Avoidance behaviour modulates but does not condition phonophobia in migraine.

Background: Past studies do not account for avoidance behaviour in migraine as a potential confounder of phonophobia.

Objective: To analyse whether phonophobia is partially driven by avoidance behaviour when using the classic methodology (method of limits).

Methods: This is a case-control study where we tested phonophobia in a cohort of high-frequency/chronic migraine patients (15.5 ± 0.74 headache days/month) and non-headache controls. Auditory stimuli, delivered in both ears, were presented using three different paradigms: the method of limits, the method of constant stimuli, and the adaptive method. Participants were asked to report how bothersome each tone was until a sound aversion threshold was estimated for each method.

Results: In this study, we successfully replicate previously reported reduction in sound aversion threshold using three different methods in a group of 35 patients and 25 controls (p < 0.0001). Avoidance behaviour in migraine reduced sound aversion threshold in the method of limits (p = 0.0002) and the adaptive method (p < 0.0001) when compared to the method of constant stimuli. While thresholds in controls remained the same across methods (method of limits, p = 0.9877 and adaptive method, p = 1).

Conclusion: Avoidance behaviour can exacerbate phonophobia. The current methodology to measure phonophobia needs to be revised.