Comparison of non-invasive neuromodulation for motor function rehabilitation in incomplete spinal cord injury: a systematic review and network meta-analysis

Spinal cord injury ( SCI) disrupts structural and functional connectivity between the brain and spinal cord, resulting in severe motor dysfunction. Various neuromodulation techniques have been applied in SCI rehabilitation and have promoted motor recovery to varying degrees. A Bayesian network meta-analysis was therefore undertaken to compare and rank the relative effects of non-invasive neuromodulation techniques on motor-related outcomes in adults with incomplete SCI. PubMed, Web of Science, Embase, and The Cochrane Library were searched for randomized controlled trials (RCTs) investigating non-invasive neuromodulation for motor function in patients with incomplete SCI, from database inception to September 13, 2025. Bayesian network meta-analysis was performed using R software. The intervention effects of different non-invasive neuromodulation techniques were compared across motor-related outcomes, including the Lower Extremity Motor Score (LEMS), the 10-Meter Walk Test (10MWT), step length, gait speed, the Modified Ashworth Scale (MAS), and the Spinal Cord Independence Measure (SCIM). Seventeen RCTs involving 523 participants were included. For lower-limb motor strength, 20-Hz repetitive transcranial magnetic stimulation (20 Hz-rTMS) and intermittent theta-burst stimulation (iTBS) both yielded favorable estimates, with iTBS slightly ahead (standardized mean difference [SMD] = 0.87, 95% credible interval [CrI] 0.60 to 1.14) of 20 Hz-rTMS (SMD = 0.83, 95% CrI 0.32 to 1.34). iTBS also conferred the largest gain in gait speed (SMD = 0.52, 95% CrI 0.25 to 0.79), whereas 20 Hz-rTMS produced the greatest reduction in spasticity (mean difference [MD] = − 0.41, 95% CrI − 0.7 to − 0.12). Functional independence on the Spinal Cord Independence Measure (SCIM) improved most with 10-Hz repetitive transcranial magnetic stimulation (10 Hz-rTMS) (SMD = 1.03, 95% CrI 0.03 to 2.03). For motor evoked potential (MEP) latency, transcutaneous spinal cord stimulation (tSCS) (SMD = − 1.21, 95% CrI − 1.94 to − 0.48) and 10 Hz-rTMS (SMD = − 1.22, 95% CrI − 2.08 to − 0.35) showed the strongest shortening, followed by iTBS (SMD = − 0.84, 95% CrI − 1.53 to − 0.14). MEP amplitude increased most under 10 Hz-rTMS (SMD = 1.003, 95% CrI 0.13 to 1.88). iTBS, 20 Hz-rTMS, 10 Hz-rTMS, and tSCS each appear to support motor recovery after incomplete SCI.However, the underlying mechanisms remain unclear. Further investigation is required to elucidate the specific mechanisms and clinical utility of different neuromodulation interventions for SCI.