Transcranial magnetic stimulation in child neurology: current and future directions

Management of Children with Speech Disorders via Transcranial Magnetic Stimulation: Non-Randomized Controlled Study

Background. Speech development impairment is urgent and common problem in pediatric neurology. Transcranial magnetic stimulation (TMS) is one of the promising treatment variants for children with speech disorders. Objective. The aim of the study is to evaluate efficacy and safety of the developed approaches to TMS usage in the management of children with speech disorders. Methods. It was non-randomized controlled study. It included 46 children with speech disorders aged from 3 to 6.5 years. All children were divided into two groups comparable by gender and age: 26 children of the treatment group received TMS course, 20 children of the control group received treatment with hopantenic acid. All patients with speech disorders underwent psychological and pedagogical evaluation of speech and cognitive development, electroencephalography (EEG) before and after treatment. Moreover, comparative analysis of TMS and nootropic therapy efficacy was carried out. Specialized examination of speech and cognitive development was also performed via E.A. Strebeleva method for psychological and pedagogical diagnosis of children development. Furthermore, we carried out side reactions / adverse events registration according to patients and/or their parents complaints confirmed by physical examination, patient’s behavior observation, data from specially developed questionnaire for assessing child’s behavior and well-being (filled up by parents). Finally, we evaluated brain bioelectric activity recorded by EEG. Results. The study results have shown that it is possible to achieve significant positive dynamics in cognitive and speech development in preschool children with speech disorders in both groups (TMS course and medical treatment). But hereby, TMS treatment has demonstrated significantly higher positive dynamics in two out of the three evaluated parameters. There were no cases of adverse events in TMS group leading to early course discontinuation. Conclusion. TMS is non-invasive and safe method for treatment of children with speech disorders. This study has demonstrated the efficacy of the method in the field of personalized management of children with impaired speech and cognitive development.

Biomarkers Obtained by Transcranial Magnetic Stimulation in Neurodevelopmental Disorders

SUMMARY

Transcranial magnetic stimulation (TMS) is a method for focal brain stimulation that is based on the principle of electromagnetic induction where small intracranial electric currents are generated by a powerful fluctuating magnetic field. Over the past three decades, TMS has shown promise in the diagnosis, monitoring, and treatment of neurological and psychiatric disorders in adults. However, the use of TMS in children has been more limited. We provide a brief introduction to the TMS technique; common TMS protocols including single-pulse TMS, paired-pulse TMS, paired associative stimulation, and repetitive TMS; and relevant TMS-derived neurophysiological measurements including resting and active motor threshold, cortical silent period, paired-pulse TMS measures of intracortical inhibition and facilitation, and plasticity metrics after repetitive TMS. We then discuss the biomarker applications of TMS in a few representative neurodevelopmental disorders including autism spectrum disorder, fragile X syndrome, attention-deficit hyperactivity disorder, Tourette syndrome, and developmental stuttering.

Thalamic deep brain stimulation modulates cycles of seizure risk in epilepsy

Chronic brain recordings suggest that seizure risk is not uniform, but rather varies systematically relative to daily (circadian) and multiday (multidien) cycles. Here, one human and seven dogs with naturally occurring epilepsy had continuous intracranial EEG (median 298 days) using novel implantable sensing and stimulation devices. Two pet dogs and the human subject received concurrent thalamic deep brain stimulation (DBS) over multiple months. All subjects had circadian and multiday cycles in the rate of interictal epileptiform spikes (IES). There was seizure phase locking to circadian and multiday IES cycles in five and seven out of eight subjects, respectively. Thalamic DBS modified circadian (all 3 subjects) and multiday (analysis limited to the human participant) IES cycles. DBS modified seizure clustering and circadian phase locking in the human subject. Multiscale cycles in brain excitability and seizure risk are features of human and canine epilepsy and are modifiable by thalamic DBS.

Bilateral Motor Responses to Transcranial Magnetic Stimulation in Preterm Children at 9 Years of Age

OBJECTIVE

This study was aimed to evaluate motor tracts integrity in nondisabled preterm-born (PT) children at 9 years of age.

METHODS

Overall, 18 PT and 13 term-born (T) children without motor disability were assessed by transcranial magnetic stimulation (TMS). Motor-evoked potentials (MEPs) were measured bilaterally from the abductor pollicis brevis (APB) and the tibialis anterior (TA) muscles. Muscle responses could be stimulated from all patients.

RESULTS

Overall, 83.3 and 23.1% of PT and T children, respectively, had mild clumsiness (p = 0.001). One PT and three T children had immediate bilateral responses in the upper extremities. Seven PT children had delayed ipsilateral APB responses after left and ten after right TMS. Three controls had delayed ipsilateral responses. Ipsilateral lower extremity responses were seen in one PT after right and two PT children and one T child after left TMS. The results did not correlate to groups, genders, clumsiness, or handedness.

CONCLUSION

Children of PT and T may have bilateral motor responses after TMS at 9 years of age. Ipsilateral conduction emerges immediately or more often slightly delayed and more frequently in upper than in lower extremities.

SIGNIFICANCE

Bilateral motor conduction reflects developmental and neurophysiological variability in children at 9 years of age. MEPs can be used as a measure of corticospinal tract integrity in PT children.

Primary hand motor representation areas in healthy children, preadolescents, adolescents, and adults

The development of the organization of the motor representation areas in children and adolescents is not well-known. This cross-sectional study aimed to provide an understanding for the development of the functional motor areas of the upper extremity muscles by studying healthy right-handed children (6-9 years, n = 10), preadolescents (10-12 years, n = 13), adolescents (15-17 years, n = 12), and adults (22-34 years, n = 12). The optimal representation site and resting motor threshold (rMT) for the abductor pollicis brevis (APB) were assessed in both hemispheres using navigated transcranial magnetic stimulation (nTMS). Motor mapping was performed at 110% of the rMT while recording the EMG of six upper limb muscles in the hand and forearm. The association between the motor map and manual dexterity (box and block test, BBT) was examined. The mapping was well-tolerated and feasible in all but the youngest participant whose rMT exceeded the maximum stimulator output. The centers-of-gravity (CoG) for individual muscles were scattered to the greatest extent in the group of preadolescents and centered and became more focused with age. In preadolescents, the CoGs in the left hemisphere were located more laterally, and they shifted medially with age. The proportion of hand compared to arm representation increased with age (p = 0.001); in the right hemisphere, this was associated with greater fine motor ability. Similarly, there was less overlap between hand and forearm muscles representations in children compared to adults (p<0.001). There was a posterior-anterior shift in the APB hotspot coordinate with age, and the APB coordinate in the left hemisphere exhibited a lateral to medial shift with age from adolescence to adulthood (p = 0.006). Our results contribute to the elucidation of the developmental course in the organization of the motor cortex and its associations with fine motor skills. It was shown that nTMS motor mapping in relaxed muscles is feasible in developmental studies in children older than seven years of age.

Non-invasive therapeutic brain stimulation for treatment of resistant focal epilepsy in a teenager

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rTMS and tDCS could be more often used for treatment-resistant focal epilepsy and tinnitus.

