Neuroimaging Investigation of Hyperphagia in Prader-Willi Syndrome
Marked hyperphagia and the resultant morbid obesity pose major health risks to people with Prader-Willi Syndrome (PWS), a genetic disorder characterized by excessive eating and food-seeking. Further study of hyperphagia and food perception in PWS is essential to better treatment in PWS. Preliminary findings from Dr. Elisabeth Dykens’ ongoing study “Prader-Willi Syndrome: Correlates of Compulsivity,” suggest that individuals with PWS show altered brain electrical activity in EEG/ERP responses to certain food images, such as contaminated food and inappropriate combinations of food. These preliminary data reveal differences in food perception and discrimination in PWS relative to controls, and across the two primary genetic subtypes of PWS, uniparental disomy (UPD) and deletion (Del) PWS. Individuals with PWS-Del tend to initially discriminate food on the basis of quantity over appropriateness, while those with PWS-UPD are more similar to controls in focusing on suitability for eating when viewing images. These data suggest novel differences in food cue processing at the neural level between individuals with the two primary genetic subtypes of PWS. The next step in understanding the neural basis of these preliminary ERP findings is to use functional MRI (fMRI) to examine regional brain activation in persons with PWS and obese controls while viewing similar food-cue paradigms.