Noninvasive brain stimulation: the potential for use in the rehabilitation of pediatric acquired brain injury

Pairing transcutaneous vagus nerve stimulation with an intensive bimanual training in children and adolescents with cerebral palsy: study protocol of a randomized sham-controlled trial

Background

Gross motor function impairments and manual dexterity deficits are frequently observed in children and adolescents with Cerebral Palsy (CP), having a major impact on their activity level and autonomy. Improving manual dexterity and activity level of patients with CP is often the focus of rehabilitation. Novel and adjuvant treatment methods that could support the standard training also in chronic conditions are a research priority. The transcutaneous Vagus Nerve Stimulation (tVNS) is a non-invasive brain stimulation technique, which provides a bottom-up stimulation of subcortical and cortical brain structures, enhancing brain GABA and Noradrenaline levels. This technique may play a pivotal role in brain plasticity, which has not been tested in CP patients before.

Methods

44 children and adolescents with CP will be involved, treated in pairs in a randomized, double-blind, pre-post test study. The two groups will undergo the Hand-Arm Bimanual Intensive Therapy Including Lower Extremities (HABIT-ILE) for 2 consecutive weeks, with 3 h daily sessions for 5 days per week, for an overall time interval of 30 h; the training will be combined with the application for 75 min/day of active or sham tVNS, in separate, randomly allocated groups. The primary outcome measure will include the scores at the Assisting Hand Assessment and Box and Block Test, and at an ad-hoc visuomotor task evaluating manual visuomotor control. Secondary outcomes will include the scores at the Children's Hand Experience Questionnaire, Canadian Occupational Performance Measure, Melbourne Assessment of Unilateral Upper Limb Function, Gross Motor Function Measure, Vineland, Pediatric quality of life inventory. The evaluation points will include pre (T0), post (T1) and 3-month follow up (T2) assessments. Safety and tolerability will also be assessed.

Results

The results of this trial will assess whether tVNS can effectively boost the effects of an intensive two-week bimanual training, in improving manual dexterity in children and adolescents with cerebral palsy, ensuring safety and tolerability throughout the intervention period.Clinical trial registration: ClinicalTrials.gov, NCT06372028.

Effect of repetitive transcranial magnetic stimulation-assisted training on lower limb motor function in children with hemiplegic cerebral palsy

OBJECTIVE

To explore the effect of repetitive transcranial magnetic stimulation (rTMS)-assisted training on lower limb motor function in children with hemiplegic cerebral palsy (HCP).

METHOD

Thirty-one children with HCP who met the inclusion criteria were selected and randomly divided into a control group (n = 16) and an experimental group (n = 15). The control group received routine rehabilitation treatment for 30 min each time, twice a day, 5 days a week for 4 weeks. Based on the control group, the experimental group received rTMS for 20 min each time, once a day, 5 days a week for 4 weeks. The outcome measures included a 10-metre walk test (10MWT), a 6-minute walk distance (6MWD) test, D- and E-zone gross motor function measurements (GMFM), the symmetry ratio of the step length and stance time and the muscle tone of the triceps surae and the hamstrings (evaluated according to the modified Ashworth scale), which were obtained in both groups of children before and after treatment.

RESULTS

After training, the 10MWT (P < 0.05), 6MWD (P < 0.01), GMFM (P < 0.001) and the symmetry ratio of the step length and stance time of the two groups were significantly improved (P < 0.05), there was more of an improvement in the experimental group compared with the control group. There was no significant change in the muscle tone of the hamstrings between the two groups before and after treatment (P > 0.05). After treatment, the muscle tone of the triceps surae in the experimental group was significantly reduced (P < 0.05), but there was no significant change in the control group (P > 0.05).

CONCLUSION

Repetitive TMS-assisted training can improve lower limb motor function in children with HCP.

