Epidural Stimulation for Upper Extremity Function

The study will enroll up to 20 participants in a single arm prospective clinical study. Potential participants will have already had a nerve transfer surgery more than 6 months prior to enrollment and will have also completed post-nerve transfer physical /occupational neurorehabilitation. At baseline, upper extremity muscle strength, muscle force and nerve health with needle electromyography and neuroimaging will be tested. Patients will undergo percutaneous (temporary) spinal cord stimulator leads placement in the cervical supralesional spine region. Week 0-4: Weekly testing of motor function and muscle contraction force with the stimulation turned on versus turned off will be performed. Stimulation parameters for each target upper extremity muscle will also be documented. Temporary leads will be removed after approximately 4 weeks. At the last research visit at approximately 6-7 weeks post leads placement muscle strength/force will be assessed to determine the duration of the stimulation effect (if it is sustained). To assess any improvement of nerve health, neuroimaging and electromyography will also be performed.