Systematic Review of fMRI Studies with Visual Food Stimuli in Anorexia Nervosa

Abstract

Anorexia Nervosa (AN) is a disease with increasing prevalence and relatively high mortality that usually begins in adolescence. Patients with AN avoid food intake and may react specifically toward food images. We present a systematic review of fMRI studies with visual food stimulation in AN, based on a search through PubMed database under the recommendations of the PRISMA guidelines. After applying dates 2004.01.01-2021.01.01, we screened 319 papers and included 27 experimental designs, with only 7 studies focusing on adolescents. Adolescents with AN showed increased activity in the medial prefrontal cortex, the inferior frontal gyrus, the insula, the hippocampus, the fusiform gyrus, the parahippocampal gyrus and the cuneus when watching food images. Adult participants with AN revealed enhanced brain activity due to visual food stimuli in the fusiform gyrus, the inferior frontal gyrus, the lingual gyrus, the medial prefrontal cortex, the right dorsolateral prefrontal cortex, the right angular gyrus. There was deactivation detected in the parahippocampal gyrus, compared to healthy participants. We have found contrary reports according increased/decreased activation of the insula, the amygdala, the hippocampus, the hypothalamus, the anterior cingulate cortex, the thalamus, the orbitofrontal cortex in adults with AN. Although AN typically develops in adolescence, there is still very little fMRI research in this age group. Careful creation of a homogeneous group of study participants is an important factor determining the reliability and unequivocalness of the experiment. Only a detailed description of participants´ characteristics that may affect the results allows solid comparison of different studies´ findings.