Migraine

Migraine is a neurological disease, of which the most common symptom is an intense and disabling episodic headache. Migraine headaches are usually characterized by severe pain on one or both sides of the head and are often accompanied by photophobia (hypersensitivity to light), phonophobia (hypersensitivity  to sound) and nausea. The word migraine is French in origin and comes from the Greek hemicrania (as does the Old English term megrim). Literally, hemicrania means "only half the head."

Signs and symptoms
The signs and symptoms of migraine vary among patients. Therefore, what a patient experiences before, during and after an attack cannot be defined exactly. The four "signs and symptoms" below are common among patients but are not necessarily experienced by all migraine sufferers:


 * 1) The prodrome, which occurs hours or days before the headache.
 * 2) The aura, which immediately precedes the headache.
 * 3) The headache phase.
 * 4) The postdrome.

Prodrome phase
Prodromal symptoms occur in 40% to 60% of migraineures. This phase consists of altered mood, irritability, depression or euphoria, fatigue, yawning, excessive sleepiness, craving for certain food (e.g., chocolate), and other vegetative symptoms. These symptoms usually precede the headache phase of the migraine attack by several hours or days, and experience teaches the patient or observant family how to detect that a migraine attack is near.

Aura phase
The migraine aura is comprised of focal neurological phenomena that precedes or accompany the attack. They appear gradually over 5 to 20 minutes and usually subside just before the headache begins. Symptoms of migraine aura are usually sensory in nature.

Visual aura is the most common of the neurological events. There is a disturbance of vision consisting usually of unformed flashes of white or rarely of multicolored lights (photopsia) or forma­tions of dazzling zigzag lines (arranged like the battlements of a castle, hence the term fortification spec­tra or teichopsia). Some patients complain of blurred or shimmering or cloudy vision, as though they were look­ing through thick or smoked glass, or, in some cases, tunnel vision. The somatosensory aura of migraine consists of digitolingual or cheiro-oral paresthesias, a feeling of pins-and-needles experienced in the hand and arm as well as in the ipsilateral nose-mouth area. Paresthesia migrate up the arm and then extend to involve the face, lips and tongue.

Headache phase
The typical migraine headache is unilateral, throbbing, moderate to severe and can be aggravated by physical activity. Not all of these features are necessary. The pain may be bilateral at the onset or start on one side and become generalized, usually alternates sides from one attack to the next. The onset is usually gradual. The pain peaks and then subsides, and usually lasts between 4 and 72 hours in adults and 1 to 48 hours in children. The frequency of attacks is extremely variable, from a few in a lifetime to several times a week, and the average migraineur experiences from one to three headaches a month. The head pain varies greatly in intensity. The pain of migraine is invariably accompanied by other features. Anorexia is common, and nausea occurs in almost 90 percent of patients, while vomiting occurs in about one third of patients. Many patients experience sensory hyperexcitability manifested by photophobia, phonophobia, osmophobia and seek a dark and quiet room. Blurred vision, nasal stuffiness, diarrhea, polyuria, pallor or sweating may be noted during the headache phase. There may be localized edema of the scalp or face, scalp tenderness, prominence of a vein or artery in the temple, or stiffness and tenderness of the neck. Impairment of concentration and mood are common. Lightheadedness, rather than true vertigo and a feeling of faintness may occur. The extremities tend to be cold and moist.

Postdrome phase
The patient may feel tired, "washed out", irritable, listless and may have impaired concentration, scalp tenderness or mood changes. Some people feel unusually refreshed or euphoric after an attack, whereas others note depression and malaise. Often, some of the minor Headache phase symptoms may continue, such as anorexia, photophobia, and lightheadedness.

Pathophysiology
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 causing a spasm of the nerve-rich arteries at the base of the brain. The spasm 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&mdash;a process which is believed to release the neurotransmitter 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. Neurological 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 which cause inflammation and swelling, and substances which 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.

