Clinical effectiveness of repetitive transcranial magnetic stimulation treatment in children and adolescents with neurodevelopmental disorders: A systematic review

Effects of repetitive transcranial magnetic stimulation in children and young people with psychiatric disorders: a systematic review

Repetitive transcranial magnetic stimulation (rTMS) has demonstrated benefits in adults with psychiatric disorders, but its clinical utility in children and young people (CYP) is unclear. This PRISMA systematic review used published and ongoing studies to examine the effects of rTMS on disorder-specific symptoms, mood and neurocognition in CYP with psychiatric disorders. We searched Medline via PubMed, Embase, PsychINFO via OVID, and Clinicaltrials.gov up to July 2023. Eligible studies involved multiple-session (i.e., treatment) rTMS in CYP (≤ 25 years-old) with psychiatric disorders. Two independent raters assessed the eligibility of studies and extracted data using a custom-built form. Out of 78 eligible studies (participant N = 1389), the majority (k = 54; 69%) reported an improvement in at least one outcome measure of disorder-specific core symptoms. Some studies (k = 21) examined rTMS effects on mood or neurocognition,: findings were largely positive. Overall, rTMS was well-tolerated with minimal side-effects. Of 17 ongoing or recently completed studies, many are sham-controlled RCTs with better blinding techniques and a larger estimated participant enrolment. Findings provide encouraging evidence for rTMS-related improvements in disorder-specific symptoms in CYP with different psychiatric disorders. However, in terms of both mood (for conditions other than depression) and neurocognitive outcomes, evidence is limited. Importantly, rTMS is well-tolerated and safe. Ongoing studies appear to be of improved methodological quality; however, future studies should broaden outcome measures to more comprehensively assess the effects of rTMS and develop guidance on dosage (i.e., treatment regimens).

A Case Series of Intermittent Theta Burst Stimulation Treatment for Depressive Symptoms in Individuals with Autistic Spectrum Disorder: Real World TMS Study in the Tokyo Metropolitan Area

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by deficits in social communication and the presence of restricted interests and repetitive behaviors. While the symptoms of ASD are present from early childhood, there has been an increase in the number of adults with ASD in recent years who visit healthcare professionals to seek the treatment of depression due to maladjustment resulting from the core symptoms and are eventually diagnosed with ASD. Currently, no treatment is available for the core symptoms of ASD, and pharmacotherapy and psychotherapy are often provided mainly for secondary disorders such as depression and anxiety. However, the effectiveness of these therapies is often limited in individuals with ASD compared to those with major depression. In this context, neuromodulation therapies such as transcranial magnetic stimulation (TMS) have gained increasing attention as potential treatments. In this case series, we retrospectively analyzed 18 cases with ASD from the TMS registry data who had failed to improve depressive symptoms with pharmacotherapy and were treated with intermittent theta burst stimulation (iTBS) therapy to the left dorsolateral prefrontal cortex (DLPFC). We also explored the relationship between treatment efficacy and clinical epidemiological profile. Our results indicated that, despite the limitations of an open-label preliminary case series, TMS therapy in the form of iTBS may have some beneficial therapeutic effects on depressive symptoms in individuals with ASD. The present findings warrant further validation through randomized, sham-controlled trials with larger sample sizes.

Non-pharmacological treatments for pediatric refractory epilepsies

INTRODUCTION

Antiseizure medications (ASMs) are the primary treatment option for epilepsies of wide etiologies, however, about 10-20% of children do not gain sustained seizure control and in this case, it is worth investigating "alternative" therapeutic approaches aside from ASMs. Nowadays, non-pharmacological strategies for epilepsy treatment encompass dietary interventions, neurostimulation-based techniques, and biobehavioral approaches.

AREAS COVERED

A search on PubMed database was conducted. Experimental and clinical studies, as well as meta-analysis and structured reviews on the latest non-pharmacological treatments for drug-resistant epilepsy (DRE) in children, were included. Special attention is given to the efficacy and tolerability outcomes, trying to infer the role novel approaches may have in the future.

