Effects Of Non-invasive Brain Stimulation Research Articles

The Effects of Non-invasive Brain Stimulation on Impulsivity in People with Mental Disorders: a Systematic Review and Explanatory Meta-Analysis.

Impulsivity is a multi-faceted construct that underpins various mental health disorders. Impulsive behavior exacts a substantial health and economic burden, hence the importance of developing specific interventions to target impulsivity. Two forms of non-invasive brain stimulation, namely transcranial direct current stimulation (tDCS) and repetitive transcranial magnetic stimulation (rTMS), have been used to modulate impulsivity. To date, no reviews have systematically examined their effects on modulating impulsivity in people with mental health disorders. We conducted a systematic review and meta-analysis of the literature from AMED, Embase, Medline and PsycINFO databases on the use of rTMS and tDCS to modulate impulsivity in people with mental health disorders. Results from 11 tDCS and 18 rTMS studies indicate that tDCS has a significant, albeit small, effect on modulating impulsivity (g = 0.29; 95% CI, 0.09 to 0.48; p = .004) whereas rTMS has no significant effect on impulsivity (g = -0.08; 95% Cl, -0.35 to 0.19; p = .550). Subgroup analyses identified the key parameters required to enhance the effects of tDCS and rTMS on impulsivity. Gender and stimulation intensity acted as significant moderators for effects of rTMS on impulsivity. There is insufficient evidence to support the use of tDCS or rTMS in clinical practice to reduce impulsivity in people with mental health disorders. The use of standardized non-invasive brain stimulation protocols and outcome measures in patients with the same diagnosis is advised to minimize methodological heterogeneity.

Effect of non-invasive brain stimulation on neuropathic pain following spinal cord injury: A systematic review and meta-analysis.

In recent years, some studies indicated that repetitive transcranial magnetic stimulation (rTMS) could relieve neuropathic pain (NP) following a spinal cord injury (SCI), whereas some studies showed no pain relief effect. In addition, some studies showed the analgesic effect of transcranial direct current stimulation (tDCS) on NP post SCI, whereas other studies showed no effect. We systematically searched on the PubMed, Web of Science, EMBASE, Medline, Google Scholar for studies exploring the analgesic effect of rTMS or tDCS on NP post SCI until November 2019. Meta-analysis was conducted to summarize results of these studies. The present quantitative meta-analysis indicated no significant difference in the effect of treatment on NP following SCI between rTMS and sham rTMS over the motor cortex at about 1 week after the end of the rTMS period (standardized mean difference (SMD) = 2.89, 95% confidence interval (CI) = -0.27 to 6.04). However, the study indicated that rTMS showed significantly better pain relief of treatment compared with sham rTMS between 2 and 6 weeks after the end of the rTMS period (SMD = 3.81, 95%CI: 0.80-7.52). However, no sufficient evidence could be provided to make a meta-analysis for the analgesic effect of tDCS on NP following SCI over the primary motor area (M1). In conclusion, the present meta-analysis suggested that rTMS did not show early analgesic effect on NP after SCI, but showed better middle-term analgesic effect, compared with sham rTMS. More large scale, blinded randomized controlled trials (RCTs) were needed to explore the analgesic effect of rTMS and tDCS on NP following SCI.

Non-invasive Brain Stimulation Effects on the Perceptual and Cognitive Processes Underlying Decision-making: a Mini Review