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tDCS can be used as maintenance treatment after initial successful rTMS treatment.

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rTMS and tDCS are safe in adolescents when current safety instructions are followed.

Aims

A 13-year-old boy with symptomatic focal epilepsy due to a right parietal dysembryoplastic neuroepithelial tumor (DNET) presented pre- and post-operatively fluctuating tinnitus and sensory symptoms which became persistent after incomplete tumor resection. He received low-frequency rTMS treatment and cathodal tDCS treatment.

Methods

Case report with clinical details and pictures from rTMS and tDCS stimulation targets.

Results

The patient became symptom free with an initial low-frequency rTMS treatment series targeted to the EEG-verified epileptic zone followed by maintenance therapy at the same region with cathodal tDCS at home.

Conclusions

Both rTMS and tDCS could be more often used in adolescents when drug treatment and surgery do not cease focal epilepsy, here with fluctuating tinnitus.

The Effects of 1 mA tACS and tRNS on Children/Adolescents and Adults: Investigating Age and Sensitivity to Sham Stimulation

The aim of this study was to investigate the effect of transcranial random noise (tRNS) and transcranial alternating current (tACS) stimulation on motor cortex excitability in healthy children and adolescents. Additionally, based on our recent results on the individual response to sham in adults, we explored this effect in the pediatric population. We included 15 children and adolescents (10-16 years) and 28 adults (20-30 years). Participants were stimulated four times with 20 Hz and 140 Hz tACS, tRNS, and sham stimulation (1 mA) for 10 minutes over the left M1_HAND. Single-pulse MEPs (motor evoked potential), short-interval intracortical inhibition, and facilitation were measured by TMS before and after stimulation (baseline, 0, 30, 60 minutes). We also investigated aspects of tolerability. According to the individual MEPs response immediately after sham stimulation compared to baseline (Wilcoxon signed-rank test), subjects were regarded as responders or nonresponders to sham. We did not find a significant age effect. Regardless of age, 140 Hz tACS led to increased excitability. Incidence and intensity of side effects did not differ between age groups or type of stimulation. Analyses on responders and nonresponders to sham stimulation showed effects of 140 Hz, 20 Hz tACS, and tRNS on single-pulse MEPs only for nonresponders. In this study, children and adolescents responded to 1 mA tRNS and tACS comparably to adults regarding the modulation of motor cortex excitability. This study contributes to the findings that noninvasive brain stimulation is well tolerated in children and adolescents including tACS, which has not been studied before. Finally, our study supports a modulating role of sensitivity to sham stimulation on responsiveness to a broader stimulation and age range.

Review of Transcranial Magnetic Stimulation in Epilepsy

PURPOSE

Despite the availability of numerous pharmacologic and nonpharmacologic antiseizure therapies, a fraction of patients with epilepsy remain refractory to current treatment options, underscoring the need for novel drugs and neuromodulatory therapies. Transcranial magnetic stimulation (TMS), coupled with either electromyography or electroencephalography, enables rapid measurement of the cortical excitation/inhibition ratio, which is pathologically shifted toward excess excitability in patients with epilepsy. In this review, we summarize: (1) TMS protocols that have been deployed to identify promising compounds in the antiepilepsy drug (AED)-development pipeline, and (2) the therapeutic potential of TMS in the treatment of drug-resistant seizures.

METHODS

A focused literature review of the use of TMS in epilepsy, using a PubMed search, was performed. Over 70 articles were included that pertained to: (1) the use of TMS-EMG and TMS-EEG in elucidating the mechanisms of action of AEDs and in discovering potential new AEDs; and (2) the use of repetitive TMS in the treatment of seizures.

FINDINGS

Studies from the literature have reported that AEDs alter TMS-derived metrics, typically by leading to a net increase in cortical inhibition with successful therapy. Preclinical TMS work in rodent models of epilepsy has led to the development of novel antiseizure drug compounds. Clinical translational studies of TMS have been used to determine guidelines on the dosages of other agents in the AED pipeline in preparation for clinical trials. Several studies have described the use of therapeutic repetitive TMS in both the ictal and interictal states of epilepsy, with inconsistent results.

IMPLICATIONS

TMS has diagnostic and therapeutic potential in epilepsy. TMS-derived markers can enable early-stage measures of AED target engagement, and can facilitate studies of the pharmacokinetic and pharmacodynamic properties of AEDs. TMS may also be used in the early prediction of the efficacy of different AEDs in treating patients, and in direct neuromodulation of epileptic networks. From the therapeutics perspective, despite favorable results in some trials, the optimization of treatment paradigms and the determination of ideal candidates for TMS are still needed. Finally, preclinical experiments of TMS have provided mechanistic insight into its effects on the excitation/inhibition ratio, and may facilitate rational drug-device coupling paradigms. Overall, the capacity of TMS in both the modulation and measurement of changes in cortical excitability highlights its unique role in advancing antiepilepsy therapeutics.

Continuous Theta-Burst Stimulation in Children With High-Functioning Autism Spectrum Disorder and Typically Developing Children

Objectives: A neurophysiologic biomarker for autism spectrum disorder (ASD) is highly desirable and can improve diagnosis, monitoring, and assessment of therapeutic response among children with ASD. We investigated the utility of continuous theta-burst stimulation (cTBS) applied to the motor cortex (M1) as a biomarker for children and adolescents with high-functioning (HF) ASD compared to their age- and gender-matched typically developing (TD) controls. We also compared the developmental trajectory of long-term depression- (LTD-) like plasticity in the two groups. Finally, we explored the influence of a common brain-derived neurotrophic factor (BDNF) polymorphism on cTBS aftereffects in a subset of the ASD group. Methods: Twenty-nine children and adolescents (age range 10-16) in ASD (n = 11) and TD (n = 18) groups underwent M1 cTBS. Changes in MEP amplitude at 5-60 min post-cTBS and their cumulative measures in each group were calculated. We also assessed the relationship between age and maximum cTBS-induced MEP suppression (ΔMEP_Max) in each group. Finally, we compared cTBS aftereffects in BDNF Val/Val (n = 4) and Val/Met (n = 4) ASD participants. Results: Cumulative cTBS aftereffects were significantly more facilitatory in the ASD group than in the TD group (P _FDR's < 0.03). ΔMEP_Max was negatively correlated with age in the ASD group (r = -0.67, P = 0.025), but not in the TD group (r = -0.12, P = 0.65). Cumulative cTBS aftereffects were not significantly different between the two BDNF subgroups (P-values > 0.18). Conclusions: The results support the utility of cTBS measures of cortical plasticity as a biomarker for children and adolescents with HF-ASD and an aberrant developmental trajectory of LTD-like plasticity in ASD.