More recent neuroimaging techniques seem to show that migraine is primarily a disorder of the brain (neurological), not of the blood vessels (vascular). A spreading depolarization (electrical change) may begin 24 hours before the attack, with onset of the headache occurring at about the time of maximum brain coverage. The effects of migraine may persist for some days after the main headache has ended. Many sufferers report a sore feeling in the area where the migraine was, and some report impaired thinking for a few days after the headache has passed.

In 2005, research was published indicating that in some people with a patent foramen ovale (PFO), a hole between the upper chambers of the heart, migraine might result and that the occurrence of migraines might end if the hole were blocked. Several clinical trials are currently under way in an effort to determine if a causal link between PFO and migraine can be found. Early speculation as to this relationship has centered on the idea that the lungs detoxify blood as it passes through. The PFO allows blood to go directly from the right side of the heart to the left without passing through the lungs.

Migraine triggers
Migraine is irregularly episodic, so there needs to be some explanation for why a particular migraine episode occurs at a particular time and not at another time. A migraine trigger is any factor that on exposure or withdrawal leads to the development of an acute migraine headache. Triggers may be categorized as behavioral, environmental, infectious, dietary, chemical, or hormonal. The trigger theory supposes that exposure to various environmental factors precipitates, or triggers, individual migraine episodes. Many people report that one or more dietary, physical, hormonal, emotional, or environmental factors precipitate their migraines. The most-often reported triggers include stress, over-illumination or glare, alcohol, foods, too much or too little sleep, and weather. Sometimes the migraine occurs with no apparent “cause.”

Migraine patients have long been advised to try to identify personal headache triggers by looking for associations between their headaches and various suspected trigger factors. Patients are urged to keep a “headache diary” in which to note what they eat and when they get a headache, to look for correlations, and to try to avoid headache by avoiding factors they identify as triggers. Typically this advice is accompanied by a list of trigger factors.

Food
Authors who in 2005 reviewed the medical literature found that the available information about dietary trigger factors relies mostly on the subjective assessments of patients. Some suspected dietary trigger factors appear to genuinely promote or precipitate migraine episodes, but many other suspected dietary triggers have never been demonstrated to trigger migraines. The review authors found that alcohol, caffeine withdrawal, and missing meals are the most important dietary migraine precipitants. The authors say dehydration deserves more attention, and that some patients are sensitive to red wine. The authors found little or no demonstrated evidence that notorious suspected triggers chocolate, cheese, or that histamine, tyramine, nitrates, or nitrites normally present in foods trigger headaches. The artificial sweetener aspartame (NutraSweet®) has not been shown to trigger headache, but in a large and definitive study monosodium glutamate (MSG) in large doses (2.5 grams) was associated with adverse symptoms including headache more often than was placebo. The review authors also note that general dietary restriction has not been demonstrated to be an effective migraine therapy.

On the other hand, several headache clinics have had good results with individually tailored dietary restriction as a therapy. Dr. Ian Livingstone, director of the Princeton Headache Clinic, recommends eliminating the following common headache triggers from the diet: Aged Cheese, Monosodium Glutamate, Processed fish and meats containing nitrates (such as hot dogs), dark chocolate, aspartame, certain alcoholic beverages (including red wine), citrus fruits, and caffeine. After a period of a month or two, these foods can be reintroduced one at a time to determine their trigger potential for that individual. Adding a lot of the suspected trigger in a short time will generate a response that is easy to observe.

Dr. David Buchholz, who treats headaches as a neurologist at Johns Hopkins, has a longer list of suspected migraine triggers. Once again, he recommends eliminating the triggers from the diet altogether, and then reintroducing them slowly after many weeks to measure the effects. His list includes: Coffee (including decaf), chocolate, monosodium glutamate, processed meats and fish (aged, canned, preserved, processed with nitrates, and some meats which contain tyramine), cheese and dairy products (the more aged, the worse), nuts, citrus and some other fruits, certain vegetables (especially onions), fresh risen yeast baked goods, dietary sources of tyramine (including the foods listed above), and whatever gives you a headache.