Effects of repetitive transcranial magnetic stimulation on motor function and language ability in cerebral palsy: A systematic review and meta-analysis

OBJECTIVE

This review was conducted to assess the quality of the evidence of effectiveness of repetitive transcranial magnetic stimulation (rTMS) in treating motor and language ability of cerebral palsy (CP).

METHOD

Medline, Cochrane library, Web of Science, Embase, PubMed, and CNKI databases were searched up to July 2021 by two independent reviewers. Randomized controlled trials (RCTs) that were published in English and Chinese and met the following criteria were included. The population comprised patients who met the diagnostic criteria for CP. Intervention included the following: comparison about rTMS and sham rTMS or comparison about rTMS combine with other physical therapy and other physical therapy. Outcomes included motor function, as follows: gross motor function measure (GMFM), Gesell Development Diagnosis Scale, fine motor function measure (FMFM), Peabody developmental motor scale, and Modified Ashworth scale. For language ability, sign-significant relation (S-S) was included. Methodological quality was assessed using the Physiotherapy Evidence Database (PEDro) scale.

RESULTS

Finally, 29 studies were included in the meta-analysis. Results of evaluation using the Cochrane Collaborative Network Bias Risk Assessment Scale showed that 19 studies specifically explained randomization, among which two studies described allocation concealment, four studies blinded participants and persons and had low risk of bias, and six studies explained that the assessment of outcome measures was blinded. Significant improvements in motor function were observed. The GMFM of total score was determined by using the random-effect model [I2= 88%; MD = -1.03; 95% CI (-1.35, -0.71); P < 0.0001] and FMFM was determined by using the fixed-effect model [P = 0.40 and I2 = 3%; SMDs = -0.48, 95% CI (-0.65, -0.30); P < 0.01]. For language ability, the language improvement rate was determined using a fixed-effect model [P = 0.88 and I2 = 0%; MD = 0.37, 95% CI (0.23, 0.57); P < 0.01]. According to the PEDro scale, 10 studies had low-quality, four studies had excellent quality, and the other studies had good quality. Using the GRADEpro GDT online tool, we included a total of 31 outcome indicators, as follows: 22 for low quality, seven for moderate quality, and two for very low quality.

CONCLUSION

The rTMS could improve the motor function and language ability of patients with CP. However, rTMS prescriptions varied, and the studies had low sample sizes. Studies using rigorous and standard research designs about prescriptions and large samples are needed to collect sufficient evidence about the effectiveness of using rTMS to treat patients with CP.

Emerging Treatments for Disorders of Consciousness in Paediatric Age

The number of paediatric patients living with a prolonged Disorder of Consciousness (DoC) is growing in high-income countries, thanks to substantial improvement in intensive care. Life expectancy is extending due to the clinical and nursing management achievements of chronic phase needs, including infections. However, long-known pharmacological therapies such as amantadine and zolpidem, as well as novel instrumental approaches using direct current stimulation and, more recently, stem cell transplantation, are applied in the absence of large paediatric clinical trials and rigorous age-balanced and dose-escalated validations. With evidence building up mainly through case reports and observational studies, there is a need for well-designed paediatric clinical trials and specific research on 0-4-year-old children. At such an early age, assessing residual and recovered abilities is most challenging due to the early developmental stage, incompletely learnt motor and cognitive skills, and unreliable communication; treatment options are also less explored in early age. In middle-income countries, the lack of rehabilitation services and professionals focusing on paediatric age hampers the overall good assistance provision. Young and fast-evolving health insurance systems prevent universal access to chronic care in some countries. In low-income countries, rescue networks are often inadequate, and there is a lack of specialised and intensive care, difficulty in providing specific pharmaceuticals, and lower compliance to intensive care hygiene standards. Despite this, paediatric cases with DoC are reported, albeit in fewer numbers than in countries with better-resourced healthcare systems. For patients with a poor prospect of recovery, withdrawal of care is inhomogeneous across countries and still heavily conditioned by treatment costs as well as ethical and cultural factors, rather than reliant on protocols for assessment and standardised treatments. In summary, there is a strong call for multicentric, international, and global health initiatives on DoC to devote resources to the paediatric age, as there is now scope for funders to invest in themes specific to DoC affecting the early years of the life course.