Biomarkers Obtained by Transcranial Magnetic Stimulation of the Motor Cortex in Epilepsy

Epilepsy is associated with numerous neurodevelopmental disorders. Transcranial magnetic stimulation (TMS) of the motor cortex coupled with electromyography (EMG) enables biomarkers that provide measures of cortical excitation and inhibition that are particularly relevant to epilepsy and related disorders. The motor threshold (MT), cortical silent period (CSP), short interval intracortical inhibition (SICI), intracortical facilitation (ICF), and long interval intracortical inhibition (LICI) are among TMS-derived metrics that are modulated by antiepileptic drugs. TMS may have a practical role in optimization of antiepileptic medication regimens, as studies demonstrate dose-dependent relationships between TMS metrics and acute medication administration. A close association between seizure freedom and normalization of cortical excitability with long-term antiepileptic drug use highlights a plausible utility of TMS in measures of anti-epileptic drug efficacy. Finally, TMS-derived biomarkers distinguish patients with various epilepsies from healthy controls and thus may enable development of disorder-specific biomarkers and therapies both within and outside of the epilepsy realm.

Safety and Feasibility of Transcranial Magnetic Stimulation as an Exploratory Assessment of Corticospinal Connectivity in Infants After Perinatal Brain Injury: An Observational Study

BACKGROUND

Perinatal brain injuries often impact the corticospinal system, leading to motor impairment and cerebral palsy. Although transcranial magnetic stimulation (TMS) has been widely used to study corticospinal connectivity in adults and older children, similar studies of young infants are limited.

OBJECTIVES

The objective was to establish the safety and feasibility of advanced TMS assessments of the corticospinal connectivity of young infants with perinatal brain injury.

DESIGN

This was a pilot, cross-sectional study of 3- to 12-month-old (corrected age) infants with perinatal stroke or intracranial hemorrhage.

METHODS

Six participants (2 term, 4 preterm) were assessed with stereotactic neuronavigation-guided TMS. Single-pulse TMS was applied to each hemisphere and responses were recorded simultaneously from both upper limbs. During data collection, vital signs and stress responses were measured to assess safety. Developmental motor outcomes were evaluated using the General Movements Assessment and Bayley Scales of Infant and Toddler Development (3rd edition). A clinical diagnosis of cerebral palsy was recorded, if available.

RESULTS

No adverse events occurred during TMS testing. All sessions were well tolerated. Contralateral motor evoked responses were detected in 4 of 6 participants. Both contralateral and ipsilateral responses were observed in 2 of 6 participants.

LIMITATIONS

TMS responses were not obtained in all participants. This could be related to the location of brain injury or developmental stage of the corticospinal system controlling the wrist flexor muscle group from which responses were recorded.

CONCLUSIONS

This study provides a summary of the framework for performing novel TMS assessments in infants with perinatal brain injury. Implementing this approach to measure corticospinal connectivity in hypothesis-driven studies in young infants appears to be justified. Such studies could inform the characterization of corticospinal development and the neural mechanisms driving recovery following early interventions.

Functional and structural asymmetry in primary motor cortex in Asperger syndrome: a navigated TMS and imaging study

Motor functions are frequently impaired in Asperger syndrome (AS). In this study, we examined the motor cortex structure and function using navigated transcranial magnetic stimulation (nTMS) and voxel-based morphometry (VBM) and correlated the results with the box and block test (BBT) of manual dexterity and physical activity in eight boys with AS, aged 8–11 years, and their matched controls. With nTMS, we found less focused cortical representation areas of distinct hand muscles in AS. There was hemispheric asymmetry in the motor maps, silent period duration and active MEP latency in the AS group, but not in controls. Exploratory VBM analysis revealed less gray matter in the left postcentral gyrus, especially in the face area, and less white matter in the precentral area in AS as compared to controls. On the contrary, in the right leg area, subjects with AS displayed an increased density of gray matter. The structural findings of the left hemisphere correlated negatively with BBT score in controls, whereas the structure of the right hemisphere in the AS group correlated positively with motor function as assessed by BBT. These preliminary functional (neurophysiological and behavioral) findings are indicative of asymmetry, and co-existing structural alterations may reflect the motor impairments causing the deteriorations in manual dexterity and other motor functions commonly encountered in children with AS.

Hearing Safety From Single- and Double-Pulse Transcranial Magnetic Stimulation in Children and Young Adults

PURPOSE

Concerns regarding hearing safety have limited the number of studies using transcranial magnetic stimulation (TMS) in children and young adults. The objective of this study was to examine the safety of TMS with regards to hearing in a group of 16 children and young adults (17.3 ± 4.9 years) with and without brain injury.

METHODS

Pure-tone hearing thresholds and distortion-product otoacoustic emissions were measured before and after exposure to single- and paired-pulse TMS (1-2 sessions of 149-446 TMS pulses at a median of 49%-100% maximum stimulator output over a 2.2 hours period).

RESULTS

No mean change in hearing outcomes was noted. In addition, no clinically significant change in hearing threshold was observed in any participant, and participants did not experience a subjective change in hearing after TMS exposure.

CONCLUSIONS

Single- and double-pulse TMS administered within the parameters used in this study, which included hearing protection, can be used in children and young adults without impacting hearing. This study provides further evidence for hearing safety after TMS exposure in children and young adults.

Proceedings of the 2016 annual meeting of the Fetal Alcohol Spectrum Disorders Study Group

The 2016 Fetal Alcohol Spectrum Disorders Study Group (FASDSG) meeting was titled "Rehabilitation in FASD: Potential Interventions and Challenges". During the previous decades, studies with human subjects and animal models have improved much of our understanding of the mechanisms underlying FASD, putting the scientific community in a good position to test hypotheses that can lead to potential therapeutic interventions. During the conference, two keynote speakers addressed potential interventions used in different fields and their applicability to FASD research. The conference also included updates from several government agencies, short presentations by junior and senior investigators that showcased the latest in FASD research, and award presentations. The conference was closed by a talk by Dr. Charles Goodlett, the recipient of the 2016 Henry Rosett award.

Persistent uncrossed corticospinal connections in patients with intractable focal epilepsy

Corticospinal connections may be bilateral at birth, but a predominantly unilateral and crossed pattern develops by the toddler years. Acquired injury can alter the normal development of laterality such that uncrossed corticospinal connections persist, particularly if the injury is early in life and involves the motor system. Whether other developmental insults, such as childhood epilepsy, affect the development of crossed laterality in the motor system is unknown, although this topic has relevance for understanding the broader impact of epilepsy on brain development. Accordingly, in a cohort of children with intractable focal epilepsy, we tested by neuronavigated transcranial magnetic stimulation (nTMS) whether childhood epilepsy is associated with persistent uncrossed corticospinal connections. Specifically, we hypothesized that in contrast to early-life neuroclastic corticospinal tract injury that induces preservation of uncrossed corticospinal connections in the contralesional hemisphere, uncrossed corticospinal connections will be preserved in the epileptic hemisphere where the corticospinal tract is intact, but overstimulated by ongoing seizures and epileptic interictal discharges. Motor cortex mapping was performed by nTMS as part of a clinical presurgical evaluation, and the analysis was limited to patients with radiographically intact motor cortices and corticospinal tracts. Given that foot motor cortex representation is often bilateral, we focused on the lateralization for the tibialis anterior muscle cortical motor representation and its relation to the seizure focus. We demonstrate preserved uncrossed corticospinal connections for the tibialis anterior region of the hemisphere affected by the epilepsy. These findings indicate a pathologically preserved immature motor lateralization in patients with epilepsy and suggest that developmental processes associated with hemispheric lateralization are affected by epilepsy.

