A Meta-Analysis of the Effectiveness of Different Cortical Targets Used in Repetitive Transcranial Magnetic Stimulation (rTMS) for the Treatment of Obsessive-Compulsive Disorder (OCD)

Neurotransmitter system gene variants as biomarkers for the therapeutic efficacy of rTMS and SSRIs in obsessive-compulsive disorder

Purpose

This study aims to examine the potential influence of RS4680 (COMT), RS16965628 (SLC6A4), and RS1019385 (GRIN2B) polymorphisms on the therapeutic response to repetitive transcranial magnetic stimulation (rTMS) and selective serotonin reuptake inhibitors (SSRIs) in individuals with obsessive-compulsive disorder (OCD).

Patients and methods

Thirty-six untreated outpatients diagnosed with OCD were recruited and allocated to active or sham rTMS groups for two weeks. The mean age of the participants was 31.61, with 17 males (47.22%) and 19 females (52.78%). Peripheral blood samples (5 mL) were collected from each participant using ethylenediaminetetraacetic acid (EDTA) vacuum tubes for genotyping purposes, clinical evaluation was taken place at baseline and second week.

Results

The A allele of RS4680, C allele of RS16965628, and GG allele of RS1019385 were identified as potential bio-markers for predicting treatment response to OCD treatments (rTMS & SSRIs).

Conclusion

Those genes may serve as bio-markers for the combined treatment of rTMS and SSRIs in OCD. The finding hold promise for further research and the potential implementation of precision treatment of OCD.

Clinical trial registration

https://www.chictr.org.cn, identifier ChiCTR1900023641.

Royal Australian and New Zealand College of Psychiatrists professional practice guidelines for the administration of repetitive transcranial magnetic stimulation

OBJECTIVES

To provide guidance for the optimal administration of repetitive transcranial magnetic stimulation, based on scientific evidence and supplemented by expert clinical consensus.

METHODS

Articles and information were sourced from existing guidelines and published literature. The findings were then formulated into consensus-based recommendations and guidance by the authors. The guidelines were subjected to rigorous successive consultation within the RANZCP, involving the Section of ECT and Neurostimulation (SEN) Committee, its broader membership and expert committees.

RESULTS

The RANZCP professional practice guidelines (PPG) for the administration of rTMS provide up-to-date advice regarding the use of rTMS in clinical practice. The guidelines are intended for use by psychiatrists and non-psychiatrists engaged in the administration of rTMS to facilitate best practice to optimise outcomes for patients. The guidelines strive to find the appropriate balance between promoting best evidence-based practice and acknowledging that evidence for rTMS use is a continually evolving.

CONCLUSION

The guidelines provide up-to-date advice for psychiatrists and non-psychiatrists to promote optimal standards of rTMS practice.

An evaluation of treatment response and remission definitions in adult obsessive-compulsive disorder: A systematic review and individual-patient data meta-analysis

INTRODUCTION

Expert consensus operationalized treatment response and remission in obsessive-compulsive disorder (OCD) as a Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) reduction ≥35% and score ≤12 with ≤2 on Clinical Global Impressions Improvement (CGI-I) and Severity (CGI-S) scales, respectively. However, there has been scant empirical evidence supporting these definitions.

METHODS

We conducted a systematic review and an individual participant data meta-analysis of randomized-controlled trials (RCTs) in adults with OCD to determine optimal Y-BOCS thresholds for response and remission. We estimated pooled sensitivity/specificity for each percent reduction threshold (response) or posttreatment score (remission) to determine response and remission defined by a CGI-I and CGI-S ≤ 2, respectively.

RESULTS

Individual participant data from 25 of 94 eligible RCTs (1235 participants) were included. The optimal threshold for response was ≥30% Y-BOCS reduction and for remission was ≤15 posttreatment Y-BOCS. However, differences in sensitivity and specificity between the optimal and nearby thresholds for response and remission were small with some uncertainty demonstrated by the confidence ellipses.

CONCLUSION

While the empirically derived Y-BOCS thresholds in our meta-analysis differ from expert consensus, given the predominance of data from more recent trials of OCD, which involved more refractory participants and novel treatment modalities as opposed to first-line therapies, we recommend the continued use of the consensus definitions.

Axon morphology and intrinsic cellular properties determine repetitive transcranial magnetic stimulation threshold for plasticity

Introduction

Repetitive transcranial magnetic stimulation (rTMS) is a widely used therapeutic tool in neurology and psychiatry, but its cellular and molecular mechanisms are not fully understood. Standardizing stimulus parameters, specifically electric field strength, is crucial in experimental and clinical settings. It enables meaningful comparisons across studies and facilitates the translation of findings into clinical practice. However, the impact of biophysical properties inherent to the stimulated neurons and networks on the outcome of rTMS protocols remains not well understood. Consequently, achieving standardization of biological effects across different brain regions and subjects poses a significant challenge.

Methods

This study compared the effects of 10 Hz repetitive magnetic stimulation (rMS) in entorhino-hippocampal tissue cultures from mice and rats, providing insights into the impact of the same stimulation protocol on similar neuronal networks under standardized conditions.

Results

We observed the previously described plastic changes in excitatory and inhibitory synaptic strength of CA1 pyramidal neurons in both mouse and rat tissue cultures, but a higher stimulation intensity was required for the induction of rMS-induced synaptic plasticity in rat tissue cultures. Through systematic comparison of neuronal structural and functional properties and computational modeling, we found that morphological parameters of CA1 pyramidal neurons alone are insufficient to explain the observed differences between the groups. Although morphologies of mouse and rat CA1 neurons showed no significant differences, simulations confirmed that axon morphologies significantly influence individual cell activation thresholds. Notably, differences in intrinsic cellular properties were sufficient to account for the 10% higher intensity required for the induction of synaptic plasticity in the rat tissue cultures.

Conclusion

These findings demonstrate the critical importance of axon morphology and intrinsic cellular properties in predicting the plasticity effects of rTMS, carrying valuable implications for the development of computer models aimed at predicting and standardizing the biological effects of rTMS.

Comparative efficacy of repetitive transcranial magnetic stimulation protocols for obsessive-compulsive disorder: A network meta-analysis

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) has been found to be helpful for the treatment of obsessive-compulsive disorder (OCD). However, the relative efficacy of different rTMS protocols is unclear.

OBJECTIVE

To conduct a systematic review and network meta-analysis (NMA) of published literature to compare the relative efficacy of different rTMS protocols for decreasing Yale-Brown Obsessive Compulsive Severity (Y-BOCS) scores in patients with OCD.

METHOD

Relevant articles published between 1985 to September 2023 were searched from the Cochrane Central Register of Controlled Trials, PubMed and PsycInfo. Double or single-blinded randomized controlled studies conducted on patients with OCD comparing an active rTMS protocol with either another active or sham rTMS protocol were included. Network meta-analysis (NMA) was conducted using a frequentist approach. Standardized mean difference (SMD) of change in Y-BOCS scores was calculated employing Hedge's g. Pairwise meta-analysis using random effects model was conducted which was extended to the NMA using restricted maximum likelihood estimation procedure. Surface under the cumulative ranking (SUCRA) probabilities were used to rank the interventions.

RESULTS

Excitatory rTMS of the bilateral dorsolateral prefrontal cortex (DLPFC), inhibitory rTMS of right DLPFC, inhibitory as well as excitatory rTMS of bilateral medial prefrontal cortex/anterior cingulate cortex (mPFC/ACC) and inhibitory rTMS of bilateral supplementary motor area (SMA) were superior to sham stimulation. The DLPFC and mPFC/ACC protocols had a higher probability of being among the top-ranked interventions. The majority of studies had a modest sample size and at least some concerns in the risk of bias assessment.

CONCLUSION

rTMS targeting either the medial or lateral prefrontal cortices is a promising intervention for resistant OCD. There is a need to confirm these findings in large systematic studies.

The Efficacy of Transcranial Magnetic Stimulation in the Treatment of Obsessive-Compulsive Disorder: An Umbrella Review of Meta-Analyses

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) has been increasingly used for treating obsessive-compulsive disorder (OCD). Although several meta-analyses have explored its effectiveness and safety, there is no umbrella review specifically focused on rTMS for OCD. This umbrella review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and analyzed relevant meta-analyses on rTMS for OCD.

METHODS

Twenty-three articles were identified from PubMed, and after screening, 12 meta-analyses were included in the review. The studies analyzed in the meta-analyses ranged from 10 to 27, with total participants ranging from 282 to 791. The most commonly studied regions were the dorsolateral prefrontal cortex (DLPFC), supplementary motor area (SMA), and orbito-frontal cortex (OFC).

RESULT

The majority of the meta-analyses consistently supported the effectiveness of rTMS in reducing OCD symptoms when applied to the DLPFC and SMA. Encouraging results were also observed when targeting the medial prefrontal cortex (mPFC) and anterior cingulate cortex (ACC) through deep transcranial magnetic stimulation (dTMS). However, there was a high level of heterogeneity in the findings of nine out of 12 meta-analyses.