Non-invasive brain stimulation (NIBS) includes transcranial magnetic (TMS), focused ultrasound (tFUS), and electrical (tES) stimulation, each of which modulates the activity of cortical neurons with the intent of modifying functional connectivity and neuroplasticity in the brain. Often employed as a tool to identify causal links between brain regions, cognitive processes, and behavioral outcomes, NIBS is also gaining popularity as a tool for enhancing decision-making under conditions of uncertainty. A literature search revealed 42 published reports conforming to our search criteria, employing diverse NIBS techniques including TMS, repetitive TMS (rTMS), and transcranial direct, alternating, and random noise stimulation (tDCS, tACS, tRNS). Identified studies also employed a range of outcome tasks including recognition memory, non-veridical, moral, economic, perceptual, and risky decision-making. Further categorization was performed to isolate six decision subprocesses, including gathering information, evaluating probabilities, weighting dimensions, integrating and assigning value, creating a strategy, and executing a decision. Most studies targeted the right or left dorsolateral prefrontal cortex (DLPFC), demonstrating critical involvement of this region in all six examined decision subprocesses. Several additional brain regions were targeted, with outcomes demonstrating disruption or facilitation of specific decision outcomes. Results are summarized for each decision subprocess, focusing on converging evidence across NIBS techniques and decision tasks. Several important directions are outlined for future research, to fill knowledge gaps, advance causal and mechanistic understandings of NIBS effects on decisions, and potentially enhance decision-making in real-world settings.

Repetitive Transcranial Magnetic Stimulation as a Potential Tool to Reduce Sexual Arousal: A Proof of Concept Study

BackgroundHypersexuality and hyposexuality occur frequently, often in a variety of psychiatric disorders, and are difficult to treat. While there is meta-analytic evidence for the significant effect of non-invasive brain stimulation on drug and food craving, no study has investigated the potential of this technique to modulate sexual behavior. AimHere, we tested the hypothesis that a single session of high-frequency repetitive transcranial magnetic stimulation (rTMS) over the dorsolateral prefrontal cortex (DLPFC) would reduce sexual arousal. MethodsWe employed a randomized, double-blind, sham-controlled crossover study design. 19 healthy male participants received high-frequency rTMS over the left DLPFC, high-frequency rTMS over the right DLPFC, and sham rTMS (each 10 Hz; 110% resting motor threshold; 60 trains with 50 pulses) in randomized and counterbalanced order with a 1-week interval between stimulation sessions to avoid carryover effects. Participants were exposed to neutral and sexual cues before and after each intervention and rated their sexual arousal after each block of cue presentation. Main Outcome MeasureEfficacy of the respective intervention was operationalized by the change of subjective sexual arousal according to a rating scale. ResultsrTMS of the right DLPFC significantly reduced subjective sexual arousal (t18 = 2.282, P = .035). In contrast, neither sham rTMS nor rTMS of the left DLPFC affected sexual arousal (P > .389). Greater rTMS-induced reduction of subjective sexual arousal was observed in participants with higher trait-based dyadic sexual desire within the last 12 months (r = −0.417, P = .038). Clinical ImplicationNon-invasive brain stimulation might hold potential for influencing hypersexual behavior. Strength & LimitationThis was a randomized, double-blind, sham-controlled crossover study with subjective but no physiological measures of sexual arousal. ConclusionThe results indicate that 1 session of high-frequency rTMS (10 Hz) of the right DLPFC could significantly reduce subjective sexual arousal induced by visual stimuli in healthy subjects. On this basis, future studies with larger sample sizes and more stimulation sessions are needed to explore the therapeutic potential of rTMS in hypersexual behavior.Schecklmann M, Sakreida K, Oblinger B, et al. Repetitive Transcranial Magnetic Stimulation as a Potential Tool to Reduce Sexual Arousal: A Roof of Concept Study. J Sex Med 2020;17:1553–1559.

Noninvasive Brain Stimulation Does Not Improve Neuropathic Pain in Individuals With Spinal Cord Injury

The aim of the study was to examine the effectiveness of noninvasive brain stimulation on neuropathic pain in individuals with spinal cord injury. A meta-analysis on pain intensity, depression, and anxiety levels was conducted to evaluate the effect of noninvasive brain stimulation on neuropathic pain in individuals with spinal cord injury. The authors searched Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (PubMed), Embase (OvidSP), PsycINFO (OvidSP), and Physiotherapy Evidence Database (PEDro). Randomized controlled trials comparing noninvasive brain stimulation with sham stimulation were included. Eleven studies were selected. The pooled analysis demonstrated no significant effect of repetitive transcranial magnetic stimulation, transcranial direct current stimulation, or cranial electrotherapy stimulation on neuropathic pain reduction after spinal cord injury. In addition, noninvasive brain stimulation showed no beneficial effect over sham stimulation on the improvement of depression, while it yielded a significant reduction of anxiety levels immediately after treatment. Subgroup analysis showed that only cranial electrotherapy stimulation had a significant effect on the reduction of anxiety levels among the three types of noninvasive brain stimulation. In individuals with spinal cord injury, no significant effects of noninvasive brain stimulation on neuropathic pain and depression were observed. Cranial electrotherapy stimulation may be beneficial for the management of anxiety. These findings do not support the routine use of noninvasive brain stimulation for neuropathic pain in individuals with spinal cord injury.

