Patients with anorexia nervosa and body dysmorphic disorder share a common abnormality in the visual cortex, which may explain distortions of appearance, preliminary data suggest.
“This understanding has the potential to lead to new strategies that can improve the way we treat these disorders,” Wei Li, a student in the UCLA PhD program for neuroscience, said in a press release.
Jamie D. Feusner
Specifically, the study data suggest that the abnormalities begin in early stages when the brain begins processing visual input, according to Li.
Fifteen patients with anorexia nervosa and 15 patients with body dysmorphic disorder were administered fMRI and electroencephalography while they were shown images of faces and houses of different spatial frequencies.
The N170 imaging test for low spatial frequency face stimuli demonstrated that the body dysmorphic group presented hypoactivity (P < .016) compared with healthy controls in the lateral occipital cortex, occipital pole and precuneus. The anorexia group presented hypoactivity (P < .016) in the precuneus and the lateral occipital cortex, according to data.
The P100 imaging test results for low spatial frequency house stimuli indicate that both groups demonstrated hypoactivity (P < .016) compared with healthy controls in the middle temporal gyrus, the occipital fusiform gyrus and the inferior temporal gyrus, the researchers wrote.
High spatial frequency house stimuli imaging tests indicate the body dysmorphic disorder group demonstrated hyperactivity (P < .016) in the temporal fusiform cortex.
The body dysmorphic group also demonstrated hypoactivity (P < .016) in the occipital fusiform cortex, lateral occipital cortex and frontal pole for low spatial frequency house stimuli, according to data.
The imaging test for low spatial frequency house stimuli using a lower statistical threshold (P < .05) indicated the body dysmorphic disorder group had hypoactivity in the occipital fusiform cortex, lateral occipital cortex and frontal pole; whereas the anorexia nervosa group showed hypoactivity in the occipital fusiform cortex, occipital pole and precuneus, they wrote.
“Previously, we knew where these visual processing abnormalities existed in the brain in body dysmorphic disorder, but did not know when they were taking place,” Jamie D. Feusner, MD, associate professor of psychiatry and director of the Obsessive-Compulsive Disorder Program at the UCLA Semel Institute for Neuroscience and Human Behavior, said in the release. “Now, knowing the timing, it is clearer that their perceptual distortions are more likely to be rooted early in their visual systems.”– by Samantha Costa
Disclosure: Strober reports support from the Resnick Endowed Chair in Eating Disorders. The study was funded by the NIH. Please see the full study for a list of all other authors’ relevant financial disclosures.