Altered cerebellar subregion functional connectivity and structure in patients with pediatric bipolar depression

To explore the structural and functional changes of Cerebellar Subregion in patients with pediatric bipolar disorder (PBD) patients and its clinical significance by using multimodal magnetic resonance imaging, so as to further explore the specific role of the cerebellum in PBD. This study included 48 pediatric patients with bipolar disorder (PBD) in the depressive phase from the outpatient clinic of the Department of Psychosomatic Medicine of the First Affiliated Hospital of Nanchang University. 22 healthy controls (HCs) matched for gender, age, handedness and education level were chosen from the community as the control group. All subjects underwent 3.0T resting-state functional magnetic resonance imaging (rs-fMRI) scans and completed clinical scales, including the Hamilton Depression Scale (HAMD) and Young Mania Rating Scale (YMRS). The cerebellum was categorized into 34 distinct subregions (R17, L17) based on SUIT and designated as seed points to perform whole-brain functional connectivity (FC). Group differences in categorical variables were assessed using the chi-square test, while continuous variables were compared employing the two-sample t-test. Correlations between FC and clinical parameters were analyzed for differential brain intervals. Compared with HCs, PBD patients in the depressive phase showed reduced FC between the left cerebellar lobules I-IV and the occipital inferior lobe (Occipital_Inf_L), cerebellar vermis VIIIa, and VIIIb; decreased FC between cerebellar cerebellar vermis VI and the frontal inferior orbital gyrus (Frontal_Inf_Orb_L), as well as the right cerebellar Crus 1; reduced FC between the left cerebellar Crus I and the dentate nucleus; decreased FC between cerebellar vermis VIIIa and the left superior frontal gyrus; reduced FC between the right cerebellar lobule IX and the right lingual gyrus; lowered FC between the left dentate and the dorsolateral prefrontal cortex, and the left lingual gyrus; FC between the left fastigial nucleus and the right cerebellar X decreased. Depressive phase of PBD patients exhibit altered functional connectivity within various subregions of the cerebellum, suggesting that the cerebellum is involved in central neural reorganization in PBD, which may be instructive for the understanding of central mechanisms and its future diagnostic and therapeutic target development.