Transcranial magnetic stimulation-based multisite neuromodulation for motor recovery after spinal cord injury: a structured narrative review

Motor impairment after spinal cord injury (SCI) is associated with disrupted corticospinal transmission and altered interactions among supraspinal, spinal, and peripheral sensorimotor pathways. Conventional transcranial magnetic stimulation (TMS) generally targets the motor cortex alone, whereas multisite approaches combine TMS with peripheral nerve, spinal cord, or nerve-root stimulation. This structured narrative review searched PubMed, Web of Science Core Collection, and SPORTDiscus from database inception through August 1, 2026. The searches identified 260 records, of which 100 unique database records remained after deduplication; five additional records were identified through citation tracking and targeted author searches. Single case reports, conference abstracts, and trial protocols were excluded from the evidence synthesis. Twenty-six eligible publications reporting completed human studies were included in the core synthesis: 17 investigated cortical–peripheral nerve stimulation, seven investigated cortical–spinal stimulation, and two investigated cortical–nerve-root stimulation. One mixed-modality multisegment Hebbian study was considered separately because of its mixed stimulation design. Studies that specified a proposed site of neural interaction and used physiology-based stimulus timing reported timing-dependent changes in corticospinal or spinal excitability. Repeated interventions were also associated with improvements in selected measures of strength, hand function, or walking. Neurophysiological effects were reported more consistently across studies than sustained clinical improvements. Interpretation was limited by small sample sizes, heterogeneous stimulation parameters, overlapping cohorts, limited use of active single-target controls, and differences in treatment exposure. Some paradigms showed timing- or component-dependent neurophysiological effects, but the available evidence does not establish durable clinical efficacy or the added benefit of a second stimulation site across approaches. Future trials should include active single-target comparators, individualized timing where relevant, matched treatment exposure, prespecified stratification by clinically relevant injury characteristics, and long-term clinically meaningful outcomes.