Spared Primary Motor Cortex and The Presence of MEP in Cerebral Palsy Dictate the Responsiveness to tDCS during Gait Training

Neural Correlates of Mobility in Children with Cerebral Palsy: A Systematic Review

Recent advances in brain mapping tools have enabled the study of brain activity during functional tasks, revealing neuroplasticity after early brain injuries and resulting from rehabilitation. Understanding the neural correlates of mobility limitations is crucial for treating individuals with cerebral palsy (CP). The aim is to summarize the neural correlates of mobility in children with CP and to describe the brain mapping methods that have been utilized in the existing literature. This systematic review was conducted based on PRISMA guidelines and was registered on PROSPERO (n° CRD42021240296). The literature search was conducted in the PubMed and Embase databases. Observational studies involving participants with CP, with a mean age of up to 18 years, that utilized brain mapping techniques and correlated these with mobility outcomes were included. The results were analyzed in terms of sample characteristics, brain mapping methods, mobility measures, and main results. The risk of bias was evaluated using a checklist previously created by our research group, based on STROBE guidelines, the Cochrane Handbook, and the Critical Appraisal Skills Programme (CASP). A total of 15 studies comprising 313 children with CP and 229 with typical development using both static and mobile techniques met the inclusion criteria. The studies indicate that children"with'CP have increased cerebral activity and higher variability in brain reorganization during mobility activities, such as gait, quiet standing, cycling, and gross motor tasks when compared with children with typical development. Altered brain activity and reorganization underline the importance of conducting more studies to investigate the neural correlates during mobility activities in children with CP. Such information could guide neurorehabilitation strategies targeting brain neuroplasticity for functional gains.

Addressing gross motor function by functional repetitive neuromuscular magnetic stimulation targeting to the gluteal muscles in children with bilateral spastic cerebral palsy: benefits of functional repetitive neuromuscular magnetic stimulation targeting the gluteal muscles

Background

Impaired selective motor control, weakness and spasticity represent the key characteristics of motor disability in the context of bilateral spastic cerebral palsy. Independent walking ability is an important goal and training of the gluteal muscles can improve endurance and gait stability. Combining conventional physical excercises with a neuromodulatory, non-invasive technique like repetitive neuromuscular magnetic stimulation probably enhances effects of the treatment. This prospective study aimed to assess the clinical effects of repetitive neuromuscular magnetic stimulation in combination with a personalized functional physical training offered to children and adolescents with bilateral spastic cerebral palsy.

Methods

Eight participants Gross Motor Function Classification System level II and III (10.4 ± 2y5m; 50% Gross Motor Function Classification System level II) received a personalized intervention applying functional repetitive neuromuscular magnetic stimulation (12 sessions within 3 weeks; 12,600 total stimuli during each session). At baseline and follow up the following assessments were performed: 10-m-walking-test, 6-min-walking-test, GMFM-66. Six weeks after the end of treatment the patient-reported outcome measure Gait Outcome Assessment List was completed.

Results

GMFM-66 total score improved by 1.4% (p = 0.002), as did scoring in domain D for standing (1.9%, p = 0.109) and domain E for walking, jumping and running (2.6%, p = 0.021). Gait speed or distance walked during 6 min did not improve from baseline to follow up. Patient-reported outcome showed improvement in 4 patients in altogether 14 ratings. Caregiver-reported outcome reported benefits in 3 participants in altogether 10 ratings.

Conclusion

Repetitive neuromuscular magnetic stimulation promises to be a meaningful, non-invasive treatment approach for children and adolescents with bilateral spastic cerebral palsy that could be offered in a resource-efficient manner to a broad number of patients. To further investigate the promising effects of repetitive neuromuscular magnetic stimulation and its mechanisms of action, larger-scaled, controlled trials are needed as well as comprehensive neurophysiological investigations.

Effects of Dual Task Training and Transcranial Direct Current Stimulation in Children with Spastic Cerebral Palsy: A Pilot Randomized Control Trial

OBJECTIVE

Compare the effectiveness of active and sham transcranial direct current stimulation (tDCS) during the training of a dual task in children with spastic cerebral palsy (CP).

METHODS

Thirty children with CP were submitted to ten sessions of either active (n = 15) or sham (n = 15) tDCS over the motor cortex for 20 minutes during the training of a dual task. Pre-intervention, post-intervention and follow-up evaluations involved measures of functional performance, intellectual performance, functional mobility and cortical excitability.

RESULTS

The combination of active tDCS and dual task training led to improvements in functional mobility as well as functional and intellectual performances one month after the end of the intervention.

CONCLUSION

The combination of active tDCS and dual task training demonstrated promising effects for children with spastic CP.

