What is a migraine headache?
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.
What are the symptoms of migraine headaches?
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.
- sleepiness,
- irritability,
- fatigue,
- depression or euphoria,
- yawning,
and
- cravings for sweet or salty foods.
Migraine aura
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; and
- a hole (scotoma) in the visual field, also known as a blind spot.
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.
What is the treatment for moderate to severe migraine headaches?
Migraine-specific abortive medications usually are necessary for moderate to severe migraine headaches. The abortive medications for moderate or severe migraine headaches are different than OTC analgesics. Instead of relieving pain, they abort headaches by counteracting the cause of the headache, dilation of the temporal arteries. In fact, they cause narrowing of the arteries. Examples of migraine-specific abortive medications are the triptans and ergot preparations.Triptans
The triptans attach to serotonin receptors on the blood vessels and nerves that surround them, constrict the blood vessels, and reduce the inflammation. This stops the headache. The triptan with the longest history of use is sumatriptan (Imitrex). Sumatriptan is available in the US as an injection, oral tablet, and nasal inhaler. Zolmitriptan (Zomig) and rizatriptan (Maxalt) are newer triptans that are available as oral tablets and as tablets that melt in the mouth. Naratriptan (Amerge), almotriptan (Axert) and frovatriptan (Frovalan) are available only as oral tablets.Traditionally, triptans were prescribed for moderate or severe migraines after OTC analgesics and other simple measures failed. Newer studies suggest that triptans can be used as the first treatment for patients with migraines that are causing disability. (Significant disability is defined as more than 10 days of at least 50% disability during a three-month period.). Triptans should be used early after the migraine begins, before the onset of pain or when the pain is mild. Using a triptan early in an attack increases its effectiveness, reduces side effects, and decreases the chance of recurrence of another headache during the following 24 hours. Used early, triptans can be expected to abort more than 80% of migraine headaches within two hours.
The U.S. Food and Drug Administration (FDA) has issued a warning about taking triptans together with medications of the SSRI (selective serotonin reuptake inhibitor) or SNRI (selective serotonin/norepinephrine reuptake inhibitor) classes. Taking these medicines together can cause a serious condition called serotonin syndrome.
Side effects of triptans
The most common side effects of triptans are facial flushing, tingling of the skin, and a sense of tightness around the chest and throat. Other less common side effects include drowsiness, fatigue, and dizziness. These side effects are short-lived and are not considered serious.
The most serious side effects of triptans are heart attacks and strokes. Triptans are effective in migraine headaches because they narrow arteries in the head; however, they also can narrow arteries in the heart. In individuals without existing carotid or coronary artery disease, the narrowing caused by triptans usually does not cause problems. However, persons whose carotid and coronary arteries are narrowed by atherosclerosis or who suffer from intermittent spasm of the coronary arteries (a condition called Prinzmetal's or variant angina), the narrowing caused by triptans can further reduce the flow of blood through the arteries and have been reported to cause heart attacks and strokes. Therefore, triptans should not be used by those who have had heart attacks and strokes, or those who have symptoms of atherosclerosis such as angina, transient ischemic attack (TIAs), and intermittent claudication.
Healthy adults may have atherosclerosis and narrowing of the coronary arteries that are "silent", that is, without past strokes, transient ischemic attacks, heart attacks, or angina. Therefore, before prescribing a triptan, a doctor should evaluate patients for possible atherosclerosis if they have one or more risk factors for developing atherosclerosis. These risk factors include cigarette smoking, diabetes mellitus, high blood pressure, high levels of LDL ("bad") cholesterol in the blood, obesity, male and over 40 years of age, female and postmenopausal, or a family member(s) who has had heart attacks at an early age. Some patients who are at risk should receive their first dose of a triptan in the doctor's office while being monitored with an electrocardiogram (EKG).