CONCLUSION

In conclusion, existing evidence suggests that rTMS targeting the DLPFC and SMA consistently reduces OCD symptoms, but targeting the mPFC and ACC through dTMS shows variable results. However, the high heterogeneity in the study findings indicates a need for further research and standardization in the field.

Individualized, connectome-based, non-invasive stimulation of OCD deep-brain targets: A proof-of-concept

Treatment-resistant obsessive-compulsive disorder (OCD) generally improves with deep-brain stimulation (DBS), thought to modulate neural activity at both the implantation site and in connected brain regions. However, its invasive nature, side-effects, and lack of customization, make non-invasive treatments preferable. Harnessing the established remote effects of cortical transcranial magnetic stimulation (TMS), connectivity-based approaches have emerged for depression that aim at influencing distant regions connected to the stimulation site. We here investigated whether effective OCD DBS targets (here subthalamic nucleus [STN] and nucleus accumbens [NAc]) could be modulated non-invasively with TMS. In a proof-of-concept study with nine healthy individuals, we used 7T magnetic resonance imaging (MRI) and probabilistic tractography to reconstruct the fiber tracts traversing manually segmented STN/NAc. Two TMS targets were individually selected based on the strength of their structural connectivity to either the STN, or both the STN and NAc. In a sham-controlled, within-subject cross-over design, TMS was administered over the personalized targets, located around the precentral and middle frontal gyrus. Resting-state functional 3T MRI was acquired before, and at 5 and 25 min after stimulation to investigate TMS-induced changes in the functional connectivity of the STN and NAc with other regions of the brain. Static and dynamic seed-to-voxel correlation analyses were conducted. TMS over both targets was able to modulate the functional connectivity of the STN and NAc, engaging both overlapping and distinct regions, and unfolding following different temporal dynamics. Given the relevance of the engaged connected regions to OCD pathology, we argue that a personalized, connectivity-based procedure is worth investigating as potential treatment for refractory OCD.

Targeting the prefrontal-supplementary motor network in obsessive-compulsive disorder with intensified electrical stimulation in two dosages: a randomized, controlled trial

Obsessive-compulsive disorder (OCD) is associated with a high disease burden, and treatment options are limited. We used intensified electrical stimulation in two dosages to target a main circuitry associated with the pathophysiology of OCD, left dorsolateral prefrontal cortex (l-DLPFC), and pre-supplementary motor area (pre-SMA) and assessed clinical outcomes, neuropsychological performance, and brain physiology. In a double-blind, randomized controlled trial, thirty-nine patients with OCD were randomly assigned to three groups of sham, 2-mA, or 1-mA transcranial direct current stimulation (tDCS) targeting the l-DLPFC (F3) and pre-SMA (FC2) with anodal and cathodal stimulation respectively. The treatment included 10 sessions of 20-minute stimulation delivered twice per day with 20-min between-session intervals. Outcome measures were reduction in OCD symptoms, anxiety, and depressive states, performance on a neuropsychological test battery (response inhibition, working memory, attention), oscillatory brain activities, and functional connectivity. All outcome measures except EEG were examined at pre-intervention, post-intervention, and 1-month follow-up times. The 2-mA protocol significantly reduced OCD symptoms, anxiety, and depression states and improved quality of life after the intervention up to 1-month follow-up compared to the sham group, while the 1-mA protocol reduced OCD symptoms only in the follow-up and depressive state immediately after and 1-month following the intervention. Both protocols partially improved response inhibition, and the 2-mA protocol reduced attention bias to OCD-related stimuli and improved reaction time in working memory performance. Both protocols increased alpha oscillatory power, and the 2-mA protocol decreased delta power as well. Both protocols increased connectivity in higher frequency bands at frontal-central areas compared to the sham. Modulation of the prefrontal-supplementary motor network with intensified tDCS ameliorates OCD clinical symptoms and results in beneficial cognitive effects. The 2-mA intensified stimulation resulted in larger symptom reduction and improved more converging outcome variables related to therapeutic efficacy. These results support applying the intensified prefrontal-SMA tDCS in larger trials.

EEG microstate co-specificity in schizophrenia and obsessive-compulsive disorder

The past 20 years of research on EEG microstates has yielded the hypothesis that the imbalance pattern in the temporal dynamics of microstates C (increased) and D (decreased) is specific to schizophrenia. A similar microstate imbalance has been recently found in obsessive-compulsive disorder (OCD). The aim of the present high-density EEG study was to examine whether this pathological microstate pattern is co-specific to schizophrenia and OCD. We compared microstate temporal dynamics using Bayesian analyses, transition probabilities analyses and the Topographic Electrophysiological State Source-Imaging method for source reconstruction in 24 OCD patients and 28 schizophrenia patients, respectively, free of comorbid psychotic and OCD symptoms, and 27 healthy controls. OCD and schizophrenia patients exhibited the same increased contribution of microstate C, decreased duration and contribution of microstate D and greater D → C transition probabilities, compared with controls. A Bayes factor of 4.424 for the contribution of microstate C, 4.600 and 3.824, respectively, for the duration and contribution of microstate D demonstrated that there was no difference in microstate patterns between the two disorders. Source reconstruction further showed undistinguishable dysregulations between the Salience Network (SN), associated with microstate C, and the Executive Control Network (ECN), associated with microstate D, and between the ECN and cognitive cortico-striato-thalamo-cortical (CSTC) loop in the two disorders. The ECN/CSTC loop dysconnectivity was slightly worsened in schizophrenia. Our findings provide substantial evidence for a common aetiological pathway in schizophrenia and OCD, i.e. microstate co-specificity, and same anomalies in salience and external attention processing, leading to co-expression of symptoms.

A Controlled Clinical Study of Accelerated High-Dose Theta Burst Stimulation in Patients with Obsessive-Compulsive Disorder

Background

Obsessive-compulsive disorder (OCD) is frequently treated using a combination of counseling, drugs, and, more recently various transcranial stimulation protocols, but all require several weeks to months for clinically significant improvement, so there is a need for treatments with faster onset. This study investigated whether an accelerated high-dose theta burst stimulation (ahTBS) protocol significantly improves the efficacy of OCD compared to traditional 1-Hz repetitive transcranial magnetic stimulation (rTMS) in the routine clinical setting.

Method

Forty-five patients with OCD were randomized into two groups and treated with ahTBS or 1-Hz rTMS for 5 days. Patients were assessed at baseline at the end of treatment using the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS).

Results

After 5 days of treatment, there was a significant decrease in Y-BOCS scores in both groups (p < 0.001), and the difference between the two groups was not statistically significant (group × time interaction, F = 1.90, p=0.18). There was also no statistically significant difference in other secondary outcome indicators, including depression, anxiety symptoms, and response rate. However, the ahTBS group had a greater trend in response rate. Neuropsychological testing showed no negative cognitive side effects of either treatment.

Conclusion

Accelerated high-dose TBS is as safe and has comparable short-term efficacy to traditional 1-Hz rTMS for the clinical treatment of OCD. Further research is needed to explore optimal ahTBS parameters, validate the utility of this treatment modality, and identify factors predictive of rapid clinical response to guide clinical decision-making. This trial is registered with NCT05221632.

Axon morphology and intrinsic cellular properties determine repetitive transcranial magnetic stimulation threshold for plasticity

Repetitive transcranial magnetic stimulation (rTMS) is a widely used therapeutic tool in neurology and psychiatry, but its cellular and molecular mechanisms are not fully understood. Standardizing stimulus parameters, specifically electric field strength and direction, is crucial in experimental and clinical settings. It enables meaningful comparisons across studies and facilitating the translation of findings into clinical practice. However, the impact of biophysical properties inherent to the stimulated neurons and networks on the outcome of rTMS protocols remains not well understood. Consequently, achieving standardization of biological effects across different brain regions and subjects poses a significant challenge. This study compared the effects of 10 Hz repetitive magnetic stimulation (rMS) in entorhino-hippocampal tissue cultures from mice and rats, providing insights into the impact of the same stimulation protocol on similar neuronal networks under standardized conditions. We observed the previously described plastic changes in excitatory and inhibitory synaptic strength of CA1 pyramidal neurons in both mouse and rat tissue cultures, but a higher stimulation intensity was required for the induction of rMS-induced synaptic plasticity in rat tissue cultures. Through systematic comparison of neuronal structural and functional properties and computational modeling, we found that morphological parameters of CA1 pyramidal neurons alone are insufficient to explain the observed differences between the groups. However, axon morphologies of individual cells played a significant role in determining activation thresholds. Notably, differences in intrinsic cellular properties were sufficient to account for the 10 % higher intensity required for the induction of synaptic plasticity in the rat tissue cultures. These findings demonstrate the critical importance of axon morphology and intrinsic cellular properties in predicting the plasticity effects of rTMS, carrying valuable implications for the development of computer models aimed at predicting and standardizing the biological effects of rTMS.

