September 17, 2011

Migraine is the second most common headache disorder, after tension-type headache. The prevalence of migraine is related to age and sex. Before puberty, boys are more susceptible than girls. After puberty, the prevalence in women increases until age 40-50 and then decreases. At age 40, 26% of women will have at least one migraine over the course of a year, compared with 8% of men.

Migraine is a hereditary illness. First-degree relatives of an affected person are 2-4 times as likely to have migraines. The mode of inheritance for most types of migraine is not known, but one form, familial hemiplegic migraine (a type of migraine that runs in families and causes bodily weakness), is known to be transmitted as an autosomal dominant trait (specific method of genetic transmission). The gene has been mapped to chromosome 19.

Migraine consists of two parts, a transient neurological symptom, called the aura, and a headache. They can occur together (migraine with aura) or separately (migraine without aura, migraine aura without headache). The aura usually precedes the headache but may occur during it or afterwards.

The most common auras are abnormalities of vision, sensation, and language ability. An aura may occur alone, or two or three may appear one after another. Visual auras are usually small and unobtrusive at first but enlarge and spread across the field of vision during a period of 10-15 min. Likewise, sensory auras start in one part of the body, usually the fingers or lips, and spread slowly to other parts. Auras usually last 15-30 min and then disappear. Visual auras often consist of an area of visual loss surrounded by a shimmer or a flickering light (scintillating scotoma), or zigzag lines in the form of a horseshoe (fortification spectrum). Sensory auras may consist of numbness or tingling and “pins and needles.” A language aura (aphasia) impairs the subject’s ability to express herself in words or to understand spoken or written language. Other less common auras include limb weakness, vertigo (dizziness), double vision, lack of coordination, and a reduced level of consciousness.

The pain of migraine may be on one or both sides of the head. it generally has a pulsating or throbbing quality, is moderate to severe in intensity, and is made worse by routine physical activity, such as climbing stairs. The headache is often associated with nausea, vomiting, and sensitivity to light (photophobia) and sound (phonophobia). Untreated, the pain lasts for 4 hr to 3 days.

Migraine headaches respond better to abortive treatment the earlier it is given after the pain starts. The choice of medication depends on the severity of the pain. Mild headaches may respond to over-the-counter pain relievers, such as aspirin and acetaminophen (with or without caffeine), and to nonsteroidal antiinflammatory drugs (NSAIDs), such as ibuprofen and naproxen. Moderate and severe headaches require a prescription drug. The most effective drugs belong to a family of agents called “triptans.” Sumatriptan (Imitrex) was the first one marketed. it is available as a tablet, a nasal spray, and a subcutaneous injection. More intense headaches require the nasal spray or injection. Dihydroergotamine, another antimigraine agent, is available as a nasal spray (Migranal) and is at least as effective as sumatriptan nasal spray, although not as effective as the injection. The nausea and vomiting of a migraine will respond to antinausea drugs, such as metoclopramide, domperidone, and prochlorperazine, taken as a tablet or suppository.

Using abortive medications for migraine more than 2 days a week can lead to medication-overuse headache, a chronic daily headache that improves with each dose of medicine but recurs in a few hours, creating a vicious cycle of withdrawal headache. In order to avoid this, many patients use preventive therapy of migraine. Preventive therapy involves taking a drug regularly, everyday, in order to reduce the frequency, severity, and duration of migraine attacks. Once the migraines have been under good control for 3-6 months, the drugs can be withdrawn. Several classes of drugs may be used: beta-blockers such as propranolol, antidepressants such as amitriptyline and phenelzine, calcium-channel blockers such as verapamil, and antiepileptic drugs such as valproate, topiramate, and gabapentin. Although beta-blockers and calcium-channel blockers are also blood pressure medicines, they are usually tolerated well when taken for migraines.

During the first trimester of pregnancy, the risk of exposing the fetus restricts the use of preventive drugs. Among abortive agents, acetaminophen, caffeine, nonsteroidal antiinflammatory drugs, narcotic analgesics, and probably sumatriptan are safe, as are the antiemetic agents (prevent vomiting) prochlorperazine and metoclopramide. Amitriptyline, as a preventive drug, is probably safe in the second and third trimesters. Late in pregnancy, nonsteroidal antiinflammatory drugs should be avoided because they inhibit closure of the fetal ductus arteriosus, causing circulatory problems in the newborn. Breast-feeding mothers should discuss medication choices with their health care provider, to avoid possible ill-effects on the infant.

Many women have migraine headaches only or mainly with their menstrual periods (menstrual migraine). These migraines are often intense, longlasting, and resist abortive treatment. Use of nonsteroidal antiinflammatory drugs or standard preventive drugs before and during the period, a short course of oral corticosteroids, or therapy with estrogen can prevent or reduce the headaches.

Hormonal contraceptives, including oral and injectable contraceptives, may cause or worsen migraine. This usually occurs within the first few cycles of their use but may not appear for years. Stopping the drug may not bring immediate relief: there may be a delay of several months or no improvement at all.

Migraine with aura and, to a lesser extent, migraine without aura, as well as the use of estrogen-containing contraceptives are all minor risk factors for ischemic stroke. Controversy continues on whether it really is too risky to use estrogen-containing contraceptives in patients with migraine. It seems reasonable, however, not to use them in migraine patients who have other stroke risk factors, such as smoking, high blood pressure, or age over 40 years. If migraine auras appear or worsen during treatment, then these contraceptives should be discontinued.

People with migraines can also develop other types of headache. Some causes of headache, such as bleeding within the skull or meningitis, are quite dangerous. Talk with your health care provider if your headaches change significantly. Warning signs of a possibly serious condition include headache that comes on suddenly without warning, pain that is different from or much worse than your usual migraine pain, headaches occurring more often or lasting longer, pain that gets worse with each new headache, headache that develops after a head injury, headache with fever or stiff neck, or headache with new neurological symptoms such as trouble walking, talking, or weakness.

SEE ALSO: Headache, Oral contraception, Pain

Suggested Reading

  • Becker, W. J. (1999). Use of oral contraceptives in patients with migraine. Neurology, 53(Suppl. 1), S19—S25.
  • Silberstein, S. D., Lipton, R. B., & Goadsby, P. J. (1998). Headache in clinical practice. Oxford: Isis Medical Media.
  • Silberstein, S. D., Stiles, A., Young, W. B., & Rozen, T. D. (2002). An atlas of headache. New York: Parthenon.


Category: M