Altered Brain Structure And Function In Women With Premenstrual Syndrome

Premenstrual syndrome(PMS)is a common gynaecological disorders recurrently occurring during the luteal phase of menstrual cycle and subsiding soon after the onset of menses.With a series of cycling physical,behavioral,emotional and cognitive syndromes,patients with severe menstrual symptoms have significant negative effect on women’s quality of life,work and social activity.Neuroimaging studies demonstrated that PMS patients have abnormal functional brain activity in the neural circuits.However,the pathophysiology of PMS remains largely unknown.Recently,magnetic resonance imaging(MRI)has been widely applied to explore the structural and functional abnormalities of the brains of mental diseases.The aim of this study is to evaluate potential brain structural and functional alterations in PMS patients based on structural and functional MRI data analyses.In the current study,PMS patients and healthy controls(HCs)were underwent structural and functional MRI scan and clinical assessment.And we then explored the potential abnormal brain regions and its relationships with clinical characteristic(e.g.daily rating of severity of problems(DRSP)in PMS patients and HCs.Firstly,we analyzed the altered brain gray matter(GM)volumes in PMS patients:(1)voxel-based morphometry(VBM)analysis was adopted to examine gray matter volumes alterations between PMS patients and HCs.Receiver operating characteristic(ROC)curve was used to investigate the most reliable biomarker for distinguishing PMS patients form HCs based on the intergroup differences;(2)correlation analysis was then performed to assess relationships between the DRSP and abnormal brain regions;and(3)the regions identified from VBM analysis were served as seeds to characterize the whole-brain structural covariance patterns.Results showed that(1)compared to HCs,PMS patients had increased GM volumes in the precuneus/posterior cingulate cortex(PCC)and thalamus,and decreased GM volumes in the insula;(2)the precuneus/PCC exhibited the highest classification power by ROC analysis,and its GM volumes positively correlated with the DRSP;and(3)different structural covariance patterns in the two groups were mainly located in the dorsolateral prefrontal cortex,anterior cingulate cortex,angular gyrus and hippocampus.These findings implicate that PMS patients had abnormal brain structure,which may be related to emotion regulation,perception of salient stimuli and unpleasant visceral sensations.Secondly,Free Surfer image analysis suite was performed to analyze the cortical thickness and subcortical volumes.Relationships between cortical thickness/subcortical volumes and DRSP score were then measured in patients.Results showed that(1)compared to HCs,PMS patients exhibited reduced cortical thickness in the medial prefrontal cortex,orbitofrontal cortex and insula,and increased subcortical volumes of the amygdala,thalamus and pallidum;(2)only negative correlations were detected between the DRSP and cortical thickness in the anterior cingulate cortex and precuneus in PMS patients.These findings indicate that PMS may be involved in abnormal regulations of the amygdala-prefrontal circuit,cortical-basal ganglia-thalamo-cortical loop and insula.Finally,we used functional connectivity between the thalamus and distinct cortical regions to identify specific thalamocortical connectivity in the PMS patients and HCs.Correlation analysis was then applied to examine relationships between the neuroimaging findings and clinical symptoms.Results showed that(1)the distinct thalamocortical connectivity maps of the two groups were similar,and the group differences were located in the prefrontal-thalamic connectivity and the posterior parietal-thalamic connectivity;(2)the DRSP score was negatively correlated with the prefrontal-thalamic connectivity.Our findings reveal that PMS patients had abnormal thalamocortical connectivity,which may disturb processing of emotion and/or attention,and may enhance unpleasant perception of visceral sensations.We hope our study findings can provide some neuroimaging evidence for the further understanding of the pathophysiology of PMS,and provide a theoretical basis for clinical diagnosis and treatment of PMS.