Transcranial direct current stimulation to facilitate neurofunctional rehabilitation in children with autism spectrum disorder: a protocol for a randomized, sham-controlled, double-blind clinical trial

Background

Anodal transcranial direct current stimulation (tDCS) over the primary motor cortex and cerebellum is gaining prominence in the literature due to its potential to favor learning and motor performance. If administered during motor training, tDCS is capable of increasing the effect of training. Considering the motor impairment presented by children with Autism Spectrum Disorders (ASD), atDCS applied during motor training may contribute to the rehabilitation of these children. However, it is necessary to examine and compare the effects of atDCS over the motor cortex and the cerebellum on the motor skills of children with ASD. This information may benefit future clinical indications of tDCS for rehabilitation of children with ASD. The aim of the proposed study is to determine whether anodal tDCS over the primary motor cortex and cerebellum can enhance the effects of gait training and postural control on motor skills, mobility, functional balance, cortical excitability, cognitive aspects and behavioral aspects in children with ASD. Our hypothesis is the active tDCS combined with motor training will enhance the performance of the participants in comparison to sham tDCS.

Methods and design

A randomized, sham-controlled, double-blind clinical trial will be conducted involving 30 children with ASD that will be recruited to receive ten sessions of sham or ten sessions of active anodal tDCS (1 mA, 20 min) over the primary motor cortex or cerebellun combined with motor training. The participants will be assessed before as well as one, four and eight weeks after the interventions. The primary outcome will be gross and fine motor skills. The secondary outcomes will be mobility, functional balance, motor cortical excitability, cognitive aspects and behavioral aspects.

Discussion

Although abnormalities in gait and balance are not primary characteristics of ASD, such abnormalities compromise independence and global functioning during the execution of routine activities of childhood. If demonstrated that anodal tDCS administered over areas of the brain involved in motor control, such as the primary motor cortex and cerebellum, can enhance the effects of gait and balance training in only ten sessions in two consecutive weeks, the clinical applicability of this stimulation modality will be expanded as well as more scientifically founded.Clinical trial registration February 16, 2023 (https://ensaiosclinicos.gov.br/rg/RBR-3bskhwf).

Safety and feasibility of transcranial direct current stimulation stratified by corticospinal organization in children with hemiparesis

Children with hemiparesis (CWH) due to stroke early in life face lifelong impairments in motor function. Transcranial direct current stimulation (tDCS) may be a safe and feasible adjuvant therapy to augment rehabilitation. Given the variability in outcomes following tDCS, tailored protocols of tDCS are required. We evaluated the safety, feasibility, and preliminary effects of a single session of targeted anodal tDCS based on individual corticospinal tract organization on corticospinal excitability. Fourteen CWH (age = 13.8 ± 3.63) were stratified into two corticospinal organization subgroups based on transcranial magnetic stimulation (TMS)-confirmed motor evoked potentials (MEP): ipsilesional MEP presence (MEPIL+) or absence (MEPIL-). Subgroups were randomized to real anodal or sham tDCS (1.5 mA, 20 min) applied to the ipsilesional (MEPIL + group) or contralesional (MEPIL- group) hemisphere combined with hand training. Safety was assessed with questionnaires and motor function evaluation, and corticospinal excitability was assessed at baseline and every 15 min for 1 h after tDCS. No serious adverse events occurred and anticipated minor side effects were reported and were self-limiting. Six of 14 participants had consistent ipsilesional MEPs (MEPIL + group). Paretic hand MEP amplitude increased in 5/8 participants who received real anodal tDCS to either the ipsilesional or contralesional hemisphere (+80% change). Application of tDCS based on individual corticospinal organization was safe and feasible with expected effects on excitability, indicating the potential for tailored tDCS protocols for CWH. Additional research involving expanded experimental designs is needed to confirm these effects and to determine if this approach can be translated into a clinically relevant intervention.

Relationship between kinematic gait quality and caregiver-reported everyday mobility in children and youth with spastic Cerebral Palsy

BACKGROUND

3D gait analysis (3DGA) is a common assessment in Cerebral Palsy (CP) to quantify the extent of movement abnormalities. Yet, 3DGA is performed in laboratories and may thus be of debatable significance to everyday life.

AIM

The aim was to assess the relationship between kinematic gait abnormality and everyday mobility in ambulatory children and youth with spastic CP.

METHODS

73 paediatric and juvenile patients with uni- or bilateral spastic CP (N = 21 USCP, N = 52, BSCP, age: 4-20 y, GMFCS I-III) underwent a 3DGA, while the MobQues47 Questionnaire quantified caregiver-reported mobility. We calculated the Gait Profile Score (GPS), a metric that summarizes how far the lower limb joint angles during walking deviate from those of matched controls.

