A migraine headache is a form of vascular headache. Migraine headache is caused by vasodilatation (enlargement of blood vessels) that causes the release of chemicals from nerve fibers that coil around the large arteries of the brain.
Enlargement of these blood vessels stretches the nerves that coil around them and causes the nerves to release chemicals. The chemicals cause inflammation, pain, and further enlargement of the artery. The increasing enlargement of the arteries 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, and this activation causes many of the symptoms associated with migraine attacks; for example, 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 underdiagnosed and undertreated. Less than half of individuals with migraine are diagnosed by their doctors.
Migraine is a chronic condition with 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 is located in the forehead, around the eye, or at 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 (on both sides of the head).
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 such as 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:
- depression or euphoria,
- 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:
- flashing, brightly colored lights in a zigzag pattern (referred to as fortification spectra), usually starting in the middle of the visual field and progressing outward;
- 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 of the body 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.
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.
Some people who suffer from migraines can clearly identify triggers or factors that cause the headaches, but many cannot.
Potential migraine triggers include:
- Allergies and allergic reactions.
- Bright lights, loud noises, and certain odors or perfumes.
- Physical or emotional stress.
- Changes in sleep patterns or irregular sleep.
- Smoking or exposure to smoke.
- Skipping meals or fasting.
- Menstrual cycle fluctuations, birth control pills, hormone fluctuations duringmenopause onset.
- Tension headaches.
- Foods containing tyramine (red wine, aged cheese, smoked fish, chicken livers, figs, and some beans), monosodium glutamate (MSG), or nitrates (like bacon, hot dogs, and salami).
- Other foods such as chocolate, nuts, peanut butter, avocado, banana, citrus, onions, dairy products, and fermented or pickled foods.
- Triggers do not always cause migraines, and avoiding triggers does not always prevent migraines.
Treatment includes therapies that may or may not involve medications.
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 in stopping an attack once it has started.
Sleep may be the best medicine if it is possible.
Preventing migraine takes motivation for the patient to make some life changes. Patients are educated as to triggering factors that can be avoided.
These triggers include:
- avoiding certain foods especially those high in tyramine such as sharp cheeses or those containing sulphites (wines) or nitrates (nuts, pressed meats).
Generally, leading a healthy life-style with good nutrition, an adequate intake of fluids, sufficient sleep and exercise may be useful. Acupuncture has been suggested to be a useful therapy.
Medication for migraine
Individuals with occasional mild migraine headaches that do not interfere with daily activities usually medicate themselves with over-the-counter (OTC or 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),
- non-steroidal anti-inflammatory drugs (NSAIDs).
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 package label.
The two types of NSAIDs:
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 arthritisand other inflammatory conditions such as bursitis, tendonitis, etc.
The difference between OTC and prescription NSAIDs usually is 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.
NSAIDs relieve pain by reducing the inflammation that causes the pain (they are called nonsteroidal antiinflammatory 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. Their full effects also require hours or days. NSAIDs do not have the same side effects that corticosteroids have and their onset of action is faster.
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, the small particles in 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 antiplatelet effects, but their antiplatelet action does not last as long as aspirin, i.e. hours rather than days.
Aspirin, acetaminophen, and caffeine also are available combined in OTC analgesics for the treatment of headaches including migraine. 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.
There are several precautions that should be observed with OTC analgesics:
- Children and teenagers should not use aspirin for the treatment of headaches, other pain, or fever, because of the risk of developing Reye's Syndrome, a life-threatening neurological disease that can lead to coma and even death.
- People with balance disorders or hearing difficulties should avoid using aspirin because aspirin may aggravate these conditions.
- People taking blood thinners such as warfarin (Coumadin) should not take aspirin and non-aspirin NSAIDs without a doctor's supervision because they add further to the risk of bleeding that is caused by the blood thinner.
- People with active ulcers of the stomach and duodenum should not take aspirin and non-aspirin NSAIDs because they can increase the risk of bleeding from the ulcer and impair healing of the ulcer.
- People with advanced liver disease should not take aspirin and non-aspirin NSAIDs because they may impair kidney function. Deterioration of kidney function in these patients can lead to failure of the kidneys.
- OTC or prescription analgesics should not be overused. Overuse of analgesics can lead to the development of tolerance (increasing ineffectiveness of the analgesic) and rebound headaches (return of the headache as soon as the effect of the analgesic wears off, usually in the early morning hours). Thus, overuse of analgesics can lead to a vicious cycle of more and more analgesics for headaches that respond less and less to treatment.