Safety of Transcranial Magnetic Stimulation in Children: A Systematic Review of the Literature

BACKGROUND

Data and best practice recommendations for transcranial magnetic stimulation (TMS) use in adults are largely available. Although there are fewer data in pediatric populations and no published guidelines, its practice in children continues to grow.

METHODS

We performed a literature search through PubMed to review all TMS studies from 1985 to 2016 involving children and documented any adverse events. Crude risks were calculated per session.

RESULTS

Following data screening we identified 42 single-pulse and/or paired-pulse TMS studies involving 639 healthy children, 482 children with central nervous system disorders, and 84 children with epilepsy. Adverse events occurred at rates of 3.42%, 5.97%, and 4.55% respective to population and number of sessions. We also report 23 repetitive TMS studies involving 230 central nervous system and 24 children with epilepsy with adverse event rates of 3.78% and 0.0%, respectively. We finally identified three theta-burst stimulation studies involving 90 healthy children, 40 children with central nervous system disorder, and no epileptic children, with adverse event rates of 9.78% and 10.11%, respectively. Three seizures were found to have occurred in central nervous system disorder individuals during repetitive TMS, with a risk of 0.14% per session. There was no significant difference in frequency of adverse events by group (P = 0.988) or modality (P = 0.928).

CONCLUSIONS

Available data suggest that risk from TMS/theta-burst stimulation in children is similar to adults. We recommend that TMS users in this population follow the most recent adult safety guidelines until sufficient data are available for pediatric specific guidelines. We also encourage continued surveillance through surveys and assessments on a session basis.

Transcranial Magnetic and Direct Current Stimulation in Children

Promising results in adult neurologic and psychiatric disorders are driving active research into transcranial brain stimulation techniques, particularly transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS), in childhood and adolescent syndromes. TMS has realistic utility as an experimental tool tested in a range of pediatric neuropathologies such as perinatal stroke, depression, Tourette syndrome, and autism spectrum disorder (ASD). tDCS has also been tested as a treatment for a number of pediatric neurologic conditions, including ASD, attention-deficit/hyperactivity disorder, epilepsy, and cerebral palsy. Here, we complement recent reviews with an update of published TMS and tDCS results in children, and discuss developmental neuroscience considerations that should inform pediatric transcranial stimulation.

Transcranial Magnetic Stimulation as an Additional Diagnostic Tool in Children with Acute Inflammatory Demyelinating Polyneuropathy

CONTEXT

The diagnosis of polyneuropathy may be challenging at the early stages of the disease. Despite electromyography (EMG) efficacy in the establishment of polyneuropathy diagnosis, in some cases, results are dubious and neurophysiologists may implement additional techniques to ensure that conduction is affected.

AIMS

The aim of the study was to evaluate motor-evoked potential (MEP) characteristics in children with acute inflammatory demyelinating polyneuropathy (AIDP).

SETTINGS AND DESIGN

The study was conducted at a pediatric research and clinical center for infectious diseases.

SUBJECTS AND METHODS

Twenty healthy children (7-14 years old) without signs of neurological disorders were enrolled as controls. Thirty-seven patients (8-13 years old) with AIDP were enrolled as the main group. EMG and transcranial magnetic stimulation (TMS) were performed on the 3^rd-7^th days from the onset of the first symptoms.

STATISTICAL ANALYSIS USED

Descriptive statistics and Student's t-test were used. Bonferroni method was applied to implement appropriate corrections for multiple comparisons.

RESULTS

Significant differences between children with AIDP and controls on latencies of both cortical and lumbar MEPs were registered. Cortical MEP shapes were disperse in 100% of the cases and lumbar MEPs were disperse in 57% of the cases.

CONCLUSIONS

Diagnostic TMS on the early stage of the AIDP in children may be implemented as the additional tool. The main finding in this population is lengthening of the latency of cortical and lumbar MEPs. Disperse shape of the lumbar MEPs may be used as the early sign of the acute demyelization.

Paired-Associative Stimulation-Induced Long-term Potentiation-Like Motor Cortex Plasticity in Healthy Adolescents

OBJECTIVE

The objective of this study was to evaluate the feasibility of using paired-associative stimulation (PAS) to study excitatory and inhibitory plasticity in adolescents while examining variables that may moderate plasticity (such as sex and environment).

METHODS

We recruited 34 healthy adolescents (aged 13-19, 13 males, 21 females). To evaluate excitatory plasticity, we compared mean motor-evoked potentials (MEPs) elicited by single-pulse transcranial magnetic stimulation (TMS) before and after PAS at 0, 15, and 30 min. To evaluate inhibitory plasticity, we evaluated the cortical silent period (CSP) elicited by single-pulse TMS in the contracted hand before and after PAS at 0, 15, and 30 min.

RESULTS

All participants completed PAS procedures. No adverse events occurred. PAS was well tolerated. PAS-induced significant increases in the ratio of post-PAS MEP to pre-PAS MEP amplitudes (p < 0.01) at all post-PAS intervals. Neither socioeconomic status nor sex was associated with post-PAS MEP changes. PAS induced significant CSP lengthening in males but not females.

CONCLUSION

PAS is a feasible, safe, and well-tolerated index of adolescent motor cortical plasticity. Gender may influence PAS-induced changes in cortical inhibition. PAS is safe and well tolerated by healthy adolescents and may be a novel tool with which to study adolescent neuroplasticity.

Evidence for reading improvement following tDCS treatment in children and adolescents with Dyslexia

PURPOSE

There is evidence that non-invasive brain stimulation transitorily modulates reading by facilitating the neural pathways underactive in individuals with dyslexia. The study aimed at investigating whether multiple sessions of transcranial direct current stimulation (tDCS) would enhance reading abilities of children and adolescents with dyslexia and whether the effect is long-lasting.

METHODS

Eighteen children and adolescents with dyslexia received three 20-minute sessions a week for 6 weeks (18 sessions) of left anodal/right cathodal tDCS set at 1 mA over parieto-temporal regions combined with a cognitive training. The participants were randomly assigned to the active or the sham treatment; reading tasks (text, high and low frequency words, non-words) were used as outcome measures and collected before treatment, after treatment and one month after the end of treatment. The tolerability of tDCS was evaluated.

RESULTS

The active group showed reduced low frequency word reading errors and non-word reading times. These positive effects were stable even one month after the end of treatment. None reported adverse effects.

CONCLUSIONS

The study shows preliminary evidence of tDCS feasibility and efficacy in improving non-words and low frequency words reading of children and adolescents with dyslexia and it opens new rehabilitative perspectives for the remediation of dyslexia.

