Brain Imaging Study Of Pediatric Bipolar Disorder Patients With And Without Psychotic Symptoms

ObjectivePediatric bipolar disorder (PBD) is a most common mental disorder in children and adolescents which has adverse effects on psychosomatic development of children and adolescents, however, to date, the pathphysiology underlying PBD remains unclear. Moreover, previous studies have reported that most PBD patients experience psychotic symptoms during their mood episodes. PBD patients with psychotic symptoms are characterized by longer disease durations, more recurrences, greater symptom severity, longer hospitalizations, increased impairments, and harder to complete remission as compared with those without. Taken together, the aims of the present study are to investigate the possible mechanisms of PBD through brain imaging and to explore the influence of psychotic symptoms on structural and functional alterations in PBD patients.MethodsA total of55children and adolescents meeting DSM-IV diagnostic criteria for BD were recruited from the child and adolescent psychiatric clinic of the Second Xiangya Hospital of Central South University including29patients with psychotic symptoms and26patients without psychotic symptoms. Simultaneously,19age-and gender-matched healthy controls (HCs) were recruited through advertisements in public schools. The3D T1-weighted magnetic resonance imaging (MRI), diffusion tensor imaging (DTI), and blood oxygenation level dependent functional MRI (fMRI) data for all subjects were obtained on a Siemens3.0Tesla scanner. According to data quality, the final number of subjects in each group included:â‘ 27PBD patients with psychotic symptoms,25PBD patients without psychotic symptoms, and18HCs for3D structural data;â‘¡26PBD patients with psychotic symptoms,24PBD patients without psychotic symptoms, and18HCs for DTI data; andâ‘¢29PBD patients with psychotic symptoms,26PBD patients without psychotic symptoms, and19HCs for resting fMRI data. Voxel-based morphometry, voxel-based, and regional homogeneity (ReHo) based analyses were conducted for data analyses, respectively. Analyses of variance (ANOVA) were performed firstly to obtain brain regions with significant differences among three groups and then post hoc tests were performed to test the differences between either two groups.Resultsâ‘ 3D data:As compared with HCs, PBD patients with psychotic symptoms (psychotic PBD) showed decreased gray matter (GM) volume in bilateral hippocampus, parahippocampal gyrus, amygdala and putamen, as well as increased GM volume in the left orbitofrontal cortex (OFC); PBD patients without psychotic symptoms (non-psychotic PBD) showed reduced GM volume in the left hippocampus, parahippocampal gyrus, and the right inferior parietal lobe (IPL) along with larger GM volume in the left OFC. When comparing to non-psychotic PBD, psychotic PBD patients exhibited decreased GM volume in the right hippocampus, parahippocampal gyrus, amygdala and bilateral putamen and increased GM volume in the right IPL.â‘¡DTI data:As compared with HCs, psychotic PBD showed decreased white matter (WM) FA values in the left thalamus, parietal lobule, and the right anterior cingulate along with increased WM FA values in the left insula; non-psychotic PBD exhibited reduced WM FA values in two brain regions which were mainly located in the left thalamus and parietal lobule. When comparing to non-psychotic PBD, psychotic PBD patients exhibited increased WM FA values in the left insula.â‘¢Resting fMRI data:As compared with HCs, psychotic PBD showed decreased ReHo in the medial prefrontal cortex (mPFC), bilateral middle frontal gyrus (MTG), parietal lobule, superior temporal gyrus (STG), fusiform gyrus, and the left insula, putamen; while non-psychotic PBD exhibited decreased ReHo in the mPFC, bilateral MTG, parietal lobule, fusiform gyrus, the left insula, and the right STG. When comparing to non-psychotic PBD, psychotic PBD patients exhibited decreased ReHo in the left MTG and putamen.ConclusionOur findings highlighted that extensive brain structural and functional lesions were existed in PBD. The widespread occurrence of structural and functional abnormalities mainly located in the anterior limbic network, including prefrontal-striatal-thalamic circuit and the associated limbic modulating regions (amygdala, hippocampus, parahippocampal gyrus). Psychotic symptoms were associated with much more severe and extensive brain impairments in PBD patients, which could be the pathological basis of more severe symptoms and worse prognosis in psychotic PBD.