Triptans can interact with other drugs. For example, there have been rare reports of triptans causing a "serotonin syndrome" when given together with a selective serotonin reuptake inhibitor. Selective serotonin reuptake inhibitors (SSRIs) are a class of medications widely used to treat depression. The symptoms of serotonin syndrome include confusion, fever, tremor, high blood pressure, diarrhea, and sweating. Certain triptans such as sumatriptan, zolmitriptan, and rizatriptan can interact with monoamine oxidase inhibitors. Propranolol (Inderal) can raise rizatriptan blood levels. Cimetidine (Tagamet) can increase zolmitriptan blood levels.
Triptans should not be used in pregnant women and are not generally used in young children.
Ergots
Ergots, like triptans, are medications that abort migraine headaches. These may be combined with caffeine and/or other pain relief medications in combination products. Examples of ergots include ergotamine preparations (Ergomar, Wigraine, and Cafergot) and dihydroergotamine preparations (Migranal, DHE-45). Ergots, like triptans, cause constriction of blood vessels, but ergots tend to cause more constriction of vessels in the heart and other parts of the body than the triptans, and their effects on the heart are more prolonged than those of the triptans. Therefore, they are not as safe as the triptans. The ergots also are more prone to cause nausea and vomiting than the triptans. The ergots can cause prolonged contraction of the uterus and miscarriages in pregnant women.Midrin
Midrin is used to abort migraine and tension headaches. It is a combination of isometheptene (a blood vessel constrictor), acetaminophen (a pain reliever), and dichloralphenazone (a mild sedative). It is most effective if used early during a headache; however, because of its potent blood vessel constricting effect, it should not be used in persons with high blood pressure, kidney disease, glaucoma, atherosclerosis, liver disease, or taking monoamine oxidase inhibitors.What other medications are used for treating migraine headaches?
Narcotics and butalbital-containing medications sometimes are used to treat migraine headaches; however, these medications are potentially addicting and are not used as initial treatment. They are sometimes used for individuals whose headaches fail to respond to OTC medications but who are not candidates for triptans either due to pregnancy or the risk of heart attack and stroke.In migraine sufferers with severe nausea, a combination of a triptan and an antinausea medication, for example, prochlorperazine (Compazine) or metoclopramide (Reglan) may be used. When nausea is severe enough that oral medications are impractical, intravenous medications such as DHE-45 (dihydroergotamine), prochlorperazine (Compazine), and valproate (Depacon) are useful.
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 are migraine triggers?
A migraine trigger is any environmental or physiological factor that leads to 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.
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 people who suffer from migraines seem to have a lower than normal threshold for light-induced headache 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 hot dogs, 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 lifestyle. Lifestyle modifications for migraine sufferers include:- Go to sleep and wake 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 avoid 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 wear 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.
Beta blockers
Beta-blockers are a class of drugs that block the effects of beta-adrenergic substances produced by the body, specifically the nerves and the adrenal gland, 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, Endep), 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 (orthostatic hypotension).
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 peole with seizures, since they can increase the risk of seizures. TCAs also are used with caution in men with enlargement of the prostate because they can make urination difficult. TCAs can cause elevated pressure in the eyes in some glaucoma sufferers. TCAs can cause excessive sedation when used with other medications that slow the brain's processes, such as alcohol, barbiturates, narcotics, and benzodiazepines, for example, lorazepam (Ativan), diazepam (Valium), temazepam (Restoril), oxazepam (Serax), clonazepam (Klonopin), and 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, shortness of breath, as well as scarring of the heart valves.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 (for example, atrial fibrillation). CCBs also appear to block the effects of 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.Who should consider prophylactic medications to prevent migraine headaches?
Not all migraine sufferers need prophylactic medications; individuals with mild or infrequent headaches that respond readily to abortive medications do not need prophylactic medications. Individuals who should consider prophylactic medications are those who:
- Require abortive medications for migraine headaches more frequently than
twice weekly.
- Have two or more migraine headaches a month that do not respond readily to
abortive medications.
- Have migraine headaches that are interfering substantially with their
quality of life and work.
- Cannot take abortive medications because of heart disease, stroke, or pregnancy, or cannot tolerate abortive medications because of side effects.