Combining HF rTMS over the Left DLPFC with Concurrent Cognitive Activity for the Offline Modulation of Working Memory in Healthy Volunteers: A Proof-of-Concept Study.

It has been proposed that the effectiveness of non-invasive brain stimulation (NIBS) as a cognitive enhancement technique may be enhanced by combining the stimulation with concurrent cognitive activity. However, the benefits of such a combination in comparison to protocols without ongoing cognitive activity have not yet been studied. In the present study, we investigate the effects of fMRI-guided high-frequency repetitive transcranial magnetic stimulation (HF rTMS) over the left dorsolateral prefrontal cortex (DLPFC) on working memory (WM) in healthy volunteers, using an n-back task with spatial and verbal stimuli and a spatial span task. In two combined protocols (TMS + WM + (maintenance) and TMS + WM + (rest)) trains of stimuli were applied in the maintenance and rest periods of the modified Sternberg task, respectively. We compared them to HF rTMS without a cognitive load (TMS + WM −) and control stimulation (TMS − WM + (maintenance)). No serious adverse effects appeared in this study. Among all protocols, significant effects on WM were shown only for the TMS + WM − with oppositely directed influences of this protocol on storage and manipulation in spatial WM. Moreover, there was a significant difference between the effects of TMS + WM − and TMS + WM + (maintenance), suggesting that simultaneous cognitive activity does not necessarily lead to an increase in TMS effects.

The Effect of Non-invasive Brain Stimulation on Language Production in Post-stroke Aphasia

The Effect of Non-invasive Brain Stimulation on Language Production in Post-stroke Aphasia

Effect of Noninvasive Brain Stimulation on Hypokinetic Dysarthria in Parkinson's Disease

Effect of Noninvasive Brain Stimulation on Hypokinetic Dysarthria in Parkinson's Disease

Effects of Non-Invasive Brain Stimulation on Clinical Pain Intensity and Experimental Pain Sensitivity Among Individuals with Central Post-Stroke Pain: A Systematic Review.

PurposeCentral post-stroke pain (CPSP) is a neuropathic disorder resulting in pain and disability. An emerging treatment for CPSP is non-invasive brain stimulation including direct current stimulation [tDCS] and repetitive transcranial magnetic stimulation [rTMS]. This systematic review analyzes the efficacy and quality of non-invasive brain stimulation intervention studies for CPSP.MethodsStudies were sought from three research databases published between 2007 and 2017. Studies were included if the sole intervention was non-invasive brain stimulation and the primary outcome either clinical or experimental pain intensity. Studies were qualitatively assessed for risk of bias.ResultsOf 1107 articles extracted, six met eligibility criteria. Five studies found a decrease in pain intensity (p<0.05) immediately and 3 weeks after rTMS or tDCS was delivered over the primary motor cortex. For experimental pain, one study found thermal pain thresholds improved for those receiving tDCS compared to sham (p<0.05), while another found normalization of the cold detection threshold only after rTMS (p<0.05). Qualitative assessment revealed only one study rated as “excellent/good” quality, while the other five were rated as “fair” or “poor”.ConclusionNon-invasive brain stimulation may have a therapeutic effect on pain level for individuals with CPSP, as evidenced by significant decreases in clinical and experimental pain scores. However, despite the impact of CPSP and the promise of non-invasive brain stimulation, few rigorous studies have been performed in this area. Future studies should aim to standardize treatment parameters, measure both clinical and experimental pain, and include long-term follow-up.