EXPERT OPINION

The large heterogeneity of primary clinical outcomes and the unavoidable subjective response of each patient to treatments prevents Researchers from the identification of a single, reliable, approach to treat DRE. The understanding of fine pathophysiologic processes is giving the way to the use of alternative therapies, such as the well-known ketogenic diet, in a "personalized" view of treatment. The goal is to apply the non-pharmacological treatment most suitable for the patient's sake.

The Sensory Abnormality Mediated Partially the Efficacy of Repetitive Transcranial Magnetic Stimulation on Treating Comorbid Sleep Disorder in Autism Spectrum Disorder Children

Sleep disorder emerges as a common comorbidity in children with autism spectrum disorder (ASD), and the interaction between the core symptoms of ASD and its sleep disorder remains unclear. Repetitive transcranial magnetic stimulation (rTMS) was used on the bilateral dorsolateral prefrontal cortex (DLPFC) to investigate the efficacy of rTMS on the core symptoms of ASD and comorbid sleep problems as well as the mediation role of the ASD symptoms between rTMS intervention and sleep improvement. A total of 41 Chinese children with ASD and who met the criteria in the fifth edition of the American Diagnostic and Statistical Manual of Mental Disorders were recruited, and 39 of them (mean age: 9.0 ± 4.4 years old; the male-female ratio was 3.9: 1) completed the study with the stimulating protocol of high frequency on the left DLPFC and low frequency on the right DLPFC. They were all assessed three times (before, at 4 weeks after, and at 8 weeks after the stimulation) by the Children's Sleep Habits Questionnaire (CSHQ), Strengths and Difficulties Questionnaire (SDQ), Childhood Autism Rating Scale, Repetitive Behavior Questionnaire-2, and Short Sensory Profile (SSP). The repeated-measures ANOVA showed that the main effect of "intervention time" of CSHQ (F = 25.103, P < 0.001), SSP (F = 6.345, P = 0.003), and SDQ (F = 9.975, P < 0.001) was statistically significant. By Bayesian mediation analysis, we only found that the total score of SSP mediated the treating efficacy of rTMS on CSHQ (αβ = 5.11 ± 1.51, 95% CI: 2.50-8.41). The percentage of mediation effect in total effect was 37.94%. Our results indicated the treating efficacy of rTMS modulation on bilateral DLPFC for both autistic symptoms and sleep disturbances. The sensory abnormality of ASD mediated the improvement of rTMS on sleep problems of ASD.

In vivo imaging of dopamine D1 receptor and activated microglia in attention-deficit/hyperactivity disorder: a positron emission tomography study

Alterations in the cortical dopamine system and microglial activation have been implicated in the pathophysiology of attention-deficit/hyperactivity disorder (ADHD), one of neurodevelopmental disorders that can be conventionally treated with a dopamine enhancer (methylphenidate) albeit unsatisfactorily. Here, we investigated the contributions of the dopamine D1 receptor (D1R) and activated microglia and their interactions to the clinical severities in ADHD individuals using positron emission tomography (PET). Twenty-four psychotropic-naïve ADHD individuals and 24 age- and sex-matched typically developing (TD) subjects underwent PET measurements with [¹¹C]SCH23390 for the D1R and [¹¹C](R)PK11195 for activated microglia as well as assessments of clinical symptoms and cognitive functions. The ADHD individuals showed decreased D1R in the anterior cingulate cortex (ACC) and increased activated microglia in the dorsolateral prefrontal cortex (DLPFC) and orbitofrontal cortex (OFC) compared with the TD subjects. The decreased D1R in the ACC was associated with severe hyperactivity in the participants with ADHD. Microglial activation in the DLPFC were associated with deficits in processing speed and attentional ability, and that in the OFC was correlated with lower processing speed in the ADHD individuals. Furthermore, positive correlations between the D1R and activated microglia in both the DLPFC and the OFC were found to be significantly specific to the ADHD group and not to the TD group. The current findings suggest that microglial activation and the D1R reduction as well as their aberrant interactions underpin the neurophysiological mechanism of ADHD and indicate these biomolecular changes as a novel therapeutic target.

