Migraine Headaches

Description

Risk Factors

Up to 30 million Americans suffer from migraine headaches. They affect up to 18% of women and 6% of men. In fact, 70% of all migraine sufferers are women. This significantly greater incidence in women holds throughout the world and in every culture. Although the incidence of migraine is similar for boys and girls during childhood, it increases in girls after puberty.

Hormone Fluctuations in Women. Most migraines in women develop during the hormonally active years between adolescence and menopause. Fluctuations of estrogen and progesterone, rather than their presence, appear to increase the risk for migraines and their severity in some women.

• About half of women with migraines report headaches associated with their menstrual cycle, although true menstrual migraines may actually be less common. So-called true menstrual migraines tend not to have auras and to increase in prevalence between two days before and five days after the onset of period.
• The first three months of pregnancy can exacerbate migraines in some women, although one study reported that pregnancy had little effect one way or the other on severity in most women with chronic headaches.
• Women whose migraines are affected by pregnancy or menstruation are also likely to have worse migraines if they take oral contraceptives or hormone replacement therapies.

Age

General Age of Onset. More than 20% of adults with migraines report that their headaches started before age 10 and over 45% say they started under age 20. The prevalence of migraine declines in both men and women after age 40.

Migraine in Children. Migraine headaches occur in all ages and can appear in children as young as four years of age. Migraines in children are equally prevalent in boys and girls. Migraine is common in children and may be underdiagnosed. Some studies estimate that about 10% of children between six and 20 years of age suffer from migraine.

In one Greek study of children, researchers reported a prevalence of migraine of 6.2%. Of the children who had migraines, 3.4% reported headaches without aura and 2.8% experienced aura with at least some of their headaches.

Migraine Onset in Older Adults. Although uncommon, late-life migraine occurs in about 1% of the population, usually in men. In such cases, it often occurs as migraine with visual disturbances but without headache.

Family History

Migraine headaches can be inherited. If both parents suffer from migraines, their children have a 75 percent chance of getting them; when only one parent gets migraines, there is a 50 percent chance his or her children will be afflicted. In March 2002, UCLA geneticists, reporting in the American Journal of Human Genetics, discovered the first evidence that migraine with aura is hereditary.

Ethnic Differences

Caucasians have a higher risk than either African Americans or Asians. Worldwide, one study reported that migraines are most common in North America. They are slightly less prevalent in South America and Europe and far less common in Asia and Africa. Investigators believe that the differences are due to genetic variations, not environmental factors.

Other Medical Conditions Associated with Migraines

People with migraine have a higher incidence of other medical conditions, including the following:

• Asthma and allergies. Some studies have reported an association between migraine and asthma. One observed that parents with migraines had a greater chance of having children with asthma and allergies. These conditions have also been associated with a higher risk for conversion from having periodic migraines attacks to a chronic form (transformed migraines).
• H. pylori infection. People who are infected with the bacteria H. pylori, the major cause of peptic ulcers, are at higher risk for migraines.
• Epilepsy. Patients with epilepsy are twice as likely to have migraines as the general population. Interestingly, a 2002 study found that menstrual migraines and certain epileptic seizures tend to occur during the same phases of the menstrual cycle.
• Fibromyalgia.
• Systemic lupus erythematosus.
• Raynaud's syndrome.
• Mitral valve prolapse.
• Narcolepsy.

Of note, in addition to asthma and allergies, a 2002 study also reported a higher risk for transformed migraines in people with migraines and hypertension or hypothyroidism.

Personality Traits

One study suggested that women with migraines tend to over-respond to stressful situations. In the study, they were more likely than other women to be diligent, conscientious, and overly sensitive to pressure from others. More likely, however, a persons family history of migraine, rather than any personality tic, is the important risk factor.