Stuttering Severity Modulates Effects of Non-invasive Brain Stimulation in Adults Who Stutter.

Stuttering is a neurodevelopmental disorder that manifests as frequent disruptions in the flow of speech, affecting 1% of adults. Treatments are limited to behavioral interventions with variable success and high relapse rates, particularly in adults. However, even in severe cases, fluency can be temporarily induced during conditions in which the speaker synchronizes his speech with external rhythmic cues, such as when reading in unison (choral speech) or with a metronome. Non-invasive neuromodulation techniques such as transcranial direct current stimulation (tDCS) have shown promise in augmenting the effects of behavioral treatment during motor and speech/language rehabilitation, but only one study to date has examined behavioral modulatory effects of tDCS in the context of stuttering. Using high-definition (HD)-tDCS electrodes, which improves focality of stimulation relative to conventional tDCS, we investigated the effects of tDCS on speech fluency and brain activation in 14 adults who stutter (AWS). Either anodal or sham stimulation was delivered on separate days over left supplementary motor area (SMA). During stimulation, participants read aloud in sync with a metronome. Measures of speech fluency and brain activity functional magnetic resonance imaging (fMRI) were collected before and after stimulation. No significant differences in brain activity or speech fluency were found when comparing active and sham stimulation. However, stuttering severity significantly modulated the effect of stimulation: active stimulation attenuated the atypically strong association between stuttering severity and right thalamocortical network activity, especially in more severe speakers. These preliminary results warrant additional research into potential application of HD-tDCS to modulate speech motor networks to enhance fluency in stuttering.

Effects of Non-Invasive Brain Stimulation on Soldiers' Cognitive and Functional Performance

Effects of Non-Invasive Brain Stimulation on Soldiers' Cognitive and Functional Performance

Review: Non-Invasive Brain Stimulation in Behavioral Addictions: Insights from Direct Comparisons With Substance Use Disorders.

Treatment models developed for substance use disorders (SUDs) are often applied to behavioral addictions (BAs), even though the correspondence between these forms of addiction is unclear. This is also the case for noninvasive brain stimulation (NIBS) techniques being investigated as potential treatment interventions for SUDs and BAs. to contribute to the development of more effective NIBS protocols for BAs. Two literature searches using PubMed and Google Scholar were conducted identifying a total of 35 studies. The first search identified 25 studies examining the cognitive and neurophysiological overlap between BAs and SUDs. The second search yielded 10 studies examining the effects of NIBS in BAs. Impulsivity and cravings show behavioral and neurophysiologic overlaps between BAs and SUDs, however, other outcomes like working-memory abilities or striatal connectivity, differ between BAs and SUDs. The most-employed NIBS target in BAs was dorsolateral prefrontal cortex (DLPFC), which was associated with a decrease in cravings, and less frequently with a reduction of addiction severity. Direct comparisons between BAs and SUDs revealed discrepancies between behavioral and neurophysiological outcomes, but overall, common and distinctive characteristics underlying each disorder. The lack of complete overlap between BAs and SUDs suggests that investigating the cognitive and neurophysiological features of BAs to create individual NIBS protocols that target risk-factors associated specifically with BAs, might be more effective than transferring protocols from SUDs to BAs. Individualizing NIBS protocols to target specific risk-factors associated with each BA might help to improve treatment interventions for BAs. (Am J Addict 2019;00:1-23).

Traumatic axonal injury influences the cognitive effect of non-invasive brain stimulation.