The effect of combined transcranial pulsed current stimulation and transcutaneous electrical nerve stimulation on lower limb spasticity in children with spastic cerebral palsy: a randomized and controlled clinical study

BACKGROUND

In the current study, we applied a combination of non-invasive neuromodulation modalities concurrently with multiple stimulating electrodes. Specifically, we used transcranial pulsed current stimulation (tPCS) and transcutaneous electrical nerve stimulation (TENS) as a novel strategy for improving lower limb spasticity in children with spastic cerebral palsy (SCP) categorized on levels III-V of the Gross Motor Function Classification System (GMFCS) with minimal side effects.

METHODS

Sixty-three SCP children aged 2-12 years, who were classified on levels III-V of the GMFCS were randomly assigned to one of two groups, resulting in 32 children in the experimental group and 31 children in the control group. The experimental group underwent a combination therapy of tPCS (400 Hz, 1 mA cerebello-cerebral stimulation) and TENS (400 Hz, max 10 mA) for 30 min, followed by 30 min of physiotherapy five times per week for 12 weeks. The control group underwent physiotherapy only 30 mins per day five times per week for 12 weeks. In total, all groups underwent 60 treatment sessions. The primary outcome measures were the Modified Ashworth Scale (MAS) and Modified Tardieu Scale (MTS). Evaluations were performed 3 days before and after treatment.

RESULTS

We found a significant improvement in MAS and MTS scores of the lower limbs in the experimental group compared to the control group in the hip adductors (Left: p = 0.002; Right: p = 0.002), hamstrings (Left: p = 0.001; Right: p < 0.001, and gastrocnemius (Left: p = 0.001; Right: p = 0.000). Moreover, MTS scores of R1, R2 and R2-R1 in left and right hip adduction, knee joint, and ankle joint all showed significant improvements (p ≤ 0.05). Analysis of MAS and MTS scores compared to baseline scores showed significant improvements in the experimental group but declines in the control group.

CONCLUSION

These results are among the first to demonstrate that a combination of tPCS and TENS can significantly improve lower limb spasticity in SCP children classified on GMFCS levels III-V with minimal side effects, presenting a novel strategy for addressing spasticity challenges in children with severe SCP.

TRIAL REGISTRATION

ChiCTR.org, ChiCTR1800020283, Registration: 22 December 2018 (URL: http://www.chictr.org.cn/showproj.aspx?proj=33953 ).

From adults to pediatrics: A review noninvasive brain stimulation (NIBS) to facilitate recovery from brain injury

Stroke is a major problem worldwide that impacts over 100 million adults and children annually. Rehabilitation therapy is the current standard of care to restore functional impairments post-stroke, however its effects are limited and many patients suffer persisting functional impairments and life-long disability. Noninvasive Brain Stimulation (NIBS) has emerged as a potential rehabilitation treatment option in both adults and children with brain injury. In the last decade, Transcranial Magnetic Stimulation (TMS), Transcranial Direct Current Stimulation (tDCS) and Transcutaneous Auricular Vagus Nerve Stimulation (taVNS) have been investigated to improve motor recovery in adults post-stroke. These promising adult findings using NIBS, however, have yet to be widely translated to the area of pediatrics. The limited studies exploring NIBS in children have demonstrated safety, feasibility, and utility of stimulation-augmented rehabilitation. This chapter will describe the mechanism of NIBS therapy (cortical excitability, neuroplasticity) that underlies its use in stroke and motor function and how TMS, tDCS, and taVNS are applied in adult stroke treatment paradigms. We will then discuss the current state of NIBS in early pediatric brain injury and will provide insight regarding practical considerations and future applications of NIBS in pediatrics to make this promising treatment option a viable therapy in children.

