Neuroimaging of brain changes associated with cognitive impairment in Parkinson's disease

Authors

  • Leigh Christopher,

    1. Division of Brain, Imaging and Behaviour – Systems Neuroscience, Toronto Western Research Institute, UHN, University of Toronto, Ontario, Canada
    2. Research Imaging Centre, Centre for Addiction and Mental Health, University of Toronto, Ontario, Canada
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  • Antonio P. Strafella

    Corresponding author
    1. Research Imaging Centre, Centre for Addiction and Mental Health, University of Toronto, Ontario, Canada
    2. Morton and Gloria Shulman Movement Disorder Unit & E.J. Safra Parkinson Disease Program, Toronto Western Hospital, UHN, University of Toronto, Ontario, Canada
    • Division of Brain, Imaging and Behaviour – Systems Neuroscience, Toronto Western Research Institute, UHN, University of Toronto, Ontario, Canada
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Correspondence should be addressed to Antonio P. Strafella, Toronto Western Hospital and Institute, CAMH- Research Imaging Centre, University of Toronto, Toronto, ON M5T 2S8 Canada (e-mails: antonio.strafella@uhnres.utoronto.ca; antonio.strafella@camhpet.ca).

Abstract

Cognitive impairment occurs frequently in Parkinson's disease (PD) and the concept of Mild Cognitive Impairment in PD (PD-MCI) has recently emerged. Patients with mild impairment are at risk of developing dementia, and thus it is a topic of growing interest. Many previous studies have investigated the neural correlates of cognitive impairment, in particular executive dysfunction, in PD patients without dementia using neuroimaging techniques including structural MRI, functional MRI and PET imaging. These studies, which have provided a foundation for understanding which brain regions and neurotransmitter systems may be involved in executive dysfunction in PD, will be reviewed. Recent neuroimaging studies that have used specific criteria to classify patients as PD-MCI, in the hopes of gaining further insight into the underlying neural mechanisms will also be discussed. In particular, this review will cover key findings involving structural MRI investigating grey and white matter changes, functional MRI to examine changes in neural activation and PET imaging to investigate metabolic and neurochemical changes that have led to an improved understanding of pathology associated with executive dysfunction in PD without dementia and PD-MCI.

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