Evaluating Error Augmentation for Neurorehabilitation

Evaluating Error Augmentation for Neurorehabilitation

This is a sub-project of a larger NIDRR Grant. One promising form of robotic training that leverages the power of neuro-plasticity is error augmentation. In this paradigm the computer singles out and magnifies a stroke survivor's movement errors from a desired trajectory, thus forcing the subjects to strengthen their control. Using the VRROOM, a state-of-the-art system which uses haptics (robotic forces) and graphics (visual display) interfaces, a subject's desired trajectory can be determined and the movement errors can be amplified in real-time with dramatic results. This project evaluates a practical approach of error augmentation, using therapist-driven trajectories. The investigators intend to determine clinical efficacy of several types of therapist-assisted error augmentation on retraining the nervous system in functional activities. The investigators will test two experimental treatments in a crossover design. The investigators hypothesize that combined haptic and visual error augmentation will lead to the best functional recovery.

Inclusion Criteria:

• adult (age >18)
• survived a single cortical stroke at least 6 months previously involving ischemia or hemorrhage of the middle cerebral artery (MCA),
• demonstrated the presence of some active shoulder and elbow movement (characterized by Fugl-Meyer Assessment Upper Extremity scores ranging from 15-50 for ARM 1; 25-50 for ARM 2).

Exclusion Criteria:

• diffuse or multiple lesion sites or multiple stroke events
• bilateral paresis
• severe spasticity or contracture (Modified Ashworth ≥3
• severe concurrent medical problems
• severe sensory deficits
• cerebellar strokes resulting in severe ataxia
• significant shoulder pain
• focal tone management with Botulinim Toxin (Botox®) injection to the hemiparetic upper extremity (UE) within the previous four months,
• aphasia that would influence the ability to perform the experiment
• cognitive impairment (Mini Mental State Examination < 23/30)
• affective dysfunction that would influence the ability to perform the experiment
• depth perception impairment (< 3 on Stereo Circle Test)
• visual field cut or hemispatial neglect that would influence the ability to participate in the activity
• inability to provide informed consent