NEUROPSYCHOLOGICAL CORRELATES OF STRIATAL DOPAMINERGIC DYSFUNCTION IN PARKINSON’S DISEASE

Abstract

OF DISSERTATION NEUROPSYCHOLOGICAL CORRELATES OF STRIATAL DOPAMINERGIC DYSFUNCTION IN PARKINSON’S DISEASE Parkinson’s disease (PD) is a common neurodegenerative disorder associated with dysfunction of the basal ganglia, which contributes to a range of motor, cognitive, and affective symptoms. Striatal dopaminergic deficits are one of the core pathological mechanisms thought to contribute to the extra-motor (i.e., cognitive and affective) symptoms in early PD. The present study investigated the relationship between striatal dopaminergic integrity and cognition in 21 patients with PD and 21 age and education matched controls. Each individual underwent dopamine transporter (DaT) imaging with single photon emission computed tomography (SPECT) (i.e., DaTscan) and standardized neuropsychological testing. Strong positive associations were found between DaT availability in the striatum and verbal memory (r = .52-.61) and problem solving/setshifting (r = .55) in patients with PD. Additional moderate to strong positive associations (r = .49-.56) between DaT concentrations and visuospatial functions in patients with PD were found. However, similar significant associations between DaT and cognition were observed in age and education matched controls. Clinically, it is important for health care professionals to consider the role of both striatal and extra-striatal mechanisms as they relate to cognition in PD. Future studies examining the full range of pathological mechanisms that contribute to cognitive dysfunction in PD over time are warranted in order to inform more effective and targeted interventions.