By Dara G. Jamieson, MD

Emeritus Associate Professor of Clinical Neurology, Weill Cornell Medical College

Dr. Jamieson reports no financial relationships relevant to this field of study.

SYNOPSIS: The degree of unexpectedness or “surprisal” associated with known migraine triggers is a predictor of headache attacks. Social avoidance behavior is positively correlated with headache disability, pain, and depression, but there is a negative correlation between headache pain endurance and anxiety.

SOURCES: Turner DP, Lebowitz AD, Chtay I, Houle TT. Headache triggers as surprise. Headache 2019;59:495-508.

Ruscheweyh R, Pereira D, Hasenbring MI, Straube A. Pain-related avoidance and endurance behaviour in migraine: An observational study. J Headache Pain 2019;20:9.

Multiple models have been used to predict triggering and chronification of migraine headaches. Turner et al examined the hypothesis that the surprising aspect of a headache trigger is associated with daily headache activity. They proposed that headache trigger exposure can be characterized based on the degree of “surprise” that the trigger presents to the individual, and that headache attacks are associated with reactions to uncommon or unexpected triggering experiences.

In this prospective cohort study using data from the Headache Prediction Study, Turner et al followed 95 individuals with episodic migraine. They analyzed diary data for daily levels of several common headache triggers: number of caffeinated beverages, number of alcoholic beverages, stress (Daily Stress Inventory), and mood disturbance (Profile of Mood States). The probability of observing variations in each headache trigger was used to estimate the “surprisal” of experiencing each trigger as a predictor of headache attacks. The analysis of statistical interactions between previous and current values of the triggers and the current headache status determined the influence of the degree of surprise in encountering the trigger.

Participants experienced headache attacks on 1,613 of 4,195 days (38.5%). Rare or surprising values were associated with headache activity consistently, and four common headache triggers (caffeine, alcohol, stress, and mood) were found to predict future headache activity. The degree of surprise associated with the trigger correlated with resultant headache activity. Each trigger surprisal was associated with development of a future headache (expressed as a 1 standard deviation change in surprisal). Odds ratios ranged from 1.11 (95% confidence interval [CI], 1.00-1.24) for alcohol to 1.30 (95% CI, 1.14-1.46) for stress. The authors stated that “surprise is not just a change in triggers.” They postulated that in the trigger surprise model, the absolute changes in triggers are not as important as the unexpectedness of the changes from their typical levels. Is avoidance of surprise a reliable method to avoid headache triggering? In the fear-avoidance model, pain is predicted to evolve from episodic to chronic because of anticipatory fear of the pain and the resultant pain-avoidant behavior. The model is offered as an explanation for chronic musculoskeletal pain in the absence of overt pathology. Also, pain-endurance behavior may exacerbate chronic musculoskeletal pain due to continuous physical overload. The significance of pain-related avoidance and endurance behavior in migraine is less known, despite the prominence of anticipatory anxiety in migraineurs and the frequent need to persevere during the attack.

Ruscheweyh et al administered the Avoidance-Endurance Questionnaire behavioral subscales, the Pain Disability Index (PDI), the Migraine Disability Assessment Scale (MIDAS), and the Hospital Anxiety and Depression Scale (HADS) to 90 episodic and 38 chronic migraineurs, with re-evaluation of 69 of 128 individuals after three to six months. Exercise, relaxation techniques, and preventive treatments also were assessed. At baseline, there was a positive correlation between avoidance (especially social avoidance behavior) and pain and headache disability as assessed by the PDI and MIDAS, respectively. There was a positive correlation between social avoidance and depression (P = 0.047) and a negative correlation between endurance and anxiety (P = 0.013) on the HADS. Neither avoidance nor endurance was related to headache intensity or frequency or to a diagnosis of episodic vs. chronic migraine.

On follow-up after treatment at the authors’ headache center, headache frequency, intensity, and pain-related disability improved significantly; however, avoidance and endurance were unchanged. Distinct characteristics of migraine may not fit into a musculoskeletal model. The authors noted that a difference between musculoskeletal disorders and migraine is that episodic migraine attacks are separated by pain-free episodes. Since physical activity can trigger and exacerbate migraine pain, physical avoidance behavior may be appropriate. Stress, as a powerful migraine trigger, may be exacerbated by increased endurance, which in migraine can range from appropriate tolerance to excessive persistence.


Migraine sufferers know that headaches occur with change in their triggers, including stress (e.g., stress relief), weather (e.g., barometric pressure changes), sleep (e.g., oversleeping), and estrogen levels (e.g., menstrual and pregnancy-related headaches). However, there may be some benefit to anticipation of the change, as opposed to experiencing a surprising change that appears to exacerbate the migraine-triggering effect. In the fear-avoidance model of headache pain, exaggerated anticipatory anxiety leads to avoidance behavior, with exacerbation of pain and disability, including depression. Since treatment in a headache center achieved improvement in headache frequency and disability in the absence of changes in avoidance or endurance behavior, there may be adaptive benefit to some degree of avoidance of unexpected triggers and to powering through (i.e., enduring) the headache, in combination with appropriate acute and chronic treatments. In the fear-avoidance model, non-threatening or transient pain is associated with less anxiety when accompanied by improved coping mechanisms. With migraine, the combination of surprising triggers and excessive avoidance, especially social avoidance behavior leading to depression, may lead to enhanced migraine disability and potentially to chronification of migraine.

If the trigger with risk of resultant migraine is anticipated with less anxiety, then the headache pain can be confronted and treated appropriately. The teaching points for migraine patients appear to be know your headache triggers and avoid those that you can control, anticipate non-modifiable triggers, and manage all triggers expectantly without socially debilitating avoidant behavior.