RESULTS

The GPS correlated well with indoor and outdoor mobility (rho = -0.69 and -0.70, both p < 0.001) and the relationships were not significantly different for USCP and BSCP. Still, mobility was lower in BSCP (p < 0.001) and more compromised outdoors (p = 0.002). Indoor mobility could be predicted by walking speed, GPS and age (adj. R² = 0.62). Outdoor mobility was best predicted by walking speed and GPS (adj. R² = 0.60). The additive explained variance by the GPS was even higher outdoors than indoors (17.1% vs. 11.4%).

CONCLUSIONS

Measuring movement deviations with 3DGA seems equally meaningful in uni- and bilaterally affected children and has considerable relevance for real-life ambulation, particurlarly outdoors, where children with spastic CP typically face greater difficulties. Therapeutic strategies that achieve faster walking and reduction of kinematic deviations may increase outdoor mobility.

Physical therapy in children with cerebral palsy in Brazil: a scoping review

AIM

To identify and assess published studies concerning physical therapy in Brazilian children and adolescents with cerebral palsy (CP) using the International Classification of Functioning, Disability and Health (ICF) framework.

METHOD

Articles in English and Portuguese published until October 2020, with no date restrictions, were searched in several different databases. Study characteristics, journal metrics, sample characteristics, and ICF domains explored intervention components and outcomes were extracted. Studies were classified according to the Oxford Centre for Evidence-Based Medicine hierarchy levels to characterize the evidence.

RESULTS

Ninety-four studies were included. Spastic CP with fewer limitations in gross motor abilities was the most reported; 67% of the studies had low levels of evidence and were published in journals without an impact factor. The three most frequent interventions were neurodevelopmental treatment, suit therapy, and transcranial direct current stimulation. Intervention components explored body functions and structures (73.4%), activity (59.6%), environment (2.1%). They did not explore participation (0%). The outcomes investigated addressed activity (79.8%), body functions and structures (67.0%), and participation (1.1%), but not environment (0%).

INTERPRETATION

Studies of physical therapy for Brazilian children and adolescents with CP focused on reducing impairments and activity limitations. Studies with higher levels of evidence and an expanded focus on participation and environmental factors are necessary.

Fisioterapia em crianças com paralisia cerebral no Brasil: uma revisão de escopo

OBJETIVO

Identificar e avaliar os estudos publicados sobre fisioterapia em crianças e adolescentes brasileiros com paralisia cerebral (PC), usando o modelo da Classificação Internacional de Funcionalidade, Incapacidade e Saúde (CIF). MÉTODO: Artigos em inglês e português publicados até outubro de 2020, sem restrição de data, foram pesquisados em diferentes bases bibliográficas. Foram extraídos dados sobre as características do estudo, métricas do periódico, características da amostra, domínios da CIF explorados a partir dos componentes e desfechos das intervenções. Para caracterizar as evidências, os estudos foram classificados de acordo com os níveis de evidência do Centro de Medicina Baseada em Evidência de Oxford.

RESULTADOS

Noventa e quatro estudos foram incluídos. Crianças com PC espástica e com menores limitações nas habilidades motoras grossas foram as mais reportadas; 67% dos estudos apresentaram baixos níveis de evidência e foram publicados em periódicos sem fator de impacto. As três intervenções mais frequentes foram o conceito neuroevolutivo Bobath/terapia do neurodesenvolvimento, a terapia com vestes e a estimulação transcraniana por corrente contínua. Os componentes das intervenções exploraram estruturas e funções do corpo (73,4%), atividade (59,6%) e ambiente (2,1%). Entretanto não exploraram a participação (0%). Os desfechos investigados abordaram atividade (79,8%), estruturas e funções do corpo (67,0%), participação (1%) e ambiente (0%). INTERPRETAÇÃO: Os estudos de intervenções fisioterapêuticas para crianças e adolescentes brasileiros com PC, apresentam maior foco em minimizar deficiências em estruturas e funções do corpo e limitações de atividades. São necessários mais estudos, com melhor nível de evidência e foco ampliado para a participação e os fatores ambientais.

