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Parkinson’s Disease
Volume 2019, Article ID 5351749, 6 pages
Research Article

Increased Cortical Thickness in Attentional Networks in Parkinson’s Disease with Minor Hallucinations

1Department of Psychology, University of Toronto, 100 St. George Street, Toronto, ON, Canada M5S 3G3
2Krembil Brain Institute at Toronto Western Hospital, 399 Bathurst Street, Toronto, ON, Canada M5T 2S8
3Department of Psychology, University of California at Davis, 1 Shields Avenue, Davis, CA 95616, USA
4Center for Neuroscience, University of California at Davis, 1544 Newton Court, Davis, CA 95618, USA

Correspondence should be addressed to Melanie Cohn; ac.nhu@nhoc.einalem

Received 29 January 2019; Revised 31 March 2019; Accepted 7 April 2019; Published 2 May 2019

Guest Editor: Matteo Bologna

Copyright © 2019 Caspian M. Sawczak et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Hallucinations are common in Parkinson’s disease (PD). Based on functional brain MRI data, hallucinations are proposed to result from alterations in the dorsal attention network (DAN), ventral attention network (VAN), and default mode network. Using structural MRI data from Parkinson’s Progression Markers Initiative (PPMI), we examined cortical thickness in these networks in PD patients with () and without () minor hallucinations who were matched on multiple clinical characteristics (e.g., age, sex, education, cognitive diagnosis, MoCA score, medication, disease duration, and severity) as well as healthy controls () matched on demographic variables. Multivariate analyses revealed mild hallucinations to be associated with thicker cortex in the DAN and VAN, and these effects were driven by the left superior precentral sulcus and postcentral sulcus for the DAN and by the right insular gyrus for the VAN. While these findings may seem at odds with prior work showing grey matter reductions, our patients are in earlier stages of the disease than those in other studies. This is consistent with an inverted U-shape pattern of cortical thickness alterations in other neurodegenerative diseases and warrants further investigations in longitudinal studies tracking brain correlates of PD psychosis progression.