Weather
Several studies have found some migraines are triggered by changes in weather. One study noted that 62% of the subjects in the study thought that weather was a factor, in fact 51% were actually sensitive to weather changes. While those whose migraines did occur during a change in weather, often the subjects picked a weather change other than the actual weather data recorded. Most likely to trigger a migraine were, in order:
 * 1) Temperature mixed with humidity.  High humidity plus high or low temperature was the biggest cause.
 * 2) Significant changes in weather
 * 3) Changes in barometric pressure

Another study studied whether chinook winds (warm westerly winds occurring in Alberta, Canada) are a migraine trigger. Many patients had increased incidence of migraines immediately before and/or during the chinook winds. The number of people reporting migrainous episodes during the chinook winds was higher on high-wind chinook days.

Treatment
Conventional treatment focuses on three areas: trigger avoidance, symptomatic control, and preventive drugs. Patients who experience migraines often find that the recommended treatments are not 100% effective at preventing migraines.

Trigger avoidance
Patients can attempt to identify and avoid factors that promote or precipitate migraine episodes. Moderation in alcohol and caffeine intake, consistency in sleep habits, and regular meals may be helpful. Beyond an often pronounced placebo effect, general dietary restriction has not been demonstrated to be an effective approach to treating migraine.

Symptomatic control to abort attacks
Migraine sufferers usually develop their own coping mechanisms for intractable pain. A cold or hot shower directed at the head, a wet washcloth, less often a warm bath, or resting in a dark and silent room may be as helpful as medication for many patients, but both should be used when needed. A simple treatment that has been effective for some, is to place spoonfuls of ice cream on the soft palate at the back of the mouth. Hold them there with your tongue until they melt. This directs cooling to the hypothalamus, which is suspected to be involved with the migraine feedback cycle, and for some it can stop even a severe headache very quickly.

For patients who have been diagnosed with recurring migraines, doctors recommend taking painkillers to treat the attack as soon as possible. Many patients avoid taking their medications when an attack is beginning, hoping that "it will go away". However in many cases once an attack is underway, it can become intensely painful, last for a long time (sometimes even for several days), and become somewhat resistant to medical treatment. In contrast, treating the attack at the onset can often abort it before it becomes serious, and can reduce the frequency of subsequent attacks in the near-term.

The first line of treatment is over-the-counter abortive medication. Doctors start patients off with simple analgesics, such as paracetamol (known as acetaminophen in the U.S.), aspirin and caffeine. They may provide some relief, although they are not effective for most sufferers. Some patients find relief from taking Benadryl or anti-nausea agents.

Narcotic pain killers (for example, codeine, morphine or other opiates) provide variable relief, but their side effects, the possibility of causing rebound headaches or analgesic overuse headache, and the risk of addiction contraindicates their general use.

If over-the-counter medications do not work, the next step for many doctors is to prescribe fioricet or fiorinal, which is a combination of butalbital (a barbiturate), acetaminophen (in fioricet) or acetylsalicylic acid (more commonly known as aspirin and present in fiorinal), and caffeine. While the risk of addiction is low, butalbital can be habit-forming if used daily, and it can also lead to rebound headaches.

Amidrine (a coctail of a pain reliever, a sedative, and a vasoconstrictor) is sometimes prescribed for migraine headaches.

Anti-emetics by suppository or injection may be needed in cases where vomiting dominates the symptoms. The earlier these drugs are taken in the attack, the better their effect.

Until the introduction of sumatriptan (Imitrex®/Imigran®) around 1985, ergot derivatives (see ergoline) were the primary oral drugs available to abort a migraine once it is underway. However, ergotamine tablets (usually with caffeine), though sometimes effective, have fallen out of favour. Absorption is erratic unless taken by suppository or injection. Dihydroergotamine (DHE), which must be injected or inhaled, can also be effective. These drugs can be used either as a preventive or abortive therapy.