Prophylactic medications can reduce the frequency and duration of migraine headaches but cannot be expected to eliminate migraine headaches completely. The success rate of most prophylactic medications is approximately 50%. Success in preventing migraine headaches is defined as more than a 50% reduction in the frequency of headaches. Prophylactic medications usually are begun at a low dose that is increased slowly in order to minimize side effects. Individuals may not notice a reduction in the frequency, severity, or duration of their headaches for 2 to 3 months after starting treatment.
What is the proper way to use preventive medications?
- Doctors familiar with the treatment of migraine headaches should prescribe preventive medications.
- Decisions about which preventive medication to use are based on the side effects of the medication and the presence of any medical conditions.
- Propranolol (Inderal) often is used first, provided that the individual does not have asthma, COPD, or heart disease. Amitriptyline (Elavil, Endep) also is used commonly.
- Preventive medications are begun at low doses and gradually increased to higher doses if needed. This minimizes side effects from the medications. Preventive medications are to be taken daily for months to years. When they are stopped, the dose needs to be gradually reduced rather than abruptly stopped. Abruptly stopping preventive medications can lead to headaches.
- In some instances, more than one drug may be needed. Non-medication and behavioral therapies also may be needed.
What is the treatment for menstrual migraine?
There are several aspects to treating menstrual migraines:- To abort menstrual migraine, take medications after the onset of menstrual migraine. Generally, medications that are effective in aborting non-menstrual migraines are effective at aborting menstrual migraines.
- To prevent menstrual migraine, take medications just before the onset of menstruation and continue for the duration of the expected headache. Taking hormones such as estrogens or estrogen-related medications also help to prevent migraine.
- To reduce the frequency and duration of menstrual migraine, take prophylactic medications (such as beta blockers, calcium channel blockers, anticonvulsants, tricyclic antidepressants) that are normally used on a continuous basis to prevent non-menstrual migraines.
Triptans (naratriptan, rizatriptan, sumatriptan, zolmitriptan) have been found to be effective in aborting menstrual migraines, as well as controlling the associated nausea and vomiting. Sumatriptan given two to three days before and continued for the duration of the expected headache was found to be effective in reducing the frequency and severity of menstrual migraine. Naratriptan used in the same manner has also been found to be effective in preventing menstrual migraine. However, in those cases where breakthrough headaches occurred, they were just as severe as in patients taking placebo. For side effects and precautions of triptans, please read the "Triptans" section of this article.
Dihydroergotamine (DHE) can be used as a nasal spray or given intramuscularly or intravenously to abort menstrual migraines. Ergotamine (oral, rectal, or intranasal) and DHE (intranasal, intramuscular, or intravenous) can be used around the time of menstruation (several days before and continued for the duration of the expected headache) to prevent menstrual migraines. For ergot side effects and precautions, please read the "Ergots" section in this article.
If these medications are ineffective, doctors may try daily preventive medications such as beta-blockers, anticonvulsants, calcium channel blockers, and tricyclic antidepressants to reduce the frequency and the severity of menstrual migraines. The choice of the preventive medications is based on the experiences and preferences of the doctor, the medication side effects, and the woman's other associated medical conditions.
For women already taking preventive medications and yet still experience headaches, the doses of preventive medications can be increased around the time of the menstruation (some doctors use preventive medications only around the time of menstruation). Alternatively doctors may try hormone treatment.
Since a drop in estrogen level just prior to menstruation is the trigger for menstrual migraines, estrogen replacement before menstruation has been used in preventing menstrual migraines. For some women with menstrual migraine, Estradiol skin patches (such as TTS 50, TTS 100) applied 2 days before and continued for 7 days during the expected headache period is effective. However, the dose of estrogen must be closely monitored, as too high of a dose can actually trigger migraine in susceptible individuals.
Some women with difficult to treat menstrual migraines may be helped by using low dose oral contraceptives to reduce the estrogen fluctuations. Other less frequently used medications for menstrual migraines include tamoxifen, bromocriptine, danazol and gonadotropin-releasing hormone (GnRH).
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