Effects of Combined Spinal Direct Current Stimulation on Upper Limb Recovery in Acquired Brain Injury

This study will compare different polarities of transcutaneous spinal direct current stimulation combined with robotic-assisted arm training (RAT) in adults with acquired brain injury (ABI). Participants will receive 20 minutes of 2.5 milliamps (mA) anodal, cathodal, and sham transpinal direct current stimulation (tsDCS) over cervical spine combined with high intensity robotic-assisted arm training, five days a week, for 2 consecutive weeks.

Acquired brain injury (ABI) is the leading cause of neurological disability in the United States and accounts for the poor physical health and the social dysfunction evident in survivors. Hemiparesis due to acquired brain injury is the primary cause of disability and arm paresis is perceived as the primary cause of disability by individuals who have suffered ABI because of the limitations it creates in performing activities of daily living (ADL). Rehabilitation of the impaired limb is essential for improving motor function after ABI, yet only 31% of ABI survivors receive outpatient rehabilitation. Therefore, effective therapy for upper-limb paresis must be addressed. Approximately 80% of all ABI survivors suffer from upper limb paresis and only 18% of these individuals gain full motor recovery with conventional treatments in the year following ABI.

The study will use cross-over, randomized, sham controlled, double-blinded design. Participants with subacute or chronic ABI will each be assigned to receive active anodal spinal stimulation, active cathodal spinal stimulation, and sham spinal stimulation for the same duration, and the order that each participant will receive anodal, cathodal, and sham stimulation will be randomized. In all the experiments participants will receive robotic assisted training for duration of 1.5 hours. The first 20 minutes of training will be coupled with spinal stimulation. Treatment will be administered at an intensity of 5 sessions per week for 2 weeks.

Eligibility Criteria:
Inclusion Criteria:

1. Providing written informed consent prior to any study related procedures;
2. Age above 18;
3. Diagnosis of acquired brain injury at least for 6 month
4. No neuropsychiatric comorbidities
5. Not being involved in any specific exercise program (e.g., neuromuscular electrical stimulation (NMES), functional electrical stimulation (FES)) within the previous 3 months;
6. No planned alteration in upper-extremity therapy or medication for muscle tone during the course of the study;
7. Eligibility for standard upper-extremity rehabilitation at the time of enrollment (i.e., absence medical comorbidities that would prevent standard rehabilitation);
8. No condition (e.g., severe arthritis, extreme shoulder pain) that would interfere with valid administration of the measures or with interpreting motor testing;
9. No contraindications to tsDCS:

   * metal in the head between stimulation area
   * metal in the spine between stimulation area
   * implanted brain medical devices
10. No pregnancy;
11. No contraindications for Transcranial Magnetic Stimulation (TMS) and magnetic resonance imaging (MRI) based on TMS and MRI screening forms

Exclusion Criteria:

1. Uncontrolled epilepsy;
2. Any joint contracture or severe spasticity in the affected upper extremity, as measured by a Modified Ashworth Score \> than 3 out of 4;
3. History of substance abuse;
4. Subject who cannot provide self-transportation to the study location