Sumatriptan and related selective serotonin receptor agonists are now the therapy of choice for severe migraine attacks that cannot be controlled by other means. They are highly effective, reducing the symptoms or aborting the attack within 30 to 90 minutes in 70-80% of patients. Some patients have a recurrent migraine later in the day, and only one such recurrence in a day can be treated with a second dose of a triptan. They have few side effects if used in correct dosage and frequency. There have been some rare instances of cardiac arrest in patients using triptans. Some members of this family of drugs are:


 * Sumatriptan (Imitrex®, Imigran®)
 * Zolmitriptan (Zomig®)
 * Naratriptan (Amerge®, Naramig®)
 * Rizatriptan (Maxalt®)
 * Eletriptan (Relpax®)
 * Frovatriptan (Frova®)
 * Almotriptan (Almogran®)

Evidence is accumulating that these drugs are effective because they act on serotonin receptors in nerve endings as well as the blood vessels. This leads to a decrease in the release of several peptides, including CGRP and Substance P.

These drugs are available only by prescription (US, Canada and UK) although Sumatriptan is to be available in the UK over the counter from mid-June, 2006. It is also expected to become eligible for generic status in the United States in 2007. Many migraine sufferers do not use them only because they have not sought treatment from a physician.

Regarding comparative effectiveness of these drugs used to abort migraine attacks, a 2004 placebo-controlled trial (Cephalalgia. 2004 Nov;24(11):947–54) reveals that acetylsalicylic acid, sumatriptan and ibuprofen are equally effective.

Triptan therapy has been shown to result in a reduction in lost productivity. Sumatriptan has been shown to result in an average of 0.5 fewer missed workdays during the first three months of therapy and 0.7 fewer missed workdays within the first six months, as well as a reduction in the number of days spent working while symptomatic. The average reduction in lost productivity has been estimated at $1,249, at a cost of $25 per day of disability avoided. The annual net savings in reduced health care costs and lost productivity, over the increased cost of triptan therapy, has been estimated at between $114 and $540 per patient; thus the use of these pharmaceuticals represents a cost savings as well as an improvement in the patients' quality of life.

Preventive drugs
Patients who have more than two headache days per week are usually recommended to use preventives and avoid overuse of acute pain medications.

Preventive medication has to be taken on a daily basis, usually for a few weeks, before the effectiveness can be determined. It is used only if attacks occur more often than every two weeks. Supervision by a neurologist is advisable. A large number of medications with varying modes of action can be used. Selection of a suitable medication for any particular patient is a matter of trial and error, since the effectiveness of individual medications varies widely from one patient to the next.

The most effective prescription medications include several classes of medications including beta blockers such as propranolol and atenolol, antidepressants such as amitriptyline, and anticonvulsants such as valproic acid and topiramate.

Sansert has been returned to the US market after being temporarily withdrawn by Novartis. Although highly effective, it has rare but serious side effects, including retroperitoneal fibrosis.

Alternative approaches
Because the conventional approaches to migraine prevention are not 100% effective and can have unpleasant side effects, many seek alternative treatments.

Physical therapy
Many physicians believe that exercise for 15-20 minutes per day is helpful for reducing the frequency of migraines. (PDF)

Massage therapy and physical therapy are often very effective forms of treatment to reduce the frequency and intensity of migraines. However, it is important to be treated by a well-trained therapist who understands the pathophysiology of migraines. Deep massage can 'trigger' a migraine attack in a person who is not used to such treatments. It is advisable to start sessions as short in duration and then work up to longer treatments.

Chiropractic adjustments to the upper cervical spine are very effective in treating migraine headaches. There is research to support these claims. One study found that the upper cervical adjustment was just as efective as drug therapy for chronic cases. It is also noted that routine spinal adjustments help prevent the frequency, duration, and intensity of the headaches.