Fatigue Potentially Reduces the Effect of Transcranial Magnetic Stimulation on Depression Following COVID-19 and Its Vaccination

COVID-19's long-term effects, known as Long-COVID, present psychiatric and physical challenges in recovered patients. Similarly, rare long-term post-vaccination side effects, resembling Long-COVID, are emerging (called Post-Vaccine). However, effective treatments for both conditions are scarce. Our clinical experience suggests that transcranial magnetic stimulation (TMS) often aids recovery in Long-COVID and Post-Vaccine patients. However, its effectiveness is reduced in patients with severe fatigue. Therefore, we retrospectively analysed Tokyo TMS Clinic's outpatient records (60 in total; mean age, 38 years) to compare Long-COVID and post-vaccine patients' characteristics and symptoms, assess the impact of TMS on their symptoms, and investigate the role of fatigue in depression recovery with TMS. The primary outcome was the regression coefficient of the initial fatigue score on depression score improvement using TMS. Secondary outcomes included psychiatric/physical scores before and after TMS and their improvement rates. We found no differences in the initial symptoms and background factors between Long-COVID and Post-Vaccine patients. After ten TMS sessions, all psychiatric and physical symptom scores improved significantly. TMS improves depression, insomnia, anxiety, and related neuropsychiatric symptoms, which were the primary complaints in this study. Thus, we conclude that TMS improves depression and anxiety. The effectiveness of TMS in treating depression in Long-COVID and Post-Vaccine patients decreased as fatigue severity increased. In conclusion, TMS relieved depressive symptoms following COVID-19 and vaccination; however, fatigue may hinder its effectiveness.

A Case Series of Continuous Theta Burst Stimulation Treatment for the Supplementary Motor Area Twice a Day in Patients with Obsessive-Compulsive Disorder: A Real World TMS Registry Study in Japan

Obsessive-compulsive disorder (OCD) is a psychiatric disorder characterized by patterns in which unwanted thoughts and fears are evoked as obsessions and furthermore, compulsive behaviors are provoked repeatedly, with a prevalence rate of 2% of the population. These obsessive-compulsive symptoms disrupt daily life and cause great distress to the individual. At present, OCD is treated with antidepressants, mainly selective serotonin reuptake inhibitors, and psychotherapy, including the exposure and response prevention method. However, these approaches may only show a certain level of efficacy, and approximately 50% of patients with OCD show treatment resistance. This situation has led to the research and development of neuromodulation therapies, including transcranial magnetic stimulation treatment, for OCD worldwide in recent years. In this case series, we retrospectively analyzed the TMS registry data of continuous theta burst stimulation (cTBS) therapy targeting the bilateral supplementary motor cortex for six patients with OCD whose obsessive-compulsive symptoms had not improved with pharmacotherapy. The results suggest that treatment with cTBS for the bilateral supplementary motor area may reduce obsessive-compulsive symptoms in patients with OCD, despite the limitations of an open-label preliminary case series. The present findings warrant further validation with a randomized, sham-controlled trial with a larger sample size in the future.

Transcriptome Sequencing of CeRNA Network Constructing in Status Epilepticus Mice Treated by Low-Frequency Repetitive Transcranial Magnetic Stimulation

It is shown that great progress was recently made in the treatment of repetitive transcranial magnetic stimulation (rTMS) for neurological and psychiatric diseases. This study aimed to address how rTMS exerted it therapeutic effects by regulating competitive endogenous RNAs (ceRNAs) of lncRNA-miRNA-mRNA. The distinction of lncRNA, miRNA and mRNA expression in male status epilepticus (SE) mice treated by two different ways, low-frequency rTMS (LF-rTMS) vs. sham rTMS, was analyzed by high-throughput sequencing. The Gene Ontology (GO) functional enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were carried out. Gene-Gene Cross Linkage Network was established; pivotal genes were screened out. qRT-PCR was used to verify gene-gene interactions. Our results showed that there were 1615 lncRNAs, 510 mRNAs, and 17 miRNAs differentially which were expressed between the LF-rTMS group and the sham rTMS group. The expression difference of these lncRNAs, mRNAs, and miRNAs by microarray detection were consistent with the results by qPCR. GO functional enrichment showed that immune-associated molecular mechanisms, biological processes, and GABA-A receptor activity played a role in SE mice treated with LF-rTMS. KEGG pathway enrichment analysis revealed that differentially expressed genes were correlated to T cell receptor signaling pathway, primary immune deficiency and Th17 cell differentiation signaling pathway. Gene-gene cross linkage network was established on the basis of Pearson's correlation coefficient and miRNA. In conclusion, LF-rTMS alleviates SE through regulating the GABA-A receptor activity transmission, improving immune functions, and biological processes, suggesting the underlying ceRNA molecular mechanisms of LF-rTMS treatment for epilepsy.

Electrical stimulation methods and protocols for the treatment of traumatic brain injury: a critical review of preclinical research

BACKGROUND

Traumatic brain injury (TBI) is a leading cause of disabilities resulting from cognitive and neurological deficits, as well as psychological disorders. Only recently, preclinical research on electrical stimulation methods as a potential treatment of TBI sequelae has gained more traction. However, the underlying mechanisms of the anticipated improvements induced by these methods are still not fully understood. It remains unclear in which stage after TBI they are best applied to optimize the therapeutic outcome, preferably with persisting effects. Studies with animal models address these questions and investigate beneficial long- and short-term changes mediated by these novel modalities.

METHODS

In this review, we present the state-of-the-art in preclinical research on electrical stimulation methods used to treat TBI sequelae. We analyze publications on the most commonly used electrical stimulation methods, namely transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), deep brain stimulation (DBS) and vagus nerve stimulation (VNS), that aim to treat disabilities caused by TBI. We discuss applied stimulation parameters, such as the amplitude, frequency, and length of stimulation, as well as stimulation time frames, specifically the onset of stimulation, how often stimulation sessions were repeated and the total length of the treatment. These parameters are then analyzed in the context of injury severity, the disability under investigation and the stimulated location, and the resulting therapeutic effects are compared. We provide a comprehensive and critical review and discuss directions for future research. RESULTS AND CONCLUSION: We find that the parameters used in studies on each of these stimulation methods vary widely, making it difficult to draw direct comparisons between stimulation protocols and therapeutic outcome. Persisting beneficial effects and adverse consequences of electrical simulation are rarely investigated, leaving many questions about their suitability for clinical applications. Nevertheless, we conclude that the stimulation methods discussed here show promising results that could be further supported by additional research in this field.

Direct changes of neurometabolic concentrations in the pregenual anterior cingulate cortex among obsessive-compulsive patients after repetitive transcranial magnetic stimulation treatment

BACKGROUND AND AIM

Although Repetitive Transcranial Magnetic Stimulation (rTMS) is a promising new noninvasive brain stimulation therapy, its underlying mechanisms of action remain unknown. OCD patients exhibit impaired response control and attention shifting, which is linked to some brain areas such as anterior cingulate cortex and basal ganglia. OCD patients also display altered neurometabolic concentrations in cortical cortical-striatal-thalamic-cortical (CSTC). In this study, we aimed to elucidate efficacy of rTMS treatment in alleviating related symptoms and pregenual anterior cingulate cortex (pACC) neurometabolites.

METHODS

OCD patients were randomly divided into either drug (n = 23) or drug + rTMS (n = 29) groups, and those in the latter group subjected to 4-week rTMS treatment. All participants were visited twice, at baseline and follow-up after four weeks. During both visits, all patients were subjected to 1H-MRS, then Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and the Global Assessment Function (GAF) used to assess severity of obsessive-compulsive symptoms. We also evaluated synchronous anxiety and depression by Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI), Hamilton Anxiety Scale (HAM-A) and Hamilton Depression Scale (HAM-D).

RESULTS

After 4 weeks of treatment, patients in the Drug + rTMS group displayed significantly lower Y-BOCS (p = 0.038), BDI (p = 0.009), HAM-D (p = 0.013), HAM-A (p = 0.012) scores than their counterparts in the Drug group. Conversely, patients in the Drug + rTMS group had significantly higher tNAA concentrations (p = 0.030) than those in the Drug group. Notably, the Drug + rTMS group exhibited higher, but insignificant Glu (p = 0.055) and Glx (p = 0.068) concentrations compared to the Drug group. Partial correlation analysis revealed a significant negative correlation between post HAM-A scores and 4-week change of pACC glutamate levels in the Drug + rTMS group (r = -0.434, p = 0.02).

CONCLUSION

rTMS treatment is an efficacious treatment therapy for OCD, mainly by inducing changes in neurometabolites.

World Federation of Societies of Biological Psychiatry (WFSBP) guidelines for treatment of anxiety, obsessive-compulsive and posttraumatic stress disorders - Version 3. Part II: OCD and PTSD

AIM

This is the third version of the guideline of the World Federation of Societies of Biological Psychiatry (WFSBP) Task Force for the Pharmacological Treatment of Anxiety, Obsessive-Compulsive and Posttraumatic Stress Disorders which was published in 2002 and revised in 2008.

