Lumy Sawaki, MD, PhD, University of Kentucky,  Physical Medicine & Rehabilitation Department, Cardinal Hill Endowed Chair

Objectives:  We propose to evaluate the effectiveness of sustained peripheral nerve stimulation (PNS) coupled with intensive task-oriented therapy to promote functional motor recovery in stroke patients with severe motor deficits.

The central hypothesis is that stroke patients with severe motor deficit receiving hand PNS and intensive task-oriented therapy will have improved motor function compared to patients receiving sham PNS and task-oriented therapy, and the degree of this behaviorally-measured effect will correlate with the neurophysiological effect measured by TMS. Severe motor deficit for this study will be defined as subjects NOT able to extend the affected metacarpophalangeal joints at least 10° and the wrist 20°for this study. We plan to accept or reject the central hypothesis by accomplishing two Specific Aims.

Specific Aim #1: Test the effect of hand PNS preceding intensive task-oriented therapy on hand motor function measured by Action Research Arm Test. The working hypothesis for this aim is:

• Hand PNS paired with task-oriented therapy will lead to a higher score in Action Research Arm Test when compared to a control stimulation group receiving sham PNS paired with task-oriented therapy.

Specific Aim #2: Test the effect of hand PNS preceding intensive task-oriented therapy on motor map of a specific muscle (extensor digitorum communis muscle) measured by transcranial magnetic stimulation (TMS). The working hypothesis for this aim is:

• PNS and training of the paretic hand will lead to an increase in TMS motor map of the relevant motor cortex, in a topographically specific manner, compared to a control stimulation group receiving sham PNS.
• The improved hand motor function will yield increased TMS motor map induced by hand PNS compared to a control stimulation group, receiving sham stimulation.