Effect of Anodal Transcranial Direct Current Stimulation Combined With Cognitive Training for Improving Cognition and Language Among Children With Cerebral Palsy With Cognitive Impairment: A Pilot, Randomized, Controlled, Double-Blind, and Clinical Trial

About 30-45% of cerebral palsy (CP) patients have cognitive impairment. Previous studies showed the evidence that transcranial direct current stimulation (tDCS) may have some benefits in attention-deficit/hyperactivity disorder, autism spectrum disorder, and motor development in CP. The aim of this study is to evaluate the effect of tDCS on cognition, language, and activities of daily living (ADL) among children with CP with cognitive impairment. It was a pilot, randomized, controlled, double-blind, clinical trial in a tertiary pediatric hospital, and 13 children with CP and a cognitive age under 42 months were enrolled. tDCS group (n = 8) had active tDCS and cognitive training (20 min/session, total 20 sessions, for 12 weeks) and sham group (n = 5) had sham tDCS and cognitive training. Primary outcome was the Bayley Scales of Infant Development II (BSID II). Secondary outcomes were the Pediatric Evaluation of Disability Inventory (PEDI), the Laboratory Temperament Assessment Battery (Lab-TAB), the Early Childhood Behavior Questionnaire (ECBQ), the Korean version of MacArthur-Bates Communicative Development Inventories (M-B CDI-K), the Sequenced Language Scale for Infants (SELSI) and the Preschool Receptive-Expressive Language Scale (PRES). After intervention, the tDCS group showed significant improvements in all measurements (p < 0.05) except the M-B CDI-K (grammar), whereas the sham group only showed significant improvements in the Lab-TAB (manipulation domain), the ECBQ (attentional shifting), and the M-B CDI-K (comprehension). The between-group differences in the degree of post-intervention improvement were not statistically significant. The degree of improvement was associated with better baseline cognitive function and younger age (p < 0.05). There were no major adverse events after tDCS. The combined application of tDCS and cognitive training was feasible and associated with improvements in cognitive function, ADL, and language among children with CP with cognitive impairment. However, considering that it is a pilot study, further larger-scale systematic investigation is needed. Clinical Trial Registration: The trial was registered in the Clinical Research Information Service database, identifier: KCT0003023.

Effect of Transcranial Direct Current Stimulation Combined With Xbox-Kinect Game Experience on Upper Limb Movement in Down Syndrome: A Case Report

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique used to enhance local synaptic efficacy and modulate the electrical activity of the cortex in neurological disorders. Researchers have sought to combine this type of stimulation with well-established therapeutic modalities, such as motor training involving Xbox Kinect games, which has demonstrated promising results. Thus, this study aimed to determine whether tDCS can enhance upper limb motor training in an eight-year-old child with Down Syndrome (DS) (cognitive age: five years, based on the Wechsler Intelligence Scale for Children). The evaluations consisted of three-dimensional analysis of upper limb kinematics during a reaching task performed before, after10 session, and one month after the intervention. The intervention protocol involved 1 20-min sessions of tDCS over the primary motor cortex at an intensity of 1 mA during Xbox Kinect game training involving an upper limb motor task. The analysis of the kinematic data revealed that in the pre-intervention evaluation, the dominant limb executed the task slowly and over a long path. These aspects improved at the post-intervention and follow-up evaluations, as demonstrated by the shorter total movement duration (3.05 vs. 1.58 vs. 1.52 s, respectively). Similar changes occurred with the non-dominant upper limb; a significant increase in movement velocity at the post-intervention and follow-up evaluations was observed (0.53 vs. 0.54 vs. 0.85 m/s, respectively). The present case report offers preliminary data from a protocol study, and the results confirm the notion that anodal tDCS combined with upper limb motor training leads to improvements in different kinematic variables.

