HIPPOCAMPAL ASYMMETRY INDEX IN MIGRAINE: FINDINGS FROM MRI-BASED VOLUMETRIC ANALYSIS

Migraine is a neurological disorder involving cognitive and emotional processing, in which the hippocampus plays a central role in pain modulation and stress response. Although hippocampal asymmetry is a recognized biomarker in other neurological disorders, its relevance in migraine remains unclear. This retrospective case–control study aimed to evaluate the hippocampal asymmetry index (AI) in individuals with migraine compared with healthy controls. Medical records of 36 patients diagnosed with migraine according to ICHD-3 criteria and 36 age- and gender-matched healthy controls were analyzed. High-resolution 3D T1-weighted MR images (1 mm slice thickness) acquired on a 1.5 Tesla scanner were analyzed. Volumetric analysis was performed using ITK-SNAP software with a rigorous semi-automatic protocol and slice-by-slice manual correction to ensure anatomical fidelity. Hippocampal segmentation was independently performed by two blinded researchers, and AI was calculated using the formula (R − L)/(L + R) × 100. Quantitative analyses revealed preserved hippocampal volumes in patients with migraine. Median right hippocampal volume was 2589.50 mm³ in the migraine group and 2615.50 mm³ in controls (p = 0.964), while left hippocampal volumes were 2633.00 mm³ and 2605.50 mm³, respectively (p = 0.710). AI values did not differ significantly between groups. Median AI was 2.37 (−3.06 to 4.12) in migraine patients and 0.44 (−0.19 to 1.28) in controls, with no statistically significant difference (p = 0.230). These findings indicate that migraine is not associated with macroscopic hippocampal asymmetry or volumetric atrophy, reinforcing the concept that migraine predominantly represents a functional disorder rather than a neurodegenerative condition.