Limits...
Effect of auditory constraints on motor performance depends on stage of recovery post-stroke.

Aluru V, Lu Y, Leung A, Verghese J, Raghavan P - Front Neurol (2014)

Bottom Line: In contrast, in spastic co-contraction, no auditory stimulation increased wrist extension and reduced co-activation.In minimal paresis, wrist extension did not improve under any condition.The findings advance our understanding of the mechanisms of progression of motor recovery and lay the foundation for personalized treatment algorithms post-stroke.

View Article: PubMed Central - PubMed

Affiliation: Department of Rehabilitation Medicine, New York University School of Medicine , New York, NY , USA.

ABSTRACT
In order to develop evidence-based rehabilitation protocols post-stroke, one must first reconcile the vast heterogeneity in the post-stroke population and develop protocols to facilitate motor learning in the various subgroups. The main purpose of this study is to show that auditory constraints interact with the stage of recovery post-stroke to influence motor learning. We characterized the stages of upper limb recovery using task-based kinematic measures in 20 subjects with chronic hemiparesis. We used a bimanual wrist extension task, performed with a custom-made wrist trainer, to facilitate learning of wrist extension in the paretic hand under four auditory conditions: (1) without auditory cueing; (2) to non-musical happy sounds; (3) to self-selected music; and (4) to a metronome beat set at a comfortable tempo. Two bimanual trials (15 s each) were followed by one unimanual trial with the paretic hand over six cycles under each condition. Clinical metrics, wrist and arm kinematics, and electromyographic activity were recorded. Hierarchical cluster analysis with the Mahalanobis metric based on baseline speed and extent of wrist movement stratified subjects into three distinct groups, which reflected their stage of recovery: spastic paresis, spastic co-contraction, and minimal paresis. In spastic paresis, the metronome beat increased wrist extension, but also increased muscle co-activation across the wrist. In contrast, in spastic co-contraction, no auditory stimulation increased wrist extension and reduced co-activation. In minimal paresis, wrist extension did not improve under any condition. The results suggest that auditory task constraints interact with stage of recovery during motor learning after stroke, perhaps due to recruitment of distinct neural substrates over the course of recovery. The findings advance our understanding of the mechanisms of progression of motor recovery and lay the foundation for personalized treatment algorithms post-stroke.

No MeSH data available.


Related in: MedlinePlus

The bars represent the mean slopes showing the effect of auditory stimulation on bimanual-to-unimanual learning for wrist extension performance variables in the three groups: (A) spastic paresis (blue); (B) spastic co-contraction (red); (C) minimal paresis (green). Error bars represent the standard error. **Represents differences between the three groups at p < 0.01, and *represents differences between the three groups at p < 0.05.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4066443&req=5

Figure 6: The bars represent the mean slopes showing the effect of auditory stimulation on bimanual-to-unimanual learning for wrist extension performance variables in the three groups: (A) spastic paresis (blue); (B) spastic co-contraction (red); (C) minimal paresis (green). Error bars represent the standard error. **Represents differences between the three groups at p < 0.01, and *represents differences between the three groups at p < 0.05.

Mentions: The slope (unit change per trial) succinctly summarizes which auditory conditions couple with bimanual training for sustained improvement on the paretic side in the three groups (Figure 6). In the spastic paresis group (Figure 6A), wrist extension improved most with the metronome beat (slope b = 0.86, p = 0.03), even though it also increased wrist flexor activity (b = 0.0021, p < 0.0001) and co-activation (b = 0.07, p = 0.004). Self-selected music did not increase wrist extension, but marginally increased flexor muscle activity (b = 0.0010, p = 0.04). Thus rhythmic auditory constraints improved motor control in subjects with spastic paresis who were at an earlier stage in motor recovery post-stroke. In the spastic co-contraction group (Figure 6B), wrist extension improved most without any auditory cueing (b = 1.83, p < 0.0001), which increased wrist extensor muscle activation (b = 0.004, p = 0.0002) and decreased co-activation across the wrist joint (b = −0.1, p = 0.0006). In contrast, self-selected music increased co-activation (b = 0.059, p = 0.04) in this group. Thus practice without auditory constraints was most beneficial in subjects with spastic co-contraction. In the minimal paresis group (Figure 6C), there was no improvement in wrist extension across the auditory conditions. The slope for wrist extension was most negative with happy sounds (b = −0.86, p = 0.03), wrist extensor activation decreased with the metronome beat (b = −0.0022, p = 0.02), and wrist flexor activation increased without auditory stimulation (b = 0.0012, p = 0.015).


