Effects of 10 Hz repetitive transcranial magnetic stimulation (rTMS) on clinical global impression in chronic schizophrenia

10 Hz repetitive transcranial magnetic stimulation (rTMS) may improve cognitive function: An exploratory study of schizophrenia patients with auditory hallucinations

Objectives

Cognitive impairment in schizophrenia patients with auditory hallucinations is more prominent compared to those without. Our study aimed to investigate the cognitive improvement effects of 10 Hz repetitive transcranial magnetic stimulation (rTMS) over the left dorsolateral prefrontal cortex (DLPFC) in schizophrenia with auditory hallucinations.

Methods

A total of 60 schizophrenic patients with auditory hallucinations in this study were randomly assigned to sham or active group. Both groups received 10 Hz or sham rTMS targeted in left DLPFC for 20 sessions. The Positive and Negative Syndrome Scale (PANSS), the Auditory Hallucination Rating Scale (AHRS), the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), and the Udvalg for Kliniske Under-sogelser (UKU) side effect scale were used to measure psychiatric symptoms, auditory hallucinations, cognition, and side reaction, respectively.

Results

Our results indicated that the active group experienced greater improvements in RBANS-total score (P = 0.043) and immediate memory subscale score (P = 0.001). Additionally, the PANSS-total score, negative and positive subscale score were obviously lower in the active group compared to the sham group (all P < 0.050). Furthermore, our study found that the improvement of RBANS-total score was positively associated with the decline of positive factor score, and the improvement of language score in RBANS was positively associated with the reduction in PANSS-total scale, negative and positive subscale score in the real stimulation group (all P < 0.050).

Conclusion

Our results demonstrated that a four-week intervention of 10 Hz rTMS over the left DLPFC can improve cognition (particularly immediate memory) among schizophrenia patients with auditory hallucinations. Future studies with larger sample size are needful to verify our preliminary findings.

Delayed improvements in visual memory task performance among chronic schizophrenia patients after high-frequency repetitive transcranial magnetic stimulation

BACKGROUND

Cognitive impairments are core characteristics of schizophrenia, but are largely resistant to current treatments. Several recent studies have shown that high-frequency repetitive transcranial magnetic stimulation (rTMS) of the left dor-solateral prefrontal cortex (DLPFC) can reduce negative symptoms and improve certain cognitive deficits in schizophrenia patients. However, results are inconsistent across studies.

AIM

To examine if high-frequency rTMS of the DLPFC can improve visual memory deficits in patients with schizophrenia.

METHODS

Forty-seven chronic schizophrenia patients with severe negative symptoms on stable treatment regimens were randomly assigned to receive active rTMS to the DLPFC (n = 25) or sham stimulation (n = 22) on weekdays for four consecutive weeks. Patients performed the pattern recognition memory (PRM) task from the Cambridge Neuropsychological Test Automated Battery at baseline, at the end of rTMS treatment (week 4), and 4 wk after rTMS treatment (week 8). Clinical symptoms were also measured at these same time points using the Scale for the Assessment of Negative Symptoms (SANS) and the Positive and Negative Syndrome Scale (PANSS).

RESULTS

There were no significant differences in PRM performance metrics, SANS total score, SANS subscores, PANSS total score, and PANSS subscores between active and sham rTMS groups at the end of the 4-wk treatment period, but PRM performance metrics (percent correct and number correct) and changes in these metrics from baseline were significantly greater in the active rTMS group at week 8 compared to the sham group (all P < 0.05). Active rTMS treatment also significantly reduced SANS score at week 8 compared to sham treatment. Moreover, the improvement in visual memory was correlated with the reduction in negative symptoms at week 8. In contrast, there were no between-group differences in PANSS total score and subscale scores at either week 4 or week 8 (all P > 0.05).

CONCLUSION

High-frequency transcranial magnetic stimulation improves visual memory and reduces negative symptoms in schizophrenia, but these effects are delayed, potentially due to the requirement for extensive neuroplastic changes within DLPFC networks.

