Narrative review examines autonomic modulation strategies for spinal cord injury recovery

This narrative review synthesizes emerging evidence from 2020–2025 on the modulatory role of the autonomic nervous system (ANS) in post-injury circuit reorganization following spinal cord injury (SCI). It examines therapeutic strategies leveraging autonomic modulation, including Vagus Nerve Stimulation (VNS) paired with task-specific training, respiratory-based protocols, Heart Rate Variability (HRV) biofeedback, and individualized aerobic exercise. The review does not report specific population details, sample size, comparator, primary outcome, or follow-up duration.

The main finding is that these autonomic modulation strategies demonstrate promising autonomic and functional effects. The review supports the view that autonomic modulation is a mechanistic boundary condition for post-injury plasticity, rather than a secondary consequence of SCI. The authors note autonomic tone influences neuronal excitability, perfusion, neurotrophin signaling, and microglia-dependent inflammatory states. Recurrent sympathetic surges during Autonomic Dysreflexia (AD) may bias networks toward maladaptive phenotypes, whereas enhanced vagal flexibility may promote neurotrophin availability, homeostatic excitability, and synaptic strengthening. No specific effect sizes, absolute numbers, or statistical significance for the interventions are reported.

Safety and tolerability data for the interventions are not reported. A key limitation is that future work requires rigorously powered, multimodal trials to refine protocols and accelerate translation. The publication type is a systematic review, but the evidence synthesis is described as a narrative review. In practice, this review provides a theoretical framework suggesting autonomic modulation may be a target for promoting recovery after SCI, but the evidence remains preliminary. Clinicians should await results from more definitive clinical trials before considering implementation.