Transcutaneous Auricular Vagus Nerve Stimulation Combined with Continuous Antidromic Pelvic Neuromodulation and Rehabilitation for Recovery of Voluntary Locomotion in Spinal Cord Injury: An Exploratory Randomized Study

This study explores the potential role of transcutaneous auricular vagus nerve stimulation (taVNS) as an adjunct to continuous antidromic pelvic neuromodulation (CAPN) and intensive rehabilitation for the recovery of voluntary locomotor function in individuals with chronic spinal cord injury (SCI). In a prospective, single-blinded randomized exploratory study, twenty adults with chronic SCI undergoing electrically assisted rehabilitation combined with CAPN were randomly assigned to receive either active taVNS or sham stimulation. Functional outcomes were assessed using the extended American Spinal Injury Association (ASIA) score for knee extension and the Walking Index for Spinal Cord Injury II (WISCI II) over a six-month follow-up period. Across both groups, 30% of participants were able to walk more than 10 meters with crutches or a walking device after six months. Although no statistically significant differences were observed between the active and sham taVNS groups, both groups demonstrated progressive improvements in locomotor function over time, with significant improvement in WISCI II scores at six months. These findings suggest that electrically assisted rehabilitation combined with CAPN may play a central role in functional recovery after chronic SCI. The observed trends in the active taVNS group raise the possibility that vagal neuromodulation could further enhance neuroplastic processes. The study also introduces the hypothesis of cortico-vagal plasticity as a potential mechanism linking supralesional and infralesional neuromodulation. Given the exploratory nature and the limited sample size, these preliminary findings require confirmation in larger clinical studies and dedicated basic research models. The present work contributes to the emerging field of bioelectronic medicine and highlights the potential of combined neuromodulation strategies to promote functional recovery after spinal cord injury.