The efficacy of transcranial magnetic stimulation (TMS) for negative symptoms in schizophrenia: a systematic review and meta-analysis

Several trials have shown preliminary evidence for the efficacy of transcranial magnetic stimulation (TMS) as a treatment for negative symptoms in schizophrenia. Here, we synthesize this literature in a systematic review and quantitative meta-analysis of double-blind randomized controlled trials of TMS in patients with schizophrenia. Specifically, MEDLINE, EMBASE, Web of Science, and PsycINFO were searched for sham-controlled, randomized trials of TMS among patients with schizophrenia. The effect of TMS vs. sham on negative symptoms in each study was quantified by the standardized mean difference (SMD, Cohen's d) with 95% confidence intervals (95%CI) and pooled across studies using an inverse variance random effects model. We identified 57 studies with a total of 2633 participants that were included in the meta-analysis. The pooled analysis showed statistically significant superiority of TMS (SMD = 0.41, 95%CI: 0.26; 0.56, p-value < 0.001), corresponding to a number needed to treat of 5. Furthermore, stratified analyses suggested that TMS targeting the left dorsolateral prefrontal cortex and using a stimulation frequency >1 Hz was most efficacious. There was, however, substantial heterogeneity and high risk of bias among the included studies. In conclusion, TMS appears to be an efficacious treatment option for patients with schizophrenia suffering from negative symptoms, but the optimal TMS parameters are yet to be established.

Potential Locations for Non-Invasive Brain Stimulation in Treating Schizophrenia: A Resting-State Functional Connectivity Analysis

Introduction: Non-invasive brain stimulation (NIBS) techniques have been widely used for the purpose of improving clinical symptoms of schizophrenia. However, the ambiguous stimulation targets may limit the efficacy of NIBS for schizophrenia. Exploring effective stimulation targets may improve the clinical efficacy of NIBS in schizophrenia.

Methods: We first conducted a neurosynth-based meta-analysis of 715 functional magnetic resonance imaging studies to identify schizophrenia-related brain regions as regions of interest. Then, we performed the resting-state functional connectivity analysis in 32 patients with first-episode schizophrenia to find brain surface regions correlated with the regions of interest in three pipelines. Finally, the 10–20 system coordinates corresponding to the brain surface regions were considered as potential targets for NIBS.

Results: We identified several potential targets of NIBS, including the bilateral dorsal lateral prefrontal cortex, supplementary motor area, bilateral inferior parietal lobule, temporal pole, medial prefrontal cortex, precuneus, superior and middle temporal gyrus, and superior and middle occipital gyrus. Notably, the 10-20 system location of the bilateral dorsal lateral prefrontal cortex was posterior to F3 (F4), not F3 (F4).

Conclusion: Conclusively, our findings suggested that the stimulation locations corresponding to these potential targets might help clinicians optimize the application of NIBS therapy in individuals with schizophrenia.

Transcranial Magnetic Stimulation for Positive Symptoms in Schizophrenia: A Systematic Review

Transcranial magnetic stimulation (TMS) has been proposed as a potential treatment add-on for positive symptoms in schizophrenia. To summarize the current evidence for its efficacy, we reviewed clinical trials from the last 20 years that investigated TMS for positive symptoms. We performed a search on the PubMed database for clinical trials that used TMS for the treatment of positive symptoms published in peer-reviewed journals. We excluded reviews, case reports, and opinion papers. Of the 30 studies included, the majority (n = 25) investigated auditory verbal hallucinations. Twelve studies found evidence for a positive treatment effect of TMS on positive symptoms, while 18 did not find enough evidence to conclude that TMS is effective for positive symptoms. However, the small sample size of the majority of studies is a limiting factor for the reliability of previous findings. In conclusion, evidence for an effect of TMS on positive symptoms was mixed. Since most of the studies were performed in patients with auditory verbal hallucinations, further research of TMS for other positive symptoms including thought disorder and delusions is warranted.