METHOD

A consensus panel of 34 international experts representing 22 countries developed recommendations based on efficacy and acceptability of the treatments. In this version, not only medications but also psychotherapies and other non-pharmacological interventions were evaluated, applying the same rigorous methods that are standard for the assessment of medication treatments.

RESULT

The present paper (Part II) contains recommendations based on published randomised controlled trials (RCTs) for the treatment of OCD (n = 291) and PTSD (n = 234) in children, adolescents, and adults. The accompanying paper (Part I) contains the recommendations for the treatment of anxiety disorders.For OCD, first-line treatments are selective serotonin reuptake inhibitors (SSRIs) and cognitive behavioural therapy (CBT). Internet-CBT was also superior to active controls. Several second-line medications are available, including clomipramine. For treatment-resistant cases, several options are available, including augmentation of SSRI treatment with antipsychotics and other drugs.Other non-pharmacological treatments, including repetitive transcranial magnetic stimulation (rTMS), deep brain stimulation (DBS) and others were also evaluated.For PTSD, SSRIs and the SNRI venlafaxine are first-line treatments. CBT is the psychotherapy modality with the best body of evidence. For treatment-unresponsive patients, augmentation of SSRI treatment with antipsychotics may be an option.

CONCLUSION

OCD and PTSD can be effectively treated with CBT and medications.

A double blind randomized clinical trial of the effectiveness of low frequency rTMS over right DLPFC or OFC for treatment of obsessive-compulsive disorder

We compared the effectiveness of low frequency repetitive transcranial magnetic stimulation over right dorsolateral prefrontal cortex (DLPFC), right orbitofrontal cortex (OFC) and sham for treatment of obsessive-compulsive disorder (OCD) and sought to determine possible predictors of effective treatment. Sixty OCD patients participated and were randomly allocated to one of the 3 treatment groups. Treatment was administered daily for 10 days. Assessments were made at the beginning and end of therapy as well as three months later using the Yale-Brown obsessive compulsive scale (Y-BOCS), Hamilton Anxiety Rating Scale (HAM-A), Beck Depression Inventory (BDI), and Clinical Global Impression - Severity scale (CGI-S). There were no significant demographic or clinical differences between the groups at baseline. One-way repeated measures ANOVA showed that participants in all 3 groups improved their scores on all rating scales following treatment. A two-way repeated measures ANOVA revealed a significant time and group interaction due to the fact that both active treatment groups outperformed the sham group, although there was no significant difference between the two. Percent improvement had significant negative correlations with the following factors: duration of illness, baseline Y-BOCS, HAM-A, and BDI. We conclude that rTMS over either right DLPFC or OFC has a therapeutic effect on OCD symptoms. Patients with lower Y-BOCS and fewer comorbidities responded best to rTMS.

Targeting Three Brain Regions (Bilateral SMA, Left and Right DLPFC) Sequentially in One Session Using Combined Repetitive Transcranial Magnetic Stimulation and Intermittent Theta-burst Stimulation in Treatment-refractory Obsessive-compulsive Disorder: A Case Report

Repetitive transcranial magnetic stimulation (rTMS) has been widely used as a therapy for refractory obsessive-compulsive disorder (OCD). However, it remains unclear which exact target and stimulation sequence of rTMS is most effective for OCD. Here, we report the case of an 18-year-old female with treatment-refractory OCD whose symptoms markedly improved after combined rTMS and intermittent theta-burst stimulation over the bilateral dorsolateral prefrontal cortex and supplementary motor area. Our report indicates that combining treatment sequences that stimulate different brain regions sequentially is feasible and may clinically benefit patients suffering from OCD.

Assessing the Effectiveness of Repetitive Transcranial Magnetic Stimulation in the Treatment of Obsessive- Compulsive Disorder

Objective. Obsessive-compulsive disorder (OCD) is a frequent and disabling neuropsychiatric disorder with a lifetime prevalence of 3%. About 40% to 60% of patients show no or just partial symptom improvement to treatment with a first-line drug and cognitive behavior therapy. Ten percent of patients remain treatment refractory despite several treatments. For these patients, repetitive Transcranial Magnetic Stimulation (rTMS) has been suggested as a treatment option. Method. We investigated the efficacy of rTMS on the Supplementary Motor Area (SMA) in 16 right handed pharmaco-resistant OCD patients in an outpatient setting. The patients have been diagnosed with OCD by two psychiatrists and referred for rTMS intervention. Patients received 16 sessions of low frequency (0.5 HZ) rTMS on SMA,100% motor threshold, 1200 stimuli/day for 40 minutes every other day. OCD, depression, and anxiety symptoms were measured at baseline, 2, 6, and 12 weeks by Yale-Brown Obsessive Compulsive Scale(Y-BOCS) and Hamilton Depressive and Anxiety rating scales (HAM-D and HAM-A). We assessed the side effects of rTMS by a self-administrative questionnaire. Results. Patients' scores in Y-BOCS, HAM-D, and HAM-A were significantly decreased following rTMS treatment. The baseline and 12 weeks scores of Y-BOCS were 28.94 and 18.31 (P-value < 0.01), HAM-D were 14.69 and 7.94 (P-value <0.01) and HAM-A were 16.38 and 6.94 (P- value < 0.01), respectively. The patients reported no serious side effects of rTMS except two case that reported light headach. Conclusion. This study showed that low-frequency rTMS on SMA improved OCD, anxiety, and depression symptoms after 16 sessions.

Continuous theta burst stimulation over the bilateral supplementary motor area in obsessive-compulsive disorder treatment: A clinical randomized single-blind sham-controlled trial

BACKGROUND

Obsessive-compulsive disorder (OCD) can cause substantial damage to quality of life. Continuous theta burst stimulation (cTBS) is a promising treatment for OCD patients with the advantages of safety and noninvasiveness.

OBJECTIVE

The present study aimed to evaluate the treatment efficacy of cTBS over the bilateral supplementary motor area (SMA) for OCD patients with a single-blind, sham-controlled design.

METHODS

Fifty-four OCD patients were randomized to receive active or sham cTBS treatment over the bilateral SMA for 4 weeks (five sessions per week, 20 sessions in total). Patients were assessed at baseline (week 0), the end of treatment (week 4), and follow-up (week 8). Clinical scales included the YBOCS, HAMD₂₄, HAMA₁₄, and OBQ₄₄. Three behavioral tests were also conducted to explore the effect of cTBS on response inhibition and decision-making in OCD patients.

RESULTS

The treatment response rates were not significantly different between the two groups at week 4 (active: 23.1% vs. sham: 16.7%, p = 0.571) and week 8 (active: 26.9% vs. sham: 16.7%, p = 0.382). Depression and anxiety improvements were significantly different between the two groups at week 4 (HAMD₂₄: F = 4.644, p = 0.037; HAMA₁₄: F = 5.219, p = 0.028). There was no significant difference between the two groups in the performance of three behavioral tests. The treatment satisfaction and dropout rates were not significantly different between the two groups.

CONCLUSIONS

The treatment of cTBS over the bilateral SMA was safe and tolerable, and it could significantly improve the depression and anxiety of OCD patients but was not enough to improve OCD symptoms in this study.

Repetitive transcranial magnetic stimulation (r-TMS) and selective serotonin reuptake inhibitor-resistance in obsessive-compulsive disorder: A meta-analysis and clinical implications

INTRODUCTION

Despite promising results from several randomized controlled trials (RCTs) and meta-analyses, the efficacy of r-TMS as a treatment for OCD remains controversial, at least in part owing to inconsistency in the trial methodologies and heterogeneity in the trial outcomes. This meta-analysis attempts to explain some of this heterogeneity by comparing the efficacy of r-TMS in patients with or without resistance to treatment with selective serotonin reuptake inhibitors (SSRI), defined using standardized criteria.

METHODS

We conducted a pre-registered (PROSPERO ID: 241381) systematic review and meta-analysis. English language articles reporting blinded RCTs were retrieved from searches using MEDLINE, PsycINFO, and Cochrane Library databases. Studies were subjected to subgroup analysis based on four stages of treatment resistance, defined using an adaptation of published criteria (1 = not treatment resistant, 2 = one SSRI trial failed, 3 = two SSRI trials failed, 4 = two SSRI trials failed plus one or more CBT trial failed). Meta-regression analyses investigated patient and methodological factors (age, duration of OCD, illness severity, stage of treatment-resistance, or researcher allegiance) as possible moderators of effect size.

RESULTS

Twenty-five independent comparisons (23 studies) were included. Overall, r-TMS showed a medium-sized reduction of Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) scores (Hedge's g: -0.47; 95%CI: - 0.67 to -0.27) with moderate heterogeneity (I² = 39.8%). Assessment of publication bias using Trim and Fill analysis suggested a reduced effect size that remained significant (g: -0.29; 95%CI: -0.51 to -0.07). Subgroup analysis found that those studies including patients non-resistant to SSRI (stage 1) (g: -0.65; 95%CI: -1.05 to -0.25, k = 7) or with low SSRI-resistance (stage 2) (g:-0.47; 95%CI: -0.86 to -0.09, k = 6) produced statistically significant results with low heterogeneity, while studies including more highly resistant patients at stage 3 (g: -0.39; 95%CI: -0.90 to 0.11, k = 4) and stage 4 (g: -0.36; 95%CI: -0.75 to 0.03, k = 8) did not. Intriguingly, the only significant moderator of the effect size found by meta-regression was the severity of baseline depressive symptoms. All trials showed evidence of researcher allegiance in favour of the intervention and therefore caution is required in interpreting the reported effect sizes.