Effects of Transcranial Direct Current Stimulation on Cognitive and Affective Outcomes Using Virtual Stimuli: A Systematic Review

Transcranial direct current stimulation (tDCS) is a noninvasive form of brain stimulation used to influence neural activity. While early tDCS studies primarily used static stimuli, there is growing interest in dynamic stimulus presentations using virtual environments (VEs). This review attempts to convey the state of the field. This is not a quantitative meta-analysis as there are not yet enough studies following consistent protocols and/or reporting adequate data. In addition to reviewing the state of the literature, this review includes an exploratory analysis of the available data. Following preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, studies were culled from several databases. Results from this review reveal differences between online and offline stimulation. While offline stimulation did not influence affective and cognitive outcomes, online stimulation led to small changes in affect and cognition. Future studies should include randomized controlled trials with larger samples. Furthermore, greater care needs to be applied to full data reporting (e.g., means, standard deviations, and data for their nonsignificant findings) to improve our understanding of the combined effects of virtual stimuli with tDCS.

tDCS and motor training in individuals with central nervous system disease: A systematic review

BACKGROUND

Transcranial direct current stimulation (tDCS) is a promising tool for patients with neurological disorders, as it increases cortical excitability, motor learning and functionality. The studies up to date have focused on the tDCS parameters while the effects of the motor training have not yet been fully addressed. The purpose of this study is to present a systematic review of all studies related to tDCS in conjunction with motor training (MT) to improve gait performance, functionality, mobility and balance in individuals with non-progressive central nervous system diseases.

METHODS

Seven databases were searched for articles from inception to October 2018. The search strategy followed Collaboration guidelines. The Physiotherapy Evidence Database (PEDro) Scale and Cochrane Collaboration's tool for assessing the risk of bias were applied to evaluate methodological quality.

RESULTS

Four hundred and sixteen recorded were screened. Ten studies met the inclusion criteria. All studies were randomized controlled trials, two of them had a crossover design and other two were pilot studies. Three paper analyzed children and adolescents with cerebral palsy, seven papers analyzed adults and elderly post stroke. tDCS with MT lead to significant results.

CONCLUSIONS

This review found limited evidence for the use of tDCS with MT for in children with CP and adults post stroke, due to the small number of studies as well as their methodological heterogeneity. In the absence of more robust evidence, further studies with a consistent methodological design are needed to endorse the clinical application of tDCS with motor training.

Mechanically assisted walking training for walking, participation, and quality of life in children with cerebral palsy

BACKGROUND

Cerebral palsy is the most common physical disability in childhood. Mechanically assisted walking training can be provided with or without body weight support to enable children with cerebral palsy to perform repetitive practice of complex gait cycles. It is important to examine the effects of mechanically assisted walking training to identify evidence-based treatments to improve walking performance.

OBJECTIVES

To assess the effects of mechanically assisted walking training compared to control for walking, participation, and quality of life in children with cerebral palsy 3 to 18 years of age.

SEARCH METHODS

In January 2020, we searched CENTRAL, MEDLINE, Embase, six other databases, and two trials registers. We handsearched conference abstracts and checked reference lists of included studies.

SELECTION CRITERIA

Randomized controlled trials (RCTs) or quasi-RCTs, including cross-over trials, comparing any type of mechanically assisted walking training (with or without body weight support) with no walking training or the same dose of overground walking training in children with cerebral palsy (classified as Gross Motor Function Classification System [GMFCS] Levels I to IV) 3 to 18 years of age.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