The Effects of Repetitive Transcranial Magnetic Stimulation in Patients with Chronic Schizophrenia: Insights from EEG Microstates

The objective of this study was to investigate the effects of 10 Hz repetitive transcranial magnetic stimulation (rTMS) in patients with schizophrenia using EEG microstates. Thirty-eight patients with chronic schizophrenia were included in a double-blind, randomized and sham-controlled trial (19 participants in the active group and 19 participants in the sham group) and received 10 Hz active or sham rTMS stimulation to the left dorsolateral prefrontal cortex (left DLPFC) 5 days per week over for 4 weeks. Four classical microstate classes (i.e., classes A, B, C and D) were identified by clustering, and the parameters (i.e., duration, occurrence and contribution) of each class were computed. Our results showed that (1) after stimulation, the positive and negative syndrome scale (PANSS) positive scores decreased significantly in the active group; (2) the duration of the microstate of class C derived from EEG data decreased significantly in the active group; and (3) the change of the duration of class D in the active group was significantly higher than that in the sham group. Our findings demonstrated that 10 Hz active rTMS stimulation was beneficial to improving the positive symptoms of patients with chronic schizophrenia, and the EEG microstate could be an effective indicator of symptom improvements.

Repetitive Transcranial Magnetic Stimulation as a Therapeutic and Probe in Schizophrenia: Examining the Role of Neuroimaging and Future Directions

Schizophrenia is a complex condition associated with perceptual disturbances, decreased motivation and affect, and disrupted cognition. Individuals living with schizophrenia may experience myriad poor outcomes, including impairment in independent living and function as well as decreased life expectancy. Though existing treatments may offer benefit, many individuals still experience treatment resistant and disabling symptoms. In light of the negative outcomes associated with schizophrenia and the limitations in currently available treatments, there is a significant need for novel therapeutic interventions. Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique that can modulate the activity of discrete cortical regions, allowing direct manipulation of local brain activation and indirect manipulation of the target's associated neural networks. rTMS has been studied in schizophrenia for the treatment of auditory hallucinations, negative symptoms, and cognitive deficits, with mixed results. The field's inability to arrive at a consensus on the use rTMS in schizophrenia has stemmed from a variety of issues, perhaps most notably the significant heterogeneity amongst existing trials. In addition, it is likely that factors specific to schizophrenia, rather than the rTMS itself, have presented barriers to the interpretation of existing results. However, advances in approaches to rTMS as a biologic probe and therapeutic, many of which include the integration of neuroimaging with rTMS, offer hope that this technology may still play a role in improving the understanding and treatment of schizophrenia.

Repetitive transcranial magnetic stimulation (rTMS) for schizophrenia patients treated with clozapine

OBJECTIVES

Biological strategies to improve treatment efficacy in clozapine-treated patients are urgently needed. Repetitive transcranial magnetic stimulation (rTMS) merits consideration as intervention for patients with persistent auditory hallucinations (AH) or negative symptoms (NS) not responding sufficiently to clozapine treatment.

METHODS

Data from 10 international RCTs of rTMS for patients being treated with clozapine were pooled. Two levels of symptomatic response were defined: improvement of ≥20% and ≥50% on study-specific primary endpoint scales. Changes in the positive and negative syndrome scale (PANSS) from baseline to endpoint assessment were also analysed.

RESULTS

Analyses of 131 patients did not reveal a significant difference for ≥20% and ≥50% response thresholds for improvement of AH, negative or total symptoms between active and sham rTMS groups. The number needed to treat (NNT) for an improvement in persistent AH was nine following active rTMS. PANSS scores did not improve significantly from baseline to endpoint between active and sham groups in studies investigating NS and AH.

CONCLUSIONS

rTMS as a treatment for persistent symptoms in clozapine-treated patients did not show a beneficial effect of active compared to sham treatment. For AH, the size of the NNTs indicates a possible beneficial effect of rTMS.

