Abnormal structural brain network and hemisphere-specific changes in bulimia nervosa

Abstract

Bulimia nervosa (BN) is characterized by episodic binge eating and purging behaviors. Disrupted neural processes of self-regulation, taste-rewarding, and body image has been associated with the pathogenesis of BN. However, the structural basis for these behavioral and functional deficits remains largely unknown. We employed diffusion tensor imaging and graph theory approaches (including the nodal properties and network-based statistics (NBS)) to characterize the whole-brain structural network of 48 BN and 44 healthy women. For nodal measures of strength, local efficiency, and betweenness centrality, BN patients displayed abnormal increases in multiple left-lateralized nodes within the mesocorticolimbic reward circuitry (including the orbitofrontal cortex, anterior cingulate, insular, medial temporal, and subcortical areas), lateral temporal-occipital cortex, and precuneus, while reduced global efficiency was observed in the right-lateralized nodes within the dorsolateral prefrontal cortex, mesocorticolimbic circuitry, somatosensory and visuospatial system. Several mesocorticolimbic nodes significantly correlated with BN symptoms. At a network level, we found increased left-lateralized connections primarily within the orbitofrontal cortex and its connections to mesocorticolimbic and lateral temporal-occipital areas, but reduced right-lateralized connections across the inferior frontal gyrus and insula, as well as their connections to the lateral temporal cortex. This study revealed BN-related changes in white-matter connections across the prefrontal control, mesocorticolimbic reward, somatosensory and visuospatial systems. The hemispheric-specific change could be an important aspect of the pathophysiology of BN. By characterizing whole-brain structural network changes of BN, our study provides novel evidence for understanding the behavioral and functional deficits of the disorder.

Volume and Connectivity Differences in Brain Networks Associated with Cognitive Constructs of Binge Eating

“…For example, connectivity between the ventral striatum and the insula and the frontal cortex (inferior and medial OFC) was shown to be increased in BN compared with HC ( Frank et al, 2016 ; Wang et al, 2019 ), while connectivity between the ventral striatum and the right basolateral amygdala (BLA) was reduced ( Frank et al, 2016 ). Network analysis in BN compared with HC shows that mesocorticolimbic pathways and other subcortical connections in the right hemisphere might be negatively affected in global efficiency ( Wang et al, 2019 ), a measure associated with parallel information processing ( Bullmore and Sporns, 2012 ). Pathways in the left hemisphere seem largely unaffected or even increased ( Wang et al, 2019 ).…”

Resting-state functional network connectivity underlying eating disorder symptoms in healthy young adults

“…At present, it appears most plausible to expect that such interactions would be bidirectional and mutually reinforcing. The relationship between eating disorder symptoms and neural circuitry may be further explored using graph theory metrics such as “network density” and “average path length,” which could help elucidate both common and unique neural network properties that may underlie potential differences in eating-related psychopathology (e.g., Geisler et al, 2016 , Wang et al, 2019 ). Furthermore, because there does not appear to be one-to-one mapping between brain regions and psychological processes ( Anderson, 2014 ), other interpretations of our results may be possible.…”

The neurostructural and neurocognitive effects of physical activity: A potential benefit to promote eating disorder recovery

“…Studies have also reported altered brain structures in individuals with bulimia nervosa (BN) (Wang et al, 2019), and individuals with bingeeating disorder (BED) have been shown to respond differently to dopamine than BMI-matched controls (Wang et al, 2011), which may indicate aberrant neurostructural or neurofunctional responses to stimuli. Specifically, MRI studies of patients within the bulimic spectrum disorders have reported decreased cortical volume and/or diminished activity within the frontostriatal circuits-areas essential in self-regulation (Donnelly et al, 2018).…”