A combined study of MEG and pico-Tesla TMS on children with autism disorder

Magnetoencephalographic (MEG) recordings from the brain of 10 children with autism (6 boys and 4 girls, with ages range from 5-12 years, mean[Formula: see text][Formula: see text][Formula: see text]SD: 8.3[Formula: see text][Formula: see text][Formula: see text]2.1) were obtained using a whole-head 122-channel MEG system in a magnetically shielded room of low magnetic noise. A double-blind experimental design was used in order to look for possible effect of external pico-Tesla Transcranial Magnetic Stimulation (pT-TMS). The pT-TMS was applied on the brain of the autistic children with proper field characteristics (magnetic field amplitude: 1-7.5[Formula: see text]pT, frequency: the alpha - rhythm of the patient 8-13[Formula: see text]Hz). After unblinding it was found a significant effect of an increase of frequencies in the range of 2-7[Formula: see text]Hz across the subjects followed by an improvement and normalization of their MEG recordings. The statistical analysis of our results showed a statistical significance at 6 out of 10 patients (60%). It is also observed an increase of alpha activity in autistic children at the end of one month after pT-TMS treatment at home. In conclusion, the application of pT-TMS has the prospective to be a noninvasive, safe and important modality in the management of autism children.

Seizure Induced by Deep Transcranial Magnetic Stimulation in an Adolescent with Depression

OBJECTIVE

Deep transcranial magnetic stimulation (TMS) with an H-1 coil was recently approved by the U.S. Food and Drug Administration (U.S. FDA) for treatment-resistant depression (TRD) in adults. Studies assessing the safety and effectiveness of deep TMS in adolescent TRD are lacking. The purpose of this brief report is to provide a case history of an adolescent enrolled in an investigational deep TMS protocol.

METHODS

A case history is described of the first participant of a sham-controlled clinical trial who had a seizure in the course of deep TMS with parameter settings extrapolated from the adult studies that led to US FDA approval (H-1 coil, 120% target stimulation intensity, 18 Hz, 55 trains of 2-second duration, total 1980 pulses).

RESULTS

The participant was a 17-year-old unmedicated female, with no significant medical history and no history of seizures or of drug or alcohol use. Brain magnetic resonance imaging showed no structural abnormalities. She initially received sham, which was well tolerated. During active treatment sessions, titration began at 85% of motor threshold (MT) and increased by 5% per day. Her weekly MT measurements were stable. On her first day of 120% MT (8th active treatment), during the 48th train, the participant had a generalized, tonic-clonic seizure that lasted 90 seconds and resolved spontaneously. She had an emergency medicine evaluation and was discharged home without anticonvulsant medications. There were no further seizures reported at a 6-month follow-up.

CONCLUSIONS

We report a deep TMS-induced generalized tonic-clonic seizure in an adolescent with TRD participating in a clinical trial. Given the demonstrated benefits of deep TMS for adult TRD, research investigating its use in adolescents with TRD is an important area. However, in light of this experience, additional precautions for adolescents should be considered. We propose that further dose-finding investigations are needed to refine adolescent-specific parameters that may be safe and effective for treating adolescents with TRD with deep TMS.

Transcranial magnetic stimulation in the semi-quantitative, pre-operative assessment of patients undergoing spinal deformity surgery

PURPOSE

To compare measurements of motor evoked potential latency stimulated either magnetically (mMEP) or electrically (eMEP) and central motor conduction time (CMCT) made pre-operatively in conscious patients using transcranial and intra-operatively using electrical cortical stimulation before and after successful instrumentation for the treatment of adolescent idiopathic scoliosis.

METHODS

A group initially of 51 patients with adolescent idiopathic scoliosis aged 12-19 years was evaluated pre-operatively in the outpatients' department with transcranial magnetic stimulation. The neurophysiological data were then compared statistically with intra-operative responses elicited by transcranial electrical stimulation both before and after successful surgical intervention. MEPs were measured as the cortically evoked compound action potentials of Abductor hallucis. Minimum F-waves were measured using conventional nerve conduction methods and the lower motor neuron conduction time was calculated and this was subtracted from MEP latency to give CMCT.

RESULTS

Pre-operative testing was well tolerated in our paediatric/adolescent patients. No neurological injury occurred in any patient in this series. There was no significant difference in the values of mMEP and eMEP latencies seen pre-operatively in conscious patients and intra-operatively in patients under anaesthetic. The calculated quantities mCMCT and eCMCT showed the same statistical correlations as the quantities mMEP and eMEP latency.

CONCLUSIONS

The congruency of mMEP and eMEP and of mCMCT and eCMCT suggests that these measurements may be used comparatively and semi-quantitatively for the comparison of pre-, intra-, and post-operative spinal cord function in spinal deformity surgery.

Treatment of dysphasia with rTMS and language therapy after childhood stroke: Multimodal imaging of plastic change

Expressive dysphasia accompanies left inferior frontal gyrus (IFG/Broca) injury. Recovery may relate to interhemispheric balance with homologous, contralesional IFG but is unexplored in children. We evaluated effects of inhibitory rTMS to contralesional IFG combined with intensive speech therapy (SLT). A 15year-old, right-handed male incurred a left middle cerebral artery stroke. After 30months, severe non-fluent dysphasia impacted quality of life. Language networks, neuronal metabolism and white matter pathways were explored using MRI. Language function was measured longitudinally. An intensive SLT program was combined with contralesional inhibitory rTMS of right pars triangularis. Procedures were well tolerated. Language function improved persisting to four months. Post-treatment fMRI demonstrated increased left perilesional IFG activations and connectivity at rest. Bilateral changes in inositol and glutamate metabolism were observed. Contralesional, inhibitory rTMS appears safe in childhood stroke-induced dysphasia. We observed clinically significant improvements after SLT coupled with rTMS. Advanced neuroimaging can evaluate intervention-induced plasticity.

Noninvasive low-frequency electromagnetic stimulation of the left stellate ganglion reduces myocardial infarction-induced ventricular arrhythmia

Noninvasive magnetic stimulation has been widely used in autonomic disorders in the past few decades, but few studies has been done in cardiac diseases. Recently, studies showed that low-frequency electromagnetic field (LF-EMF) might suppress atrial fibrillation by mediating the cardiac autonomic nervous system. In the present study, the effect of LF-EMF stimulation of left stellate ganglion (LSG) on LSG neural activity and ventricular arrhythmia has been studied in an acute myocardium infarction canine model. It is shown that LF-EMF stimulation leads to a reduction both in the neural activity of LSG and in the incidence of ventricular arrhythmia. The obtained results suggested that inhibition of the LSG neural activity might be the causal of the reduction of ventricular arrhythmia since previous studies have shown that LSG hyperactivity may facilitate the incidence of ventricular arrhythmia. LF-EMF stimulation might be a novel noninvasive substitute for the existing implant device-based electrical stimulation or sympathectomy in the treatment of cardiac disorders.

The role of transcranial magnetic stimulation in evaluation of motor cortex excitability in Rett syndrome

Rett syndrome (RTT) is a frequent neurodevelopmental disorder confirmed by clinical criteria and supported by the methyl-CpG-binding protein 2 gene (MECP2) mutation. A short central motor conduction time (CMCT) was reported in transcranial magnetic stimulation (TMS) studies performed in RTT. This was attributed to hyperexcitability of the motor cortex and/or spinal motor neurons, but was not studied further.

