Virtual Reality Arm Supported Training Reduces Motor Impairment In Two Patients with Severe Hemiparesis

http://www.jscimedcentral.com/Neuroscience/Articles/neuroscience-1-1018.php

Przybyla^1,2, Good DC² and Sainburg RL^1,2*

¹Department of Kinesiology, Pennsylvania State University, 29 Recreation Building,University Park, PA 16802, USA
²Department of Neurology, Penn State Hershey Medical Center, 500 University Drive,Hershey, PA 17033, USA

*Corresponding author: Robert L. Sainburg, 29 Recreation Building, University Park, PA 16802, USA, Tel: +1-814-865-7937; Fax: +1-814-865-1275; E-mail:rls45@psu.edu

Submitted: 09 August 2013 Accepted: 13 September 2013 Published: 15 September 2013

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Stroke is one of the leading causes of motor disability in the United States [1]. Although conventional therapies involve different forms of movement practice, technological advances have allowed the development of interactive therapies using robotics and other computer based interventions, such as virtual reality and computer games. These approaches have the advantages of monitoring movement features on a continuous and incremental basis, as well as providing feedback to patients about instantaneous performance. To date, such approaches have overwhelmingly focused on patients with mild motor deficits [2]. This is likely related to the fact that motor disabilities reduce a patient’s ability to interact with such systems, and because patients with more severe disorders show smaller responses to intervention. In fact, a recent review by Coupar and colleagues suggested that the level of initial severity of motor deficits is the most important predictive factor for recovery of function in the upper limb [3]. Patients with moderate to severe paresis tend to have limited active range of motion due to decreased voluntary control, abnormal synergies, and spasticity. However, movement range can be systematically increased when the limb is supported against gravity in patients with moderate to severe paresis [4-6]. We now combine the approaches of supporting the arm against gravity with a virtual reality interactive design that is tailored to the patients’ abilities in two individuals with chronic and severe hemiparesis. The patients’ arms are supported on a friction free air-sled system to remove the effects of gravity and friction and optimize range of motion in the horizontal plane. We present an interactive computer-game system using our custom virtual reality display system, adjusting the gain of the feedback to encourage maximal engagement in the game-like reaching task. We then adjust feedback gains, in accord with improvements in movement amplitude, in order to encourage continuous adaptation. We evaluate a 4-week training regime by assessing reaching performance during a 3-dimensional unsupported reaching task, as well as, assessing changes in dysfunction level, using the Fugl-Meyer Motor Assessment (FMA) protocol [7]. Following a 4-week training protocol, involving 3 one-hour sessions per week, our results show significant improvements in movement range and quality during unsupported reaching and clinically significant improvements in the FMA of sensorimotor dysfunction.