Date Presented Accepted for AOTA INSPIRE 2021 but unable to be presented due to online event limitations.
People with Parkinson’s disease (PD) without dementia often have cognitive deficits that impact daily function. This study explored functional cognition and its neural substrates in PD without dementia. We found dissociable relationships between aspects of daily cognitive function and functional connectivity of cognitive brain networks. This information may ultimately guide OT practice that will improve or maintain functional cognition in those with PD.
Primary Author and Speaker: Anneliese Schlesinger
Additional Authors and Speakers: Erin Foster
BACKGROUND/PURPOSE: Parkinson’s disease (PD) is associated with subtle cognitive deficits early in the disorder. These deficits are attributed to frontostriatal circuitry dysfunction and cause increased mortality, caregiver burden, and decreased independence and quality of life. Such effects highlight the need for interventions to address functional cognition in those with PD to aid in maintaining their and their caregiver’s independence and quality of life. The purpose of this study was to investigate functional cognition and its neural correlates among non-demented people with PD. This information could guide the development of biobehavioral interventions to address functional cognition in PD.
DESIGN: This was a cross-sectional analysis of data from an ongoing longitudinal study of cognition in people with PD and healthy controls (HC). The sample included 105 participants: 45 HC and 60 mild-moderate PD with normal cognition (i.e., Hoehn & Yahr I-III; no dementia or mild cognitive impairment, determined by neuropsychological testing and Clinical Dementia Rating Scale).
METHOD: The Frontal Systems Behavioral Scale (FRSBE), a self-report measure of everyday cognitive problems associated with frontostriatal circuitry dysfunction, was used as an indicator of functional cognition. The FRSBE yields three subscale scores: apathy (A), disinhibition (D), and executive dysfunction (E). Resting-state functional connectivity magnetic resonance imaging (rs-fcMRI) was used to measure the integrity of cognitive networks relevant to frontostriatal circuitry and/or everyday cognitive functions assessed by the FRSBE. Specifically, integrity was calculated for the default mode (DMN), parietal memory (PMN), cingulo-opercular control (CON), dorsal attention (DAN), ventral attention (VAN), and fronto-parietal control (FPN) networks. Independent samples t-tests and Pearson correlations were used to compare groups and explore the relationships between FRSBE scores and network integrity, respectively.
RESULTS: There were no group differences in FRSBE scores or rs-fcMRI cognitive network integrity (p > 0.19). Within PD, FRSBE-A correlated with DMN (r = -.321, p < 0.01), DAN (r = -.304, p < 0.02), and CON (r = -.295, p < 0.02), while FRSBE-D correlated with VAN (r = .302, p < 0.02). Within HC, FRSBE-A correlated with CON (r = -.325, p < 0.03) and FPN (r = -.330, p < 0.01), while FRSBE-E correlated with CON (r = -.309, p < 0.04). The correlations were such that poorer everyday cognitive function related to lower network integrity with the exception of the correlation between FRSBE-D and VAN in the PD group, where poorer everyday cognitive function related to higher network integrity.
CONCLUSION/IMPACT: There were no differences between the PD and HC groups in everyday cognitive function or network integrity, highlighting the subtle nature of cognitive and neural dysfunction in the PD sample. Although they differed slightly across groups, the correlational findings are fairly consistent with our current understanding of neural-cognitive relationships. The DMN, CON, FPN, and DAN all have prominent nodes within the anterior cingulate cortex (ACC), explaining their associations to apathy in both groups. The CON is critical for executive control, explaining its relationship to executive dysfunction in the HC group. The VAN is implicated in stimulus-driven attentional control, which may explain its association with disinhibition in the PD group. These results are important to science because they help advance knowledge related to the neural mechanisms of everyday cognitive function. Ultimately, this may impact occupational therapy practice by informing targeted and mechanistically-driven assessment and intervention to improve or maintain functional cognition in clients with PD.
References
Bonelli, R. M., & Cummings, J. L. (2007). Frontal-subcortical circuitry and behavior. Dialogues in clinical neuroscience, 9(2), 141–151.
Dosenbach, N. U., Fair, D. A., Cohen, A. L., Schlaggar, B. L., & Petersen, S. E. (2008). A dual-networks architecture of top-down control. Trends in cognitive sciences, 12(3), 99–105. https://doi.org/10.1016/j.tics.2008.01.001
Watson, G. S., & Leverenz, J. B. (2010). Profile of cognitive impairment in Parkinson’s disease. Brain Pathology, 20(3), 640-645. https://doi.org/10.1111/j.1750-3639.2010.00373.x
