Repeated Transcranial Magnetic Stimulation Combined with Action Observation Training in Children with Spastic Cerebral Palsy

Summary

Children with spastic cerebral palsy (SCP) have limb spasticity, movement disorders, and abnormal posture due to injury to the cerebral cortex motor area, resulting in inability to stand and walk normally. Therefore, alleviating limb spasticity and enhancing gross motor function in children with SCP have become important therapeutic goals.

Abstract

This study presents the results of a randomized controlled trial utilizing a 2 x 2 factorial design, comparing the effects of repeated transcranial magnetic stimulation (rTMS) and action observation training (AOT) intervention methods on spasticity, balance function, and motor function in children with spastic cerebral palsy (SCP). The study aimed to investigate whether the combination of the two interventions produces greater improvement than either treatment alone or conventional treatment.

Subject children in this study, in accordance with the random number table, were randomly divided into four groups: conventional group, rTMS group, AOT group, and combined intervention group. All the children in the four groups received conventional rehabilitation treatment, on the basis of which they were given different therapeutic programs of rehabilitation measures. The conventional group had no other treatment while the rTMS group received rTMS, the AOT group received AOT and the combined intervention group was given a combined intervention of rTMS and AOT. They were trained five days per week for 12 weeks. Changes in scores of spasticity, balance function, walking ability, and gross motor function were assessed at the onset of the training program and upon completion of 12 weeks of treatment.

A total of 64 Children with SCP completed the study, and their results were analyzed. The total gross motor function efficiency of 87.50% in the experimental group was significantly higher than that of 25.00% in the conventional group, 62.50% in the rTMS group, and 68.75% in the AOT group. The preliminary results showed that combined intervention of rTMS and AOT could effectively improve the balance function and motor function of children, and the therapeutic effect of the combined intervention was better than that of conventional treatment, rTMS or AOT alone. Finally, clinical efficacy and optimal treatment parameters of the combined intervention were clarified to provide a clinical basis for therapists to conduct lower limb function rehabilitation for children with SCP.

Introduction

Cerebral palsy¹ (CP) is one of the most common disabling disorders in children and is a group of persistent syndromes caused by non-progressive brain damage in developing fetuses and infants, including central dyskinesia, abnormal posture, and limited mobility. Currently, there are approximately 17 million children worldwide affected by cerebral palsy², with over 5 million cases in China. Among various forms of cerebral palsy, spastic cerebral palsy (SCP) accounts for roughly 80%³. Children with SCP suffer from brain damage resulting in muscle spasms, diminished sensory function, impaired muscle coordination, and decreased balance capabilities, all of which hinder independent walking and daily activities. Current rehabilitation measures for enhancing gross motor function in children with SCP encompass activities such as core stability training⁴, task-oriented training⁵, constraint-induced movement therapy⁶, and mirror visual feedback therapy⁷. These measures can improve clinical symptoms of children by regulating and reshaping the central nervous system from bottom to top by improving the functions of peripheral organs.

Transcranial magnetic stimulation (TMS)^8,9 is a painless, non-invasive, and safe therapeutic method. rTMS refers to the continuous release of stimuli at equal intervals after a single command, which is one of the regular repetitive stimulation patterns. Based on the principle of electromagnetic induction and electromagnetic conversion, it applies transient currents through stimulation coils to form a pulsed magnetic field to penetrate the skull, generate induction current to stimulate neurons and trigger a series of physiological and biochemical responses. rTMS has been applied to the monitoring, evaluation, and treatment of neurological diseases, providing a novel approach to exploring the structure and function of the brain¹⁰. Existing studies^11,12 have shown that rTMS has varying therapeutic effects on limb spasms and motor function in children with CP. Moreover, the effect of rTMS treatment combined with other rehabilitation techniques is more noticeable.

AOT is a rehabilitation method that utilizes the Mirror Neuron System (MNS) to establish motor learning and memory^13,14. The essence of AOT is to make the observer carefully observe actions in the video and subsequently try their best to imitate what they observed. The observing process might trigger activation in the neural network known as MNS, akin to the activation that occurs when one is personally engaged in executing those actions¹⁵, which provides a neurophysiological basis for AOT. AOT has shown success in improving motor skills in patients with movement disorders, yielding positive outcomes in stroke recovery and rehabilitation of upper limb motor function in cerebral palsy patients^16,17.

Our previous studies have found that AOT based on the mirror neuron system could effectively improve the balance and walking ability of children with cerebral palsy¹⁸. In addition, studies¹⁹ have shown that rTMS can improve muscle spasticity, movement, and gait in children with SCP, but treatment standards of rTMS applied to children with cerebral palsy have not been unified, and it is an urgent problem to explore the influence of different parameters of rTMS on children with CP, to provide a personalized and precise treatment standard. We believe that combining rTMS with AOT has the potential to develop into a valuable physical therapy strategy for the neurological rehabilitation of cerebral palsy. Both rTMS and AOT stimulated the cerebral cortex in children with SCP²⁰, thereby aiding gross motor function development. This study aimed to find out whether the combination of rTMS and AOT could achieve a greater synergistic effect than conventional treatment or rTMS or AOT alone.

Protocol

This study was carried out in strict accordance with the national standards for human experimentation, and the clinical study was approved by the Ethics Association of Xiangya Boai Rehabilitation Hospital (ethics approval number: 20211223). The children's guardians agreed to participate in this training program and signed informed consent forms. Children with SCP were recruited in the Xiangya Boai Rehabilitation Hospital and Xiangya Hospital of Central South University from February 2022 to December 2022. <p clas…

Representative Results

This paper presents the results of 64 children with SCP (Supplementary Table S1 and Supplementary File 1), who were randomly divided into four groups according to the numerical table method and given different rehabilitation measures for 12 weeks. During the entire process, the participating children had no adverse reactions such as headaches, dizziness, and seizures. The demographic data of the four groups of children are shown in Table 1. Be…

Discussion

For children with SCP, increased activity of γ and α neurons leads toinhibition of corticospinal tract input, which results in increased muscle tension known as spasm. As limb spasms significantly affect the development of lower limb motor function of children with SCP, one of the crucial training goals is to reduce spasticity. Currently, stepwise treatment strategies are employed to alleviate spasticity, including rehabilitation nursing, physical therapy, orthopedic brace application, botulinum toxin injection…

Materials

K6 multimedia scene interactive training system	Hunan Le Jiekang technology Co., LTD		Program implementation
KLW-SLL type spa machine for children	Nanjing Kanglongwei Technology Industrial Co., LTD		Conventional therapy
Pulse magnetic field stimulator model YRD CCY-II	Shenzhen Yingzhi technology Co., LTD		Program implementation
SPSS26 software	IBM		Statistic analysis