AIM

We performed TMS in RTT to evaluate motor cortex excitability by determining the cortical motor threshold (CMT) and motor cortex inhibition by the cortical silent period (CSP) besides measuring CMCT.

METHODS

Single-pulse TMS was performed in 17 Rett patients, diagnosed by clinical criteria and MECP2 mutation testing, and the same number of healthy controls. The outcome measures were compared between RTT groups with different antiepileptic drugs (AED) and those with and without the MECP2 mutation.

RESULTS

CMCT was shorter, but we found elevated CMT and shorter CSP, which suggests decreased excitatory and inhibitory motor cortical function. The outcome was independent of AED and the presence or absence of the MECP2 mutation.

INTERPRETATION

Decreased excitatory and inhibitory motor cortical function could explain the short CMCT, with higher stimulus intensities needed to excite pyramidal neurons.

Noninvasive Brain Stimulation in Pediatric Attention-Deficit Hyperactivity Disorder (ADHD): A Review

Attention-deficit hyperactivity disorder (ADHD) is one of the most prevalent neurodevelopmental disorders in the pediatric population. The clinical management of ADHD is currently limited by a lack of reliable diagnostic biomarkers and inadequate therapy for a minority of patients who do not respond to standard pharmacotherapy. There is optimism that noninvasive brain stimulation may help to address these limitations. Transcranial magnetic stimulation and transcranial direct current stimulation are 2 methods of noninvasive brain stimulation that modulate cortical excitability and brain network activity. Transcranial magnetic stimulation can be used diagnostically to probe cortical neurophysiology, whereas daily use of repetitive transcranial magnetic stimulation or transcranial direct current stimulation can induce long-lasting and potentially therapeutic changes in targeted networks. In this review, we highlight research showing the potential diagnostic and therapeutic applications of transcranial magnetic stimulation and transcranial direct current stimulation in pediatric ADHD. We also discuss the safety and ethics of using these tools in the pediatric population.

Ten minutes of 1 mA transcranial direct current stimulation was well tolerated by children and adolescents: Self-reports and resting state EEG analysis

Transcranial direct current stimulation (tDCS) is a promising and well-tolerated method of non-invasive brain stimulation, by which cortical excitability can be modulated. However, the effects of tDCS on the developing brain are still unknown, and knowledge about its tolerability in children and adolescents is still lacking. Safety and tolerability of tDCS was assessed in children and adolescents by self-reports and spectral characteristics of electroencephalogram (EEG) recordings. Nineteen typically developing children and adolescents aged 11-16 years participated in the study. Anodal and cathodal tDCS as well as sham stimulation were applied for a duration of 10 min over the left primary motor cortex (M1), each with an intensity of 1 mA. Subjects were unable to identify whether they had received active or sham stimulation, and all participants tolerated the stimulation well with a low rate of adverse events in both groups and no serious adverse events. No pathological oscillations, in particular, no markers of epileptiform activity after 1mA tDCS were detected in any of the EEG analyses. In summary, our study demonstrates that tDCS with 1mA intensity over 10 min is well tolerated, and thus may be used as an experimental and treatment method in the pediatric population.

Transcranial magnetic stimulation facilitates neurorehabilitation after pediatric traumatic brain injury

Traumatic brain injury (TBI) is the leading cause of death and disability among children in the United States. Affected children will often suffer from emotional, cognitive and neurological impairments throughout life. In the controlled cortical impact (CCI) animal model of pediatric TBI (postnatal day 16-17) it was demonstrated that injury results in abnormal neuronal hypoactivity in the non-injured primary somatosensory cortex (S1). It materializes that reshaping the abnormal post-injury neuronal activity may provide a suitable strategy to augment rehabilitation. We tested whether high-frequency, non-invasive transcranial magnetic stimulation (TMS) delivered twice a week over a four-week period can rescue the neuronal activity and improve the long-term functional neurophysiological and behavioral outcome in the pediatric CCI model. The results show that TBI rats subjected to TMS therapy showed significant increases in the evoked-fMRI cortical responses (189%), evoked synaptic activity (46%), evoked neuronal firing (200%) and increases expression of cellular markers of neuroplasticity in the non-injured S1 compared to TBI rats that did not receive therapy. Notably, these rats showed less hyperactivity in behavioral tests. These results implicate TMS as a promising approach for reversing the adverse neuronal mechanisms activated post-TBI. Importantly, this intervention could readily be translated to human studies.

Promoting social plasticity in developmental disorders with non-invasive brain stimulation techniques

Being socially connected directly impacts our basic needs and survival. People with deficits in social cognition might exhibit abnormal behaviors and face many challenges in our highly social-dependent world. These challenges and limitations are associated with a substantial economical and subjective impact. As many conditions where social cognition is affected are highly prevalent, more treatments have to be developed. Based on recent research, we review studies where non-invasive neuromodulatory techniques have been used to promote Social Plasticity in developmental disorders. We focused on three populations where non-invasive brain stimulation seems to be a promising approach in inducing social plasticity: Schizophrenia, Autism Spectrum Disorder (ASD) and Williams Syndrome (WS). There are still very few studies directly evaluating the effects of transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS) in the social cognition of these populations. However, when considering the promising preliminary evidences presented in this review and the limited amount of clinical interventions available for treating social cognition deficits in these populations today, it is clear that the social neuroscientist arsenal may profit from non-invasive brain stimulation techniques for rehabilitation and promotion of social plasticity.

Clinical Applications of Transcranial Magnetic Stimulation in Pediatric Neurology

Noninvasive brain stimulation is now an accepted technique that is used as a diagnostic aid and in the treatment of neuropsychiatric disorders in adults, and is being increasingly used in children. In this review, we will discuss the basic principles and safety of one noninvasive brain stimulation method, transcranial magnetic stimulation. Improvements in the spatial accuracy of transcranial magnetic stimulation are described in the context of image-guided transcranial magnetic stimulation. The article describes and provides examples of the current clinical applications of transcranial magnetic stimulation in children as an aid in the diagnosis and treatment of neuropsychiatric disorders and discusses future potential applications. Transcranial magnetic stimulation is a noninvasive tool that is safe for use in children and adolescents for functional mapping and treatment, and for many children it aids in the preoperative evaluation and the risk-benefit decision making.

Evaluating developmental motor plasticity with paired afferent stimulation

AIM

Brain plasticity mechanisms are probably different in children but remain poorly understood. Paired afferent stimulation (PAS) combines peripheral sensory stimulation with transcranial magnetic stimulation (TMS) of primary motor cortex to induce rapid, reversible, topographically specific increases in primary motor cortex excitability suggestive of long-term potentiation in adults. Our aim was to determine frequency, characteristics, age effects, and reproducibility of PAS in school-age children.

METHOD

Typically developing right-handed children (6-18y) were recruited. Median nerve stimulation was delivered 25ms before suprathreshold primary motor cortex stimulation (0.2Hz, 7.5min). Primary outcome was changed in the amplitude of motor evoked potentials (MEPs) at five time points after PAS (0, 15, 30, 45, 75min) expressed as area under the curve. Reproducibility was evaluated. Secondary outcomes included stimulus response curves and safety/tolerability.

