It is impossible to determine the cause of a patient's migraine episodes without undergoing formal experiments, say researchers.
The majority of migraine sufferers try to figure out for themselves what causes their headaches based on real world conditions, said lead author Timothy T. Houle, Ph.D, associate professor of anesthesia and neurology at Wake Forest Baptist.
"But our research shows this is a flawed approach for several reasons," he said. "Correctly identifying triggers allows patients to avoid or manage them in an attempt to prevent future headaches. However, daily fluctuations of variables - such as weather, diet, hormone levels, sleep, physical activity and stress - appear to be enough to prevent the perfect conditions necessary for determining triggers."
For example, said Houle, the simple act of drinking a glass of wine one day and not on the next could be complicated by inconsistencies in other factors. Similarly, a patient may drink wine for several days, but adding cheese to the mix one day could further skew results. In fact, a valid self-evaluation requires such perfect conditions that only occur about once every two years, he said.
"Many patients live in fear of the unpredictability of headache pain. As a result, they often restrict their daily lives to prepare for the eventuality of the next attack that may leave them bedridden and temporarily disabled," Houle said. "They may even engage in medication-use strategies that inadvertently worsen their headaches. The goal of this research is to better understand what conditions must be true for an individual headache sufferer to conclude that something causes their headaches."
Houle and co-author Dana P. Turner, M.S.P.H., also of the Wake Forest Baptist anesthesiology department, have published two related papers on the subject in the journal Headache
, which were published online ahead of print this month.
For the study, nine women who had regular menstrual cycles and were diagnosed with migraine either with or without aura provided data for three months by completing a daily diary and tracking stress with the Daily Stress Inventory, a self-administered questionnaire to measure the number and impact of common stressors experienced in everyday life. Morning urine was also collected daily for hormone level testing. Houle and Turner also reviewed three years worth of weather data from a local weather station.
Because of the difficulty in recreating identical conditions each time a patient evaluates a potential trigger, determining triggers proves difficult even for physicians, said Turner. "People who try to figure out their own triggers probably don't have enough information to truly know what causes their headaches," she said. "They need more formal experiments and should work with their doctors to devise a formal experiment for testing triggers."