Brain imaging and behavior
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Brain Imaging Behav · Oct 2017
Non-demented Parkinson's disease patients with apathy show decreased grey matter volume in key executive and reward-related nodes.
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. ⋯ 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.