Cognitive Virtual-Reality Based Stroke Rehabilitation.

Stroke is a debilitating condition with major costs for patients and their care-givers. Here we present a novel virtual reality (VR) based cognitive neurorehabilitation system for improving the rehabilitation of stroke patients with arm and hand paresis. Using a custom, low-cost kinematic tracking system designed for clinical or home use, patients engage in task-oriented interactions with objects in a virtual environment. Our paradigm is based on the hypothesis that observed actions correlated with self-generated or intended actions activate the motor pathways by means of the so-called "mirror-system". This cognitive approach engages cortical motor observation, planning and execution areas. Combined with intensive, task-oriented acute-phase training (1-6 weeks after stroke) when the factors for facilitating recovery are at their highest levels, we postulate that our approach will facilitate cortical plasticity and improve recovery of upper limb function. The tasks range from simple (hitting moving virtual objects) to complex (grasping and moving virtual objects). In the first-person VR environment the patient controls a displayed pair of upper limbs that follow the position and movements of his/her own arms and hands while performing the tasks. The therapist can adjust the contribution of the non-paretic hand in "assisting" the representation of the paretic hand to varying degrees in performing the tasks, simultaneously stimulating the action recognition systems and increasing patient motivation through graded task success. In this paper we present the neuroscientific background of the system, a technical description of its components, and results from testing on healthy subjects and stroke patients. [ABSTRACT FROM AUTHOR]