Disrupted Rich Club Organization of Hemispheric White Matter Networks in Bipolar Disorder

Abstract

Neuroimaging studies suggest disrupted connections of the brain white matter (WM) network in bipolar disorder (BD). A group of highly interconnected high-density structures, termed the 'rich club,' represents an important network for brain functioning. Recent works have revealed abnormal rich club organization in brain networks in BD. However, little is known regarding changes in the rich club organization of the hemispheric WM network in BD. Forty-nine BD patients and fifty-five age-and sex-matched normal controls (NCs) underwent diffusion tensor imaging (DTI). Graph theory approaches were applied to quantify group-specific rich club organization and nodal degree of hemispheric WM networks. We demonstrated that rich club organization of hemispheric WM networks in BD was disrupted, with disrupted feeder and local connections among hub and peripheral regions located in the default mode network (DMN) and the control execution network (CEN). In addition, BD patients showed abnormal asymmetry in the feeder and local connections, involving the hub and peripheral regions associated with emotion regulation and visuospatial functions. Moreover, the clinical symptoms of BD showed a significant correlation with the aberrant asymmetry in the regional degree of peripheral regions. These findings reveal that BD is closely associated with disrupted feeder and local connections but no alteration in richclub connections in the rich club organization of hemispheric WM networks and provide novel insight into the changes of brain functions in BD.

Age Trajectories of the Structural Connectome in Child and Adolescent Offspring of Individuals With Bipolar Disorder or Schizophrenia

“…Correspondingly, siblings of individuals with schizophrenia exhibit RC disruptions ( 33 ). Again, in individuals with bipolar disorder, findings have been more varied, with studies reporting unaltered ( 17 , 18 , 19 ), decreased ( 20 ), or increased ( 21 , 22 , 23 ) RC connectivity, and previous studies in BDo also presented no significant differences in RC connectivity ( 15 , 34 , 35 ) compared with Co. Our cross-sectional findings at time point 1 in child and adolescent offspring are consistent with these patterns, demonstrating suggestive evidence for lower RC connectivity only in SZo ( 34 ). Our analyses revealed a nonsignificant effect of familial risk of schizophrenia on the age trajectory of RC connectivity but in the same direction as cross-sectional findings and previous literature.…”

“…A growing body of literature has demonstrated disruptions of the connectome—the comprehensive network of the brain’s structural connections—in individuals with bipolar disorder ( 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ) and schizophrenia ( 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ), as well as their siblings ( 33 ) and offspring ( 15 , 34 , 35 , 36 ). A recurrent finding in both patient groups ( 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 30 ) and their relatives ( 33 , 34 ) has been the aberrant connectivity of the brain network’s “rich club” (RC), a coherent constellation of highly interconnected hubs reputed to act as the backbone for global brain integration ( 37 , 38 , 39 ).…”

Altered structural connectome of children with Auditory Processing Disorder: A diffusion MRI study

“…Rich-club organization is a key characteristic of brain networks, and its existence has not only been found during human brain development (Sa de Almeida et al, 2021; van den Heuvel & Sporns, 2011), but also in numerous neurological diseases (Cao et al, 2014; Collin, Kahn, et al, 2014; Cui et al, 2022; D. Li et al, 2020; Liu et al, 2021; Peng et al, 2021; Ray et al, 2014; Van Den Heuvel et al, 2013). In our study, the rich-club network of densely interconnected hubs was observed for both APD and HC groups in the left fusiform gyrus, left precuneus, bilateral parietooccipital sulcus, bilateral hippocampus, bilateral basal ganglia (i.e., caudate, globus pallidus, putamen, nucleolus accumbens), and bilateral thalamus.…”

“…Rich-club organization is a key characteristic of brain networks, and its existence has not only been found during human brain development (Sa de Almeida et al, 2021;van den Heuvel & Sporns, 2011), but also in numerous neurological diseases (Cao et al, 2014;Collin, Kahn, et al, 2014;Cui et al, 2022;D. Li et al, 2020;Liu et al, 2021;Peng et al, 2021;Ray et al, 2014;.…”