The predominance of certain triggers for migraine was assessed in 494 migraine patients. Stress (62%) was the most frequently cited precipitant. Weather changes (43%), missing a meal (40%), and bright sunlight (38%) were also prominent factors. Sexual activity (5%) was the precipitant cited by the least number of patients. Significant differences were found between men and women
in their responses to weather changes, perfumes, cigarette smoke, missing a meal, and sexual activity. Spring was cited by 14% of patients as a time for increased migraine attacks, following by fall (13%), summer (11%), and winter (7%).
A variety of external and internal stimulating factors have been demonstrated to precipitate migraines. Most migraineurs list several triggers, and we utilize the presence or absence of precipitating factors in aiding the formulation of the diagnosis of migraine. However, trigger factors are rarely consistent in producing a headache, and migraineurs are able to identify precipitating factors in only a minority of attacks. Sensitivity to various stimuli may begin years after the onset of headache, or patients can become less susceptible to triggers over time. Because trigger factors are helpful in diagnosing migraine, we assessed these factors retrospectively in 494 migraineurs.
Subjects and Methods:
Included in the study were 494 randomly selected migraineurs: 393 women, and 101 men. The larger number of women is not surprising since more women than men suffer from this disease. All were long-term patients of the Robbins Headache Clinic. Each patient had a well-established diagnosis of migraine, with or without aura. Data was gathered from the Headache Intake Assessment Form, completed by the patient and neurologist on the first visit to the Clinic.
The questions on the form pertained only to migraine, not to coexistent tension or daily headaches. Patients were asked to circle the factors on the Assessment Form that consistently trigger their migraine and to indicate the effect of the seasons. The physician then interviewed the patient and recorded sensitivity to the various trigger factors.
The patients were between the ages of 18 and 60. Table 1 summarizes the percentages of patients who were sensitive to each of the various precipitating factors. The leading trigger factors for migraine were: stress, weather changes, perimenstrual, and sunlight. Men and women differed in their response to various factors.
Percentage of Patients Sensitive to Trigger Factors
% of patients affected
(woman only) Past or Present
|Missing a Meal
|After Stress is Over
Our 494 migraineurs reported slight seasonal variations,
with increased headaches during Spring and Fall.
Table 2: Seasonal Variation: Percentage of
Patients Reporting Increased
Headaches in Various Seasons
Among seasons, there were differences between men
and women at the 1% confidence level in Summer and Fall. In Spring, there was a difference at the 5% confidence level. Winter produced no difference between men and women.
Stress is a common precipitating factor in migraine, and was the major trigger reported by our patients. Migraineurs simply may respond to stress with a headache. Intense
stress is common as an initiating factor for the first attack of migraine.
Weather changes were a major trigger in our study. Previous studies have suggested that weather may affect the severity
but not the frequency of migraine. Geomagnetic activity may play a role in weather-related migraine, as may ionic and serotonergic changes in the bloodstream. Platelet serotonin has been experimentally decreased by the inhalation of negative ions.
In this study, migraines were significantly increased
perimenstrually in 50% of women. Previous studies of hormonal cycles and levels in women have reported conflicting results. The decrease in plasma estradiol appears to be the primary event triggering the menstrual-related migraines, but prostaglandin effects may play a crucial role in hormonal
Missing meal, or hunger, was listed by 40% of our patients as a precipitant for migraine. Migraineurs probably do not suffer from true hypoglycemia, but rather it is a reaction of the nervous system to a normal drop in blood sugar.
Sunlight or bright light exposure was a trigger factor
for 38% of our patients. Bright lights usually exacerbate a pre-existing migraine headache. Migraineurs tend to wear sunglasses more often than non-headache-prone individuals. As with other weather changes, sunlight may affect the severity of the headaches more than the frequency.
Undersleeping was listed as a precipitant by 31% of
migraineurs, and oversleeping was stated to be a factor by 24%. Earlier studies have recognized the relationship between sleep and migraine. Much evidence links the regulation of migraine with sleep mechanisms.
Sensitivity to certain foods was a trigger for 30% of migraineurs. Red wine, beer, chocolate, and MSG have traditionally been listed as common precipitants for migraine. Previous studies have suggested that foods play a major role as migraine triggers, but this has been difficult to prove.
In our examination of seasonal variation in migraine,
Spring was listed as an increased time for migraine by 13.9% of respondents, while 12.7% listed Fall, 10.7% listed Summer, and 7.6% stated that Winter was a time of increased migraine. One previous study failed to demonstrate seasonal variation among migraineurs.
Comparing the responses of men and women, the factors
where the sexes differed significantly at the 1% confidence level were: weather changes, perfumes, and cigarettes. Differences were significant at the 5% level for missing a meal and sexual activity. In most categories, a lower percentage of men reported being influenced by a particular trigger factor.