Safety and Feasibility of Paired Transcutaneous Auricular Vagus Nerve Stimulation (taVNS) With Upper Limb Rehabilitation in Incomplete Spinal Cord Injury

Inclusion Criteria: * diagnosis of traumatic incomplete (AIS B-D) cervical spinal cord injury (C8 and above) * at least 12 months post-traumatic SCI but less than 10 years post-SCI * demonstrate some residual movement in the upper limb (e.g., able to perform pinch movement with thumb and index finger sufficient to grip small objects such as marble) Exclusion Criteria: * non-traumatic SCI * recent ear trauma and skin lesions at the site of stimulation, such as sunburn, cuts, and open sores, * facial or ear pain, * allergic reaction to adhesives and electrodes, * any current or past history of cardiovascular disorders, * intracranial metal implants, pacemakers, * concomitant clinically significant brain injury, * receiving medication that may significantly interfere with the actions of VNS on neurotransmitter systems at study entry * If there is a plan for alteration in upper-extremity therapy or medication for muscle tone during the course of the study; * medical or mental instability; * pregnancy or plans to become pregnant during the study period