Double stimulation may restore arm movement in spinal cord injury

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * 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. * Grip strength: MMT grade 3 or higher in finger flexors (C8 myotome) on at least one side. * Hand function: Able to transfer at least 1 block across the partition within 60 seconds on the more impaired side. * Sitting tolerance: Able to tolerate upright seated posture in own wheelchair for at least 1 continuous hour without symptomatic orthostatic hypotension or pressure-related discomfort requiring position change. * Medical stability: No acute medical complications * Informed consent: Able to provide written informed consent and comply with the study schedule * Medications: Stable regimen for 4 weeks prior, AND participant plus clinician agreement that dosage (baclofen, tizanidine, botulinum toxin) remains unchanged throughout the 12-week intervention; any change logged as protocol deviation * Surgical clearance: Cleared by neurosurgeon or orthopedic surgeon for participation in tSCS-based rehabilitation Exclusion Criteria: * 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 * Psychiatric or cognitive: Active psychiatric illness (eg, untreated major depression, psychosis) or cognitive impairment precluding informed consent * Concurrent neurological disease: Progressive or degenerative neurological condition (eg, multiple sclerosis, motor neuron disease) * Concurrent trials: Participation in another interventional rehabilitation or neurostimulation trial * Skin integrity: Skin lesions or breakdown at electrode placement sites (scalp or posterior cervical spine) * Cortical excitability medications: Medications known to alter cortical excitability (eg, antiepileptic drugs, high-dose benzodiazepines) that cannot be stabilized for at least 2 weeks prior to enrollment * Severe spasticity: Modified Tardieu Scale muscle reaction grade 4 (unfatigable clonus \>10 s) at elbow or wrist flexors on the more impaired side, or spasticity judged by the treating physician as unresponsive to optimised pharmacological management.