Puzzle Pieces: Neural Structure and Function in Prader-Willi Syndrome

Abstract

Prader-Willi syndrome (PWS) is a neurodevelopmental disorder of genomic imprinting, presenting with a behavioural phenotype encompassing hyperphagia, intellectual disability, social and behavioural difficulties, and propensity to psychiatric illness. Research has tended to focus on the cognitive and behavioural investigation of these features, and, with the exception of eating behaviour, the neural physiology is currently less well understood. A systematic review was undertaken to explore findings relating to neural structure and function in PWS, using search terms designed to encompass all published articles concerning both in vivo and post-mortem studies of neural structure and function in PWS. This supported the general paucity of research in this area, with many articles reporting case studies and qualitative descriptions or focusing solely on the overeating behaviour, although a number of systematic investigations were also identified. Research to date implicates a combination of subcortical and higher order structures in PWS, including those involved in processing reward, motivation, affect and higher order cognitive functions, with both anatomical and functional investigations indicating abnormalities. It appears likely that PWS involves aberrant activity across distributed neural networks. The characterisation of neural structure and function warrants both replication and further systematic study.

Keywords: Prader-Willi syndrome; brain; neuroimaging; post-mortem; systematic review.

Figure 1

Article identification process for systematic literature review of neural structure and function in Prader-Willi syndrome (PWS). Literature search was carried out on 28 April 2015. Note that subcategories (e.g., case studies/series) within each main category (e.g., structural anatomy) are not mutually exclusive and references may be featured in more than one subcategory. *: One study features in both categories.