Prism eyeglasses
At least two British studies have shown a relationship between the use of eyeglasses containing prisms and a reduction in migraine headaches.

Turville, A. E. (1934) Refraction and migraine. Br. J. Physiol. Opt. 8, 62–89, contains a good review of the literature and theories existing in 1934, and includes the vascular theory of migraine that is popular today. In that study, Turville suggests that many patients were provided with complete relief from migraine symptoms with proper eyeglass prescriptions that included prescribed prism.

Wilmut, E. B. (1956) Migraine. Br. J. Physiol. Opt. 13, 93–97, replicated Turville's work. Both studies are subject to criticism because of sample bias, sample size, and the lack of a control group.

Neither study is available online, but another study which found that precision tinted lenses may be an effective migraine treatment and which references the Turville and Wilmut studies can be found here. (PDF)

Turville's and Wilmut's conclusions have largely been ignored since 1956 and it is widely believe that vision problems are not migraine triggers. However, a casual search of the usenet archives maintained by Google Groups shows many anecdotal reports demonstrating a relationship between migraines and eyeglasses. 

Most optometrists avoid prescribing prism because, when incorrectly prescribed, it can cause headaches. Prism has been proven effective at relieving motion sickness, which itself has many symptoms that are similar to the aura that accompanies migraine.

Herbal and nutritional supplements
50 mg or 75 mg/day of butterbur (Petasites hybridus) rhizome extract was shown in a controlled trial to provide 50% or more reduction in the number of migraines to 68% of participants in the 75 mg dose group, 56% in the 50 mg dose group and 49% in the placebo group after four months. Native butterbur contains some carcinogenic compounds, but a purified version, Petodolax®, does not.

Cannabis was a standard treatment for migraines from the mid-19th century until it was outlawed in the early 20th century in the USA. It has been reported to help people through an attack by relieving the nausea and dulling the head pain. There is some indication that semi-regular use may reduce the frequency of attacks. Further studies are being conducted.

Supplementation of coenzyme Q10 has been found to have a beneficial effect on the condition of some sufferers of migraines. In a well-controlled trial, Young and Silberstein found that 61.3% of patients treated with 100 mg/day had a greater than 50% reduction in number of days with migraine, making it more effective than most prescription prophylactics. Fewer than 1% reported any side effects. 

The plant feverfew (Tanacetum parthenium) is a traditional herbal remedy believed to reduce the frequency of migraine attacks. Clinical trials have been carried out, and appear to confirm that the effect is genuine (though it does not completely prevent attacks).

Kudzu root (Pueraria lobata) has been demonstrated to help with menstrual migraine headaches and cluster headaches. While the studies on menstrual migraine assumed that kudzu acted by imitating estrogen, it has since been shown that kudzu has significant effects on the serotonin receptors. Kudzu Monograph at Med-Owl.

Magnesium citrate has reduced the frequency of migraine in an experiment in which the magnesium citrate group received 600mg per day oral of trimagnesium dicitrate. In weeks 9-12, the frequency of attacks was reduced by 41.6% in the magnesium citrate group and by 15.8% in the placebo group.

Non-drug medical treatments
Botox has been used by some sufferers in an attempt to reduce the frequency and/or severity of migraine attacks (Botox for Migraines).

Spinal cord stimulators are an implanted medical device sometimes used for those that suffer severe migraines several days each month.

Transacranial Magnetic Stimulation (TMS): At the 49th Annual meeting of the American Headache Society in June 2006, scientists from Ohio State University Medical Center presented medical research on 47 candidates which demonstrated that TMS–a medically non-invasive technology for treating depression, obsessive compulsive disorder and tinnitus among other ailments–helped to prevent and even reduce the severity of migraines among its patients. It essentially disrupts the aura phase of migraines before patients develop full-blown migraines. In about 74% of the migraine headaches, TMS was found to eliminate or reduce nausea and sensitivity to noise and light. Their research suggests that TMS could be more effective than medications in treating migraines and that there is a neurological component to migraines. However, a larger study will be conducted in the future to better assess its effectiveness. 

