Abnormal fronto‐striatal activation as a marker of threshold and subthreshold Bulimia Nervosa

Abstract

This study aimed to determine whether functional disturbances in fronto-striatal control circuits characterize adolescents with Bulimia Nervosa (BN) spectrum eating disorders regardless of clinical severity. FMRI was used to assess conflict-related brain activations during performance of a Simon task in two samples of adolescents with BN symptoms compared with healthy adolescents. The BN samples differed in the severity of their clinical presentation, illness duration and age. Multi-voxel pattern analyses (MVPAs) based on machine learning were used to determine whether patterns of fronto-striatal activation characterized adolescents with BN spectrum disorders regardless of clinical severity, and whether accurate classification of less symptomatic adolescents (subthreshold BN; SBN) could be achieved based on patterns of activation in adolescents who met DSM5 criteria for BN. MVPA classification analyses revealed that both BN and SBN adolescents could be accurately discriminated from healthy adolescents based on fronto-striatal activation. Notably, the patterns detected in more severely ill BN compared with healthy adolescents accurately discriminated less symptomatic SBN from healthy adolescents. Deficient activation of fronto-striatal circuits can characterize BN early in its course, when clinical presentations are less severe, perhaps pointing to circuit-based disturbances as useful biomarker or risk factor for the disorder, and a tool for understanding its developmental trajectory, as well as the development of early interventions.

The elusive functional bases of appetite control in the brain

“…In BN compared to AN, deactivation of parietal cortex and dorsal posterior cingulate cortex (somatosensory areas), and greater activation of the striatum (reward/motivation processing), superior temporal gyrus, right insula (associated with anxiety) and supplementary motor area (linked to uncontrolled decision-making behaviour) was observed. These regional activation differences are in line with recent, more sophisticated analyses of neural processes in BN using multi-variate analyses based on machine learning [ 4 ]. Cyr and colleagues demonstrated that women with BN show diminished recruitment of prefrontal cortex circuitry and deficient regulation of the striatum by the prefrontal regions that may classify both chronic and sub-threshold BN with lower disorder severity.…”

Control of response interference: caudate nucleus contributes to selective inhibition

“…As noted above, asymmetrical Simon effects between hemifields were found in two previous behavioral studies that used a unimanual Simon task, with smaller mean Simon effects on the side of the responding hand 45,72 . Still, other fMRI studies using unimanual variants of the Simon task did not report asymmetries in task performance 39,[77][78][79] . To our knowledge, there are currently no studies available that analyzed the time course of the Simon effect across the RT distribution as a function of lateralized visual stimuli (neither for bimanual nor unimanual response set-ups).…”

Cognitive Neuroscience of Eating Disorders

“…89,90 Machine learning approaches using these altered patterns of activation can reliably distinguish BN cases from healthy controls. 91,92 One study has used a go/no-go task to examine differences in response inhibition to food and neutral images and found that only a BN subgroup with the most frequent binge eating showed decreased activation during response inhibition to neutral images in dorsal striatum, with additional hypoactivation in sensorimotor areas. 92 One emotional go/no-go study found that individuals with BN showed age-dependent deficits in PFC activation during emotional go/no-go task response inhibition relative to healthy controls.…”