Effects of High-Frequency rTMS on Negative Symptoms and Cognitive Function in Hospitalized Patients With Chronic Schizophrenia: A Double-Blind, Sham-Controlled Pilot Trial

This study aimed to evaluate the efficacy of high-frequency repetitive transcranial magnetic stimulation (rTMS) over left dorsolateral pre-frontal cortex (DLPFC) in ameliorating negative symptoms and cognitive impairments in patients with chronic schizophrenia. Fifty-two patients with chronic schizophrenia were randomly assigned to two groups: active rTMS group and sham rTMS group, with existing antipsychotic drugs combined 20 sessions of 10 Hz active/sham rTMS over DLPFC (20 min/session, 5 times/week). The PANSS, RBANS, and SCWT were used to evaluate the clinical symptoms and cognitive functions of the patients. Our results indicated significant improvements in clinical symptoms (PANSS total and subscale scores) and cognitive functions (RBANS total and subscale scores, card 1 and card 3 of the SCWT test) (All p <0.05) after 4-week intervention both in active and sham rTMS group. Moreover, the active rTMS group showed more effective on ameliorating negative symptoms (p = 0.002), immediate memory (p = 0.016) and delayed memory (p = 0.047) compared to the sham group. Interestingly, PANSS negative symptom scores was negatively correlated with RBANS language scores in the real stimulation group (p = 0.046). The study found that the high frequency rTMS stimulation over left DLPFC as a supplement to antipsychotics may have potential benefits in improving clinical symptoms and cognitive functions in patients with chronic schizophrenia.

Resting frontal EEG asymmetry and schizotypal traits: a test-retest study

Introduction: Increase in right relative to left frontal electroencephalography (EEG) activity has been observed in patients with schizophrenia, both in cognitive tasks and during rest; and this lateralisation may be related to the severity of schizotypal traits. Methods: We used the Schizotypal Personality Questionnaire (SPQ) to assess schizotypal traits, and examined the correlation between these traits and resting EEG frontal asymmetry (left-right) in 52 college students, as well as the reliability of this correlation over a three-month interval. Results: A higher total score on the SPQ was correlated with reduced asymmetry in different frequency bands: gamma and beta2 frequency bands at baseline, and delta and alpha frequency bands three months later. Additionally, the reduced left relative to right frontal gamma and beta2 asymmetry was correlated with the participants' verbal fluency ability. However, this correlation was no longer statistically significant after the total SPQ score was controlled. Conclusions: These findings suggest that resting frontal EEG asymmetry is correlated with powers in different frequency bands, and may be an endophenotype for schizophrenia spectrum disorders.

The safety and efficacy of adjunctive 20-Hz repetitive transcranial magnetic stimulation for treatment of negative symptoms in patients with schizophrenia: A double-blinded, randomized, sham-controlled study

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) is a promising treatment strategy for negative symptoms. However, the evidence for its efficacy is mixed, with contradictory results between studies due to lack of consensus about the optimal stimulation parameters.

AIM

The present study was planned to assess the safety and efficacy of 20-Hz rTMS over left dorsolateral prefrontal cortex (Lt-DLPFC) with more robust stimulation parameters for adjunctive treatment of negative symptoms in patients with schizophrenia.

MATERIALS AND METHODS

Thirty patients with negative symptoms of schizophrenia (Positive and Negative Syndrome Scale [PANSS] negative subscore ≥15) were randomized to receive a 4-week treatment with either real-rTMS (n = 15) or sham-rTMS (n = 15). The study outcomes were assessed at baseline, after 5^th and 20^th rTMS sessions with PANSS, Scale for the Assessment of Negative Symptoms (SANS), Calgary Depression Scale for Schizophrenia, Clinical Global Impressions-Severity of illness scale, and rTMS side-effect checklist.

RESULTS

There was significantly greater reduction in negative symptoms assessed by SANS score in the real rTMS group, compared with the sham rTMS group. There was no significant difference in the rate of side-effects reported between the two groups. The rTMS treatment was well-tolerated by all the patients, except one seizure episode reported in the active group.

CONCLUSION

The high-frequency rTMS protocol was safe and well-tolerated, provided patients prone to developing seizure were excluded by baseline electroencephalography prior to starting of the treatment. The 20-Hz rTMS over Lt-DLPFC with more robust stimulation parameters (100% motor threshold and 40,000 pulses) might be an effective augmentation strategy for the treatment of negative symptoms in schizophrenia.