CONCLUSION

This meta-analysis shows that r-TMS is an effective treatment for OCD, but largely for those not resistant to SSRI or failing to respond to only one SSRI trial. As a consequence, r-TMS may be best implemented earlier in the care pathway. These findings would have major implications for clinical service development, but further well-powered RCTs, which eliminate bias from researcher allegiance, are needed before definitive conclusions can be drawn.

Boosting psychological change: Combining non-invasive brain stimulation with psychotherapy

Mental health disorders and substance use disorders are a leading cause of morbidity and mortality worldwide, and one of the most important challenges for public health systems. While evidence-based psychotherapy is generally pursued to address mental health challenges, psychological change is often hampered by non-adherence to treatments, relapses, and practical barriers (e.g., time, cost). In recent decades, Non-invasive brain stimulation (NIBS) techniques have emerged as promising tools to directly target dysfunctional neural circuitry and promote long-lasting plastic changes. While the therapeutic efficacy of NIBS protocols for mental illnesses has been established, neuromodulatory interventions might also be employed to support the processes activated by psychotherapy. Indeed, combining psychotherapy with NIBS might help tailor the treatment to the patient's unique characteristics and therapeutic goal, and would allow more direct control of the neuronal changes induced by therapy. Herein, we overview emerging evidence on the use of NIBS to enhance the psychotherapeutic effect, while highlighting the next steps in advancing clinical and research methods toward personalized intervention approaches.

Adjunctive neuronavigated accelerated continuous theta-burst stimulation in obsessive-compulsive disorder: a randomized sham-controlled study

BACKGROUND

Approximately 40% of patients treated for obsessive-compulsive disorder (OCD) do not respond to standard and second-line augmentation treatments leading to the exploration of alternate biological treatments. Continuous theta burst stimulation (cTBS) is a form of repetitive transcranial magnetic stimulation inducing more rapid and longer-lasting effects on synaptic plasticity than the latter. To the best of our knowledge, only one recent study and a case report investigated the effect of cTBS at the supplementary motor area (SMA) in OCD.

OBJECTIVE

This study aimed to examine the effect of accelerated robotized neuronavigated cTBS over SMA in patients with OCD.

METHODS

A total of 32 patients with OCD were enrolled and randomized into active and sham cTBS groups. For active cTBS stimulation, an accelerated protocol was used. Bursts of three stimuli at 50 Hz, at 80% of MT, repeated at 5 Hz were used. Daily 2 sessions of 900 pulses each, for a total of 30 sessions over 3 wk (weekly 10 sessions), were given. Yale-Brown Obsessive-Compulsive Rating Scale (YBOCS), Clinical Global Impressions scale (CGI), Hamilton Depression Rating Scale (HAM-D), and Hamilton Anxiety Rating Scale (HAM-A) were administered at baseline and at end of weeks 3 and 8.

RESULTS

A total of 26 patients completed the study. Active cTBS group showed significant group × time effect in YBOCS obsession (P < .001, η2 = 0.288), compulsion (P = .004, η2 = 0.207), YBOCS total (P < .001, η2 = 0.288), CGI-S (P = .010, η2 = 0.248), CGI-C (P = .010, η2 = 0.248), HAM-D (P = .014, η2 = 0.224) than sham cTBS group.

CONCLUSIONS

Findings from our study suggest that adjunctive accelerated cTBS significantly improves psychopathology, severity of illness, and depression among patients with OCD. Future studies with larger sample sizes will add to our knowledge.

The functional connectivity predictor of therapeutic effect of continuous theta burst stimulation on obsessive-compulsive disorder: A preliminary study

OBJECTIVE

To evaluate the efficacy of continuous theta burst stimulation (cTBS) on the bilateral supplementary motor area (SMA) among patients with obsessive-compulsive disorder (OCD) and to explore the potential predictors of cTBS outcome based on neuroimaging.

METHODS

29 OCD patients and 29 healthy controls (HCs) were enrolled in this pilot study. Twenty consecutive cTBS intervention targeting at bilateral SMA was applied. MRI scan was carried out before cTBS and 15 regions in the executive control and sensorimotor network were chosen and analyzed using MATLAB, DPABI, and SPM12.

RESULTS

11 out of 29 patients responded to cTBS (37.93%), and the clinical symptom of OCD patients was significantly relieved after receiving regular cTBS. Also, the FC between Cerebelum_Crus2_L and Frontal_Inf_Tri_L of OCD patients showed positive prognosis for the efficacy of cTBS, with the area under the curve (AUC) of 0.85 (95% confidence interval: 0.718-0.989, p = 0.002). None of the patients had any serious adverse event.

CONCLUSION

cTBS intervention on bilateral SMA can significantly improve the symptoms of medicated OCD patients with moderate severity. And the pretherapy FC could be a valuable potential predictor of the cTBS treatment outcome among OCD patients.

Neuromodulation of OCD: A review of invasive and non-invasive methods

Early research into neural correlates of obsessive compulsive disorder (OCD) has focused on individual components, several network-based models have emerged from more recent data on dysfunction within brain networks, including the the lateral orbitofrontal cortex (lOFC)-ventromedial caudate, limbic, salience, and default mode networks. Moreover, the interplay between multiple brain networks has been increasingly recognized. As the understanding of the neural circuitry underlying the pathophysiology of OCD continues to evolve, so will too our ability to specifically target these networks using invasive and noninvasive methods. This review discusses the rationale for and theory behind neuromodulation in the treatment of OCD.

Exploring the spatial resolution of TMS-EEG coupling on the sensorimotor region

The use of TMS-EEG coupling as a neuroimaging tool for the functional exploration of the human brain recently gained strong interest. If this tool directly inherits the fine temporal resolution from EEG, its spatial counterpart remains unknown. In this study, we explored the spatial resolution of TMS-EEG coupling by evaluating the minimal distance between two stimulated cortical sites that would significantly evoke different response dynamics. TMS evoked responses were mapped on the sensorimotor region in twenty participants. The stimulation grid was composed of nine targets separated between 10 and 15 mm on average. The dynamical signatures of TMS evoked activity were extracted and compared between sites using both local and remote linear regression scores and spatial generalized mixed models. We found a significant effect of the distance between stimulated sites on their dynamical signatures, neighboring sites showing differentiable response dynamics. Besides, common dynamical signatures were also found between sites up to 25-30 mm from each other. This overlap in dynamical properties decreased with distance and was stronger between sites within the same Brodmann area. Our results suggest that the spatial resolution of TMS-EEG coupling might be at least as high as 10 mm. Furthermore, our results reveal an anisotropic spatial resolution that was higher across than within the same Brodmann areas, in accordance with the TMS induced E-field modeling. Common cytoarchitectonic leading to shared dynamical properties within the same Brodmann area could also explain this anisotropy. Overall, these findings suggest that TMS-EEG benefits from the spatial resolution of TMS, which makes it an accurate technique for meso-scale brain mapping.

Transcranial Magnetic Stimulation in the Treatment of Neurological Diseases

Transcranial Magnetic Stimulation (TMS) has widespread use in research and clinical application. For psychiatric applications, such as depression or OCD, repetitive TMS protocols (rTMS) are an established and globally applied treatment option. While promising, rTMS is not yet as common in treating neurological diseases, except for neurorehabilitation after (motor) stroke and neuropathic pain treatment. This may soon change. New clinical studies testing the potential of rTMS in various other neurological conditions appear at a rapid pace. This can prove challenging for both practitioners and clinical researchers. Although most of these neurological applications have not yet received the same level of scientific/empirical scrutiny as motor stroke and neuropathic pain, the results are encouraging, opening new doors for TMS in neurology. We here review the latest clinical evidence for rTMS in pioneering neurological applications including movement disorders, Alzheimer's disease/mild cognitive impairment, epilepsy, multiple sclerosis, and disorders of consciousness.

Damage to the dorsolateral prefrontal cortex is associated with repetitive compulsive behaviors in patients with penetrating brain injury

Background

Damage to cortico-striato-thalamo-cortical (CSTC) circuits is associated with the development of repetitive behaviours in animals and humans. However, the types of repetitive behaviours that are developed after injury to these structures are poorly defined. This study examines the effect of damage to separate elements of CSTC circuits sustained by veterans of the Vietnam War on obsessions, compulsions, and tics.

Methods

We performed partial correlations (correcting for cognition, age, education, and global brain damage) between volume loss from traumatic brain injury in specific elements of CSTC circuits (lateral and medial orbitofrontal and dorsolateral prefrontal cortices, anterior cingulate cortex, thalamus, and basal ganglia) and scores on a modified version of the Yale-Brown Obsessive Compulsive Scale Symptom Checklist and the Yale Global Tic Severity Scale in 83 Vietnam war veterans with penetrating brain injuries at different sites throughout the brain.

