Morphometric Analysis of the Corpus Callosum in Relation to Adult Migraine: Association with Disease Duration and Clinical Disability.

BACKGROUND: Migraine is increasingly recognized as a disorder associated with widespread neuroanatomical and white-matter alterations rather than a purely episodic pain condition. The corpus callosum, the largest interhemispheric commissural tract, plays a critical role in sensory integration, pain modulation, and interhemispheric connectivity. Structural alterations of the corpus callosum may therefore reflect cumulative neurobiological effects of chronic migraine. OBJECTIVES: To compare corpus callosum morphometric characteristics between adult patients with migraine and controls without migraine and to investigate the associations between callosal morphology and clinical disease burden, including migraine duration, age at onset, attack frequency, and migraine-related disability. STUDY DESIGN: Single-center, cross-sectional observational study. SETTING: Tertiary referral neurology center with retrospective magnetic resonance imaging evaluation and prospective clinical assessment. METHODS: A total of 101 adult patients diagnosed with migraine according to ICHD-3 criteria and 101 age- and gender-matched controls without migraine were included in our study. Morphometric measurements of the corpus callosum were obtained from midsagittal fluid-attenuated inversion recovery magnetic resonance images using the Witelson segmentation method, assessing genu, truncus, and splenium thickness, as well as anteroposterior length. Group comparisons were performed using the Mann-Whitney U test and the Welch t test, as appropriate. Associations between callosal measurements and clinical variables, including disease duration, age at migraine onset, attack frequency, and Migraine Disability Assessment Scores, were analyzed using the Spearman rank correlation. A receiver operating characteristic analysis was conducted to evaluate the discriminative ability of callosal measurements. RESULTS: Compared with controls, patients with migraine had statistically significant reduced mean (SD) thickness of the genu (10.41 [1.35] mm vs 11.43 [1.08] mm), truncus (5.91 [0.73] mm vs 6.68 [0.84] mm), and splenium (10.73 [1.16] mm vs 11.13 [1.16] mm) all P < 0.05; anteroposterior length did not differ significantly. Within the migraine group, genu thickness correlated positively with age at onset (r = 0.33) and Migraine Disability Assessment Score (r = 0.37) and negatively with disease duration (r = -0.30). Attack frequency showed no significant association with any morphometric parameter. A receiver operating characteristic analysis showed a modest discriminatory performance for genu and truncus thickness. LIMITATIONS: Our study's cross-sectional design precludes causal inference. Also, morphometric measurements were limited to a 2-dimensional assessment thereby making us unable to conduct diffusion or volumetric analyses. CONCLUSIONS: Adult migraine is associated with segmental thinning of the corpus callosum, particularly in the genu and splenium. The relationships with age at onset and disease duration support the concept of cumulative, long-term interhemispheric remodeling in migraine, rather than short-term attack-related effects.