Non-invasive brain stimulation has been widely investigated as a potential treatment for a range of neurological and psychiatric conditions, including brain injury. However, the behavioural effects of brain stimulation are variable, for reasons that are poorly understood. This is a particular challenge for traumatic brain injury, where patterns of damage and their clinical effects are heterogeneous. Here we test the hypothesis that the response to transcranial direct current stimulation following traumatic brain injury is dependent on white matter damage within the stimulated network. We used a novel simultaneous stimulation-MRI protocol applying anodal, cathodal and sham stimulation to 24 healthy control subjects and 35 patients with moderate/severe traumatic brain injury. Stimulation was applied to the right inferior frontal gyrus/anterior insula node of the salience network, which was targeted because our previous work had shown its importance to executive function. Stimulation was applied during performance of the Stop Signal Task, which assesses response inhibition, a key component of executive function. Structural MRI was used to assess the extent of brain injury, including diffusion MRI assessment of post-traumatic axonal injury. Functional MRI, which was simultaneously acquired to delivery of stimulation, assessed the effects of stimulation on cognitive network function. Anodal stimulation improved response inhibition in control participants, an effect that was not observed in the patient group. The extent of traumatic axonal injury within the salience network strongly influenced the behavioural response to stimulation. Increasing damage to the tract connecting the stimulated right inferior frontal gyrus/anterior insula to the rest of the salience network was associated with reduced beneficial effects of stimulation. In addition, anodal stimulation normalized default mode network activation in patients with poor response inhibition, suggesting that stimulation modulates communication between the networks involved in supporting cognitive control. These results demonstrate an important principle: that white matter structure of the connections within a stimulated brain network influences the behavioural response to stimulation. This suggests that a personalized approach to non-invasive brain stimulation is likely to be necessary, with structural integrity of the targeted brain networks an important criterion for patient selection and an individualized approach to the selection of stimulation parameters.

Electroencephalography and Functional Magnetic Resonance Imaging-Guided Simultaneous Transcranial Direct Current Stimulation and Repetitive Transcranial Magnetic Stimulation in a Patient With Minimally Conscious State.

ObjectiveA minimally conscious state (MCS) is characterized by discernible behavioral evidence of consciousness that cannot be reproduced consistently. This condition is highly challenging to treat. Recent studies have demonstrated the potential therapeutic effect of non-invasive brain stimulation in patients with MCS. In one patient in an MCS, we delivered simultaneous transcranial direct current stimulation (tDCS) and repetitive transcranial magnetic stimulation (rTMS) based on an individual brain network analysis and evaluated the therapeutic effect.MethodsThe directional transfer function (DTF) was calculated based on electroencephalograph (EEG) analysis. Global brain connectivity was calculated based on functional magnetic resonance imaging (fMRI) analysis. By referring to the EEG and fMRI results, we identified inferior parietal lobes (IPLs) as targets. In the 2-week treatment period, 14 sessions were applied to the identified bilateral parietal regions. Simultaneous 1.5-mA anodal tDCS and 5-Hz rTMS were delivered for 20 min per hemisphere in each session. Clinical evaluation scores were recorded weekly throughout the treatment. A second patient given the routine treatment was evaluated as a control.ResultsThe clinical scores of patient 1 with MCS improved after 2 weeks of stimulation treatment, and the effect lasted for up to 1 month. EEG analysis showed a significant increase (p < 0.001) in the DTF value in the gamma band in a bilateral set of posterior regions, and fMRI showed a trend toward normalized activity in the IPLs. The clinical scores of patient 2 with coma did not improve much after 2 weeks of routine treatment. The EEG analysis showed a significant increase (p = 0.021) in the DTF value in the gamma band in a bilateral set of posterior regions.ConclusionThe application of EEG and fMRI to characterize the functional connectivity features of the network in an MCS patient provided a reasonable and accurate stimulation target and verified the changes in functional connectivity resulting from stimulation.

The Effects of Non-invasive Brain Stimulation on Treatment Adherence in Schizophrenia

The Effects of Non-invasive Brain Stimulation on Treatment Adherence in Schizophrenia

Inverse effects of tDCS over the left versus right DLPC on emotional processing: A pupillometry study.

