So you measured something. What the hell use is that to getting survivors 100% recovered? That is the only goal in stroke research. At least it would be if I was in charge.
Measuring Habitual Arm Use Post-stroke With a Bilateral Time-Constrained Reaching Task
- 1Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA, United States
- 2Physical Therapy, Jeonju University, Jeonju, South Korea
- 3Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States
- 4Department of Electronics and Information Engineering, Korea University, Sejong, South Korea
Background: Spontaneous use of the
more-affected arm is a meaningful indicator of stroke recovery. The
Bilateral Arm Reaching Test (BART) was previously developed to quantify
arm use by measuring arm choice to targets projected over a horizontal
hemi-workspace. In order to improve clinical validity, we constrained
the available movement time, thereby promoting more spontaneous decision
making when selecting between the more-affected and less affected arm
during the BART.
Methods: Twenty-two individuals with
mild to moderate hemiparesis were tested with the time-based BART in
three time-constraint conditions: no-time constraint, medium, and fast
conditions. Arm use was measured across three sessions with a 2-week
interval in a spontaneous choice block, in which participants were
instructed to use either the more-affected or the less-affected arm to
reach targets. We tested the effect of time-constraint condition on the
more-affected arm use, external validity of the BART with the Actual
Amount of Use Test (AAUT), and test-retest reliability across the three
test sessions.
Results: The fast condition in the
time-based BART showed reduced use of the more-affected arm compared to
the no-time constraint condition P < 0.0001) and the medium condition P = 0.0006; Tukey post hoc analysis after mixed-effect linear regression). In addition, the fast condition showed strong correlation with the AAUT r = 0.829, P < 0.001), and excellent test-retest reliability (ICC = 0.960, P < 0.0001).
Conclusion: The revised BART with a
time-restricted fast condition provides an objective, accurate, and
repeatable measure of spontaneous arm use in individuals with chronic
stroke hemiparesis.
Introduction
Spontaneous use of the more-affected upper extremity post-stroke is often lower than would be expected from impairment levels (1, 2), with low use associated with a reduced quality of life (3).
Besides the common therapy goal of improving motor performance of the
more-affected arm/hand, an additional approach would be to influence the
decision-making system (4), with the aim to improve use of the more-affected arm/hand.
The three instruments commonly used for measuring
spontaneous arm/hand use in the natural environment are the Motor
Activity Log [MAL; (5)], the Actual Amount of Use Test [AAUT; (6)], and accelerometers (7, 8).
These instruments are not ideal, however: the MAL relies on
self-reported ratings from memory; the AAUT cannot be administered
repeatedly once participants recognize that they are being tested,
thereby revealing its covert nature; and accelerometers only provide
overall activity, and thus not a direct measure of functional arm use.
We previously developed a simple and objective
assessment tool, the Bilateral Arm Reaching Test (BART) to address these
limitations (1). With BART, arm use is measured in a spontaneous choice block,
in which participants are instructed to choose either the more-affected
or the less-affected arm to reach displayed targets on a table. (I would never use my affected arm to reach for anything, spasticity prevents opening the hand, so success would never occur. So first of all you need to develop a cure for spasticity. Follow the goddamned stroke strategy. )
Although arm use as assessed with BART showed good test-retest
reliability, it was only moderately correlated with the AAUT (1).
In seeking to improve BART, we sought a better way to capture
real-world spontaneous arm use. We turned to previous research in
decision-making (9–11).
Contemporary decision models posit that choices between potentially
rewarding actions are driven by a combination of a goal-oriented system
and a habitual system. The goal-directed system is called “model-based”
because individuals learn through experience, and then mentally
simulate, models of the decision environment to prospectively evaluate
the outcomes of possible actions. In contrast, the habitual system is
“model-free,” because choice is performed via direct comparison of
expected rewards for each potential action (12).
Mental simulations in the goal-directed system is a time-consuming
process. As a result, performing choices under time-pressure enhances
expression of the time-insensitive habitual system (13). For this reason, we modified BART by adding a short time-constraint condition to the experimental paradigm.
The aim of this study was to accurately quantify arm/hand
use post-stroke with the time-based BART system. We hypothesized that a
reduction of available decision time would reduce affected arm use. In
addition, we reasoned that affected arm use in the time-constrained
condition would more strongly correlate with arm use as assessed by the
covert AAUT than arm use without time constraint.
Much more at link.
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