Wednesday, September 24, 2008

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.

Migraine afflicts 28 million Americans, with females suffering more frequently (17%) than males (6%). Missed work and lost productivity from migraine create a significant public burden. Nevertheless, migraine still remains largely undertreated and underdiagnosed. Less than half the sufferers are diagnosed by their doctors.

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 is a migraine headache diagnosed?

Migraine headaches are usually diagnosed when the symptoms described above are present. Migraine generally begins in childhood to early adulthood. While migraines can first occur in an individual beyond the age of fifty, advancing age makes other types of headaches more likely. A family history is usually present, suggesting a genetic predisposition in migraine sufferers. In addition to diagnosing migraine from the clinical presentation there is usually an accompanying normal examination.

Patients with the first headache ever, worst headache ever, or where there is a significant change in headache or the presence of nervous system symptoms, like visual or hearing or sensory loss, may require additional tests. The tests may include blood testing, brain scanning (either CT or MRI), and a spinal tap.

Monday, September 22, 2008

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.

How are migraine headaches prevented?

There are two ways to prevent migraine headaches: 1) by avoiding factors ("triggers") that cause the headaches, and 2) by preventing headaches with medications (prophylactic medications). Neither of these preventive strategies is 100% effective. The best one can hope for is to reduce the frequency of headaches.

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.