Migraine
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Migraine is a form of headache, usually very intense and disabling. It is a neurologic disease of neuronal origin. The word "migraine" comes from the Greek construction hemikranion (pain affecting one side of the head) [1] (http://dictionary.reference.com/search?q=migraine&r=67).
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Symptoms
Migraine is characterized by attacks of moderate or severe pain and must include one of the following: pain on only one side of the head, nausea, vomiting, photophobia and phonophobia, or pain worst with movement. The symptoms and their timing vary considerably among migraine sufferers, and to a lesser extent from one migraine attack to the next. Migraine had been thought to be caused by vasodilation in the head and neck, however newer research suggests the cause of the pain itself is from activation of the trigeminal nerve. The trigger of the migraine may be overactivity of nerve cells in certain areas of the brain (for example, the raphe nucleus). Dilation of the blood vessels is now known to be caused from chemicals released from nerve terminals and inflammatory cells.
Classical migraine or migraine with aura is preceded by a group of specific symptoms called aura, most commonly experienced as a visual disturbance. Common migraine or migraine without aura, in contrast, lacks this specific warning. Many migraine patients will experience a prodrome, a vague sensation that things are just not right that may precede the headache by several hours. Some experience aura without migraine, a condition formerly called amigrainous migraine and usually called acephalic migraine. Although sometimes comparable in severity, the symptoms of migraine differ from those of cluster headache.
The most common aura preceding a migraine attack is a multicolored zig-zag pattern which grows from a small dot until it covers a large part of the left or right visual field of both eyes. The aura must last less than 60 minutes and the headache must begin sometime after the start of the aura until 60 minutes from the end of the aura. Auras can be any specific neurological symptom complex and some experience tingling sensations called paresthesias or disturbances of other regions of the brain (such as language ability or smell) instead of a visual aura, either as an occasional alternate or their normal aura.
Migraine can accompany, in many cases, another type of headache called tension headache. Studies have demonstrated in those patients that get both migraine and tension type headaches, that their tension headaches will respond to their usual migraine treatment. This is in contrast to patients who only get tension type headaches. Migraines can be associated with seizures. Stroke symptoms are seen in some patients and are known as complicated migraine. These symptoms should not be permanent.
Migraine often runs in families and starts in adolescence, although some research indicates that it can start in early childhood or even in utero. Migraine occurs more frequently in women than men, and is most common between ages 15-45, with the frequency of attacks declining with age in most cases.
Because their symptoms vary, an intense headache may be misdiagnosed as a migraine by a layperson. Where possible, see a doctor to determine if the headaches are a symptom of something else.
Treatment
Conventional treatment focuses on three areas: trigger avoidance, symptomatic control, and preventive drugs.
Elimination of triggers
In a minority of patients the incidence of migraine can be reduced through dietary changes to avoid certain chemicals present in such foods as cheddar cheese, chocolate, nuts and most alcoholic beverages. Some triggers (for example, hunger or stress) may be situational and can be avoided through lifestyle changes. However, other triggers such as particular points in the menstrual cycle or certain weather patterns are impossible or impractical to avoid.
Avoid bright flashing lights if you notice these trigger attacks; most migraineurs are sensitive and avoid bright or flickering lights. Relaxation after stress, notably weekends and holidays, is a potent trigger; wind down gradually if possible.
Symptomatic control to abort attacks
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, 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 medications. Doctors start patients off with simple analgesics, such as paracetamol (acetaminophen), aspirin and caffeine. They may provide some relief, although they are not effective for most sufferers.
Narcotic pain killers (for example, codeine, morphine or other opiates) provide variable relief, but their side effects and high 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 barbituate), acetaminophen (in fioricet) or acetylsalicylic acid (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.
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 serotonin 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 rebound migraine later in the day, and only one such rebound 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. 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 on the nerve endings as well as the blood vessels. This leads to a decrease in the release of a several peptides including CGRP, Substance P, among others.
These drugs are available only by prescription (US and UK). Many migraine sufferers do not use them only because they have not sought treatment from a physician.
Preventive drugs
It is critically important that patients who have more than 2 headaches days per week be placed on preventatives 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.
Migraine sufferers usually develop their own coping mechanisms for intractable pain. A cold or hot shower directed at the head, 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.
Alternative approaches
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 the only 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.
Biofeedback has been used successfully by some to control migraine symptoms through training and practice.
Supplementation of coenzyme Q10 has been found to have a beneficial effect on the condition of some sufferers of migraines.
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 (http://www.med-owl.com/clusterheadaches/tiki-index.php?page=Kudzu).
Diet, visualization, and self-hypnosis are also important alternative treatment and prevention approaches.
History
The human side of migraine has been expertly captured in Oliver Sacks's book Migraine, although the book was last revised in 1982 and the science in the book is no longer current.
References
- Pearce, J.M.S. (1994). Headache. Neurological Management series. Journal of Neurology Neurosurgery and Psychiatry. 57, 134-144.
External links
- General Information
- Migraine Information from the US National Institute of Neurological Disorders and Stroke (http://www.ninds.nih.gov/disorders/headache/detail_headache.htm)
- A migraine series of articles from a neurologist who specializes in headaches and migraines (http://www.loftusmd.com/Articles/Migraine/MigraineOverview.html)
- Migraine Headache: Clinical and Alternative Treatment (http://goldbamboo.com/topic-t2901-migraine.html)
- Migraine (http://news.bbc.co.uk/1/hi/health/medical_notes/437825.stm) - gives a quick overview of the phenomenon as well as some suggestions on diet (from the BBC).
- FAQ on migraine treatment (http://www.mhni.com/faqs_treatment.html) (Michigan Head Pain and Neurological Institute)
- CVSA (http://www.cvsa.org.uk) information on a potential migraine variant Cyclical Vomiting Syndrome
- Organizations
- MAGNUM (http://www.migraines.org) - popular website of the U.S. National Migraine Association
- The Migraine Trust (http://www.migrainetrust.org/) (medical research and patient support charity)
- Diagnostic criteria
- Migraine with Aura (http://www.w-h-a.org/wha2/Newsite/resultsnav.asp?color=C2D9F2&idContentNews=394)
- Migraine without Aura (http://www.w-h-a.org/wha2/Newsite/resultsnav.asp?color=C2D9F2&idContentNews=398)
- Specific treatments
- Fiorinal, Fioricet, and other Butalbital Compounds for Headaches and Migraine (http://headaches.about.com/cs/druginfo/a/fiorinal_care.htm)de:Migräne