Other alternatives
Some migraine sufferers find relief through acupuncture which is usually used to help prevent headaches from developing. Sometimes acupuncture is used to relieve the pain of an active migraine headache. In one controlled trial of acupuncture with a sham control in migraine, the acupuncture was not more effective than the sham acupuncture but was more effective than delayed acupuncture.

There is a point between the thumbs and index finger that is shown to help subside headaches if the headache or migraine isn't too severe. Apply pressure with your opposite index finger and thumb close to where the thumb connects to the index. A slight pain is often the signal that it is the correct point.

Incense and smells are shown to help. The smell and incense of apples and lavender have been proven to help with migraines and headaches more so than most other scents.

Biofeedback has been used successfully by some to control migraine symptoms through training and practice.

Sleep is often a good solution if a migraine is not so severe as to prevent it, as when a person awakes the symptoms will have most like subsided.

Diet, visualization, and self-hypnosis are also alternative treatments and prevention approaches.

Bruxism, clenching or grinding of teeth, especially at night, is a trigger for many migraineurs. A device called a nociceptive trigeminal inhibitor (NTI) takes advantage of a reflex limiting the force of clenching. It can be fitted by dentists and clips over the front teeth at night, preventing contact between the back teeth. It has a success rate similar to butterbur and co-enzyme Q10. Massage therapy of the jaw area can also reduce such pain.

In many cases where a migrain follows a particular cycle, attempting to interupt the cycle may prolong the symptoms. Letting a headache "run its course" by not using painkillers can sometimes decrease the length of an episode. This is especially true of cases where vomiting is common, as often times the headache will subside immediately after vomiting. Curbing the pain may delay vomiting, and prolong the headache.

History
The history of humanity's suffering from headache dates back to 9000 years ago when basic drastic therapy of that time was trepanation. Headache with neuralgia was recorded in the medical documents of the ancient Egyptians as early as 1200 BC. In 400 BC Hippocrates described the visual aura that can precede the migraine headache, and the relief that can be induced by vomiting. Aretaeus of Cappadocia is credited as the discoverer of migraine because of his classic description of the symptoms of a unilateral headache associated with vomiting with headache free intervals in between attacks in the 2nd century. Galenus of Pergamon used the term "hemicrania", from which the word "migraine" was derived. He thought there was a connection between the stomach and the brain because of the nausea and vomiting that often accompany an attack. For relief of migraine, Spanish-born physician Abulcasis, also known as Abu El Quasim, suggested application of a hot iron to the head or insertion of garlic into an incision made in the temple. In the Medieval Ages migraine was recognized as a discrete medical disorder with treatment ranging from hot irons to blood letting and even witchcraft. Followers of Galenus explained migraine as caused by aggressive yellow bile. Ebn Sina (Avicenna) described migraine in his textbook “El Qanoon fel teb” as “… small movements, drinking and eating, and sounds provoke the pain… the patient cannot tolerate the sound of speaking and light. He would like to rest in darkness alone”. Abu Bakr Mohamed Ibn Zakariya Râzi noted the association of headache with different events in the lives of women, “...And such a headache may be observed after delivery and abortion or during menopause and dysmenorrhea”.

In 1712 Bibliotheca Anatomica, Medic, Chirurgica, published in London, characterized five major types of headaches, including the "Megrim," recognizable as classic migraine. Graham and Wolff (1938) published their paper advocating ergotamine tart for relieving migraine. Later in the 20th century, Harold Wolff (1950) developed the experimental approach to the study of headache and elaborated the vascular theory of migraine, which has come under attack as the pendulum again swings to the neurogenic theory.

