Effect of transcranial direct current stimulation combined with gait and mobility training on functionality in children with cerebral palsy: study protocol for a double-blind randomized controlled clinical trial

Background: The project proposes three innovative intervention techniques (treadmill training, mobility training with virtual reality and transcranial direct current stimulation that can be safely administered to children with cerebral palsy. The combination of transcranial stimulation and physical therapy resources will provide the training of a specific task with multiple rhythmic repetitions of the phases of the gait cycle, providing rich sensory stimuli with a modified excitability threshold of the primary motor cortex to enhance local synaptic efficacy and potentiate motor learning. Methods/design: A prospective, double-blind, randomized, controlled, analytical, clinical trial will be carried out. Eligible participants will be children with cerebral palsy classified on levels I, II and III of the Gross Motor Function Classification System between four and ten years of age. The participants will be randomly allocated to four groups: 1) gait training on a treadmill with placebo transcranial stimulation; 2) gait training on a treadmill with active transcranial stimulation; 3) mobility training with virtual reality and placebo transcranial stimulation; 4) mobility training with virtual reality and active transcranial stimulation. Transcranial direct current stimulation will be applied with the anodal electrode positioned in the region of the dominant hemisphere over C3, corresponding to the primary motor cortex, and the cathode positioned in the supraorbital region contralateral to the anode. A 1 mA current will be applied for 20 minutes. Treadmill training and mobility training with virtual reality will be performed in 30-minute sessions five times a week for two weeks (total of 10 sessions). Evaluations will be performed on four occasions: one week prior to the intervention; one week following the intervention; one month after the end of the intervention; and 3 months after the end of the intervention. The evaluations will involve three-dimensional gait analysis, analysis of cortex excitability (motor threshold and motor evoked potential), Six-Minute Walk Test, Timed Up-and-Go Test, Pediatric Evaluation Disability Inventory, Gross Motor Function Measure, Berg Balance Scale, stabilometry, maximum respiratory pressure and an effort test. Discussion: This paper offers a detailed description of a prospective, double-blind, randomized, controlled, analytical, clinical trial aimed at demonstrating the effect combining transcranial stimulation with treadmill and mobility training on functionality and primary cortex excitability in children with Cerebral Palsy classified on Gross Motor Function Classification System levels I, II and III. The results will be published and will contribute to evidence regarding the use of treadmill training on this population.