This study evaluates the use of robotic rehabilitation with and without transcranial direct current stimulation (tDCS) to improve motor performance in children with hemiparetic cerebral palsy. Half of the participants will receive robotic rehabilitation and half will receive robotic rehabilitation with tDCS. We hypothesize that tDCS may augment the robotic therapy and show greater improvements than robotic therapy alone.

The defining feature of hemiparetic cerebral palsy is motor impairments primarily on one side of the body. Robotic rehabilitation and non-invasive brain stimulation are both emerging technologies that may be beneficial in improving motor performance in individuals with hemiparetic cerebral palsy. Robotic rehabilitation can allow for hundreds of arm movements in the span of an hour, a level of concentrated repetitions that is not possible in traditional rehabilitation. Additionally, robotics can target specific deficits, such as coordinating both arms together, improving accuracy of reaching movements, or improving proprioception, while simultaneously giving the therapist and patient quantitative feedback on performance. Non-invasive brain stimulation using transcranial direct current stimulation (tDCS) can safely modulate activity in regions of the brain and has emerged as a tool to enhance motor learning in typically developing children and augment therapy in children with hemiparetic cerebral palsy.

Children with hemiparetic cerebral palsy will be randomized to receive robotic rehabilitation with tDCS or robotic rehabilitation with sham-tDCS. Participants and the assessors will be blinded to the treatment. All children will complete 10 sessions within 3 weeks of 1.5 hours of robotic rehabilitation. The Kinarm Exoskeleton Robot will be used and children will play games with their affected arm or both arms to target different aspects of sensorimotor control. Children will simultaneously receive real or sham tDCS for the first 20 minutes of the session. tDCS will consist of 1 mA current with the cathode applied over the contralesional M1 area. All children will be assessed before and after the 10 session intervention period using robotic and clinical measures of motor and sensory performance, and at a 3 month follow up.

Inclusion Criteria:

• confirmed diagnosis of hemiparetic cerebral palsy due to unilateral perinatal stroke
• age 6-18 years
• Manual Ability Classification System (MACS) Level I-III
• Modified Ashworth Score in shoulder and elbow <=3;
• Visual acuity (corrected) better than 20/50 in both eyes
• able to follow instructions and comply with protocol;
• able to give consent/assent;
• able to commit to all assessment and intervention sessions.

Exclusion Criteria:

• significant contractures in the upper extremity;
• other neurological conditions or active medical disease;
• unstable epilepsy;
• contraindications to tDCS;
• botulinum toxin A injections in the upper extremity in the past 6 months;
• upper extremity surgical intervention in past 6 months;
• involvement in another interventional study.