Background and objectivesThe Dorsolateral prefrontal cortex (DLPFC) is implicated in cognitive and emotional responses. Yet, research that investigates the causal role of the left versus right DLPFC during the processes of emotion appraisal is lacking. In the current study, transcranial direct current stimulation (tDCS) was used to disentangle the functional lateralization of the DLPFC on emotional processing in response to the anticipation of, and subsequent confrontation with emotional stimuli in healthy volunteers.MethodsForty-eight subjects received both active and sham (on separate days) anodal tDCS over either the left (N = 24) or right (N = 24) DLPFC. Subjects’ pupil dilation (PD, a physiological marker of cognitive resource allocation) was recorded while performing an appraisal task in which negative and positive emotion eliciting images were presented, each preceded by an informative cue indicating the valence of the upcoming stimulus.ResultsAs compared to sham stimulation, left DLPFC anodal tDCS resulted in increased PD when confronted with negative emotional images, whereas right DLPFC anodal tDCS resulted in decreased PD when confronted with emotional images, irrespective of valence.LimitationsThe interpretation of pupil dilation in response to emotional stimuli is limited.ConclusionThese findings suggest inverse lateralized DLPFC effects on cognitive resource allocation (as measured by pupillary responses) when confronted with emotional stimuli. The current findings may shed some light on mechanisms that explain the antidepressant effects of non-invasive brain stimulation of the left DLPFC.

Inverse effects of tDCS over the left versus right DLPC on emotional processing: A pupillometry study

Background The Dorsolateral prefrontal cortex (DLPFC) is implicated in the top-down modulation of emotional responses. Research that investigates the causal role of the left versus right DLPFC on emotional responding, both during the anticipation and confrontation with emotional stimuli, is lacking. In the current study, transcranial direct current stimulation (tDCS) was used to investigate the DLPFC functional lateralization regarding spontaneously exerted effort to control emotional responses during the anticipation of, and confrontation with emotional stimuli in healthy volunteers. Methods Forty-eight subjects received both active and sham (on separate days) anodal tDCS over either the left (n = 24) or right (n = 24) DLPFC. Subjects’ pupil dilation (PD; i.e., a physiological marker for cognitive effort to control emotional responses) was recorded while performing an appraisal task in which negative and positive emotion eliciting images were presented, each preceded by an informative cue indicating the valence of the upcoming stimulus. Results Left DLPFC anodal tDCS (compared to sham tDCS) resulted in increased PD when confronted with negative emotional images, whereas right DLPFC anodal tDCS (compared to sham tDCS) resulted in decreased PD when confronted emotional pictures, irrespective of valence. Conclusion This study established a basic proof of concept for inverse lateralized DLPFC effects on cognitive effort to control automatic emotional responses (as measured by pupillary responses) when attending, but not preparing for, emotional stimuli. The current findings may shed some light on mechanisms that explain the antidepressant effects of non-invasive brain stimulation of the left DLPFC. However, further research is warranted to investigate these processes more closely.

The road towards personalized medicine: Increasing the effects of brain stimulation using individual characteristics

Non-invasive brain stimulation (NIBS) techniques, such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) have shown high treatment potential for a broad variety of neuropsychiatric disorders. However, the application of ‘standard’ protocols results in high inter-individual differences in the responses and reduce the overall efficacy. In this symposium, individual characteristics that are linked to the clinical outcome of stimulation treatment will be highlighted. It can be hypothesized that inter-individual differences in responses to stimulation can be assigned to variations in individual neurocircuitries. Therefore, the first two presentations will focus on functional connectivities (FC) on network level. Firstly, the use of graph analysis to study the effect of accelerated intermittent theta burst stimulation (aiTBS) is explained (n = 50, major depressive disorder patients). Also it will be shown that baseline graph measures can predict the clinical efficacy of this stimulation protocol. Clinical efficacy in this case was derived from the 17-item Hamilton questionnaire. Secondly, the influence of different stimulation positions, derived from FC within two different networks, on the effect of one iTBS session on an n-back task will be presented (n = 12, healthy subjects). Being more or less vulnerable to psychopathology can also affect the outcome of NIBS. For example, the tendency to ruminate in daily life influences the outcome of iTBS (n = 38, healthy subjects). Here, the effect of iTBS was quantified using cortisol recovery. Moreover, the application of prefrontal tDCS before listening to self-referent criticism affects FC between the left dorsal anterior cingulate cortex and the right dorsomedial prefrontal cortex distinctively in healthy women low versus high in perceived criticism (n = 46). In conclusion, this symposium will show that individual mechanisms play a role in the effect of NIBS. Therefore, in future protocols, personalized characteristics might enhance clinical efficacy.