RESULTS

Of 28 children (20 males, mean age 12y), 64% demonstrated PAS effects (11 definite, seven probable). PAS effects were sustained across all time points to 75min (p=0.004). Stimulus response curve scores increased after PAS (n=9, p=0.02). PAS effect and age were not correlated. PAS was highly reproducible (p=0.925, r=0.283). Tolerability was favorable without adverse events.

INTERPRETATION

PAS effects are present and reproducible in children. Pediatric PAS paradigms appear safe and tolerable. PAS may provide insight into endogenous developmental plasticity, informing future studies in children with cerebral palsy and other motor disorders.

The Epilepsy Foundation's 4th Biennial Epilepsy Pipeline Update Conference

On June 5 and 6, 2014, the Epilepsy Foundation held its 4th Biennial Epilepsy Pipeline Update Conference, an initiative of the Epilepsy Therapy Project, which showcased the most promising epilepsy innovations from health-care companies and academic laboratories dedicated to pioneering and advancing drugs, biologics, technologies, devices, and diagnostics for epilepsy. Speakers and attendees included emerging biotech and medical technology companies, major pharmaceutical and device companies, as well as investigators and innovators at the cutting-edge of epilepsy. The program included panel discussions on collaboration between small and large companies, how to get products in need of funding to the marketplace, who is currently funding epilepsy and CNS innovation, and how the NIH facilitates early-stage drug development. Finally, the conference featured the third annual "Shark Tank" competition. The presentations are summarized in this paper, which is followed by a compilation of the meeting poster abstracts.

Safety of primed repetitive transcranial magnetic stimulation and modified constraint-induced movement therapy in a randomized controlled trial in pediatric hemiparesis

OBJECTIVE

To investigate the safety of combining a 6-Hz primed low-frequency repetitive transcranial magnetic stimulation (rTMS) intervention in the contralesional hemisphere with a modified constraint-induced movement therapy (mCIMT) program in children with congenital hemiparesis.

DESIGN

Phase 1 randomized, double-blinded, placebo-controlled pretest/posttest trial.

SETTING

University academic facility and pediatric specialty hospital.

PARTICIPANTS

Subjects (N = 19; age range, 8-17 y) with congenital hemiparesis caused by ischemic stroke or periventricular leukomalacia. No subject withdrew because of adverse events. All subjects included completed the study.

INTERVENTIONS

Subjects were randomized to 1 of 2 groups: either real rTMS plus mCIMT (n = 10) or sham rTMS plus mCIMT (n = 9).

MAIN OUTCOME MEASURES

Adverse events, physician assessment, ipsilateral hand function, stereognosis, cognitive function, subject report of symptoms assessment, and subject questionnaire.

RESULTS

No major adverse events occurred. Minor adverse events were found in both groups. The most common events were headaches (real: 50%, sham: 89%; P = .14) and cast irritation (real: 30%, sham: 44%; P = .65). No differences between groups in secondary cognitive and unaffected hand motor measures were found.

CONCLUSIONS

Primed rTMS can be used safely with mCIMT in congenital hemiparesis. We provide new information on the use of rTMS in combination with mCIMT in children. These findings could be useful in research and future clinical applications in advancing function in congenital hemiparesis.

Stimulation intensities of transcranial direct current stimulation have to be adjusted in children and adolescents

OBJECTIVE

The aim of the present study was to investigate the effect of the transcranial direct current stimulation (tDCS) on motor cortex excitability in healthy children and adolescents.

METHODS

We applied 1mA anodal or cathodal tDCS for 10min on the left primary motor cortex of 19 healthy children and adolescents (mean age 13.9±0.4years). In order to prove whether the effects of tDCS may be attributed to the stimulation intensity, 10 children and adolescents were studied again using 0.5mA anodal and cathodal tDCS. Sham stimulation was used as a control.

RESULTS

Compared with sham stimulation, both 1mA anodal and cathodal tDCS resulted in a significant increase of Motor evoked potentials (MEP) amplitudes which remained to be prominent even one hour after the end of stimulation. Interestingly, the 0.5mA cathodal tDCS decreased cortico-spinal excitability whereas the 0.5mA anodal stimulation did not result in any effect.

CONCLUSION

For the first time, the study demonstrates age-specific influences of tDCS on cortical excitability of the primary motor cortex.

SIGNIFICANCE

Thus, the stimulation protocols of the tDCS have to be optimized according to age by planning studies in pediatric population.

Feasibility of transcranial direct current stimulation use in children aged 5 to 12 years

Transcranial direct current stimulation is a noninvasive brain stimulation technique that has been studied for the treatment of neuropsychiatric disorders in adults, with minimal side effects. The objective of this study is to report the feasibility, tolerability, and the short-term adverse effects of transcranial direct current stimulation in children from 5 to 12 years of age. It is a naturalistic study of 14 children who underwent 10 sessions of transcranial direct current stimulation as an alternative, off-label, and open-label treatment for various languages disorders. Frequency, intensity, adverse effects, and perception of improvement reported by parents were collected. The main side effects detected were tingling (28.6%) and itching (28.6%), acute mood changes (42.9%), and irritability (35.7%). Transcranial direct current stimulation is a feasible and tolerable technique in children, although studies regarding plastic and cognitive changes in children are needed to confirm its safety. In conclusion, this is a naturalistic report in which we considered transcranial direct current stimulation as feasible in children.

Modulation of corticospinal excitability by transcranial magnetic stimulation in children and adolescents with autism spectrum disorder

The developmental pathophysiology of autism spectrum disorders (ASD) is currently not fully understood. However, multiple lines of evidence suggest that the behavioral phenotype may result from dysfunctional inhibitory control over excitatory synaptic plasticity. Consistent with this claim, previous studies indicate that adults with Asperger’s Syndrome show an abnormally extended modulation of corticospinal excitability following a train of repetitive transcranial magnetic stimulation (rTMS). As ASD is a developmental disorder, the current study aimed to explore the effect of development on the duration of modulation of corticospinal excitability in children and adolescents with ASD. Additionally, as the application of rTMS to the understanding and treatment of pediatric neurological and psychiatric disorders is an emerging field, this study further sought to provide evidence for the safety and tolerability of rTMS in children and adolescents with ASD. Corticospinal excitability was measured by applying single pulses of TMS to the primary motor cortex both before and following a 40 s train of continuous theta burst stimulation. 19 high-functioning males ages 9–18 with ASD participated in this study. Results from this study reveal a positive linear relationship between age and duration of modulation of rTMS after-effects. Specifically we found that the older participants had a longer lasting response. Furthermore, though the specific protocol employed typically suppresses corticospinal excitability in adults, more than one third of our sample had a paradoxical facilitatory response to the stimulation. Results support the safety and tolerability of rTMS in pediatric clinical populations. Data also support published theories implicating aberrant plasticity and GABAergic dysfunction in this population.

rTMS neuromodulation improves electrocortical functional measures of information processing and behavioral responses in autism

Objectives: Reports in autism spectrum disorders (ASD) of a minicolumnopathy with consequent deficits of lateral inhibition help explain observed behavioral and executive dysfunctions. We propose that neuromodulation based on low frequency repetitive Transcranial Magnetic Stimulation (rTMS) will enhance lateral inhibition through activation of inhibitory double bouquet interneurons and will be accompanied by improvements in the prefrontal executive functions. In addition we proposed that rTMS will improve cortical excitation/inhibition ratio and result in changes manifested in event-related potential (ERP) recorded during cognitive tests.

