title: Morphometric changes in the reward system of Parkinson's disease patients with impulse control disorders.
abstract: Impulse control disorders (ICDs) occur in a subset of patients with Parkinson's disease (PD) who are receiving dopamine replacement therapy. In this study, we aimed to investigate structural abnormalities within the mesocortical and limbic cortices and subcortical structures in PD patients with ICDs. We studied 18 PD patients with ICDs, 18 PD patients without ICDs and a group of 24 age and sex-matched healthy controls. Cortical thickness (CTh) and subcortical nuclei volume analyses were carried out using the automated surface-based analysis package FreeSurfer (version 5.3.0). We found significant differences in MRI measures between the three groups. There was volume loss in the nucleus accumbens of both PD patients with ICDs and without ICDs compared to the control group. In addition, PD patients with ICDs showed significant atrophy in caudate, hippocampus and amygdala compared to the group of healthy controls. PD patients with ICDs had significant increased cortical thickness in rostral anterior cingulate cortex and frontal pole compared to PD patients without ICDs. Cortical thickness in rostral anterior cingulate and frontal pole was increased in PD patients with ICDs compared to the control group, but the differences failed to reach corrected levels of statistical significance. PD patients with ICDs showed increased cortical thickness in medial prefrontal regions. We speculate that these findings reflect either a pre-existing neural trait vulnerability to impulsivity or the expression of a maladaptive synaptic plasticity under non-physiological dopaminergic stimulation.
authors.affiliation: Division of Brain Sciences, Neurology Imaging Unit, Centre of Neuroinflammation and Neurodegeneration, Hammersmith Campus, Imperial College London, London, UK.|Department of Neuroscience, Mental Health and Sensory Organs-(NESMOS), Sapienza University, Rome, Italy.
authors.forename: Clelia
authors.initials: C
authors.lastname: Pellicano
authors.affiliation: Division of Brain Sciences, Neurology Imaging Unit, Centre of Neuroinflammation and Neurodegeneration, Hammersmith Campus, Imperial College London, London, UK.|Neurodegeneration Imaging Group, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, 1 Windsor Walk, London, SE5 8AF, UK.
authors.forename: Flavia
authors.initials: F
authors.lastname: Niccolini
authors.affiliation: Division of Brain Sciences, Neurology Imaging Unit, Centre of Neuroinflammation and Neurodegeneration, Hammersmith Campus, Imperial College London, London, UK.
authors.forename: Kit
authors.initials: K
authors.lastname: Wu
authors.affiliation: Reta Lila Weston Institute of Neurological Studies, University College London, London, UK.
authors.forename: Sean S
authors.initials: SS
authors.lastname: O'Sullivan
authors.affiliation: Cardiff University Brain Research Imaging Centre (CUBRIC) and School of Psychology, Cardiff University, Cardiff, UK.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Lawrence
authors.affiliation: Reta Lila Weston Institute of Neurological Studies, University College London, London, UK.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Lees
authors.affiliation: Division of Brain Sciences, Neurology Imaging Unit, Centre of Neuroinflammation and Neurodegeneration, Hammersmith Campus, Imperial College London, London, UK.
authors.forename: Paola
authors.initials: P
authors.lastname: Piccini
authors.affiliation: Division of Brain Sciences, Neurology Imaging Unit, Centre of Neuroinflammation and Neurodegeneration, Hammersmith Campus, Imperial College London, London, UK. marios.politis@kcl.ac.uk.|Neurodegeneration Imaging Group, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, 1 Windsor Walk, London, SE5 8AF, UK. marios.politis@kcl.ac.uk.
authors.forename: Marios
authors.initials: M
authors.lastname: Politis
mesh_terms: D000328:Adult; D000368:Aged; D000679:Amygdala / Q000473:pathology; D002421:Caudate Nucleus / Q000473:pathology; D003342:Corpus Striatum / Q000473:pathology*; D007174:Disruptive, Impulse Control, and Conduct Disorders / Q000209:etiology / Q000473:pathology*; D005260:Female; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D008032:Limbic System / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009714:Nucleus Accumbens / Q000473:pathology; D010300:Parkinson Disease / Q000150:complications / Q000473:pathology*; D017397:Prefrontal Cortex / Q000473:pathology*; D012201:Reward
keywords: Cortical thickness; Impulse control disorders; MRI; Parkinson’s disease