Transcranial direct current stimulation in Autism Spectrum Disorder: A systematic review and meta-analysis

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that has gained relevance in recent years as an alternative treatment for neuropsychiatric conditions. The aim of this study is to conduct a systematic review of the use of tDCS in Autism Spectrum Disorder (ASD). Both electronic and manual searches were conducted to identify studies published in peer-reviewed scientific journals addressing the use of tDCS in ASD population. A total of 16 studies fulfilled the criteria to be included in the review. Studies were conducted both in child and adult population. Anodal stimulation on the left dorsolateral prefrontal cortex was the most commonly chosen methodology. Outcomes addressed ASD symptoms and neuropsychological functions. Meta-analytic synthesis identified improvements in social, health, and behavioral problem domains of the Autism Treatment Evaluation Checklist. Limitations included high heterogeneity in the methodology and low-efficacy study designs (pre-post and single-case studies). Recent controlled trials shed promising results for the use of tDCS in ASD. A standardized stimulation protocol and a consensus in the measures used in the evaluation of the efficacy are imperative.

Effects of non-invasive brain stimulation in children and young people with psychiatric disorders: a protocol for a systematic review

BACKGROUND

Most psychiatric disorders have their onset in childhood or adolescence, and if not fully treated have the potential for causing life-long psycho-social and physical sequelae. Effective psychotherapeutic and medication treatments exist, but a significant proportion of children and young people do not make a full recovery. Thus, novel, safe, brain-based alternatives or adjuncts to conventional treatments are needed. Repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) are non-invasive brain stimulation (NIBS) techniques which have shown clinical benefits in adult psychiatric conditions. However, in children and young people their efficacy is not well established. The objective of this study will be to systematically evaluate the evidence on clinical effects of NIBS in children and young people with psychiatric disorders, assessing disorder-specific symptoms, mood and neurocognitive functions.

METHODS

We designed and registered a study protocol for a systematic review. We will include randomised and non-randomised controlled trials and observational studies (e.g. cohort, case-control, case series) assessing the effects of NIBS in children and young people (aged ≤ 24 years old) for psychiatric disorders. The primary outcome will be reduction of disorder-specific symptoms. Secondary outcomes will include effects on mood and cognition. A comprehensive search from database inception onwards will be conducted in MEDLINE, EMBASE and PsycINFO. Grey literature will be identified through searching multiple clinical trial registries. Two reviewers will independently screen all citations, full-text articles and abstract data. The methodological quality of the studies will be appraised using appropriate tools. We will provide a narrative synthesis of the evidence and according to heterogeneity will conduct an appropriate meta-analysis. Additional analyses will be conducted to explore the potential sources of heterogeneity.

DISCUSSION

This systematic review will provide a broad and comprehensive evaluation of the evidence on clinical effects of NIBS in children and young people with psychiatric disorders. Our findings will be reported according to the PRISMA guidelines and will be of interest to multiple audiences (including patients, researchers, healthcare professionals and policy-makers). Results will be published in a peer-reviewed journal.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019158957.

Transcranial Magnetic Stimulation in Autism Spectrum Disorders: Neuropathological Underpinnings and Clinical Correlations

Despite growing knowledge about autism spectrum disorder (ASD), research findings have not been translated into curative treatment. At present, most therapeutic interventions provide for symptomatic treatment. Outcomes of interventions are judged by subjective endpoints (eg, behavioral assessments) which alongside the highly heterogeneous nature of ASD account for wide variability in the effectiveness of treatments. Transcranial magnetic stimulation (TMS) is one of the first treatments that targets a putative core pathologic feature of autism, specifically the cortical inhibitory imbalance that alters gamma frequency synchronization. Studies show that low frequency TMS over the dorsolateral prefrontal cortex of individuals with ASD decreases the power of gamma activity and increases the difference between gamma responses to target and nontarget stimuli. TMS improves executive function skills related to self-monitoring behaviors and the ability to apply corrective actions. These improvements manifest themselves as a reduction of stimulus bound behaviors and diminished sympathetic arousal. Results become more significant with increasing number of sessions and bear synergism when used along with neurofeedback. When applied at low frequencies in individuals with ASD, TMS appears to be safe and to improve multiple patient-oriented outcomes. Future studies should be conducted in large populations to establish predictors of outcomes (eg, genetic profiling), length of persistence of benefits, and utility of booster sessions.

