Comparison of brain volumes in episodic and chronic migraine using automated whole-brain volumetry.

Migraine chronification is associated with increased clinical burden, yet structural neuroimaging findings remain inconsistent. We compared global and regional brain volumes among patients with episodic migraine (EM), chronic migraine (CM), and healthy controls (HC) using an automated whole-brain volumetric approach. This retrospective study included 58 CM patients, 55 EM patients, and 60 age- and sex-matched HC. Diagnoses were established according to the International Classification of Headache Disorders, 3rd edition (ICHD-3). Structural MRI data acquired on a 1.5-T scanner were processed using the automated volBrain pipeline. Regional brain volumes were compared using one-way ANOVA. To address multiple testing across 220 regions, family-wise error rate (FWER) was controlled with Holm-Bonferroni and false discovery rate (FDR) with Benjamini-Hochberg. Cohen's d values were calculated as exploratory effect sizes. Monthly attack frequency was significantly higher in CM than EM (p < 0.001), while disease duration was similar. No significant differences were observed among EM, CM, and HC in global or regional brain volumes after FWER and FDR correction. Regions showing nominal uncorrected differences demonstrated small and inconsistent effect sizes. With rigorous whole-brain correction, automated volumetry did not reveal robust structural differences between episodic and chronic migraine. If present, migraine-related morphometric alterations are likely subtle and methodologically sensitive. Larger longitudinal studies using higher-resolution imaging are needed.