Enhancing Plasticity in Stroke Patients With Severe Motor Deficit

This study will evaluate the effectiveness of sustained peripheral nerve stimulation coupled with functional motor training, to improve hand motor function in poorly recovered stroke patients. The central hypothesis is that stroke patients with severe motor deficit receiving hand nerve stimulation and intensive task-oriented therapy will have improved motor function compared to patients receiving sham nerve stimulation and task-oriented therapy.

Stroke is one of the most devastating and prevalent diseases, but efforts to limit the amount of tissue damaged in the acute phase have been disappointing, highlighting the need for effective therapeutic interventions after neurologic damage has occurred. Data from animal and human models have suggested that sensory input plays an important role in motor output, possibly by influencing cortical plasticity. However, in spite of the advances to date, little is known about the extent to which sensory input in the form of peripheral nerve stimulation can be successfully combined to physical training especially in poorly recovered stroke patients. This study will evaluate the effectiveness of sustained peripheral nerve stimulation coupled with functional motor training, to improve hand motor function in stroke patients with severe motor deficit. The central hypothesis is that stroke patients with severe motor deficit receiving hand nerve stimulation and intensive task-oriented therapy will have improved motor function compared to patients receiving sham nerve stimulation and task-oriented therapy, and the degree of this behaviorally-measured effect will correlate with the neurophysiological effect measured by transcranial magnetic stimulation.

2 hours of active peripheral nerve stimulation (intervention) paired with 4 hours of intensive task-oriented upper extremity training. Peripheral nerve stimulation of Erb's point, radial and median nerves paired with task-oriented therapy. Peripheral nerve stimulation will be delivered using a S88 Dual Output Stimulator by Grass Technologies.

2 hours of sham peripheral nerve stimulation (intervention) paired with 4 hours of intensive task-oriented upper extremity training. Peripheral nerve stimulation of Erb's point, radial and median nerves paired with task-oriented therapy. Peripheral nerve stimulation will be delivered using a S88 Dual Output Stimulator by Grass Technologies.

Peripheral nerve stimulation of Erb's point, radial and median nerves paired with task-oriented therapy

Score after intervention minus baseline score, score at 1-month follow-up minus baseline score. The possible scores range from 0 to 66, with 66 indicating the best performance.

Score at post-intervention minus baseline, score at 1-month follow-up minus baseline. The possible scores range from 0 to 57, with higher scores indicating better performance.

Score at post-intervention minus baseline, score at 1-month follow-up minus baseline. Each task is scored as amount of time taken to complete a task, which may range from just over 0 to 120 seconds. If the subject is unable to complete the task within 120 seconds, a score of 121 seconds is given. The scores from the 15 individual tasks are averaged, then the log is taken, resulting in the overall score. Therefore, the larger the score, the longer required to perform the tasks. Negative changes in score indicate that a subject, on average, was able to complete the tasks faster at post-intervention or at 1-month follow-up than at baseline.

Inclusion Criteria: Chronic stroke patients Single stroke Chronic (more than 12 months after from stroke) At least 21 years old, but there is no upper age range for this project. Participants NOT able to extend the affected metacarpophalangeal joints at least 10° and the wrist 20°. Exclusion Criteria: History of carpal tunnel syndrome and conditions that commonly cause peripheral neuropathy, including diabetes, uremia, or associated nutritional deficiencies History of head injury with loss of consciousness, severe alcohol or drug abuse, psychiatric illness Within 3 months of recruitment, use of drugs known to exert detrimental effects on motor recovery Cognitive deficit severe enough to preclude informed consent Positive pregnancy test or being of childbearing age and not using appropriate contraception Participants with history of untreated depression.

Carrico C, Chelette KC 2nd, Westgate PM, Powell E, Nichols L, Fleischer A, Sawaki L. Nerve Stimulation Enhances Task-Oriented Training in Chronic, Severe Motor Deficit After Stroke: A Randomized Trial. Stroke. 2016 Jul;47(7):1879-84. doi: 10.1161/STROKEAHA.116.012671. Epub 2016 May 17.