Differences in Cortical Morphology in People With and Without Migraine

BACKGROUND AND OBJECTIVES: Structural imaging can offer insights into the cortical morphometry of migraine, which might reflect adaptations to recurring nociceptive messaging. This study compares cortical morphometry between a large sample of people with migraine and healthy controls, as well as across migraine subtypes. METHODS: Adult participants with migraine and age-matched and sex-matched healthy controls attended a single MRI session with magnetization-prepared rapid acquisition gradient echo and fluid-attenuated inversion recovery sequences at 3T. Cortical surface area, thickness, and volume were compared between participants with migraine (including subgroups) and healthy controls across the whole cortex within FreeSurfer and reported according to the Desikan-Killiany atlas. The analysis used cluster-determining thresholds of p < 0.0001 and cluster-wise thresholds of p < 0.05, adjusted for age, sex, and total intracranial volume. RESULTS: A total of 296 participants with migraine (mean age 41.6 years ± 12.4 SD, 261 women) and 155 healthy controls (mean age 41.1 years ± 11.7 SD, 133 women) were included. Among the participants with migraine, 180 (63.5%) had chronic migraine, 103 (34.8%) had migraine with aura, and 88 (29.7%) experienced a migraine headache during the scan. The total cohort of participants with migraine had reduced cortical surface area in the left insula, compared with controls (p < 0.0001). Furthermore, participants with chronic migraine (n = 180) exhibited reduced surface area in the left insula (p < 0.0001) and increased surface area in the right caudal anterior cingulate cortex (p < 0.0001), compared with controls. We found no differences specific to participants with aura or ongoing migraine headache. Post hoc tests revealed a positive correlation between monthly headache days and surface area within the identified anterior cingulate cluster (p = 0.014). DISCUSSION: The identified cortical changes in migraine were limited to specific pain processing regions, including the insula and caudal anterior cingulate gyrus, and were most notable in participants with chronic migraine. These findings suggest persistent cortical changes associated with migraine. TRIAL REGISTRATION INFORMATION: The REFORM study (clinicaltrials.gov identifier: NCT04674020).