This review includes 17 studies with 451 participants (GMFCS Levels I to IV; mean age range 4 to 14 years) from outpatient settings. The duration of the intervention period (4 to 12 weeks) ranged widely, as did intensity of training in terms of both length (15 minutes to 40 minutes) and frequency (two to five times a week) of sessions. Six studies were funded by grants, three had no funding support, and eight did not report information on funding. Due to the nature of the intervention, all studies were at high risk of performance bias. Mechanically assisted walking training without body weight support versus no walking training Four studies (100 participants) assessed this comparison. Compared to no walking, mechanically assisted walking training without body weight support increased walking speed (mean difference [MD] 0.05 meter per second [m/s] [change scores], 95% confidence interval [CI] 0.03 to 0.07; 1 study, 10 participants; moderate-quality evidence) as measured by the Biodex Gait Trainer 2™ (Biodex, Shirley, NY, USA) and improved gross motor function (standardized MD [SMD] 1.30 [postintervention scores], 95% CI 0.49 to 2.11; 2 studies, 60 participants; low-quality evidence) postintervention. One study (30 participants) reported no adverse events (low-quality evidence). No study measured participation or quality of life. Mechanically assisted walking training without body weight support versus the same dose of overground walking training Two studies (55 participants) assessed this comparison. Compared to the same dose of overground walking, mechanically assisted walking training without body weight support increased walking speed (MD 0.25 m/s [change or postintervention scores], 95% CI 0.13 to 0.37; 2 studies, 55 participants; moderate-quality evidence) as assessed by the 6-minute walk test or Vicon gait analysis. It also improved gross motor function (MD 11.90% [change scores], 95% CI 2.98 to 20.82; 1 study, 35 participants; moderate-quality evidence) as assessed by the Gross Motor Function Measure (GMFM) and participation (MD 8.20 [change scores], 95% CI 5.69 to 10.71; 1 study, 35 participants; moderate-quality evidence) as assessed by the Pediatric Evaluation of Disability Inventory (scored from 0 to 59), compared to the same dose of overground walking training. No study measured adverse events or quality of life. Mechanically assisted walking training with body weight support versus no walking training Eight studies (210 participants) assessed this comparison. Compared to no walking training, mechanically assisted walking training with body weight support increased walking speed (MD 0.07 m/s [change and postintervention scores], 95% CI 0.06 to 0.08; 7 studies, 161 participants; moderate-quality evidence) as assessed by the 10-meter or 8-meter walk test. There were no differences between groups in gross motor function (MD 1.09% [change and postintervention scores], 95% CI -0.57 to 2.75; 3 studies, 58 participants; low-quality evidence) as assessed by the GMFM; participation (SMD 0.33 [change scores], 95% CI -0.27 to 0.93; 2 studies, 44 participants; low-quality evidence); and quality of life (MD 9.50% [change scores], 95% CI -4.03 to 23.03; 1 study, 26 participants; low-quality evidence) as assessed by the Pediatric Quality of Life Cerebral Palsy Module (scored 0 [bad] to 100 [good]). Three studies (56 participants) reported no adverse events (low-quality evidence). Mechanically assisted walking training with body weight support versus the same dose of overground walking training Three studies (86 participants) assessed this comparison. There were no differences between groups in walking speed (MD -0.02 m/s [change and postintervention scores], 95% CI -0.08 to 0.04; 3 studies, 78 participants; low-quality evidence) as assessed by the 10-meter or 5-minute walk test; gross motor function (MD -0.73% [postintervention scores], 95% CI -14.38 to 12.92; 2 studies, 52 participants; low-quality evidence) as assessed by the GMFM; and participation (MD -4.74 [change scores], 95% CI -11.89 to 2.41; 1 study, 26 participants; moderate-quality evidence) as assessed by the School Function Assessment (scored from 19 to 76). No study measured adverse events or quality of life.

AUTHORS' CONCLUSIONS

Compared with no walking, mechanically assisted walking training probably results in small increases in walking speed (with or without body weight support) and may improve gross motor function (with body weight support). Compared with the same dose of overground walking, mechanically assisted walking training with body weight support may result in little to no difference in walking speed and gross motor function, although two studies found that mechanically assisted walking training without body weight support is probably more effective than the same dose of overground walking training for walking speed and gross motor function. Not many studies reported adverse events, although those that did appeared to show no differences between groups. The results are largely not clinically significant, sample sizes are small, and risk of bias and intensity of intervention vary across studies, making it hard to draw robust conclusions. Mechanically assisted walking training is a means to undertake high-intensity, repetitive, task-specific training and may be useful for children with poor concentration.

Fluctuations in Human Corticospinal Activity Prior to Grasp

Neuronal firing rate variability prior to movement onset contributes to trial-to-trial variability in primate behavior. However, in humans, whether similar mechanisms contribute to trial-to-trial behavioral variability remains unknown. We investigated the time-course of trial-to-trial variability in corticospinal excitability (CSE) using transcranial magnetic stimulation (TMS) during a self-paced reach-to-grasp task. We hypothesized that CSE variability will be modulated prior to the initiation of reach and that such a modulation would explain trial-to-trial behavioral variability. Able-bodied individuals were visually cued to plan their grip force before exertion of either 30% or 5% of their maximum pinch force capacity on an object. TMS was delivered at six time points (0.5, 0.75, 1, 1.1, 1.2, and 1.3 s) following a visual cue that instructed the force level. We first modeled the relation between CSE magnitude and its variability at rest (n = 12) to study the component of CSE variability pertaining to the task but not related to changes in CSE magnitude (n = 12). We found an increase in CSE variability from 1.2 to 1.3 s following the visual cue at 30% but not at 5% of force. This effect was temporally dissociated from the decrease in CSE magnitude that was observed from 0.5 to 0.75 s following the cue. Importantly, the increase in CSE variability explained at least ∼40% of inter-individual differences in trial-to-trial variability in time to peak force rate. These results were found to be repeatable across studies and robust to different analysis methods. Our findings suggest that the neural mechanisms underlying modulation in CSE variability and CSE magnitude are distinct. Notably, the extent of modulation in variability in corticospinal system prior to grasp within individuals may explain their trial-to-trial behavioral variability.

