Regional homogeneity alterations reflect pain and emotional dysregulation in adenomyosis

Purpose Adenomyosis (AM) with dysmenorrhea (AMD) is a global public health concern that may involve abnormal brain function and heightened vulnerability to anxiety and depression. This study aimed to investigate static and dynamic regional homogeneity (sReHo and dReHo) alterations in AMD and their associations with clinical symptoms.Methods Fifty-two patients with AMD and 52 age- and education-matched healthy controls (HCs) underwent resting-state functional magnetic resonance imaging (rs-MRI). sReHo and dReHo maps were generated and compared using two-sample t-tests (voxel-level p < 0.01; cluster-level, Gaussian random field corrected p < 0.05), with age, education and head motion as covariates. Effect sizes (Cohen’s d) were calculated for significant clusters. Partial correlation analyses assessed relationships between regional homogeneity (ReHo) alterations and clinical measures, controlling for medication use, menstrual phase and psychiatric history.Results Compared with HCs, AMD patients showed significantly increased sReHo and dReHo in the right fusiform gyrus (FFG; d = 0.84, p < 0.001) and decreased values in the bilateral supramarginal gyri (SMG; d = −0.73, p < 0.001). Additional regiongs exhibiting abnormal dReHo were included the bilateral angular gyri, right hippocampus, right cerebellum (lobule 4_5) , left middle frontal gyrus (MFG) and multiple subdivisions of the inferior frontal gyrus. Importantly, ReHo in the right FFG positively correlated with pain severity (visual analogue scale (VAS): r = 0.539-0.797, p < 0.001) and anxiety (Hamilton Anxiety Scale (HAMA): r = 0.442, p = 0.001). Abnormalities in the right hippocampus and cerebellum were also significantly associated with anxiety and depression scores (r = 0.555–0.861, all p < 0.001).Conclusions AMD is characterized by altered intrinsic brain activity in pain- and emotion-related regions, supporting a central mechanism underlying chronic pain and affective symptoms. These findings provide neuroimaging evidence for AMD-related brain dysfunction. Longitudinal studies with larger cohorts and hormonal control are warranted to confirm these results and clarify causal relationships.