Pediatric Stroke: Unique Implications of the Immature Brain on Injury and Recovery

Pediatric stroke causes significant morbidity for children resulting in lifelong neurological disability. Although hyperacute recanalization therapies are available for pediatric patients, most patients are ineligible for these treatments. Therefore the mainstay for pediatric stroke treatment relies on rehabilitation to improve outcomes. Little is known about the ideal rehabilitation therapies for pediatric patients with stroke and the unique interplay between the developing brain and our models of stroke recovery. In this review, we first discuss the consequences of pediatric stroke. Second, we examine the scientific evidence that exists between the mechanisms of recovery and how they are different in the pediatric developing brain. Finally, we evaluate potential interventions that could improve outcomes.

Single-arm, open-label, dose escalation phase I study to evaluate the safety and feasibility of transcranial direct current stimulation with electroencephalography biomarkers in paediatric disorders of consciousness: a study protocol

INTRODUCTION

Children with disorders of consciousness (DOC) represent the highest end of the acquired brain injury (ABI) severity spectrum for survivors and experience a multitude of functional impairments. Current clinical management in DOC uses behavioural evaluation measures and interventions that fail to (1) describe the physiological consequences of ABI and (2) elicit functional gains. In paediatric DOC, there is a critical need to develop evidence-based interventions to promote recovery of basic responses to improve rehabilitation and aid decision-making for medical teams and caregivers. The purpose of this investigation is to examine the safety, tolerability and feasibility of transcranial direct current stimulation (tDCS) in children with DOC.

METHODS AND ANALYSIS

This study is an open-label dose escalation trial evaluating the safety, tolerability and feasibility of tDCS in 10 children (5-17 years) receiving inpatient rehabilitation for DOC. This study will follow a modified rule-based design, allowing for intrapatient escalation, where a cohort of patients will be assigned to an initial tDCS current of 0.5 or 1 mA based on participant's head circumference and according to the safety data available in other paediatric populations. The subsequent assignment of increased current (1 or 2 mA) according to the prespecified rules will be based on the clinical observation of adverse events in the patients. The study will include up to three, 20 min sessions of anodal tDCS (sham, 0.5 or 1 mA, 1 or 2 mA) applied over the dorsolateral prefrontal cortex. The primary outcomes are adverse events, pain associated with tDCS and intolerable disruption of inpatient care. Secondary outcomes are changes in electroencephalography (EEG) phase-locking and event-related potential components and the Coma Recovery Scale-Revised total score from prestimulation to poststimulation.

ETHICS AND DISSEMINATION

The Johns Hopkins IRB (#IRB00174966) approved this study. Trial results will be disseminated through journals and conferences.

REGISTRATION NUMBER

NCT03618849.

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.

High-Density Electroencephalographic Recordings During Sleep in Children and Adolescents With Acquired Brain Injury

BACKGROUND

Acquired brain injuries (ABI) such as traumatic brain injury (TBI) or stroke can result in motor, language, or cognitive impairments. Although a considerable number of studies have investigated functional recovery, underlying brain reorganization remains poorly understood. Accumulating evidence indicates that plastic processes in the brain are linked to changes in electroencephalographic (EEG) slow wave activity (SWA) during deep sleep (EEG spectral power 1-4.5 Hz).

OBJECTIVE

We investigated sleep SWA in children and adolescents with ABI.

METHODS

We used high-density EEG (128 electrodes) to record sleep in 22 young patients with ABI (age range = 4-16 years). We compared patients to 52 previously measured typically developing children and adolescents (age range = 4-16 years).

RESULTS

The pattern of alterations in SWA differed between particular patient groups. In patients with bilateral stroke, SWA was globally reduced across the entire scalp. Patients with unilateral stroke showed a local reduction in SWA over lesion areas and an increase over perilesional and contralateral brain areas. In patients with severe TBI, we found a reduction in SWA over the midline and an increase over lateral brain areas. We found no consistent pattern in patients with mild to moderate TBI.

