This clinical trial investigates whether combining cortical and spinal neuromodulation can improve upper limb motor recovery in adults with chronic incomplete cervical spinal cord injury (SCI). Restoring upper limb function is the top rehabilitation priority for individuals with tetraplegia, yet effective interventions remain limited.
The study combines transcutaneous spinal cord stimulation (tSCS), which enhances spinal circuit excitability, with intermittent theta burst stimulation (iTBS), a form of repetitive transcranial magnetic stimulation that increases cortical excitability and strengthens descending motor pathways. While each approach has shown independent promise, their combined use has not been evaluated in a controlled trial.
Eligible participants are adults aged 21-65 with chronic (\>12 months post-injury) incomplete cervical SCI (ASIA Impairment Scale grade C or D, levels C2-C8). A total of 24 participants will be randomised 1:1 to either combined iTBS and tSCS plus standardised upper limb rehabilitation, or tSCS plus rehabilitation alone, across 24 sessions over 12 weeks.
The primary outcome is change in Upper Extremity Motor Score from baseline to week 12. Secondary outcomes cover functional performance, independence, spasticity, corticospinal excitability, quality of life, and goal attainment. Assessments occur at baseline, post-intervention, and at 4- and 12-week follow-up.
As a pilot randomised controlled trial, this study will generate the first controlled evidence on adjunctive cortical neuromodulation alongside tSCS-based rehabilitation, while also producing feasibility data to inform the design of a future definitive multicentre trial.
Chronicity: More than 12 months post-injury at enrollment
Injury type: Traumatic or non-traumatic incomplete cervical SCI, neurological level C2 to C8
AIS classification: Grade C or D
UEMS: 10 to 20 out of 25 on the more impaired side; lower bound 10 ensures sufficient voluntary activation for task training and elicitable MEPs, upper bound avoids ceiling effects.
Seizure history: History of seizures or epilepsy
Implanted devices: Intracranial metallic implants, cochlear implants, cardiac pacemakers, or other implanted electronic devices. Cervical spinal instrumentation (e.g., posterior rods, plates, or screws at C2 to T1) is not an exclusion for tSCS provided overlying skin is intact; participants with hardware directly beneath planned electrode sites will undergo low-intensity test stimulation during screening, and electrode placement will be shifted by one interspace if current distortion, focal discomfort, or unexpected motor thresholds are observed. Intracranial hardware remains an absolute exclusion for iTBS.
Prior craniotomy: Prior neurosurgical procedure involving craniotomy
Pregnancy: Currently pregnant or intending to become pregnant during the study period