Longitudinal changes in neural responses to fearful faces in adolescents with anorexia nervosa - A fMRI study.

OBJECTIVE: Although proven neuronal changes are correlated with anorexia nervosa (AN), where these changes occur and how they change during the course of this disease are often unclear; this is especially true regarding emotion processing, e.g., of anxiety, despite a growing body of literature on its importance for the pathophysiology and clinical course of patients with AN. METHODS: Twenty-two female adolescent patients with AN were scanned during acute starvation and after short-term weight recovery and were compared to 27 healthy controls. A well-established face-matching paradigm involving individuals with different emotions was used during fMRI. RESULTS: Patients with AN selectively showed significantly increasing neural activation in the somatomotor cortex when viewing fearful faces following short-term weight recovery. No differences were found compared to healthy controls or for neutral, angry or surprised faces. Neural activation in response to fearful faces during acute starvation was associated with lower BMI-SDS and greater illness burden. CONCLUSION: Higher somatomotor activity could represent anxiety-induced preparations for motor reactions (e.g., fight or flight) that are more pronounced in more affected patients. These results align with recent models of AN that increasingly incorporate anxiety into the pathophysiological and prognostic model of AN and help elucidate its underlying neurological mechanisms.

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 gray matter volume (GMV) changes on resting-state functional magnetic resonance imaging 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), patients who recovered from AN (n = 21, mean age 22.3 years), and two groups of healthy age-matched control subjects (both n = 22, mean age 16.0 and 22.5 years, respectively). Whole-brain measures of resting-state activity and functional connectivity were computed (network-based statistics, global correlation, integrated local correlation, and fractional amplitude of low-frequency fluctuations) to assess resting-state functional magnetic resonance imaging 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-term recovered AN and absent in long-term recovered patients. CONCLUSIONS: Resting-state functional magnetic resonance imaging 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.