Combining transcranial direct-current stimulation with gait training in patients with neurological disorders: a systematic review

BACKGROUND

Transcranial direct-current stimulation (tDCS) is an easy-to-apply, cheap, and safe technique capable of affecting cortical brain activity. However, its effectiveness has not been proven for many clinical applications.

OBJECTIVE

The aim of this systematic review was to determine whether the effect of different strategies for gait training in patients with neurological disorders can be enhanced by the combined application of tDCS compared to sham stimulation. Additionally, we attempted to record and analyze tDCS parameters to optimize its efficacy.

METHODS

A search in Pubmed, PEDro, and Cochrane databases was performed to find randomized clinical trials that combined tDCS with gait training. A chronological filter from 2010 to 2018 was applied and only studies with variables that quantified the gait function were included.

RESULTS

A total of 274 studies were found, of which 25 met the inclusion criteria. Of them, 17 were rejected based on exclusion criteria. Finally, 8 trials were evaluated that included 91 subjects with stroke, 57 suffering from Parkinson's disease, and 39 with spinal cord injury. Four of the eight assessed studies did not report improved outcomes for any of its variables compared to the placebo treatment.

CONCLUSIONS

There are no conclusive results that confirm that tDCS can enhance the effect of the different strategies for gait training. Further research for specific pathologies, with larger sample sizes and adequate follow-up periods, are required to optimize the existing protocols for applying tDCS.

Effect of Anodic tDCS Over Motor Cortex Versus Cerebellum in Cerebral Palsy: A Study Protocol

PURPOSE

To compare the clinical and functional effects of treadmill training combined with anodic transcranial direct current stimulation (atDCS) on the primary motor cortex (Cz), specifically on the area of motor cortex representation of the lower limbs, and on the cerebellum (Cb) in children with spastic cerebral palsy (CP).

METHODS

Thirty children and adolescents with spastic CP will be randomly allocated in 3 groups: (1) treadmill training and atDCS on Cz; (2) treadmill training and atDCS on Cb; (3) treadmill training and sham tDCS on Cz. Evaluations of gait spatial-temporal parameters, functional mobility, functional balance, gross motor function, and functional performance will be performed 1 week before intervention and 1 week, 1 month, and 3 months after intervention. Every 3 months the participants will cross over groups.

DISCUSSION

This is a protocol for an intervention study comparing the clinical and functional effects of atDCS over Cz and Cb.

Effects of transcranial direct current stimulation (tDCS) on balance improvement: a systematic review and meta-analysis

Background: Transcranial direct current stimulation (tDCS) has emerged as a promising therapeutic tool to improve balance and optimize rehabilitation strategies. However, current literature shows the methodological heterogeneity of tDCS protocols and results, hindering any clear conclusions about the effects of tDCS on postural control. Objective: Evaluate the effectiveness of tDCS on postural control, and identify the most beneficial target brain areas and the effect on different populations. Methods: Two independent reviewers selected randomized tDCS clinical-trials studies from PubMed, Scopus, Web of Science, and reference lists of retrieved articles published between 1998 and 2017. Most frequently reported centre of pressure (COP) variables were selected for meta-analysis. Other postural control outcomes were discussed in the review. Results: Thirty studies were included in the systematic review, and 11 were submitted to a meta-analysis. A reduction of COP displacement area has been significantly achieved by tDCS, evidencing an improvement in balance control. Individuals with cerebral palsy (CP) and healthy young adults are mostly affected by stimulation. The analysis of the impact of tDCS over different brain areas revealed a significant effect after primary motor cortex (M1) stimulation, however, with no clear results after cerebellar stimulation due to divergent results among studies. Conclusions: tDCS appears to improve balance control, more evident in healthy and CP subjects. Effects are observed when primary MI is stimulated. Cerebellar stimulation should be better investigated.

Anodal Transcranial Direct Current Stimulation over the Vertex Enhances Leg Motor Cortex Excitability Bilaterally

In many studies, anodal transcranial Direct Current Stimulation (tDCS) is applied near the vertex to simultaneously facilitate leg motor cortex (M1) of both hemispheres and enhance recovery of gait and balance in neurological disorders. However, its effect on the excitability of leg M1 in either hemisphere is not well known. In this double-blind sham-controlled study, corticospinal excitability changes induced in leg M1 of both hemispheres by anodal (2 mA for 20 minutes) or sham tDCS (for 20 min) over the vertex were evaluated. Peak amplitudes of Transcranial Magnetic Stimulation (TMS) induced motor evoked potentials (MEPs) were measured over the contralateral Tibialis Anterior (TA) muscle before and up to 40 min after tDCS in 11 normal participants. Analysis of data from all participants found significant overall increase in the excitability of leg M1 after tDCS. However, in individual subjects there was variability in observed effects. In 4 participants, 20 min of tDCS increased mean MEPs of TAs on both sides; in 4 participants there was increased mean MEP only on one side and in 3 subjects there was no change. It’s not known if the benefits of tDCS in improving gait and balance are dependent on excitability changes induced in one or both leg M1; such information may be useful to predict treatment outcomes.

