The Therapeutic Effect of Transcranial Direct Current Stimulation and Treadmill in Children With Cerebral Palsy

Introduction Motor control and coordination in pediatric cerebral palsy patients have been improved through various methods. Treadmill training demonstrates efficacy in enhancing gait velocity, balance, and functional independence. Furthermore, transcranial direct current stimulation (tDCS) presents a non-invasive and safe alternative to surgical or pharmacological treatments. Collectively, these interventions have proven effective in advancing gait performance and functional capabilities in this population.

The optimal protocol for administering tDCS to pediatric cerebral palsy patients has yet to be established. Contrary to earlier studies that utilized unilateral anodal stimulation targeting the contralateral motor cortex, a hypothesis suggests that bilateral stimulation of both hemispheres could yield superior outcomes. This premise is supported by magnetoencephalography (MEG) a widespread disruption in neural excitability within both sensory-motor cortices of children with CP. This bilateral impairment occurs even in cases of unilateral lesions and contributes to reduced activation in corticospinal pathways. Accordingly, subsequent research applying unilateral anodal tDCS to the ipsilateral motor cortex (non-lesioned hemisphere) demonstrated enhancements in motor functions such as reaching skills and movement duration.

As a feasibility study, this pilot research assessed the practicality and initial effects of administering bilateral anodal tDCS concurrently with treadmill training to enhance gait parameters, range of motion, and reduce spasticity in pediatric patients with diplegic CP.

Methods Study design & participants This clinical study was approved by the IRB committee of Jordan University of Science and Technology and the King Abdullah University Hospital (#2019/420) based on the Declaration of Helsinki. Five children (aged 4-12 years) with spastic diplegic CP were enrolled. Inclusion criteria stipulated a Gross Motor Function Classification System (GMFCS) level of I-III, the ability to walk independently for at least 10 meters, and an IQ greater than 70. Key exclusion criteria included a history of orthopedic surgery, neurolytic blocks, or Botox injections in the past six months, as well as the presence of concurrent orthopedic impairments, epilepsy, intracranial metal implants, or hearing aids. In addition, voluntary written informed consent was obtained from all participant children by their legal guardians before participation in the study.

Treadmill training & tDCS intervention While prior research utilizing unilateral anodal tDCS in children with CP positioned a single anode over the C3 or C4 motor cortex and a cathode on the supra-orbital area according to the 10-20 EEG system, the present study employed a bilateral montage. Using the 10-10 EEG system for more precise placement, two anodes were positioned over the left FC1 and right FC2 regions (encompassing motor and frontal areas), with two corresponding cathodes located over the bilateral supra-orbital areas. A low current intensity of 1mA was applied.