Recovery-associated resting-state activity and connectivity alterations in Anorexia nervosa

Background: Previous studies provided controversial insight on the impact of starvation, disease status and underlying grey matter volume (GMV) changes on resting-state functional magnetic resonance imaging (rsfMRI) alterations in Anorexia nervosa (AN). Here we adapt a combined longitudinal and cross-sectional approach to disentangle the effects of these factors on resting-state alterations in AN.Methods: Overall, 87 female subjects were included in the study: adolescent patients with acute AN scanned at inpatient admission (N = 22, mean age 15.3 years) and at discharge (N = 21), 21 patients recovered from AN (22.3 years) and two groups of healthy age-matched controls (both N = 22, 16.0 and 22.5 years). Whole-brain measures of resting-state activity and functional connectivity were computed (Network Based Statistics, Global Correlation, Integrated Local Correlation, fractional Amplitude of Low Frequency Fluctuations) to assess rsfMRI alterations over the course of AN treatment before and after controlling for underlying GMV.Results: Patients with acute AN displayed strong and widespread prefrontal, sensorimotor, parietal, temporal, precuneal and insular reductions of resting-state connectivity and activity. All alterations were independent of GMV and were largely normalized in short- and absent in long-term recovered AN.Conclusions: Resting-state fMRI alterations in AN constitute acute and GMV independent presumably starvation-related phenomena. The majority of alterations found here normalized over the course of recovery without evidence for possible preexisting trait- or remaining "scar"-effects.Keywords: Anorexia nervosa; functional connectivity; grey matter volume; longitudinal; recovery; resting-state functional magnetic resonance imaging