Cerebral pAlsy Motor Promotion With Transcranial Direct Current Stimulation (CAMP-tDCS)

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.

• tDCS (Device), also known as transcranial direct current stimulation: tDCS will be delivered anodal for 20 minutes at an intensity between 1mA and 2mA for 15 sessions.
• CIMT (Behavioral), also known as constraint induced movement therapy: CIMT will be administered for two hours a day, five days a week, and three weeks in a row.
• sham tDCS (Device): sham tDCS

Primary outcomes

• gross manual dexterity [With the first day of the intervention defined as day 1, this measure will be assessed in one of the three days before day 1, on day 15 or day 16 or day 17, and on day 181 or day 182 or day 183.]: It will be measured by the box and block test to assess how many blocks one can move from one box to another in one minute.
• fine manual dexterity [With the first day of the intervention defined as day 1, this measure will be assessed in one of the three days before day 1, on day 15 or day 16 or day 17, and on day 181 or day 182 or day 183.]: It will be measured by the nine-hole peg test to assess the time one needs to place nine pins into a reservior.

Secondary outcomes

• quality of upper extremity skill [With the first day of the intervention defined as day 1, this measure will be assessed in one of the three days before day 1, on day 15 or day 16 or day 17, and on day 181 or day 182 or day 183.]: It will be subjectively assessed with the Quality of Upper Extremity Skill Test (QUEST) to measure functions and use of both upper limbs.
• finger touch sensitivity [With the first day of the intervention defined as day 1, this measure will be assessed in one of the three days before day 1, on day 15 or day 16 or day 17, and on day 181 or day 182 or day 183.]: It will be measured with a two-point discriminator to assess the minimal displacement between two points of touch on fingertip one can perceive.

Sex: All, ages: 5 Years to 17 Years

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

• Yanlong Song, PhD, Principal investigator, University of Texas Southwestern Medical Center