[Procognitive effects of transcranial magnetic stimulation in the light of neurocognitive deficit in schizophrenia]

Transcranial magnetic stimulation (TMS) is a relatively new method of non-invasive therapy of mental and neurological diseases that has great potential of therapeutic and diagnostic application. In schizophrenia, TMS may exert a positive effect on cognitive deficit. However this issue remains open. The authors analyze recent studies focused on the dynamics of neurocognitive deficit in TMS therapy and consider clinical effects of TMS in schizophrenia. The analysis has shown that TMS is successfully implemented in treatment of auditory positive symptoms and studies on its effect on negative symptoms of schizophrenia are perspective. Procognitive effect was found in working memory domain, and partially in perception domain within the perception of faces and facial expressions. The data on regulative functions, attention, speech, and nondeclarative memory remains controversial. It has been concluded that further research is needed to clarify the place of TMS in schizophrenia therapy.

Schizophrenia TreAtment with electRic Transcranial Stimulation (STARTS): design, rationale and objectives of a randomized, double-blinded, sham-controlled trial

INTRODUCTION

Schizophrenia is a severe mental disorder. While some antipsychotic medications have demonstrated efficacy in treating positive symptoms, there is no widely recognized treatment for negative symptoms, which can cause significant distress and impairment for patients with schizophrenia. Here we describe the rationale and design of the STARTS study (Schizophrenia TreAtment with electRic Transcranial Stimulation), a clinical trial aimed to test the efficacy of a non-pharmacological treatment known as transcranial direct current stimulation (tDCS) for treating the negative symptoms of schizophrenia.

METHODS

The STARTS study is designed as a randomized, sham-controlled, double-blinded trial evaluating tDCS for the treatment of the negative symptoms of schizophrenia. One-hundred patients will be enrolled and submitted to 10 tDCS sessions over the left dorsolateral prefrontal cortex (anodal stimulation) and left temporoparietal junction (cathodal stimulation) over 5 consecutive days. Participants will be assessed using clinical and neuropsychological tests before and after the intervention. The primary outcome is change in the Positive and Negative Syndrome Scale (PANSS) negative subscale score over time and across groups. Biological markers, including blood neurotrophins and interleukins, genetic polymorphisms, and motor cortical excitability, will also be assessed.

RESULTS

The clinical results will provide insights about tDCS as a treatment for the negative symptoms of schizophrenia, and the biomarker investigation will contribute towards an improved understanding of the tDCS mechanisms of action.

CONCLUSION

Our results could introduce a novel therapeutic technique for the negative symptoms of schizophrenia. Clinical trial registration: ClinicalTrials.gov, NCT02535676 .

Effects of High-Frequency Transcranial Magnetic Stimulation for Cognitive Deficit in Schizophrenia: A Meta-Analysis

Objective: Repetitive transcranial magnetic stimulation (rTMS) has been applied to dorsolateral prefrontal cortex (DLPFC) to improve cognitive function of patients with schizophrenia (SZs). The aim of this meta-analysis was to evaluate whether a high-frequency rTMS course could enhance cognitive function in SZs. Methods: Studies published in PubMed, Cochrane Library, Embase, ScienceDirect, and Web of science were searched until April 2018. The search terms included: "repetitive transcranial magnetic stimulation" or "Rtms," "SZ," or "schizophrenia," and "neuro-cognition" or "neurocognitive performance" or "cognitive effects" or "cognitive" or "cognition" or "working memory" or "executive function" or "language function" or "processing speed," After screening the literatures according to inclusion and exclusion criteria, extracting data, and evaluating the methodological quality of the included studies, a meta-analysis was performed using RevMan 5.3 software (The Cochrane Collaboration, USA). Results: A total of 9 studies on cognitive dysfunction of SZs were included and involved 351 patients. A significant efficacy of high-frequency rTMS on working memory in SZs was found compared to sham stimulation [p = 0.009, standardized mean difference (SMD) = 0.34]. Specifically, rTMS treatment positioned on the left DLPFC, with a total pluses <30,000 was more significantly more effective in improving the working memory (SMD = 0.33, p = 0.03). No improvement was found in other cognitive domains such as executive function, attention, processing speed, and language function. For the follow-up observations, high-frequency rTMS had long-lasting sustained effects on working memory (SMD = 0.45, p = 0.01) and language function (SMD = 0.77, p = 0.02) in SZs. Conclusions: High-frequency rTMS over the left DLPFC with a total pulses <30,000 stimulation could significantly improve working memory in SZs for an extended period of time.