Results

We found that volume loss in the left dorsolateral prefrontal cortex was associated with the development of compulsive behaviours (r=0.32, padj<0.05) whereas volume loss in the basal ganglia was associated with the development of tics (r=0.33, padj<0.05).

Conclusion

Our findings indicate that damage to specific CSTC elements can be associated with the development of compulsive behaviours and tics that are not necessarily accompanied by obsessions.

Altered Spontaneous Brain Activity Patterns in Children With Strabismic Amblyopia After Low-Frequency Repetitive Transcranial Magnetic Stimulation: A Resting-State Functional Magnetic Resonance Imaging Study

Objective

Previous studies have demonstrated altered brain activity in strabismic amblyopia (SA). In this study, low-frequency repetitive transcranial magnetic stimulation (rTMS) was applied in children with strabismic amblyopia after they had undergone strabismus surgery. The effect of rTMS was investigated by measuring the changes of brain features using the amplitude of low-frequency fluctuation (ALFF).

Materials and Methods

In this study, 21 SA patients (12 males and 9 females) were recruited based on their age (7–13 years old), weight, and sex. They all had SA in their left eyes and they received rTMS treatment one month after strabismus surgery. Their vision before and after surgery were categorized as pre-rTMS (PRT) and post-rTMS (POT). All participants received rTMS treatment, underwent magnetic resonance imaging (MRI), and their data were analyzed using the repeated measures t-test. The team used correlation analysis to explore the relationship between logMAR visual acuity and ALFF.

Results

Pre- versus post-rTMS values of ALFF were significantly different within individuals. In the POT group, ALFF values were significantly decreased in the Angular_R (AR), Parietal_Inf_L (PIL), and Cingulum_Mid_R (CMR) while ALFF values were significantly increased in the Fusiform_R (FR) and Frontal_Inf_Orb_L(FIL) compared to the PRT stage.

Conclusion

Our data showed that ALFF recorded from some brain regions was changed significantly after rTMS in strabismic amblyopes. The results may infer the pathological basis of SA and demonstrate that visual function may be improved using rTMS in strabismic amblyopic patients.

Repetitive transcranial magnetic stimulation for obsessive-compulsive disorder: A systematic review and pairwise/network meta-analysis

Background We evaluated the efficacy and safety of repetitive transcranial magnetic stimulation (rTMS) for obsessive-compulsive disorder (OCD), and ranked the relative efficacy of different stimulation protocols. Methods We performed a search for randomised, sham-controlled trials of rTMS for OCD. The primary analysis included both a pairwise meta-analysis and a series of frequentist network meta-analyses (NMA) of OCD symptom severity. Secondary analyses were carried out on relevant clinical factors and safety. Results 21 studies involving 662 patients were included. The pairwise meta-analysis showed that rTMS for OCD is efficacious across all protocols (Hedges' g=-0.502 [95%CI= -0.708, -0.296]). The first NMA, with stimulation protocols clustered only by anatomical location, showed that both dorsolateral prefrontal cortex (dlPFC) stimulation and medial frontal cortex stimulation were efficacious. In the second NMA, considering each unique combination of frequency and location separately, low frequency (LF) pre-supplementary motor area (preSMA) stimulation, high frequency (HF) bilateral dlPFC stimulation, and LF right dlPFC stimulation were all efficacious . LF right dlPFC was ranked highest in terms of efficacy, although the corresponding confidence intervals overlapped with the other two protocols. Limitations Evidence base included mostly small studies, with only a few studies using similar protocols, giving a sparse network. Studies were heterogeneous, and a risk of publication bias was found. Conclusions rTMS for OCD was efficacious compared with sham stimulation. LF right dlPFC, HF bilateral dlPFC and LF preSMA stimulation were all efficacious protocols with significant and comparable clinical improvements. Future studies should further investigate the relative merits of these three protocols.

Safety and efficacy of early augmentation with repetitive transcranial magnetic stimulation in the treatment of drug-free patients with obsessive-compulsive disorder

BACKGROUND

Obsessive-compulsive disorder (OCD) is a chronic psychiatric disorder that results in significant disability and substantial compromise in the quality of life. Until now, the role of repetitive transcranial magnetic stimulation (rTMS) has been primarily explored in individuals with treatment-resistant OCD. In this study, we investigated the safety and efficacy of rTMS as an early augmentation strategy in drug-free patients with OCD.

METHODS

This is a randomized double-blind, placebo-controlled study that involved the administration of a total of 20 sessions of rTMS (active/sham) to drug-naïve OCD patients using a standard protocol (1-Hz; 20 trains [80 pulses/train]; 1600 pulses per session at 100% resting motor threshold) at supplementary motor area. All patients (active and sham) were started on escitalopram 10 mg/d, which was subsequently increased to 20 mg/d after 10 days.

RESULTS

Out of the 24 patients, 13 received active and 11 received sham rTMS. At the end of rTMS therapy, there was a substantial reduction (P = .001) in total Yale-Brown Obsessive-Compulsive Scale, obsessions (P = .030) and compulsions (P = .001) between the groups. Only few patients (N = 8) reported mild side effect with rTMS, local pain, and headache being the commonest. The study revealed large effect size (Cohen's d = 1.6) of rTMS as an early augmentation strategy in drug-free patients of OCD.

CONCLUSIONS

rTMS is a safe and effective early augmentation strategy in the management of OCD. Larger randomized controlled trials are required to establish the therapeutic role of rTMS as early augmentation in OCD.

Psychiatric Applications of Repetitive Transcranial Magnetic Stimulation

Transcranial magnetic stimulation (TMS) is an increasingly popular noninvasive brain stimulation modality. In TMS, a pulsed magnetic field is used to noninvasively stimulate a targeted brain region. Repeated stimulation produces lasting changes in brain activity via mechanisms of synaptic plasticity similar to long-term potentiation. Local application of TMS alters activity in distant, functionally connected brain regions, indicating that TMS modulates activity of cortical networks. TMS has been approved by the U.S. Food and Drug Administration for the treatment of major depressive disorder, obsessive-compulsive disorder, and smoking cessation, and a growing evidence base supports its efficacy in the treatment of other neuropsychiatric conditions. TMS is rapidly becoming part of the standard of care for treatment-resistant depression, where it yields response rates of 40%-60%. TMS is generally safe and well tolerated; its most serious risk is seizure, which occurs very rarely. This review aims to familiarize practicing psychiatrists with basic principles of TMS, including target localization, commonly used treatment protocols and their outcomes, and safety and tolerability. Practical considerations, including evaluation and monitoring of patients undergoing TMS, device selection, treatment setting, and insurance reimbursement, are also reviewed.

Motor cortical inhibitory deficits in patients with obsessive-compulsive disorder-A systematic review and meta-analysis of transcranial magnetic stimulation literature

INTRODUCTION

Obsessive-compulsive disorder (OCD) is a highly prevalent chronic disorder, often refractory to treatment. While remaining elusive, a full understanding of the pathophysiology of OCD is crucial to optimize treatment. Transcranial magnetic stimulation (TMS) is a non-invasive technique that, paired with other neurophysiological techniques, such as electromyography, allows for in vivo assessment of human corticospinal neurophysiology. It has been used in clinical populations, including comparisons of patients with OCD and control volunteers. Results are often contradictory, and it is unclear if such measures change after treatment. Here we summarize research comparing corticospinal excitability between patients with OCD and control volunteers, and explore the effects of treatment with repetitive TMS (rTMS) on these excitability measures.

METHODS

We conducted a systematic review and meta-analysis of case-control studies comparing various motor cortical excitability measures in patients with OCD and control volunteers. Whenever possible, we meta-analyzed motor cortical excitability changes after rTMS treatment.

RESULTS

From 1,282 articles, 17 reporting motor cortex excitability measures were included in quantitative analyses. Meta-analysis regarding cortical silent period shows inhibitory deficits in patients with OCD, when compared to control volunteers. We found no statistically significant differences in the remaining meta-analyses, and no evidence, in patients with OCD, of pre- to post-rTMS changes in resting motor threshold, the only excitability measure for which longitudinal data were reported.

DISCUSSION

Our work suggests an inhibitory deficit of motor cortex excitability in patients with OCD when compared to control volunteers. Cortical silent period is believed to reflect activity of GABA_B receptors, which is in line with neuroimaging research, showing GABAergic deficits in patients with OCD. Regardless of its effect on OCD symptoms, rTMS apparently does not modify Resting Motor Threshold, possibly because this measure reflects glutamatergic synaptic transmission, while rTMS is believed to mainly influence GABAergic function. Our meta-analyses are limited by the small number of studies included, and their methodological heterogeneity. Nonetheless, cortical silent period is a reliable and easily implementable measurement to assess neurophysiology in humans, in vivo. The present review illustrates the importance of pursuing the study of OCD pathophysiology using cortical silent period and other easily accessible, non-invasive measures of cortical excitability.