Transcranial direct current stimulation for promoting motor function in cerebral palsy: a review

Transcranial direct current stimulation (tDCS) has the potential to improve motor function in a range of neurological conditions, including Cerebral Palsy (CP). Although there have been many studies assessing tDCS in adult stroke, the literature regarding the efficacy of tDCS in CP is more limited. This review therefore focuses on the neurophysiological and clinical findings in children and adolescents with CP. Initial studies applying anodal tDCS to promote lower limb function are promising, with improvements in gait, mobility and balance reported. However, the results of upper limb studies are mixed and more research is needed. Studies investigating neurophysiological changes or predictors of response are also lacking. Large-scale longitudinal studies are needed for the lower limb to ascertain whether the initial pilot results translate into clinically meaningful improvements. Future studies of the upper limb should focus on determining the optimal stimulation parameters and consider tailoring stimulation to the individual based on the (re)organisation of their motor system.

Transcranial Direct Current Stimulation in Pediatric Motor Disorders: A Systematic Review and Meta-analysis

OBJECTIVE

To systematically examine the safety and effectiveness of transcranial direct current stimulation (tDCS) interventions in pediatric motor disorders.

DATA SOURCES

PubMed, EMBASE, Cochrane, CINAHL, Web of Science, and ProQuest databases were searched from inception to August 2018.

STUDY SELECTION

tDCS randomized controlled trials (RCTs), observational studies, conference proceedings, and dissertations in pediatric motor disorders were included. Two authors independently screened articles based on predefined inclusion criteria.

DATA EXTRACTION

Data related to participant demographics, intervention, and outcomes were extracted by 2 authors. Quality assessment was independently performed by 2 authors.

DATA SYNTHESIS

A total of 23 studies involving a total of 391 participants were included. There was no difference in dropout rates between active (1 of 144) and sham (1 of 144) tDCS groups, risk difference 0.0, 95% confidence interval (-.05 to .04). Across studies, the most common adverse effects in the active group were tingling (17.2%), discomfort (8.02%), itching (6.79%), and skin redness (4%). Across 3 studies in children with cerebral palsy, tDCS significantly improved gait velocity (MD=.23; 95% confidence interval [0.13-0.34]; P<.0005), stride length (MD=0.10; 95% confidence interval [0.05-0.15]; P<.0005), and cadence (MD=15.7; 95% confidence interval [9.72-21.68]; P<.0005). Mixed effects were found on balance, upper extremity function, and overflow movements in dystonia.

CONCLUSION

Based on the studies reviewed, tDCS is a safe technique in pediatric motor disorders and may improve some gait measures and involuntary movements. Research to date in pediatric motor disorders shows limited effectiveness in improving balance and upper extremity function. tDCS may serve as a potential adjunct to pediatric rehabilitation; to better understand if tDCS is beneficial for pediatric motor disorders, more well-designed RCTs are needed.

Effect of Transcranial Direct Current Stimulation of Motor Cortex in Cerebral Palsy: A Study Protocol

PURPOSE

To assess the best electrode position of transcranial direct current stimulation combined with treadmill training in children with unilateral spastic cerebral palsy.

METHODS

Thirty children with cerebral palsy were randomly allocated to 3 groups: (1) treadmill training combined with anodal electrode positioned over the primary motor cortex in the region of the dominant hemisphere and the cathode positioned in the supraorbital region contralateral to anode; (2) sham anodal transcranial direct current stimulation over the primary motor cortex and sham cathode over the contralateral supraorbital region combined with treadmill training; (3) treadmill training combined with the anodal electrode positioned over the primary motor cortex in the region of the injured hemisphere and the cathode positioned contralateral to anode over the primary motor cortex. Evaluations of gait, balance, quality of life, and electromyographic activity were performed.

DISCUSSION

This is the protocol for an intervention study investigating electrode position to achieve improved function.

Effectiveness of Virtual Reality in Children With Cerebral Palsy: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Researchers recently investigated the effectiveness of virtual reality (VR) in helping children with cerebral palsy (CP) to improve motor function. A systematic review of randomized controlled trials (RCTs) using a meta-analytic method to examine the effectiveness of VR in children with CP was thus needed.

PURPOSE

The purpose of this study was to update the current evidence about VR by systematically examining the research literature.

