No funds are available to support implementation of this project.

This study aims to test if transcranial direct current stimulation (tDCS) can be applied to boost the efficacy of constraint-induced movement therapy (CIMT) in children with HCP and examine brain mechanisms related to individual outcomes.

Currently, clinical treatment of hand/arm motor deficits in children affected by cerebral palsy is mainly rehabilitation and behaviorally oriented. Constraint-induced movement therapy (CIMT) has emerged as a frequently used rehabilitation intervention in children with hemiplegic cerebral palsy (HCP). In CIMT sessions, the unaffected upper limb is restrained with a cast or similar device, and the affected hand/arm is intensively and structurally trained. With different variations, such as constraint and intensity, CIMT has been demonstrated to be efficacious in improving hand-and-arm use in children with HCP. However, clinical outcomes across individuals who receive CIMT can show vast variation. How to improve the efficacy of CIMT and reduce individual variation will be of direct and profound clinical impacts. Motor deficits of children with HCP have a source origin of early brain injury, which often disrupts some regions of the brain and can cause changes in brain functions. Alteration or normalization of brain neuronal activities may influence motor functions in children with HCP and might boost the efficacy of CIMT. Transcranial direct current stimulation (tDCS), a type of non-invasive weak electric stimulation, has been demonstrated to be capable of influencing cognition and behaviors in abundant laboratory research tasks, hinting at potential clinical effects. Specific to the pediatric population with HCP, a few preliminary studies have tested the safety of tDCS when applied in children with HCP. This study will test how tDCS influences the efficacy of CIMT in children with HCP by comparing motor performances between two groups. The first group of children with HCP will receive anodal tDCS and CIMT while the second group of children with HCP will receive sham tDCS and CIMT during the intervention phase.

Inclusion Criteria:

• formal diagnosis of hemiplegic cerebral palsy
• unilateral upper limb (arm and hand) motor and sensory impairments
• capable of understanding and following experimental instructions and procedures
• capable of performing study procedures without assistance
• 5-17 years of age, including 5-year-old and 17-year-old

Exclusion Criteria:

• brain surgery, peripheral nerve surgery, genetic disorders, other neurological disorders or injuries
• muscle toxin injection within six months before recruitment
• received constraint-induced movement therapy (CIMT) within one year before recruitment
• uncontrolled seizures within one year before recruitment
• orthopedic surgery in upper limb within one year before recruitment
• incapable of understanding and following experimental instructions and procedures
• non-removable metallic objects or infusion pumps in the body
• psychoactive or myorelaxant medication during study procedures
• less than five years of age and older than 17 years of age

Participants' identifiers and linkages between study IDs and participants' identifiers will not be shared to protect participants' privacy, rights, and confidentiality. All other individual participant data will be preserved and shared. All data to be shared will be de-identified prior to receipt by any data repository. The information needed to generate a global unique identifier for a repository will be kept for each participant.

IPD and supporting information will be shared at the end of the study.

Access to the shared IPD and supporting information will not be controlled.