SYSTEMATIC REVIEW REGISTRATION

[https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020201764], identifier [CRD42020201764].

Efficacy and Tolerability of Repetitive Transcranial Magnetic Stimulation on Suicidal Ideation: A Systemic Review and Meta-Analysis

OBJECTIVE

This study aimed to investigate the efficacy of repetitive transcranial magnetic stimulation (rTMS) in treating suicidal ideation in patients with mental illness.

METHOD

We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Major electronic databases were systematically searched from the time of their inception until July 22, 2021. The primary outcome was the mean change in the scores for suicidal ideation. The secondary outcome was the mean change in depression severity.

RESULTS

Ten randomized controlled trials were eligible with 415 participants in the active treatment group (mean age = 53.78 years; mean proportion of women = 54.5%) and 387 participants in the control group (mean age = 55.52 years; mean proportion of women = 51.78%). rTMS significantly reduced suicidal ideation (k = 10, n = 802, Hedges' g = -0.390, 95% confidence interval [CI] = -0.193 to -0.588, p <.001) and severity of depressive symptoms (k = 9, n = 761, Hedges' g = -0.698, 95% CI = -1.023 to -0.372, p < 0.001) in patients with major mental disorders. In the subgroup analysis, rTMS reduced suicidal ideation among patients with non-treatment-resistant depression (non-TRD) (-0.208) but not in those with TRD. rTMS as combination therapy had a larger effect than did monotherapy (-0.500 vs. -0.210). Suicidal ideation significantly reduced in patients receiving more than ten treatment sessions (-0.255). Importantly, the rTMS group showed favorable tolerability without major adverse events.

CONCLUSION

The study showed that rTMS was effective and well-tolerated in reducing suicidal ideation and depression severity in patients with major mental disorders.

Classification of Obsessive-Compulsive Disorder Using Distance Correlation on Resting-State Functional MRI Images

Both the Pearson correlation and partial correlation methods have been widely used in the resting-state functional MRI (rs-fMRI) studies. However, they can only measure linear relationship, although partial correlation excludes some indirect effects. Recent distance correlation can discover both the linear and non-linear dependencies. Our goal was to use the multivariate pattern analysis to compare the ability of such three correlation methods to distinguish between the patients with obsessive-compulsive disorder (OCD) and healthy control subjects (HCSs), so as to find optimal correlation method. The main process includes four steps. First, the regions of interest are defined by automated anatomical labeling (AAL). Second, functional connectivity (FC) matrices are constructed by the three correlation methods. Third, the best discriminative features are selected by support vector machine recursive feature elimination (SVM-RFE) with a stratified N-fold cross-validation strategy. Finally, these discriminative features are used to train a classifier. We had a total of 128 subjects out of which 61 subjects had OCD and 67 subjects were normal. All the three correlation methods with SVM have achieved good results, among which distance correlation is the best [accuracy = 93.01%, specificity = 89.71%, sensitivity = 95.08%, and area under the receiver-operating characteristic curve (AUC) = 0.94], followed by Pearson correlation and partial correlation is the last. The most discriminative regions of the brain for distance correlation are right dorsolateral superior frontal gyrus, orbital part of left superior frontal gyrus, orbital part of right middle frontal gyrus, right anterior cingulate and paracingulate gyri, left the supplementary motor area, and right precuneus, which are the promising biomarkers of OCD.

Improvements in error-monitoring and symptoms following low-frequency rTMS of dorsal anterior cingulate cortex in obsessive compulsive disorder; a randomized, sham-controlled study

Action monitoring deficit is a core underlying characteristic and endophenotype of Obsessive Compulsive Disorder (OCD). Dorsal anterior cingulate cortex (dACC) is heavily involved in error monitoring and cognitive control, and the hyperactivity in this region is associated with OCD symptom severity. This study aimed to test whether low frequency (LF) repetitive transcranial magnetic stimulation (rTMS) targeting dACC improves both error-monitoring performance and OCD symptoms in a randomized, sham-controlled, double-blind trial design. 20 OCD patients were randomly assigned to receive 20 sessions of Active (n = 10) or Sham (n = 10) rTMS administered twice-daily. Error-monitoring performance and symptom severity were measured pre- and post-treatment using Erikson Flanker tasks and the Yale-Brown Obsessive Compulsive Scale (Y-BOCS), with three month symptom follow-up. Following active-but not sham-rTMS, patients showed improved response time for incongruent stimuli, trials following a correct response, and for reporting and correcting errors. Significant OCD symptom improvement was observed at one-month follow-up for patients who received Active (28.0% reduction) but not Sham (11.7% reduction) stimulation. In OCD patients, LF rTMS of the dACC can simultaneously improve on-line adjustment of behaviour-by enhancing the capacity for rapid error monitoring-and clinical symptoms, suggesting a link between error monitoring impairment and OCD pathophysiology.

Efficacy of repetitive transcranial magnetic stimulation in patients with obsessive-compulsive disorder: a pilot study

BACKGROUND

Obsessive-compulsive disorder (OCD) is a common disabling psychiatric disorder. Considering the lack of an acceptable treatment response in many patients, several efforts have been made to increase the efficacy of therapy. We aimed to evaluate the efficacy of repetitive transcranial magnetic stimulation (rTMS) on the supplementary motor area in the treatment of patients with drug-resistant OCD and examine changes in brain function.

METHODS

This quasi-experimental study was performed on 12 patients who were referred to outpatient clinics of Ibn-e-Sina psychiatric hospital and were diagnosed with OCD according to the clinical and diagnostic criteria of Diagnostic and Statistical Manual of Mental Disorders (DSM-5). All patients received 20 rTMS sessions in their right supplementary motor region. Main outcomes were assessed using quantitative electroencephalography (qEEG) and the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) before and after the intervention. In addition, Y‑BOCS was completed after 10 rTMS sessions and after the 6‑week follow-up. Data were analyzed with SPSS.

RESULTS

Ten of 12 patients completed this study, of whom 7 (70%) were female. The mean age was 36.66 ± 10.28 years. Y‑BOCS overall score significantly decreased over time during the course of study compared to baseline (P < 0.05). A significant decrease in beta wave activity of the parietal and occipital regions was seen in posttreatment qEEG, compared with baseline (P < 0.05).

CONCLUSIONS

rTMS over the supplementary motor area at 20 sessions could effectively improve Y‑BOCS score and decrease beta wave activity in parietal and occipital regions. Further studies are needed to approve these findings in a controlled design.

Toward a neurocircuit-based taxonomy to guide treatment of obsessive-compulsive disorder

An important challenge in mental health research is to translate findings from cognitive neuroscience and neuroimaging research into effective treatments that target the neurobiological alterations involved in psychiatric symptoms. To address this challenge, in this review we propose a heuristic neurocircuit-based taxonomy to guide the treatment of obsessive-compulsive disorder (OCD). We do this by integrating information from several sources. First, we provide case vignettes in which patients with OCD describe their symptoms and discuss different clinical profiles in the phenotypic expression of the condition. Second, we link variations in these clinical profiles to underlying neurocircuit dysfunctions, drawing on findings from neuropsychological and neuroimaging studies in OCD. Third, we consider behavioral, pharmacological, and neuromodulatory treatments that could target those specific neurocircuit dysfunctions. Finally, we suggest methods of testing this neurocircuit-based taxonomy as well as important limitations to this approach that should be considered in future research.

Therapeutic Neurostimulation in Obsessive-Compulsive and Related Disorders: A Systematic Review

Invasive and noninvasive neurostimulation therapies for obsessive-compulsive and related disorders (OCRD) were systematically reviewed with the aim of assessing clinical characteristics, methodologies, neuroanatomical substrates, and varied stimulation parameters. Previous reviews have focused on a narrow scope, statistical rather than clinical significance, grouped together heterogenous protocols, and proposed inconclusive outcomes and directions. Herein, a comprehensive and transdiagnostic evaluation of all clinically relevant determinants is presented with translational clinical recommendations and novel response rates. Electroconvulsive therapy (ECT) studies were limited in number and quality but demonstrated greater efficacy than previously identified. Targeting the pre-SMA/SMA is recommended for transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS). TMS yielded superior outcomes, although polarity findings were conflicting, and refinement of frontal/cognitive control protocols may optimize outcomes. For both techniques, standardization of polarity, more treatment sessions (>20), and targeting multiple structures are encouraged. A deep brain stimulation (DBS) 'sweet spot' of the striatum for OCD was proposed, and CBT is strongly encouraged. Tourette's patients showed less variance and reliance on treatment optimization. Several DBS targets achieved consistent, rapid, and sustained clinical response. Analysis of fiber connectivity, as opposed to precise neural regions, should be implemented for target selection. Standardization of protocols is necessary to achieve translational outcomes.