DATA SOURCES

A systematic literature search of PubMed, CINAHL, Cochrane Central Register of Controlled Trials, ERIC, PsycINFO, and Web of Science up to December 2016 was conducted.

STUDY SELECTION

Studies with an RCT design, children with CP, comparisons of VR with other interventions, and movement-related outcomes were included.

DATA EXTRACTION

A template was created to systematically code the demographic, methodological, and miscellaneous variables of each RCT. The Physiotherapy Evidence Database (PEDro) scale was used to evaluate the study quality. Effect size was computed and combined using meta-analysis software. Moderator analyses were also used to explain the heterogeneity of the effect sizes in all RCTs.

DATA SYNTHESIS

. The literature search yielded 19 RCT studies with fair to good methodological quality. Overall, VR provided a large effect size (d = 0.861) when compared with other interventions. A large effect of VR on arm function (d = 0.835) and postural control (d = 1.003) and a medium effect on ambulation (d = 0.755) were also found. Only the VR type affected the overall VR effect: an engineer-built system was more effective than a commercial system.

LIMITATIONS

The RCTs included in this study were of fair to good quality, had a high level of heterogeneity and small sample sizes, and used various intervention protocols.

CONCLUSIONS

Then compared with other interventions, VR seems to be an effective intervention for improving motor function in children with CP.

Multivariate Analysis and Machine Learning in Cerebral Palsy Research

Cerebral palsy (CP), a common pediatric movement disorder, causes the most severe physical disability in children. Early diagnosis in high-risk infants is critical for early intervention and possible early recovery. In recent years, multivariate analytic and machine learning (ML) approaches have been increasingly used in CP research. This paper aims to identify such multivariate studies and provide an overview of this relatively young field. Studies reviewed in this paper have demonstrated that multivariate analytic methods are useful in identification of risk factors, detection of CP, movement assessment for CP prediction, and outcome assessment, and ML approaches have made it possible to automatically identify movement impairments in high-risk infants. In addition, outcome predictors for surgical treatments have been identified by multivariate outcome studies. To make the multivariate and ML approaches useful in clinical settings, further research with large samples is needed to verify and improve these multivariate methods in risk factor identification, CP detection, movement assessment, and outcome evaluation or prediction. As multivariate analysis, ML and data processing technologies advance in the era of Big Data of this century, it is expected that multivariate analysis and ML will play a bigger role in improving the diagnosis and treatment of CP to reduce mortality and morbidity rates, and enhance patient care for children with CP.

Low intensity transcranial electric stimulation: Safety, ethical, legal regulatory and application guidelines

Low intensity transcranial electrical stimulation (TES) in humans, encompassing transcranial direct current (tDCS), transcutaneous spinal Direct Current Stimulation (tsDCS), transcranial alternating current (tACS), and transcranial random noise (tRNS) stimulation or their combinations, appears to be safe. No serious adverse events (SAEs) have been reported so far in over 18,000 sessions administered to healthy subjects, neurological and psychiatric patients, as summarized here. Moderate adverse events (AEs), as defined by the necessity to intervene, are rare, and include skin burns with tDCS due to suboptimal electrode-skin contact. Very rarely mania or hypomania was induced in patients with depression (11 documented cases), yet a causal relationship is difficult to prove because of the low incidence rate and limited numbers of subjects in controlled trials. Mild AEs (MAEs) include headache and fatigue following stimulation as well as prickling and burning sensations occurring during tDCS at peak-to-baseline intensities of 1-2mA and during tACS at higher peak-to-peak intensities above 2mA. The prevalence of published AEs is different in studies specifically assessing AEs vs. those not assessing them, being higher in the former. AEs are frequently reported by individuals receiving placebo stimulation. The profile of AEs in terms of frequency, magnitude and type is comparable in healthy and clinical populations, and this is also the case for more vulnerable populations, such as children, elderly persons, or pregnant women. Combined interventions (e.g., co-application of drugs, electrophysiological measurements, neuroimaging) were not associated with further safety issues. Safety is established for low-intensity 'conventional' TES defined as <4mA, up to 60min duration per day. Animal studies and modeling evidence indicate that brain injury could occur at predicted current densities in the brain of 6.3-13A/m2 that are over an order of magnitude above those produced by tDCS in humans. Using AC stimulation fewer AEs were reported compared to DC. In specific paradigms with amplitudes of up to 10mA, frequencies in the kHz range appear to be safe. In this paper we provide structured interviews and recommend their use in future controlled studies, in particular when trying to extend the parameters applied. We also discuss recent regulatory issues, reporting practices and ethical issues. These recommendations achieved consensus in a meeting, which took place in Göttingen, Germany, on September 6-7, 2016 and were refined thereafter by email correspondence.