Economic impact
In addition to being a major cause of pain and suffering, chronic migraine headaches are a significant source of both medical costs and lost productivity. Medical costs per migraine sufferer (mostly physician and emergency room visits) averaged $107 over six months in one 1988 study, with total costs including lost productivity averaging $313. Annual employer cost of lost productivity due to migraines was estimated at $3,309 per sufferer. Total medical costs associated with migraines in the United States amounted to one billion dollars in 1994, in addition to lost productivity estimated at thirteen to seventeen billion dollars per year. It is essential that employers educate themselves on the effects of migraines in order to facilitate a better understanding in the workplace. The workplace model of 9-5/ 7 days a week may not be viable for a migraine sufferer. With education and understanding an employer could compromise with an employee to create a workable solution for all.

Basilar type migraine
Basilar type migraine (BTM) is an uncommon type of migraine with aura that occurs in the brainstem. To meet the criteria for diagnosing BTM, aura symptoms must include at least two of the following: diplopia, simultaneous bilateral nasal and temporal visual changes, hypacusia (impaired hearing), tinnitus, dysarthria, ataxia, vertigo, simultaneous bilateral paresthesias, or decreased level of consciousness. Muscle weakness (called "motor weakness") is not part of the aura of BTM. BTM aura symptoms are reversible, and a migraine headache occurs either during the aura or within 60 minutes. Other neurological disorders may also cause these type of symptoms, so further evaluation is generally needed. Medications such as the triptans and ergotamines are contraindicated for BTM. This type of migraine is also called Basilar artery migraine, Basilar migraine, and Bickerstaff syndrome.

Familial hemiplegic migraine
Familial hemiplegic migraine 'FHM' is a type of migraine with a possible polygenetic component. These headaches may last 1-3 days and are apparently caused by ion channel mutations, 3 types of which have been identified to date. Patients who experience this syndrome have relatively typical migraine headaches preceded and/or accompanied by reversible limb weakness on one side as well as visual, sensory or speech difficulties. A non-familial form exists as well, "sporadic hemiplegic migraine".

Acephalalgic migraine
Acephalalgic migraine is a neurological syndrome. It is a variant of migraine in which the patient may experience aura, nausea, photophobia, hemiparesis and other migraine symptoms but does not experience headache. Acephalalgic migraine is also referred to as amigrainous migraine, ocular migraine, optical migraine or scintillating scotoma.

Sufferers of acephalalic migraine are more likely than the general population to develop classical migraine with headache.

The prevention and treatment of acephalalgic migraine is broadly the same as for classical migraine. However, because of the absence of "headache," diagnosis of acephalalgic migraine is apt to be significantly delayed and the risk of misdiagnosis significantly increased.

Visual snow might be a form of acephalalgic migraine.

Migraine and stroke risk
Recent studies have suggested that migraine sufferers may be at increased risk of stroke in later life. A meta-analysis of several such studies published in the British Medical Journal in 2005 appeared to confirm this association, with young adult sufferers and women taking the oral contraceptive pill at particular risk. The mechanism of any association is unclear, but chronic abnormalities of cerebral blood vessel tone may be involved.

Migraine triggers

 * Federation of American Societies for Experimental Biology [FASEB] [1995]. Analysis of adverse reactions to monosodium glutamate (MSG). Bethesda, MD: Life Sciences Research Office, FASEB.

Treatment

 * Pearce, J.M.S. (1994). Headache. Neurological Management series. Journal of Neurology Neurosurgery and Psychiatry. 57, 134-144.
 * Mayo Clinic Staff. (2005). Migraine Headache. Retrieved Aug. 14, 2005
 * Cathy Wong, ND. (2005). Migraine Elimination Diet Retrieved Aug. 14, 2005
 * Treatment Articles (2005). Butterbur, Co-enzyme Q-10, Melatonin, Folic Acid
 * Buchholz, D. (2002) Heal your headache: The 1-2-3 Program, New York: Workman Publishing, ISBN 0-7611-2566-3
 * Livingstone, I. and Novak, D. (2003) Breaking the Headache Cycle, New York: Henry Holt and Co. ISBN 0-8050-7221-7

