Differences in gray matter volume in episodic migraine patients with and without prior diagnosis or clinical care: a cross-sectional study

Background: Migraine sufferers face difficulties getting appropriate care and treatment. Migraine is associated with reduced gray matter volume (GMV) in several brain regions, which could be related to various clinical characteristics of the disorder. Objectives: To examine differences in GMV in migraine patients with and without prior clinical care for migraine and examine differences in migraine clinical variables, psychosocial symptoms and their relationship with GMV. Methods: We utilized the baseline MRI scan and psychosocial symptom questionnaires from a longitudinal randomized controlled trial. Prior care of migraine was determined by diagnosis by a medical practitioner or prescription of migraine specific medication. Results: 117 patients were included in the study. Patients without prior care (n=23) had reduced GMV in the right dorsal medial prefrontal cortex (dMPFC) relative to patients who had prior care (p=0.034, FWE corrected). Both patient groups had reduced GMV compared to healthy controls (n=36). Patient groups did not differ in headache clinical variables. Regardless of care status, increasing scores on the stress (Perceived Stress Score) and depression questionnaires (Patient Health Questionnaire) were associated with increased GMV in the dMPFC. Conclusions: Clinical care may impact GMV in migraine patients. Patients may need different treatment options to address this baseline deficit. Trial registration: NCT02133209.