Interoception and dissociation in migraine: a case-control study of chronic and episodic subtypes.

Background: Migraine is one of the most common neurological disorders. Despite advances in understanding of episodic migraine, little is understood about the mechanisms underlying the chronification of migraine. Recently, increasing attention has been given to the potential roles of interoceptive abnormalities and dissociation. Therefore, we sought to explore differences in interoception and dissociation in individuals with episodic and chronic migraine versus individuals without migraine. Methods: A total of 49 participants were analysed of which 26 had migraine (15 chronic and 11 episodic) and 23 were control subjects without a headache disorder. Their objective interoceptive accuracy was assessed using the heartbeat tracking and discrimination tasks. Interoceptive sensibility was assessed using the Porges body perception questionnaire. Interoceptive trait prediction error (ITPE) was calculated based on the discrepancy between their task performance and sensibility. Interoceptive state prediction error (ISPE) was calculated based on the trial-by-trial correspondence between task performance and confidence. The level of their dissociation was assessed via self-report questionnaires. Results: Patients with migraine had lower interoceptive accuracy for the tracking task (median (interquartile range) 0.50 (0.43) in migraine vs. 0.78 (0.26) in control, Mann-Whitney U test, effect size r = 0.35, Conclusion: This is the first study to demonstrate interoceptive abnormalities in migraine, specifically of greater interoceptive prediction errors. Interoceptive abnormalities may represent a transdiagnostic mechanisms relevant to the chronification of migraine, and to frequent co-morbidities such as dissociation.