Category: Parkinson's Disease: Cognitive functions
Objective: We used a digitizing tablet during PCT as a potential tool for assessing early cognitive deficits in PD yet without major cognitive impairment. We also aimed to uncover neural correlates of identified parameter(s) using whole brain MRI.
Background: Impaired copy of intersecting pentagons from MMSE (Pentagon Copy Test, PCT) has been shown to predict dementia in PD.
Method: We enrolled 27 PD patients without major cognitive impairment (median age 67.0, median disease duration 4.0.) and 25 age-matched healthy controls (HC) (median age 67.1). During parametrisation of drawing, we focused on the commonly used features and compared both groups using the Mann-Whitney U test. We further focused on parameters with significant correlation with cognitive domains’ z-scores. Selected parameters were used as covariates in the whole brain voxel-wise analysis using 3T MRI and voxel-based morphometry.
Results: PD patients differed from HC only in attention domain (p<0.0001). Regarding the drawing parameters, groups differed in Shannon entropy (horizontal in-air, p=0.003) which quantifies uncertainty of movement above a paper when performing a transition between two strokes (higher in PD than in HC). In PD we found a significant correlation between attention z-scores and median of Shannon entropy (horizontal in-air; R=-0.55, p=0.006, and vertical in-air; R=-0.56, p=0.004). MRI results revealed an association between median of Shannon entropy (horizontal in-air) and gray matter volume in the right superior parietal lobe (SPL) (p<0.05,FWE threshold p<0.001).
Conclusion: Using a digitizing tablet during PCT we identified a novel entropy-based parameter that differed between HC and PD groups and correlated with attention in PD. The parameter is associated with the right SPL gray matter variability.
To cite this abstract in AMA style:
L. Brabenec, P. Klobusiakova, J. Mekyska, I. Rektorova. Shannon entropy: a novel tool for assessing pentagon drawing in Parkinson’s disease [abstract]. Mov Disord. 2021; 36 (suppl 1). https://www.mdsabstracts.org/abstract/shannon-entropy-a-novel-tool-for-assessing-pentagon-drawing-in-parkinsons-disease/. Accessed September 7, 2024.« Back to MDS Virtual Congress 2021
MDS Abstracts - https://www.mdsabstracts.org/abstract/shannon-entropy-a-novel-tool-for-assessing-pentagon-drawing-in-parkinsons-disease/