Translational Neuroscience in Autism: From Neuropathology to Transcranial Magnetic Stimulation Therapies

The presence of heterotopias, increased regional density of neurons at the gray-white matter junction, and focal cortical dysplasias all suggest an abnormality of neuronal migration in autism spectrum disorder (ASD). The abnormality is borne from a dissonance in timing between radial and tangentially migrating neuroblasts to the developing cortical plate. The uncoupling of excitatory and inhibitory cortical cells disturbs the coordinated interactions of neurons within local networks, thus providing abnormal patterns of brainwave activity in the gamma bandwidth. In ASD, gamma oscillation abnormalities and autonomic markers offer measures of therapeutic progress and help in the identification of subgroups.

Transcranial Direct Current Stimulation in ADHD: A Systematic Review of Efficacy, Safety, and Protocol-induced Electrical Field Modeling Results

Transcranial direct current stimulation (tDCS) is a promising method for altering cortical excitability with clinical implications. It has been increasingly used in neurodevelopmental disorders, especially attention-deficit hyperactivity disorder (ADHD), but its efficacy (based on effect size calculations), safety, and stimulation parameters have not been systematically examined. In this systematic review, we aimed to (1) explore the effectiveness of tDCS on the clinical symptoms and neuropsychological deficits of ADHD patients, (2) evaluate the safety of tDCS application, especially in children with ADHD, (3) model the electrical field intensity in the target regions based on the commonly-applied and effective versus less-effective protocols, and (4) discuss and propose advanced tDCS parameters. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses approach, a literature search identified 14 empirical experiments investigating tDCS effects in ADHD. Partial improving effects of tDCS on cognitive deficits (response inhibition, working memory, attention, and cognitive flexibility) or clinical symptoms (e.g., impulsivity and inattention) are reported in 10 studies. No serious adverse effects are reported in 747 sessions of tDCS. The left and right dorsolateral prefrontal cortex are the regions most often targeted, and anodal tDCS the protocol most often applied. An intensity of 2 mA induced stronger electrical fields than 1 mA in adults with ADHD and was associated with significant behavioral changes. In ADHD children, however, the electrical field induced by 1 mA, which is likely larger than the electrical field induced by 1 mA in adults due to the smaller head size of children, was sufficient to result in significant behavioral change. Overall, tDCS seems to be a promising method for improving ADHD deficits. However, the clinical utility of tDCS in ADHD cannot yet be concluded and requires further systematic investigation in larger sample sizes. Cortical regions involved in ADHD pathophysiology, stimulation parameters (e.g. intensity, duration, polarity, and electrode size), and types of symptom/deficit are potential determinants of tDCS efficacy in ADHD. Developmental aspects of tDCS in childhood ADHD should be considered as well.

Motor cortex excitability and inhibitory imbalance in autism spectrum disorder assessed with transcranial magnetic stimulation: a systematic review

Cortical excitation/inhibition (E/I) imbalances contribute to various clinical symptoms observed in autism spectrum disorder (ASD). However, the detailed pathophysiologic underpinning of E/I imbalance remains uncertain. Transcranial magnetic stimulation (TMS) motor-evoked potentials (MEP) are a non-invasive tool for examining cortical inhibition in ASD. Here, we conducted a systematic review on TMS neurophysiology in motor cortex (M1) such as MEPs and short-interval intracortical inhibition (SICI) between individuals with ASD and controls. Out of 538 initial records, we identified six articles. Five studies measured MEP, where four studies measured SICI. There were no differences in MEP amplitudes between the two groups, whereas SICI was likely to be reduced in individuals with ASD compared with controls. Notably, SICI largely reflects GABA(A) receptor-mediated function. Conversely, other magnetic resonance spectroscopy and postmortem methodologies assess GABA levels. The present review demonstrated that there may be neurophysiological deficits in GABA receptor-mediated function in ASD. In conclusion, reduced GABAergic function in the neural circuits could underlie the E/I imbalance in ASD, which may be related to the pathophysiology of clinical symptoms of ASD. Therefore, a novel treatment that targets the neural circuits related to GABA(A) receptor-mediated function in regions involved in the pathophysiology of ASD may be promising.