Targeted HD-tDCS to Improve Upper Limb Rehabilitation in SCI

The proposed project seeks to maximize the functional recovery achieved during the rehabilitation of the paretic upper limbs in individuals with SCI. The investigation will work towards optimizing the use of transcranial direct current stimulation (tDCS), an adjunct known to improve the effectiveness of rehabilitation. In particular, the relationship between the specificity of current delivery and functional benefit will be explored, and findings may lead to a framework that can be translated to the clinic setting.

Inclusion Criteria: * Provision of signed and dated informed consent form * Stated willingness to comply with all study procedures and availability for the duration of the study * Age between 18 and 75 years * Physician diagnosed cervical incomplete spinal cord injury or lesion (iSCI) * Classified by the American Spinal Cord Association (AIS) impairment scale as AIS C or D * iSCI occurred at least 18 months ago * Level of injury or lesion is between C2 and T1 * Bicep strength must be classified as ≥ 3 muscle grade as defined by the medical research council (MRC) scale * Tricep strength must be at least an MRC grade of 2 and be at least 1 muscle grade lower than bicep * Both the biceps and triceps will be required to elicit an active motor evoked potential \>200 uV with transcranial magnetic stimulation * Must maintain current medication regime * Must present with a weaker side of the body, as indicated by a Upper Extremity Motor Score (UEMS) score difference between the left and right side * UEMS \< 40 (50 max score) Exclusion Criteria: * Pacemaker or other implanted device * Metal in the skull * History of seizures * Pregnancy * First-degree relative with medication-resistant epilepsy * Current participation in upper limb rehabilitation therapies * Current use of illicit drugs, abusing alcohol, or have withdrawn from alcohol in the last 6 months * Other neurological impairment or condition * Pressure ulcers * Significant lower motor neuron loss at C7 as noted by a nerve conduction velocity \ 4. * Documented, non-sedated post-traumatic amnesia lasting more than 48 hours * Demonstrated present gains in motor recovery as noted by a \>10% change in triceps strength from pre-test #1 to pre-test #2 * A neuroactive medication that has the potential to lower the seizure threshold