Neurostimulation for Respiratory Function After Spinal Cord Injury

Inclusion Criteria: 1. Male and females between ages 18-85 years 2. SCI at least 6 months post-injury 3. Spinal Cord injury at C1-C5 4. Demonstrate respiratory deficit following spinal cord injury as following: (1) Individuals using mechanical ventilation, and (2) individuals with pulmonary function testing (PFT) deficits corresponding to having a vital capacity (VC) \< 80% (predicted) 5. Must have a family member or caregiver who is trained and willing to operate the mechanical ventilator during study visits. Exclusion Criteria: 1. Any illness or condition that based on the research team's assessment, will compromise with the participant's ability to comply with the protocol, patient safety, or the validity of the data collected during this study. 2. Any debilitating disease prior to the SCI that caused exercise intolerance. 3. Individuals entirely dependent on the support of a diaphragmatic pacer (24 hours per day). 4. Premorbid, ongoing major depression or psychosis, altered cognitive status. 5. History of head injury or stroke 6. Vascular, traumatic, tumoral, infectious, or metabolic lesion of the brain, even without a history of seizure, and without anticonvulsant medication 7. History of seizures or epilepsy 8. Receiving drugs acting primarily on the central nervous system, which lower the seizure threshold 9. Pregnant females 10. If a woman of childbearing age is unsure of the pregnancy, and does not want to take the pregnancy test 11. Ongoing cord compression or a syrinx in the spinal cord or who suffer from a spinal cord disease such as spinal stenosis, spina bifida, MS, or herniated disk 12. Metal plate in skull 13. Individuals with scalp shrapnel, cochlear implants, or aneurysm clips 14. Individuals taking Bupropion, Dolutegravir, Lacosamide, Trilaciclib, or PR Interval prolonging drugs