Frontocingular Dysfunction in Bulimia Nervosa when Confronted with Disease-specific Stimuli

Objective: Bulimia nervosa (BN) is characterized by dysregulation of impulse control, in other words, uncontrolled eating. Functional neuroimaging studies have been sparse and have used variable methodologies.

Method: Thirteen medication-free female BN patients and 13 female healthy controls were investigated by functional magnetic resonance imaging using a disease-specific food paradigm. Stimuli were rated after the scanning procedure.

Results: Bulimia nervosa patients showed increased fear ratings and a trend for increased disgust. Magnetic resonance imaging data of 10 BN patients could be analysed. Three BN patients had to be excluded from the analysis because of minimal blood oxygen level dependent signals. Compared with healthy controls, BN patients showed less activation of the anterior cingulate cortex, which extended into the lateral prefrontal cortex. Furthermore, the right temporal pole showed decreased reactivity.

Discussion: This study substantiates a key role of lateral prefrontal dysfunction in BN, a brain region involved in impulse control. Furthermore, the anterior cingulate cortex, which plays a key role in emotion processing, is dysfunctional. A major limitation of this study is the small sample size.