A new study has shown that “triggers” for migraine with aura may not be as strongly associated with migraines as is commonly thought. Such triggers, including flashing lights and exercise, are often avoided by patients who suffer frequent migraines.

“People with migraine with aura are told to avoid possible triggers, which may lead them to avoid a wide range of suspected factors,” said Dr. Jes Olesen, author of the study at the University of Copenhagen and a Fellow of the American Academy of Neurology. “Yet the most commonly reported triggers are stress, bright light, emotional influences and physical effort, which can be difficult to avoid and potentially detrimental, if people avoid all physical activity.”

The study, published recently in the journal Neurology, looked at 27 people with migraine with aura who reported that a migraine attack had been triggered by flickering light or vigorous exercise. The patients exercised for one hour, either biking or running, and reached at least 80% of their max heart rate. The were also exposed to flashing lights for 30 to 40 minutes. After their sessions, patients were observed for three hours and told to report any migraine symptoms.

“Our study suggests that if a person is exposed to a suspected trigger for three months and does not have a migraine attack, they no longer have to worry about avoiding that trigger,” said Olesen.

Only 11% of the patients reported a migraine with aura after their trigger exposure, and another 11% experienced a migraine without aura. None of the patients had a migraine with aura following light exposure alone.

“Perhaps rather than triggers, these behaviors are a brain-driven response to the early phases of the migraine itself,” said Dr. Peter Goadsby of the University of California, San Francisco in an accompanying editorial. “Maybe people are driven to exercise as an early symptom and the association with light is simply the sensitivity to light that occurs with the attack itself?”