Effect of auditory constraints on motor performance depends on stage of recovery post-stroke.

Aluru V, Lu Y, Leung A, Verghese J, Raghavan P - Front Neurol (2014)

The bars represent the mean slopes showing the effect of auditory stimulation on bimanual-to-unimanual learning for wrist extension performance variables in the three groups: (A) spastic paresis (blue); (B) spastic co-contraction (red); (C) minimal paresis (green). Error bars represent the standard error. **Represents differences between the three groups at p < 0.01, and *represents differences between the three groups at p < 0.05.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4066443&req=5

Figure 6: The bars represent the mean slopes showing the effect of auditory stimulation on bimanual-to-unimanual learning for wrist extension performance variables in the three groups: (A) spastic paresis (blue); (B) spastic co-contraction (red); (C) minimal paresis (green). Error bars represent the standard error. **Represents differences between the three groups at p < 0.01, and *represents differences between the three groups at p < 0.05.
Mentions: The slope (unit change per trial) succinctly summarizes which auditory conditions couple with bimanual training for sustained improvement on the paretic side in the three groups (Figure 6). In the spastic paresis group (Figure 6A), wrist extension improved most with the metronome beat (slope b = 0.86, p = 0.03), even though it also increased wrist flexor activity (b = 0.0021, p < 0.0001) and co-activation (b = 0.07, p = 0.004). Self-selected music did not increase wrist extension, but marginally increased flexor muscle activity (b = 0.0010, p = 0.04). Thus rhythmic auditory constraints improved motor control in subjects with spastic paresis who were at an earlier stage in motor recovery post-stroke. In the spastic co-contraction group (Figure 6B), wrist extension improved most without any auditory cueing (b = 1.83, p < 0.0001), which increased wrist extensor muscle activation (b = 0.004, p = 0.0002) and decreased co-activation across the wrist joint (b = −0.1, p = 0.0006). In contrast, self-selected music increased co-activation (b = 0.059, p = 0.04) in this group. Thus practice without auditory constraints was most beneficial in subjects with spastic co-contraction. In the minimal paresis group (Figure 6C), there was no improvement in wrist extension across the auditory conditions. The slope for wrist extension was most negative with happy sounds (b = −0.86, p = 0.03), wrist extensor activation decreased with the metronome beat (b = −0.0022, p = 0.02), and wrist flexor activation increased without auditory stimulation (b = 0.0012, p = 0.015).

Bottom Line: In contrast, in spastic co-contraction, no auditory stimulation increased wrist extension and reduced co-activation.In minimal paresis, wrist extension did not improve under any condition.The findings advance our understanding of the mechanisms of progression of motor recovery and lay the foundation for personalized treatment algorithms post-stroke.

View Article: PubMed Central - PubMed

Affiliation: Department of Rehabilitation Medicine, New York University School of Medicine , New York, NY , USA.

ABSTRACT
In order to develop evidence-based rehabilitation protocols post-stroke, one must first reconcile the vast heterogeneity in the post-stroke population and develop protocols to facilitate motor learning in the various subgroups. The main purpose of this study is to show that auditory constraints interact with the stage of recovery post-stroke to influence motor learning. We characterized the stages of upper limb recovery using task-based kinematic measures in 20 subjects with chronic hemiparesis. We used a bimanual wrist extension task, performed with a custom-made wrist trainer, to facilitate learning of wrist extension in the paretic hand under four auditory conditions: (1) without auditory cueing; (2) to non-musical happy sounds; (3) to self-selected music; and (4) to a metronome beat set at a comfortable tempo. Two bimanual trials (15 s each) were followed by one unimanual trial with the paretic hand over six cycles under each condition. Clinical metrics, wrist and arm kinematics, and electromyographic activity were recorded. Hierarchical cluster analysis with the Mahalanobis metric based on baseline speed and extent of wrist movement stratified subjects into three distinct groups, which reflected their stage of recovery: spastic paresis, spastic co-contraction, and minimal paresis. In spastic paresis, the metronome beat increased wrist extension, but also increased muscle co-activation across the wrist. In contrast, in spastic co-contraction, no auditory stimulation increased wrist extension and reduced co-activation. In minimal paresis, wrist extension did not improve under any condition. The results suggest that auditory task constraints interact with stage of recovery during motor learning after stroke, perhaps due to recruitment of distinct neural substrates over the course of recovery. The findings advance our understanding of the mechanisms of progression of motor recovery and lay the foundation for personalized treatment algorithms post-stroke.

No MeSH data available.


Related in: MedlinePlus