Pre-supplementary motor network connectivity and clinical outcome of magnetic stimulation in obsessive-compulsive disorder

A large proportion of patients with obsessive–compulsive disorder (OCD) respond unsatisfactorily to pharmacological and psychological treatments. An alternative novel treatment for these patients is repetitive transcranial magnetic stimulation (rTMS). This study aimed to investigate the underlying neural mechanism of rTMS treatment in OCD patients. A total of 37 patients with OCD were randomized to receive real or sham 1‐Hz rTMS (14 days, 30 min/day) over the right pre‐supplementary motor area (preSMA). Resting‐state functional magnetic resonance imaging data were collected before and after rTMS treatment. The individualized target was defined by a personalized functional connectivity map of the subthalamic nucleus. After treatment, patients in the real group showed a better improvement in the Yale–Brown Obsessive Compulsive Scale than the sham group (F_1,35 = 6.0, p = .019). To show the neural mechanism involved, we identified an “ideal target connectivity” before treatment. Leave‐one‐out cross‐validation indicated that this connectivity pattern can significantly predict patients' symptom improvements (r = .60, p = .009). After real treatment, the average connectivity strength of the target network significantly decreased in the real but not in the sham group. This network‐level change was cross‐validated in three independent datasets. Altogether, these findings suggest that personalized magnetic stimulation on preSMA may alleviate obsessive–compulsive symptoms by decreasing the connectivity strength of the target network.

Efficacy and tolerability of repetitive transcranial magnetic stimulation for the treatment of obsessive-compulsive disorder in adults: a systematic review and network meta-analysis

Repetitive transcranial magnetic stimulation (rTMS) has been widely used as an alternative treatment for obsessive-compulsive disorder (OCD). However, the most effective rTMS parameters, such as the targets and stimulation frequencies, remain controversial. Therefore, we aimed to compare and rank the efficacy and tolerability of different rTMS strategies for OCD treatment. We searched five electronic databases from the date of their inception to March 25, 2020. Pairwise meta-analyses and network meta-analyses were performed to synthesize data. We assessed the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework. Twenty-two eligible randomized controlled trials (RCTs) were included. For efficacy, low-frequency (LF) rTMS over the dorsolateral prefrontal cortex (DLPFC; mean difference (MD) 6.34, 95% credible interval (CrI) 2.12-10.42) and supplementary motor area (MD 4.18, 95% CrI 0.83-7.62), and high-frequency rTMS over the DLPFC (MD 3.75, 95% CrI 1.04-6.81) were more effective than sham rTMS. Regarding tolerability, all rTMS treatment strategies were similar to the sham rTMS. The estimated ranking probabilities of treatments showed that LF-rTMS over the DLPFC might be the most effective intervention among all rTMS strategies. However, the quality of evidence regarding efficacy was evaluated as very low. Current evidence suggested a marginal advantage for LF-rTMS over the DLPFC on OCD treatment. High-quality RCTs with low selection and performance bias are needed to further verify the efficacy of specific rTMS strategies for the OCD treatment.

Shared and unique neural mechanisms underlying pediatric trichotillomania and obsessive compulsive disorder

BACKGROUND

Little is known about the neural underpinnings of pediatric trichotillomania (TTM). We examined error-related negativity (ERN)-amplitude and theta-EEG power differences among youth with TTM, OCD, and healthy controls (HC).

METHODS

Forty channel EEG was recorded from 63 pediatric participants (22 with TTM, 22 with OCD, and 19 HC) during the Eriksen Flanker Task. EEG data from inhibitory control were used to derive estimates of ERN amplitude and event-related spectral power associated with motor inhibition.

RESULTS

TTM and HC were similar in brain activity patterns in frontal and central regions and TTM and OCD were similar in the parietal region. Frontal ERN-amplitude was significantly larger in OCD relative to TTM and HC, who did not differ from each other. The TTM group had higher theta power compared to OCD in frontal and central regions, and higher theta than both comparison groups in right motor cortex and superior parietal regions. Within TTM, flanker task performance was correlated with EEG activity in frontal, central, and motor cortices whereas global functioning and impairment were associated with EEG power in bilateral motor and parietal cortices.

CONCLUSIONS

Findings are discussed in terms of shared and unique neural mechanisms in TTM and OCD and treatment implications.

An international survey of different transcranial magnetic stimulation (TMS) protocols for patients with obsessive-compulsive disorder (OCD)

This study aims to evaluate current preferences and trends in the delivery of Transcranial Magnetic Stimulation (TMS) for Obsessive-Compulsive Disorder (OCD). A 10-item online questionnaire was developed and conducted online between April to June 2020, surveying providers of TMS for patients with OCD internationally. A total of 27 valid responses were analysed from 10 countries. The most common target for TMS was the supplementary motor area and stimulation was commonly given bilaterally, but techniques differed between centres. Exposure tasks were not commonly used during TMS. The study calls for more research clarifying the best mode of TMS delivery for OCD.

Functional connectivity changes and symptoms improvement after personalized, double-daily dosing, repetitive transcranial magnetic stimulation in obsessive-compulsive disorder: A pilot study

BACKGROUND

intrusive thoughts and compulsive behaviors that characterize obsessive compulsive disorder (OCD) are associated to aberrant resting state functional connectivity (rsFC) patterns within the cortico-striatal-thalamo-cortical (CSTC) circuits. A high percentage of OCD patients do not respond to conventional pharmacological treatments or psychotherapy. In these patients, inhibitory repetitive transcranial magnetic stimulation (rTMS) of the Supplementary Motor Area (SMA) resulted in a significant clinical benefit.

METHODS

In the current study, we applied a novel protocol of 1-week MRI-guided individualized double-daily sessions of rTMS treatment (1-Hz; 110% of resting Motor Threshold/7200 pulses/day), to bilateral SMA in 9 OCD patients. We tested its (i) feasibility-safety, (ii) clinical efficacy and (iii) rsFC related changes.

RESULTS

Patients reported no side effects during and after rTMS. Personalized rTMS treatment led to a significant improvement of OCD symptoms (average 25%; p = .005) and persistence of benefit up to 3-month follow-up. rsFC analysis revealed a significant reduction of connectivity patterns between bilateral SMA and subcortical regions, specifically in the basal ganglia and thalamus. Additional analysis showed that OCD symptoms severity correlates with a higher connectivity pattern between bilateral SMA and subcortical regions.

CONCLUSIONS

rTMS double-daily sessions are safe, feasible and effective in OCD. The clinical outcomes, that are consistent with those found in our previous RCT, are linked to a decreased connectivity between SMA and subcortical brain areas implicated in control over obsessions and maladaptive compulsive behavior.

Repetitive Transcranial Magnetic Stimulation for Obsessive-Compulsive Disorder: A Meta-analysis of Randomized, Sham-Controlled Trials

BACKGROUND

Obsessive-compulsive disorder (OCD) is a chronic, disabling mental health condition with limited treatment options available to date. Numerous randomized controlled trials have explored the efficacy of repetitive transcranial magnetic stimulation (rTMS) in OCD. This meta-analysis synthesized data from selected randomized controlled trials and examined the impact of different treatment parameters to generate hypotheses that would direct future randomized controlled trials.

METHODS

A database search was performed to identify studies published in English up to October 2020. Randomized, sham-controlled studies that used rTMS to treat OCD were included. Effect sizes were calculated using Hedges' g for pre- to post-treatment Yale-Brown Obsessive Compulsive Scale scores. Subgroup analyses were conducted to assess the effects of variations in rTMS treatment parameters.

RESULTS

A total of 26 studies with 781 participants were included. Overall, rTMS demonstrated a modest effect on reduction of Yale-Brown Obsessive Compulsive Scale scores (Hedges' g = 0.64, 95% confidence interval = 0.39-0.89; p < .0001). The largest significant effect size was obtained by targeting the bilateral dorsolateral prefrontal cortex. High- and low-frequency rTMS showed comparable effects. Studies with follow-up data suggested that the effects of active rTMS remain significantly superior to those of sham 4 weeks after treatment.

CONCLUSIONS

The therapeutic effects of rTMS are superior to those of sham in the treatment of OCD. Targeting the bilateral dorsolateral prefrontal cortex was the most favorable approach in administering rTMS. Further research is required to determine the optimal frequency, total pulses per session, and duration of treatment with rTMS for OCD.

Lateralized readiness potentials and sensorimotor activity in adults with obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) patients are known to have various functional abnormalities in prefrontal and motor areas. Given the presence of compulsions in many OCD patients, impaired response preparation processes could be a core feature of OCD. Yet, these processes remain understudied from a neurophysiological standpoint. Nineteen OCD patients were matched on age and sex to 19 healthy controls. Continuous EEG was recorded in all participants during a stimulus-response compatibility task. EEG from electrodes C3 and C4 was then averaged into stimulus- and response-locked LRPs. We compared both groups on various LRP measures, such as the LRP onset, the Gratton dip, and the maximum LRP peak. OCD patients showed significantly larger LRP peak than healthy controls, as well as larger Gratton dip. However, there was no group difference regarding LRP onset. Among OCD patients, it seems that motor regions are overactive during response preparation. Such overactivity was found for both incorrect responses that are aborted before execution and responses that are truly executed. These results suggest that regulation of sensorimotor activity should be addressed in the treatment of OCD.