TY - JOUR
T1 - Non-demented Parkinson’s disease patients with apathy show decreased grey matter volume in key executive and reward-related nodes
AU - Martinez-Horta, Saul
AU - Sampedro, Frederic
AU - Pagonabarraga, Javier
AU - Fernandez-Bobadilla, Ramón
AU - Marin-Lahoz, Juan
AU - Riba, Jordi
AU - Kulisevsky, Jaime
PY - 2017/10/1
Y1 - 2017/10/1
N2 - © 2016, Springer Science+Business Media New York. Apathy is a common but poorly understood neuropsychiatric disturbance in Parkinson’s disease (PD). In a recent study using event-related brain potentials we demonstrated impaired reward processing and compromised mesocortico-limbic pathways in PD patients with clinical symptoms of apathy. Here we aimed to further investigate the involvement of reward circuits in apathetic PD patients by assessing potential differences in brain structure. Using structural magnetic resonance imaging (MRI) and voxel-based morphometry (VBM) we quantified grey matter volume (GMV) in a sample of 18 non-demented and non-depressed PD patients with apathy, and 18 matched non-apathetic patients. Both groups were equivalent in terms of sociodemographic characteristics, disease stage, cognitive performance and L-Dopa equivalent daily dose. Apathetic patients showed significant GMV loss in cortical and subcortical brain structures. Various clusters of cortical GMV decrease were found in the parietal, lateral prefrontal cortex, and orbitofrontal cortex (OFC). The second largest cluster of GMV loss was located in the left nucleus accumbens (NAcc), a subcortical structure that is a key node of the human reward circuit. Isolated apathy in our sample is explained by the combined GMV loss in regions involved in executive functions, and cortical and subcortical structures of the mesolimbic reward pathway. The correlations observed between apathy and cognition suggests apathy as a marker of more widespread brain degeneration even in a sample of non-demented PD patients.
AB - © 2016, Springer Science+Business Media New York. Apathy is a common but poorly understood neuropsychiatric disturbance in Parkinson’s disease (PD). In a recent study using event-related brain potentials we demonstrated impaired reward processing and compromised mesocortico-limbic pathways in PD patients with clinical symptoms of apathy. Here we aimed to further investigate the involvement of reward circuits in apathetic PD patients by assessing potential differences in brain structure. Using structural magnetic resonance imaging (MRI) and voxel-based morphometry (VBM) we quantified grey matter volume (GMV) in a sample of 18 non-demented and non-depressed PD patients with apathy, and 18 matched non-apathetic patients. Both groups were equivalent in terms of sociodemographic characteristics, disease stage, cognitive performance and L-Dopa equivalent daily dose. Apathetic patients showed significant GMV loss in cortical and subcortical brain structures. Various clusters of cortical GMV decrease were found in the parietal, lateral prefrontal cortex, and orbitofrontal cortex (OFC). The second largest cluster of GMV loss was located in the left nucleus accumbens (NAcc), a subcortical structure that is a key node of the human reward circuit. Isolated apathy in our sample is explained by the combined GMV loss in regions involved in executive functions, and cortical and subcortical structures of the mesolimbic reward pathway. The correlations observed between apathy and cognition suggests apathy as a marker of more widespread brain degeneration even in a sample of non-demented PD patients.
KW - Apathy
KW - Behavior
KW - MRI
KW - Motivation
KW - Parkinson’s disease
KW - VBM
U2 - 10.1007/s11682-016-9607-5
DO - 10.1007/s11682-016-9607-5
M3 - Article
SN - 1931-7557
VL - 11
SP - 1334
EP - 1342
JO - Brain Imaging and Behavior
JF - Brain Imaging and Behavior
IS - 5
ER -