that a significant blow to the head will cause pain. Post-injury headaches, however, can reflect serious damage, ranging from skull fractures to internal bleeding.

Disorders of the Meninges. The meninges are the membranes covering the brain and the spinal cord. In very rare instances, ordinary physical strain may injure or weaken the meninges, causing a leakage of cerebrovascular fluid. This can cause severe headache and nausea, which are relieved by lying flat. The condition is very treatable. Meningitis, which is an infection or irritation of these membranes, is an uncommon but potentially serious cause of severe headache. Other symptoms include nausea and stiffness or pain in the neck.

Gynecologic Problems. Many clinicians have anecdotally linked gynecologic problems, such as ovarian cysts and menstrual disorders, to chronic headaches, and new data are emerging to support this association.

Temporal (Giant Cell) Arteritis. Certain causes of headaches are unique to the elderly, such as temporal arteritis, also called giant cell arteritis. Inflammation in arteries that carry blood to the head, neck, and sometimes the upper part of the body can cause very severe headaches. In addition to being over 70, the risk for this headache is highest among women, people of European heritage, and patients with polymyalgia rheumatica.

Miscellaneous Causes of Benign Headaches. Rapid consumption of ice cream or other very cold foods or beverages is the most common trigger of sudden headache pain, which may be prevented by warming the food or drink for a few seconds in the front of the mouth before swallowing. Other common benign causes of headache include eyestrain, dental problems, allergies, systemic infections, and caffeine withdrawal. Headaches may be induced by sexual activity or intense physical exertion.

CAUSE

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.

A person can be born with a potential for migraine and things that are really not so terrible trigger the headache. These triggers include stress and other normal emotions, as well as biological and environmental conditions. Fatigue, glaring or flickering lights, the weather, and certain foods can set off migraine. It may seem hard to believe that eating such seemingly harmless foods as yogurt, nuts, and lima beans can result in a painful migraine headache. However, some scientists believe that these foods and several others contain chemical substances, such as tyramine, which 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.

While a food-triggered migraine usually occurs soon after eating, other triggers may not cause immediate pain. Scientists report that people can develop migraine not only during a period of stress but also afterwards when their vascular systems are still reacting. For example, migraines that wake people up in the middle of the night are believed to result from a delayed reaction to stress. 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 creating a spasm in 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 that 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 inflammation and swelling 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 migraines

Although both males and females seem to be affected by migraine, the condition is more common in adult women. Both sexes may develop migraine in infancy, but most often the disorder begins between the ages of 5 and 35.

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. Scientists report that 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 when they take birth control pills. And normal women who do not suffer from headaches may develop migraines as a side effect when they use oral contraceptives. Investigators around the world are studying hormonal changes in women with migraine in the hope of identifying the specific ways these naturally occurring chemicals cause headaches.

SYMPTOMS

A typical migraine attack produces throbbing pain on one side of the head, often accompanied by nausea, sometimes with vomiting; visual symptoms are common, and facial tingling or numbness may occur. If untreated, attacks usually last from 4 to 72 hours. Pain sometimes spreads to affect the entire head and is worsened by physical activity. Extreme sensitivity to light and noise are common, and patients may feel cold and look pale.

Other forms of Migraine

In addition to classic and common, migraine headache can take several other forms:

Patients with hemiplegic migraine have temporary paralysis on one side of the body, a condition known as hemiplegia. Some people may experience vision problems and vertigo -- a feeling that the world is spinning. These symptoms begin 10 to 90 minutes before the onset of headache pain.

In ophthalmoplegic migraine, the pain is around the eye and is associated with a droopy eyelid, double vision, and other sight problems.

Basilar artery migraine involves a disturbance of a major brain artery. Pre-headache symptoms include vertigo, double vision, and poor muscular coordination. This type of migraine occurs primarily in adolescent and young adult women and is often associated with the menstrual cycle.

Running, lifting, coughing, sneezing, or bending brings on benign exertional headache. The headache begins at the onset of activity, and pain rarely lasts more than several minutes.

Status migrainosus is a rare and severe type of migraine that can last 72 hours or longer. The pain and nausea are so intense that people who have this type of headache must be hospitalized. The use of certain drugs can trigger status migrainosus. Neurologists report that many of their status migrainosus patients were depressed and anxious before they experienced headache attacks.

Headache-free migraine is characterized by such migraine symptoms as visual problems, nausea, vomiting, constipation, or diarrhea. Patients, however, do not experience head pain. Headache specialists have suggested that unexplained pain in a particular part of the body, fever, and dizziness could also be possible types of headache-free migraine.

TREATMENT

During the Stone Age, pieces of a headache sufferer's skull were cut away with flint instruments to relieve pain. Another unpleasant remedy used in the British Isles around the ninth century involved drinking "the juice of elderseed, cow's brain, and goat's dung dissolved in vinegar." Fortunately, today's headache patients are spared such drastic measures.

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 using cold packs or by pressing on the bulging artery found in front of the ear on the painful side of the head.

Drug Therapy There are two ways to approach the treatment of migraine headache with drugs: prevent the attacks, or relieve symptoms after the headache occurs.

For infrequent migraine, drugs can be taken at the first sign of a headache in order to stop it or to at least ease the pain. People who get occasional mild migraine may benefit by taking aspirin or acetaminophen at the start of an attack. Aspirin raises a person's tolerance to pain and also discourages clumping of blood platelets. Small amounts of caffeine may be useful if taken in the early stages of migraine. But for most migraine sufferers who get moderate to severe headaches, and for all cluster patients, stronger drugs may be necessary to control the pain.

One of the most commonly used drugs for the relief of classic and common migraine symptoms is ergotamine tartrate, a vasoconstrictor which helps counteract the painful dilation stage of the headache. For optimal benefit, the drug is taken during the early stages of an attack. If a migraine has been in progress for about an hour and has passed into the final throbbing stage, ergotamine tartrate will probably not help.

Because ergotamine tartrate can cause nausea and vomiting, it may be combined with antinausea drugs. Research scientists caution that ergotamine tartrate should not be taken in excess or by people who have angina pectoris, severe hypertension, or vascular, liver, or kidney disease. Patients who are unable to take ergotamine tartrate may benefit from other drugs that constrict dilated blood vessels or help reduce blood vessel inflammation.

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. Research scientists are studying the mechanisms underlying these self-regulation treatments.

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 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 that your hands feel very warm and heavy."

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 Anti-Migraine 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 dilation of the blood vessels in the head. 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 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 migraine patients avoid oversleeping on weekends. Sleeping late can change the body's normal blood sugar level and lead to a headache.

PREVENTION

For headaches 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; and amitriptyline, an antidepressant.

Antidepressants called MAO inhibitors also prevent migraine. These drugs block an enzyme called monoamine oxidase that 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.

Several drugs for the prevention of migraine have been developed in recent years, including drugs that mimic the action of serotonin, including serotonin agonists, which mimic the action of this key brain chemical. Prompt administration of these drugs is important.

Many antimigraine drugs can have adverse side effects. But like most medicines they should be 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 to stop taking them as soon as possible.

CONDITION & SUPPORT SITES