Insula Response to Interoception Is Inversely Correlated with Trait Mindfulness, Self-compassion, and Migraine Frequency in Patients with Episodic Migraine

Abstract

Migraine is a highly prevalent chronic pain disorder that is characterized by sensitization and dysregulation of the central autonomic nervous system. Interoception is the sensing of signals originating from within the body, and is altered in chronic pain conditions including episodic migraine. The relationship between brain mechanisms of interoceptive awareness and clinical measures of migraine severity has not been fully explored. We used functional MRI to investigate whether insula response to interoceptive awareness is associated with clinical and behavioral measures in patients with episodic migraine. In this study, 18 patients with episodic migraine (17 F, 1 M, mean age ± SD: 41.3 ± 13.1 years). All patients underwent a 3-Tesla fMRI scan and completed a novel interoceptive awareness task (TR=2s,). During the task, patients were asked to focus on and rate the intensity of sensation for two interoceptive conditions (heart and lungs), as well as two exteroceptive conditions (sight and sound). Participants completed survey measures related to interoception, mindfulness, self-compassion, and migraine frequency. Bold response to the interoception - exteroception task contrast (z > 3.1, p = 0.05 corrected) included two clusters overlapping with bilateral mid-insula (left center: x=-46,y=-1.5,z=7.4, 2615 voxels, 33% overlap with anatomical insula, right center: x=44,y=7.1,z=3.9, 1332 voxels, 46% overlap with anatomical insula). Significant inverse associations were observed between insula response to interoception and SCS (r = -0.65, p = 0.003), Freiburg Mindfulness (r = -0.68, p = 0.002), and the number of migraine days reported within 30 days prior to the MRI scan (r = -0.64, p = 0.004) (all significant after Bonferroni correction). Patients with episodic migraine showed insula response during a novel interoceptive awareness task, and this response was inversely correlated with recent migraine frequency, and measures of both trait mindfulness and self-compassion. Grant support from NIH NCCIH P01AT009965.