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 facili- tate 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 dis- played pair of upper limbs that follow the position and move- ments 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, simultane- ously 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 test- ing on healthy subjects and stroke patients.