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Randomized Controlled Trial
. 2014 Feb;28(2):120-8.
doi: 10.1177/1545968313498649. Epub 2013 Aug 8.

Error augmentation enhancing arm recovery in individuals with chronic stroke: a randomized crossover design

Farnaz Abdollahi  1 , Emily D Case Lazarro, Molly Listenberger, Robert V Kenyon, Mark Kovic, Ross A Bogey, Donald Hedeker, Borko D Jovanovic, James L Patton
Affiliations
Randomized Controlled Trial

Error augmentation enhancing arm recovery in individuals with chronic stroke: a randomized crossover design

Farnaz Abdollahi et al. Neurorehabil Neural Repair. 2014 Feb.

Abstract

Background: Neurorehabilitation studies suggest that manipulation of error signals during practice can stimulate improvement in coordination after stroke.

Objective: To test visual display and robotic technology that delivers augmented error signals during training, in participants with stroke.

Methods: A total of 26 participants with chronic hemiparesis were trained with haptic (via robot-rendered forces) and graphic (via a virtual environment) distortions to amplify upper-extremity (UE) tracking error. In a randomized crossover design, the intervention was compared with an equivalent amount of practice without error augmentation (EA). Interventions involved three 45-minute sessions per week for 2 weeks, then 1 week of no treatment, and then 2 additional weeks of the alternate treatment. A therapist provided a visual cursor using a tracking device, and participants were instructed to match it with their hand. Haptic and visual EA was used with blinding of participant, therapist, technician-operator, and evaluator. Clinical measures of impairment were obtained at the beginning and end of each 2-week treatment phase as well as at 1 week and at 45 days after the last treatment.

Results: Outcomes showed a small, but significant benefit to EA training over simple repetitive practice, with a mean 2-week improvement in Fugl-Meyer UE motor score of 2.08 and Wolf Motor Function Test of timed tasks of 1.48 s.

Conclusions: This interactive technology may improve UE motor recovery of stroke-related hemiparesis.

Keywords: error augmentation; haptic technology; physical therapy; robotics; stroke rehabilitation; upper extremity.

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Conflict of interest statement

Declaration of Conflicting Interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Figures

Figure 1.
Figure 1.
Participant recruitment flow diagram.
Figure 2.
Figure 2.
Experimental setup: therapist (right) and participant (left) sat side by side in front of the virtual display. The robot handle is attached to the participant’s hand, and the therapist holds a position tracker. Projected image of a hand (controlled by the therapist) and a green cursor representing the participant’s hand position were projected onto a back projection screen and 2 mirrors, thus giving the illusion of an interactive 3-dimensional environment.
Figure 3.
Figure 3.
Study layout (top), session layout (bottom).
Figure 4.
Figure 4.
Clinical score changes from the first visit: AMFM score (left), WMFT score (middle), WMFT time (right). Thick line shows the EA treatment, thin line is the standard treatment, and dashed lines are the rest periods. Each group is shown in a different color. Abbreviations: AMFM, arm motor section of the Fugl-Meyer; WMFT, Wolf Motor Function Test; EA, error augmentation; STD, standard treatment.
See this image and copyright information in PMC

References

    1. Wolf SL, Winstein CJ, Miller JP, et al. Effect of constraint-induced movement therapy on upper extremity function 3 to 9 months after stroke: the EXCITE randomized clinical trial. JAMA. 2006;296:2095–2104. - PubMed
    1. Wolf SL, Winstein CJ, Miller JP, et al. Retention of upper limb function in stroke survivors who have received constraint-induced movement therapy: the EXCITE randomised trial. Lancet Neurol. 2008;17:33–40. - PMC - PubMed
    1. Dean CM, Shepherd RB. Task related training improves performance of seated reaching tasks after stroke: a randomize controlled trial. Stroke. 1997;28:722–728. - PubMed
    1. Sanchez RJ, Liu J, Rao S, et al. Automating arm movement training following severe stroke: functional exercises with quantitative feedback in a gravity-reduced environment. IEEE Trans Neural Syst Rehabil Eng. 2006;14:378–389. - PubMed
    1. Volpe BT, Ferraro M, Lynch D, et al. Robotics and other devices in the treatment of patients recovering from stroke. Curr Neurol Neurosci Rep. 2005;5:465–470. - PubMed

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