CONCLUSIONS

Sleep SWA seems to be a sensitive measure to assess individual alterations in neural activity after ABI. Deviations from age norms might indirectly indicate plastic processes that have occurred since injury. Improving our understanding of neural activity after ABI could optimize clinical prognosis and guide the development of novel therapeutic interventions.

Direct-current Stimulation and Multi-electrode Array Recording of Seizure-like Activity in Mice Brain Slice Preparation

Cathodal transcranial direct-current stimulation (tDCS) induces suppressive effects on drug-resistant seizures. To perform effective actions, the stimulation parameters (e.g., orientation, field strength, and stimulation duration) need to be examined in mice brain slice preparations. Testing and arranging the orientation of the electrode relative to the position of the mice brain slice are feasible. The present method preserves the thalamocingulate pathway to evaluate the effect of DCS on anterior cingulate cortex seizure-like activities. The results of the multichannel array recordings indicated that cathodal DCS significantly decreased the amplitude of the stimulation-evoked responses and duration of 4-aminopyridine and bicuculline-induced seizure-like activity. This study also found that cathodal DCS applications at 15 min caused long-term depression in the thalamocingulate pathway. The present study investigates the effects of DCS on thalamocingulate synaptic plasticity and acute seizure-like activities. The current procedure can test the optimal stimulation parameters including orientation, field strength, and stimulation duration in an in vitro mouse model. Also, the method can evaluate the effects of DCS on cortical seizure-like activities at both the cellular and network levels.

Transcranial direct current stimulation in children and adolescents: a comprehensive review

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation method that has shown promising results in various neuropsychiatric disorders in adults. This review addresses the therapeutic use of tDCS in children and adolescents including safety, ethical, and legal considerations. There are several studies addressing the dosage of tDCS in children and adolescents by computational modeling of electric fields in the pediatric brain. Results suggest halving the amperage used in adults to obtain the same peak electric fields, however, there are some studies reporting on the safe application of tDCS with standard adult parameters in children (2 mA; 20-30 min). There are several randomized placebo controlled trials suggesting beneficial effects of tDCS for the treatment of cerebral palsy. For dystonia there are mixed data. Some studies suggest efficacy of tDCS for the treatment of refractory epilepsy, and for the improvement of attention deficit/hyperactivity disorder and autism. Interestingly, there is a lack of data for the treatment of childhood and adolescent psychiatric disorders, i.e., childhood onset schizophrenia and affective disorders. Overall, tDCS seems to be safe in pediatric population. More studies are needed to confirm the preliminary encouraging results; however, ethical deliberation has to be weighed carefully for every single case.

Paediatric arterial ischemic stroke: acute management, recent advances and remaining issues

Stroke is a rare disease in childhood with an estimated incidence of 1-6/100.000. It has an increasingly recognised impact on child mortality along with its outcomes and effects on quality of life of patients and their families. Clinical presentation and risk factors of paediatric stroke are different to those of adults therefore it can be considered as an independent nosological entity. The relative rarity, the age-related peculiarities and the variety of manifested symptoms makes the diagnosis of paediatric stroke extremely difficult and often delayed. History and clinical examination should investigate underlying diseases or predisposing factors and should take into account the potential territoriality of neurological deficits and the spectrum of differential diagnosis of acute neurological accidents in childhood. Neuroimaging (in particular diffusion weighted magnetic resonance) is the keystone for diagnosis of paediatric stroke and other investigations might be considered according to the clinical condition. Despite substantial advances in paediatric stroke research and clinical care, many unanswered questions remain concerning both its acute treatment and its secondary prevention and rehabilitation so that treatment recommendations are mainly extrapolated from studies on adult population. We have tried to summarize the pathophysiological and clinical characteristics of arterial ischemic stroke in children and the most recent international guidelines and practical directions on how to recognise and manage it in paediatric emergency.