Alterations in resting‐state whole‐brain functional connectivity pattern similarity in bipolar disorder patients

Abstract

Background Previous neuroimaging studies have extensively demonstrated many signs of functionally spontaneous local neural activity abnormalities in bipolar disorder (BD) patients using resting‐state functional magnetic resonance imaging (rs‐fMRI). However, how to identify the changes of voxel‐wise whole‐brain functional connectivity pattern and its corresponding functional connectivity changes remain largely unclear in BD patients. The current study aimed to investigate the voxel‐wise changes of functional connectivity patterns in BD patients using publicly available data from the UCLA CNP LA5c Study. Methods A total of 45 BD patients and 115 healthy control subjects were finally included and whole‐brain functional connectivity homogeneity (FcHo) was calculated from their rs‐fMRI. Moreover, the alterations of corresponding functional connectivity were subsequently identified using seed‐based resting‐state functional connectivity analysis. Results Individuals with BD exhibited significantly lower FcHo values in the left middle temporal gyrus (MTG) when compared with controls. Functional connectivity findings further indicated decreased functional connectivities between left MTG and cluster 1 (left superior temporal gyrus, extend to middle temporal gyrus, rolandic operculum), cluster 2 (right postcentral, extend to right precentral) in BD patients. The mean FcHo values of left MTG were positively correlated with insomnia, middle scores and appetite increase scores. The mean functional connectivities of left MTG to cluster 1 were negatively correlated with grandiose delusions scores. While the functional connections between left MTG with cluster 2 were negatively correlated with delusions of reference and positively correlated with insomnia, middle scores in BD patients. Conclusions Our findings suggested that abnormal FcHo and functional connections in those areas of the brain involving DMN and SMN networks might play a crucial role in the neuropathology of BD.

Structural and functional MRI correlates of inflammation in bipolar disorder: a systematic review

“…These findings associate somatomotor network FC to BD symptoms, suggesting for instance that SMN hypoconnectivity may predominate in more depressed states in association with reduced psychomotor activity, while SMN hyperconnectivity has been proposed to occur in (hypo)manic states (when psychomotor agitation is more predominant) (Martino et al, 2016;Zhu et al, 2022). Furthermore, increasing evidence points to the involvement of SMN in emotional processing in BD (Ellard et al, 2018;Kebets et al, 2019;Magioncalda et al, 2020;Ping et al, 2022;Tang et al, 2021;Wang et al, 2020;Zhu et al, 2022). While these findings remain preliminary due to the caveats discussed above, and the direction of causality of these associations has yet to be uncovered, the correlations between altered FC in these brain regions and markers of inflammation strengthen the hypothesis that a pro-inflammatory state may underlie altered brain function in BD and, speculatively, BD symptoms, given the involvement of brain circuits that have been associated with affective and somatomotor processing.…”

Dynamic functional hippocampal markers of residual depressive symptoms in euthymic bipolar disorder

“…The latter includes for instance motor agitation and hyperesthesia during mania, or the somatomotor slowing and dulling associated with depressive symptoms (Bowden, 2005). Interestingly, increasing evidence points to the involvement of somatomotor networks (SMN) in emotional and cognitive processing, with SMN having recently become a pivotal area of brain networks research in BD (Ellard et al., 2018; Kebets et al., 2019; Magioncalda et al., 2020; Ping et al., 2022; Saccaro et al., 2023; Tang et al, 2021; Wang et al., 2020; Zhu et al., 2022). Disrupted internetwork stationary functional connectivity (FC) has been shown in BD in the somatomotor network (SMN), default mode network (DMN), salience system (SN), and frontoparietal network (FPN).…”

Enhanced Dynamic Laterality Based on Functional Subnetworks in Patients with Bipolar Disorder

“…Bipolar disorder (BD) is a chronic mental disorder caused by disturbances in the functioning of the brain, characterized by alternating episodes of depression and hypomania [1,2]. BD severely affects more than 1% of the world's population and is characterized by lifelong episodes [3].…”