Abstract
Objective
To investigate the reliability and validity of pupillary response during dual-task
balance conditions in individuals with Parkinson disease (PD).
Design
Cross-sectional study.
Setting
University of Kansas Medical Center Parkinson's Disease and Movement Disorder Center.
Participants
Participants (N=68) included individuals with PD (n=33) and healthy controls (n=35).
Interventions
Not applicable.
Main Outcome Measures
Pupillary response was the main outcome measure that was measured during the following
conditions: single-task balance eyes open, single-task balance eyes occluded, dual-task
eyes open, and dual-task eyes occluded. After each condition, the National Aeronautics
and Space Administration-Task Load Index (NASA-TLX) was administered to assess self-reported
cognitive workload. To examine the test-retest reliability of the pupillary response,
the conditions were administered twice for each individual within 2 hours. Intraclass
correlation coefficients (ICC) were used to analyze the test-retest reliability of
pupillary response in each condition for both groups. Pearson’s r correlation was used to assess the convergent validity of pupillary response against
the NASA-TLX.
Results
The test-retest reliability was excellent for both groups in almost all conditions
(ICC>0.75). There were no correlations between pupillary response and the NASA-TLX.
However, increased mental demand (a subitem of the NASA-TLX) significantly correlated
with increased pupillary response in individuals with PD (r=0.38; P=.03).
Conclusions
Pupillary response showed excellent test-retest reliability and validity during dual-task
balance for individuals with PD and healthy controls. Overall, these results suggest
that pupillary response represents a stable index of cognitive workload during dual-task
balance in individuals with PD.
Keywords
List of abbreviations:
EEG (electroencephalogram), H&Y (Hoehn and Yahr), ICA (Index of Cognitive Activity), ICC (intraclass correlation coefficient), NASA-TLX (National Aeronautics and Space Administration-Task Load Index), PD (Parkinson disease)To read this article in full you will need to make a payment
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Article info
Publication history
Published online: September 17, 2020
Footnotes
Supported in part by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (grant no. T32HD057850), the Mabel A. Woodyard Fellowship in Neurodegenerative Disorders (M.K.), and the National Institute on Aging of the National Institutes of Health (award no. K01AG058785 to H.D.).
Disclosures: none.
Identification
Copyright
© 2020 by the American Congress of Rehabilitation Medicine
