Small gray matter volume in orbitofrontal cortex in Prader-Willi syndrome: A voxel-based MRI study

Abstract

Prader-Willi syndrome (PWS) is a genetically determined neurodevelopmental disorder presenting with behavioral symptoms including hyperphagia, disinhibition, and compulsive behavior. The behavioral problems in individuals with PWS are strikingly similar to those in patients with frontal pathologies, particularly those affecting the orbitofrontal cortex (OFC). However, neuroanatomical abnormalities in the frontal lobe have not been established in PWS. The aim of this study was to look, using volumetric analysis, for morphological changes in the frontal lobe, especially the OFC, of the brains of individuals with PWS. Twelve adults with PWS and 13 age- and gender-matched control subjects participated in structural magnetic resonance imaging (MRI) scans. The whole-brain images were segmented and normalized to a standard stereotactic space. Regional gray matter volumes were compared between the PWS group and the control group using voxel-based morphometry. The PWS subjects showed small gray-matter volume in several regions, including the OFC, caudate nucleus, inferior temporal gyrus, precentral gyrus, supplementary motor area, postcentral gyrus, and cerebellum. The small gray-matter volume in the OFC remained significant in a separate analysis that included total gray matter volume as a covariate. These preliminary findings suggest that the neurobehavioral symptoms in individuals with PWS are related to structural brain abnormalities in these areas.

Anomalous basal ganglia connectivity and obsessive–compulsive behaviour in patients with Prader Willi syndrome

“…10,11 The morphology of the frontobasal systems is also subtly altered in patients with OCD. [12][13][14] In patients with Prader Willi syndrome, measurements of brain regional tissue volume, 15,16 perfusion,…”

Spatial Competences in Prader–Willi Syndrome: A Radial Arm Maze Study

“…These maladaptive behaviors have been related to a dysfunctioning of the elementary frontal cognitive processes (Jauregi et al 2007). This hypothesis was confirmed by a recent voxel based MRI study that showed reduced gray matter volume in the orbitofrontal cortex (Ogura et al 2010) retained to play a crucial role in several functions and in compulsive behavior in particular (Kim and Lee 2002).…”

“…By using three-dimensional MRI, Miller et al (2007) evidenced a decreased volume of brain tissue in the parietal-occipital lobe. Very recently, Ogura and collaborators have evidenced reduced graymatter volume including the orbito-frontal cortex, caudate nucleus, inferior temporal gyrus, precentral gyrus, supplementary motor area, postcentral gyrus, and cerebellum (Ogura et al 2010). Neuro-anatomical abnormalities of fronto-parietal network were also found in individuals with paternal deletion PWS performing a task switching (Woodcock et al 2010).…”

Explorative function in Prader–Willi syndrome analyzed through an ecological spatial task

“…While the brain abnormalities of WS individuals have been well described (Atkinson et al, 2006;Tomaiuolo et al, 2002), only few studies documented the brain abnormalities in PWS subjects. In particular, neuro-pathological anomalies in cerebellar and fronto-parietal structures (Hayashi et al, 1992;Woodcock et al, 2010), decreased volume of the parietal-occipital lobe (Miller et al, 2007), reduced gray-matter volume in the orbito-frontal cortex, caudate nucleus, inferior temporal gyrus, precentral gyrus, supplementary motor area, postcentral gyrus, and cerebellum (Ogura et al, 2011) have been described. These neuro-anatomical abnormalities may be the structural basis of the spatial procedural deficit of the PWS participants observed in the present research, since the dysfunction of fronto-parietal circuit as well as the alterations of sub-cortical structures are retained to be closely related to impaired spatial strategies .…”