Active tDCS Versus Sham tDCS for Upper Limb Recovery in Incomplete Tetraplegic Patients

Pilot Randomized Controlled Study on Neuromodulation Through Active tDCS Versus Sham tDCS to Support Upper Limb Motor and Functional Recovery in Sub-acute, Incomplete, Tetraplegic Spinal Cord Injured Patients

Spinal Cord Injury (SCI) at the cervical level results in motor and sensory impairment below the lesion level and may determine a consistent loss of the use of the upper limbs, with a substantial impact on daily life activities. Therefore, functionality recovery of the upper limbs, of the hands in particular, represents a priority rehabilitation target. Studies in the literature show that the most relevant recovery occurs in the first months after SCI and that neuromodulation techniques may facilitate it. Transcranial Direct Current Stimulation (tDCS ) is a non-invasive neuromodulation technique. The present pilot, randomized controlled study aims at exploring the feasibility and efficacy of an early application of tDCS, in addition to the traditional physiotherapy treatment for the functional recovery of the upper limb, in incomplete traumatic tetraplegic subjects in the sub-acute phase after SCI occurrence. Patients hospitalized at the Montecatone Rehabilitation Institute are randomly assigned to Active tDCS or Sham tDCS.

Spinal Cord Injury (SCI) at the cervical level results in motor and sensory impairment below the lesion level and may determine a consistent loss of the use of the upper limbs, with a substantial impact on daily life activities. Therefore, functionality recovery of upper limbs, of the hands in particular, represents a priority rehabilitation target. In cases of incomplete tetraplegia, the main rehabilitation goal is the recovery of the maximum functional capacity, in order to improve autonomy or, in the most serious cases, avoid complications due to immobilization.

Studies in the literature show that the most relevant recovery occurs in the first months after SCI and that neuromodulation techniques may facilitate it.

Transcranial Direct Current Stimulation (tDCS ) is a non-invasive neuromodulation technique capable of modifying cortical excitability through direct, low intensity current, generated by a programmable medical device and delivered through electrodes placed on the scalp. Some authors have explored its potential role in facilitating functional recovery and treating spasticity in SCI subjects, however there are few studies on the use of neuromodulation induced by tDCS as an aid for the functional recovery of upper limbs in tetraplegic subjects. Moreover, most of such studies are on chronic SCI persons only.

The present pilot, randomized controlled study aims at exploring the feasibility and efficacy of an early application of tDCS, in the sub-acute phase after SCI occurrence, for the functional recovery of the upper limb, in addition to the traditional physiotherapy treatment, in incomplete traumatic tetraplegic patients, hospitalized at the Montecatone Rehabilitation Institute. They are randomly assigned to Active tDCS (A) or Sham tDCS (S) (parallel arms design,1:1 allocation ratio). Two tDCS daily sessions for 5 days a week, for 2 consecutive weeks, are carried out simultaneously with the usual rehabilitation treatment of the upper limb, that is administered also at least 4 weeks before and 4 weeks after the tDCS treatment period.

Most outcomes are measured up to 4 weeks after the completion of the tDCS treatment period.

Inclusion Criteria:

• Traumatic SCI;
• SCI neurological level, according to the American Spinal Injury Association (ASIA) definitions, from C3 to C7, included;
• incomplete SCI (i.e. ASIA Impairment Scale: B, C or D);
• distance from the SCI event: from 3 to 6 months;
• residual motor ability of the target upper limb;
• stable clinical conditions;
• tolerance to sitting position for at least 45 minutes;
• subjects capable and collaborating, able to give informed consent in person.

Exclusion Criteria:

• presence of implanted devices (e.g. pacemakers, intrathecal infusers, neurostimulators, hearing aids);
• positive history of brain lesions;
• presence of cerebral metallic implants (clips) or intracranial implants (e.g. ventriculoperitoneal shunt);
• history of epilepsy or previous state of epileptic disease;
• mechanical ventilation in place;
• history of psychotic disorders;
• history of severe neurodegenerative disease;
• concomitant pre-existing clinical conditions that may interfere with movements of the target arm or hand (e.g. severe osteoarthritis, joint injuries, plexus injuries, peripheral nerve injuries, partial amputations);
• use of antiepileptic drugs blocking Sodium o Calcium channels (e.g. Carbamazepine) or N-Methyl-D-Aspartate receptor antagonists (e.g. Dextromethorphan);
• history of drugs abuse;
• further contraindications to the use of TMS for PEMs elicitation (e.g. migraine with aura, permanent head / face tattoos);
• presence of brain tumor;
• pregnancy in progress.