Materials and Methods: Along with traditional clinical behavioral evaluations the current study used ERPs in a visual oddball task with illusory figures. We compared clinical, behavioral and electrocortical outcomes in two groups of children with autism (TMS, wait-list group). We predicted that 18 session long course in autistic patients will have better behavioral and ERP outcomes as compared to age- and IQ-matched WTL group. We used 18 sessions of 1 Hz rTMS applied over the dorso-lateral prefrontal cortex in 27 individuals with ASD diagnosis. The WTL group was comprised of 27 age-matched subjects with ASD tested twice. Both TMS and WTL groups were assessed at the baseline and after completion of 18 weekly sessions of rTMS (or wait period) using clinical behavioral questionnaires and during performance on visual oddball task with Kanizsa illusory figures.

Results: Post-TMS evaluations showed decreased irritability and hyperactivity on the Aberrant Behavior Checklist (ABC), and decreased stereotypic behaviors on the Repetitive Behavior Scale (RBS-R). Following rTMS course we found decreased amplitude and prolonged latency in the frontal and fronto-central N100, N200 and P300 (P3a) ERPs to non-targets in active TMS treatment group. TMS resulted in increase of P2d (P2a to targets minus P2a to non-targets) amplitude. These ERP changes along with increased centro-parietal P100 and P300 (P3b) to targets are indicative of more efficient processing of information post-TMS treatment. Another important finding was decrease of the latency and increase of negativity of error-related negativity (ERN) during commission errors that may reflect improvement in error monitoring and correction function. Enhanced information processing was also manifested in lower error rate. In addition we calculated normative post-error treaction time (RT) slowing response in both groups and found that rTMS treatment was accompanied by post-error RT slowing and higher accuracy of responses, whereas the WTL group kept on showing typical for ASD post-error RT speeding and higher commission and omission error rates.

Conclusion: Results from our study indicate that rTMS improves executive functioning in ASD as evidenced by normalization of ERP responses and behavioral reactions (RT, accuracy) during executive function test, and also by improvements in clinical evaluations.

A review of traditional and novel treatments for seizures in autism spectrum disorder: findings from a systematic review and expert panel

Despite the fact that seizures are commonly associated with autism spectrum disorder (ASD), the effectiveness of treatments for seizures has not been well studied in individuals with ASD. This manuscript reviews both traditional and novel treatments for seizures associated with ASD. Studies were selected by systematically searching major electronic databases and by a panel of experts that treat ASD individuals. Only a few anti-epileptic drugs (AEDs) have undergone carefully controlled trials in ASD, but these trials examined outcomes other than seizures. Several lines of evidence point to valproate, lamotrigine, and levetiracetam as the most effective and tolerable AEDs for individuals with ASD. Limited evidence supports the use of traditional non-AED treatments, such as the ketogenic and modified Atkins diet, multiple subpial transections, immunomodulation, and neurofeedback treatments. Although specific treatments may be more appropriate for specific genetic and metabolic syndromes associated with ASD and seizures, there are few studies which have documented the effectiveness of treatments for seizures for specific syndromes. Limited evidence supports l-carnitine, multivitamins, and N-acetyl-l-cysteine in mitochondrial disease and dysfunction, folinic acid in cerebral folate abnormalities and early treatment with vigabatrin in tuberous sclerosis complex. Finally, there is limited evidence for a number of novel treatments, particularly magnesium with pyridoxine, omega-3 fatty acids, the gluten-free casein-free diet, and low-frequency repetitive transcranial magnetic simulation. Zinc and l-carnosine are potential novel treatments supported by basic research but not clinical studies. This review demonstrates the wide variety of treatments used to treat seizures in individuals with ASD as well as the striking lack of clinical trials performed to support the use of these treatments. Additional studies concerning these treatments for controlling seizures in individuals with ASD are warranted.

Motor development and motor resonance difficulties in autism: relevance to early intervention for language and communication skills

Research suggests that a sub-set of children with autism experience notable difficulties and delays in motor skills development, and that a large percentage of children with autism experience deficits in motor resonance. These motor-related deficiencies, which evidence suggests are present from a very early age, are likely to negatively affect social-communicative and language development in this population. Here, we review evidence for delayed, impaired, and atypical motor development in infants and children with autism. We then carefully review and examine the current language and communication-based intervention research that is relevant to motor and motor resonance (i.e., neural "mirroring" mechanisms activated when we observe the actions of others) deficits in children with autism. Finally, we describe research needs and future directions and developments for early interventions aimed at addressing the speech/language and social-communication development difficulties in autism from a motor-related perspective.

NON-INVASIVE BRAIN STIMULATION IN CHILDREN: APPLICATIONS AND FUTURE DIRECTIONS

Transcranial magnetic stimulation (TMS) is a neurostimulation and neuromodulation technique that has provided over two decades of data in focal, non-invasive brain stimulation based on the principles of electromagnetic induction. Its minimal risk, excellent tolerability and increasingly sophisticated ability to interrogate neurophysiology and plasticity make it an enviable technology for use in pediatric research with future extension into therapeutic trials. While adult trials show promise in using TMS as a novel, non-invasive, non-pharmacologic diagnostic and therapeutic tool in a variety of nervous system disorders, its use in children is only just emerging. TMS represents an exciting advancement to better understand and improve outcomes from disorders of the developing brain.

Contribution of the corticospinal tract to motor impairment in spina bifida

We aimed to disentangle the proportional contributions of upper and lower motor neuron dysfunction to motor impairment in children with spina bifida. We enrolled 42 children (mean age, 11.2 years; standard deviation, 2.8 years) with spina bifida and 36 control children (mean age, 11.4 years; standard deviation, 2.6 years). Motor impairment was graded to severity scales in children with spina bifida. We recorded motor evoked potentials after transcranial and lumbosacral magnetic stimulation and compound muscle action potentials after electric nerve stimulation. Regarding lower motor neuron function, severely impaired children with spina bifida demonstrated smaller compound muscle action potential areas and lumbosacral motor evoked potential areas than control children; mildly impaired children hardly differed from control children. Compound muscle action potential latencies and lumbosacral motor evoked potential latencies did not differ between children with spina bifida and control children. Regarding upper motor neuron function, children with spina bifida demonstrated smaller transcranial motor evoked potential areas and longer central motor conduction times than control children. The smallest motor evoked potential areas and longest central motor conduction times were observed in severely impaired children. In children with spina bifida, the contribution of upper motor neuron dysfunction to motor impairment is more considerable than expected from clinical neurologic examination.