Research will take place at the James J. Peters VA Medical Center (JJPVAMC), Bronx, NY. There are seven visits in total, including an initial evaluation and clinical assessment session. Each visit will last roughly 5 hours or less. We plan to enroll 28 participants with spinal cord injury over a two-year period.~The study is designed as a double-blind, placebo-controlled, single-dose, randomized crossover investigation involving four study drug visits (CPH, CD-LD, ATX, or placebo).~The same participants will partake in all four interventions in randomized order with at least 1-week washout representative of greater than 5x drug half-life; to avoid accumulative effects. To reduce potential learning effects from motor training and task-related outcome measurements, participants will partake in two motor training practice sessions prior to commencing the experiments for task familiarity.~This study will consist of electromyography (surface recordings of muscle activity), peripheral nerve stimulation, transcranial magnetic brain stimulation (TMS), and transcutaneous electrical spinal cord stimulation (TSCS), targeting the hand/arm muscles.~Though it is unlikely given the single-dose nature, participants may experience side effects following drug administration. Prior to consenting, all volunteers will undergo a comprehensive pre-screening evaluation including blood tests to ensure there are no contraindications.~Please note, there is no expectation of long-term benefit from this study.
The purpose of this study is to investigate the short-term effects of 3 approved FDA drugs (cyproheptadine (CPH), carbidopa-levodopa (CD-LD), and atomoxetine (ATX)) on motor responses when delivered in combination with hand training exercises in people with chronic spinal cord injury. The goal is to learn how to better strengthen connections between the brain and spinal cord after spinal cord injury, and if this connection is improved by one(or more) of the drugs. Multiple aspects of nerve transmission and muscle response will be measured via noninvasive brain and spinal cord stimulation, along with motor performance (dexterity and strength).