Partially restored resting-state functional connectivity in women recovered from anorexia nervosa

Abstract

Background: We have previously shown increased resting-state functional connectivity (rsFC) in the frontoparietal network (FPN) and the default mode network (DMN) in patients with acute anorexia nervosa. Based on these findings we investigated within-network rsFC in patients recovered from anorexia nervosa to examine whether these abnormalities are a state or trait marker of the disease. To extend the understanding of functional connectivity in patients with anorexia nervosa, we also estimated rsFC between large-scale networks.

Methods: Girls and women recovered from anorexia nervosa and pair-wise, age- and sex-matched healthy controls underwent a resting-state fMRI scan. Using independent component analyses (ICA), we isolated the FPN, DMN and salience network. We used standard comparisons as well as a hypothesis-based approach to test the findings of our previous rsFC study in this recovered cohort. Temporal correlations between network time-course pairs were computed to investigate functional network connectivity (FNC).

Results: Thirty-one patients recovered from anorexia nervosa and 31 controls participated in our study. Standard group comparisons revealed reduced rsFC between the dorsolateral prefrontal cortex (dlPFC) and the FPN in the recovered group. Using a hypothesis-based approach we extended the previous finding of increased rsFC between the angular gyrus and the FPN in patients recovered from anorexia nervosa. No group differences in FNC were revealed.

Limitations: The study design did not allow us to conclude that the difference found in rsFC constitutes a scar effect of the disease.

Conclusion: This study suggests that some abnormal rsFC patterns found in patients recovered from anorexia nervosa normalize after long-term weight restoration, while distorted rsFC in the FPN, a network that has been associated with cognitive control, may constitute a trait marker of the disorder.

Fig. 1

Spatial maps of 6 independent components (IC) of interest grouped by network: frontoparietal network (FPN), default mode network (DMN) and salience network. Spatial maps are plotted as t statistics thresholded at p < 0.05, family-wise error–corrected.

Fig. 2

Group difference at a threshold of p < 0.05, family-wise error–corrected, between patients recovered from anorexia nervosa (recAN) and healthy controls (HC) in component 5, representing the frontoparietal network (FPN; peak coordinates in Montreal Neurological Institute space: x, y, z = 42, 46, 14).

Fig. 3

Targeted follow-up approach: group difference at a threshold of p = 0.05, familiy-wise error–corrected, between patients recovered from anorexia nervosa (recAN) and healthy controls (HC) in component 5, representing the frontoparietal network (FPN; peak coordinates in Montreal Neurological Institute space: x, y, z = 36, −64, 44). Applied mask covering the previous finding at angular gyrus (AG) is displayed in white.

Fig. 4

Functional network connectivity in (A) patients recovered from anorexia nervosa (recAN) and (B) healthy controls (HC). Arrows show the significant correlation between resting-state networks. The direction of the arrow corresponds with the direction of the delay between 2 components. DMN = default mode network; FPN = frontoparietal network; IC = independent component; SN = salience network.