Triptans

 * Cohen JA, Beall D, Beck A, et al. Sumatriptan treatment for migraine in a health maintenenace organization: economic, humanistic, and clinical outcomes. Clin Ther 1999;21:190-205.
 * Adelman JU, Sharfman M, Johnson R, et al. Impact of oral sumatriptan on workplace productivity, health-related quality of life, healthcare use, and patient satisfaction with medication in nurses with migraine. Am J Manag Care 1996;2:1407-1416.
 * Cohen JA, Beall DG, Miller DW, Beck A, Pait G, Clements BD. Subcutaneous sumatriptan for the treatment of migraine: humanistic, economic, and clinical consequences. Fam Med 1996;28:171-177.
 * Jhingran P, Cady RK, Rubino J, Miller D, Grice RB, Gutterman DL. Improvements in health-related quality of life with sumatriptan treatment for migraine. J Med Econ 1996;42:36-42.
 * Solomon GD, Nielsen K, Miller D. The effects of sumatriptan on migraine: health-related quality of life. Med Interface 1995;June:134-141.
 * Solomon GD, Skobieranda FG, Genzen JR. Quality of life assessment among migraine patients treated with sumatriptan. Headache 1995;35:449-454.
 * Santanello NC, Polis AB, Hartmaier SL, Kramer MS, Block GA, Silberstein SD. Improvement in migrainespecific quality of life in a clinical trial of rizatriptan. Cephalalgia 1997;17:867-872.
 * Caro JJ, Getsios D. Pharmacoeconomic evidence and considerations for triptan treatment of migraine. Expert Opin Pharmacother 2002;3:237-248.
 * Lofland JH, Johnson NE, Batenhorst AS, Nash DB. Changes in resource use and outcomes for patients with migraine treated with sumatriptan: a managed care perspective. Arch Intern Med 1999;159: 857-863.
 * Cady RC, Ryan R, Jhingran P, O’Quinn S, Pait DG. Sumatriptan injection reduces productivity loss during a migraine attack. Arch Intern Med 1998;158: 1013-1018.
 * Litaker DG, Solomon GD, Genzen JR. Impact of sumatriptan on clinic utilization and costs of care in migraineurs. Headache 1996;36:538-541.
 * Greiner DL, Addy SN. Sumatriptan use in a large group-model health maintenance organization. Am J Health Syst Pharm 1996;53:633-638.
 * Lofland JH, Kim SS, Batenhorst AS, et al. Cost-effectiveness and cost-benefit of sumatriptan in patients with migraine. Mayo Clin Proc 2001;76:1093- 1101.
 * Biddle AK, Shih YC, Kwong WJ. Cost-benefit analysis of sumatriptan tablets versus usual therapy for treatment of migraine. Pharmacotherapy 2000;20: 1356-1364.
 * Caro JJ, Getsios D, Raggio G, Caro G, Black L. Treatment of migraine in Canada with naratriptan: a costeffectiveness analysis. Headache 2001;41:456-464.

General

 * Sacks, Oliver (1999) Migraine, Vintage ISBN 0-5200-8223-0

Economic impact

 * Edmeads J, Mackell JA. The economic impact of migraine: an analysis of direct and indirect costs. Headache 2002;42:501-509.
 * Gerth WC, Carides GW, Dasbach EJ, Visser WH, Santanello NC. The multinational impact of migraine symptoms on healthcare utilisation and work loss. Pharmacoeconomics 2001;19:197-206.
 * Hu XH, Markson LE, Lipton RB, Stewart WF, Berger ML. Burden of migraine in the United States: disability and economic costs. Arch Intern Med 1999;159:813-818.
 * Osterhaus JT, Gutterman DL, Plachetka JR. Healthcare resource and low labour costs of migraine headaches in the US. Pharmacoeconomics 1992;2:2-11.