3010 Effects of non-invasive brain stimulation on speech fluency and brain activity in adults who stutter: a randomized controlled clinical trial

OBJECTIVES/SPECIFIC AIMS: The goal of this study is to measure speech fluency and brain activity before and after 5 days of behavioral speech fluency training alone (sham group) or speech training plus stimulation (active group). A 1-month follow up will also be completed. The first primary outcome measure is changes in brain activation in speech motor control/timing network. The second primary outcome measure is changes in percentage of stuttered syllables during speech sample (speech fluency). The secondary outcome measure is changes from baseline on the Overall Assessment of Speakers Experience of Stuttering (OASES), a detailed subject rating of how stuttering affects their lives. METHODS/STUDY POPULATION: This study is a between subjects, counterbalanced, sham-controlled, double-blind design. Participants will be 40 adults who stutter who will be randomized (using minimization) into either the active or sham stimulation group, with all other study procedures being the same in both groups. Participants will completed 2 days of baseline testing, 5 consecutive days of brain stimulation during speech training, 2 days of post-testing, and a 1-month follow up. All outcome measures will be completed immediately before and after the 5 days of brain stimulation, as well as at follow-up. as of submission, 10 subjects have completed the study. Data collection is ongoing. RESULTS/ANTICIPATED RESULTS: Expected results. Questions this study aims to answer: 1) Does a more intensive training period lead to decreased stuttering? We expect that both groups will show improvements in speech fluency immediately after training. We expect that those in the active group will continue to exhibit improved speech fluency at 1 month follow up. 2) Does a more intensive training period lead to changes in brain activity? We expect that both groups will exhibit increased activity in auditory/motor regions immediately after training. We expect that the active group will continue to exhibit an increase in activity in these regions at 1 month follow up. DISCUSSION/SIGNIFICANCE OF IMPACT: This is the first RCT study involving brain stimulation in adults who stutter. We expect to provide preliminary evidence for the effectiveness of tDCS as an augmentative agent for increased speech fluency in adults who stutter during a brief, intensive training paradigm. We also expect to be able to provide information on the effects of tDCS on brain activity in speech and auditory-motor regions of the brain. The findings will add to the growing body of literature suggesting that developmental stuttering is a neurodevelopmental disorder with roots in timing and rhythmic aspects of speech motor control and auditory-motor integration.

Effects of non-invasive brain stimulation on freezing of gait in parkinsonism: A systematic review with meta-analysis

IntroductionTo investigate the effect of non-invasive brain stimulation (NIBS), including repetitive transcranial magnetic stimulation and transcranial direct current stimulation, on freezing of gait (FOG) in parkinsonism. MethodsThe PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and Physiotherapy Evidence Database (PEDro) databases were searched up to October 2018 for articles published in English or Korean. Quality assessment was performed using the PEDro scale. Studies with random allocation and pre-intervention and post-intervention assessments for FOG were included, and the standardized mean differences for each outcome were calculated. ResultsSeven studies including 102 participants were included in the final analysis. The meta-analysis showed a significant improvement in freezing of gait questionnaire (FOG-Q) scores (SMD = 0.28; 95% CI, 0.01 to 0.55) and turning time (SMD = 0.30; 95% CI, 0.02 to 0.58). When analyzing only participants with Parkinson's disease, the effect size according to the FOG-Q score was greater (SMD = 0.57; 95% CI, 0.15 to 0.98) and the United Parkinson's disease rating scale-III score was significantly improved after NIBS (SMD = 0.43; 95% CI, 0.01 to 0.86). Both motor and frontal cortex stimulation didn't reveal significant improvement for FOG, but, the effect size of motor cortex stimulation (SMD = 0.35; 95% CI, −0.06 to 0.76) was almost double compared with that of frontal cortex stimulation (SMD = 0.19; 95% CI, −0.26 to 0.63). ConclusionNIBS showed a beneficial effect on FOG in parkinsonism, and the effects were more prominent in Parkinson's disease. Further studies are needed to determine the optimal protocol and elucidate effects according to the intervention and disease type.