Non-invasive brain stimulation for negative symptoms in schizophrenia: An updated systematic review and meta-analysis

BACKGROUND

Schizophrenia is a mental disorder with significant socioeconomic burden. Although current pharmacological treatments are effective for treating positive symptoms, medications have little-to-no effect in the treatment of negative symptoms.

OBJECTIVE

To assess the efficacy of non-invasive brain stimulation (NIBS) for negative symptoms in schizophrenia in randomized clinical trials (RCTs).

METHODS

A systematic review in Medline and Cochrane Library databases was performed up to May 31, 2017. The primary outcome was Hedges' g for continuous scores in a random-effects model. Heterogeneity was evaluated with the I² and χ² tests. Publication bias was assessed using Begg's funnel plot.

RESULTS

31 RCTs (n = 1272) were included, most with small-to-modest sample sizes. Both repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) were superior to sham (Hedges' g = 0.19; 95% CI 0.07-0.32; and 0.5; 0.02-0.97, respectively). Only one study evaluated the use of transcutaneous auricular vagus nerve stimulation (taVNS). The funnel plot and Eggers test showed that the risk of publication bias was low. In relation to heterogeneity, we found an I² of 0% (p = 0.749) and 51.3% (0.055) for rTMS and tDCS, respectively.

CONCLUSION

Both rTMS and tDCS were superior to sham stimulation for ameliorating negative symptoms in schizophrenia. We found no considerable heterogeneity or publication bias in our analysis, corroborating the strength of our findings. Not enough studies on other NIBS techniques, such as taVNS, were found for an isolated analysis. Further RCTs with larger sample sizes are needed to clarify the specific impact of NIBS on negative symptoms in schizophrenia.

Effects of transcranial direct current stimulation on working memory and negative symptoms in schizophrenia: a phase II randomized sham-controlled trial

BACKGROUND

The lack of efficacy of pharmacological treatments for cognitive and negative symptoms in schizophrenia highlights the need for new interventions. We investigated the effects of tDCS on working memory and negative symptoms in patients with schizophrenia.

METHOD

Double-blinded, randomized, sham-controlled clinical trial, investigating the effects of 10 sessions of tDCS in schizophrenia subjects. Stimulation used 2 mA, for 20 min, with electrodes of 25 cm2 wrapped in cotton material soaked in saline solution. Anode was positioned over the left DLPFC and the cathode in the contralateral area. Twenty-four participants were assessed at baseline, after intervention and in a three-months follow-up. The primary outcome was the working memory score from MATRICS and the secondary outcome the negative score from PANSS. Data were analyzed using generalized estimating equations.

RESULTS

We did not find group ∗ time interaction for the working memory (p = 0.720) score or any other cognitive variable (p > 0.05). We found a significant group ∗ time interaction for PANSS negative (p < 0.001, d = 0.23, CI.95 = -0.59-1.02), general (p = 0.011) and total scores (p < 0.001). Exploratory analysis of PANSS 5 factors suggests tDCS effect on PANSS negative (p = 0.012), cognitive (p = 0.016) and depression factors (p = 0.029).

CONCLUSION

The results from this trial highlight the therapeutic effects of tDCS for treatment of persistent symptoms in schizophrenia, with reduction of negative symptoms. We were not able to confirm the superiority of active tDCS over sham to improve working memory performance. Larger sample size studies are needed to confirm these findings.

Changing Brain Networks Through Non-invasive Neuromodulation

Background/Objective: Non-invasive neuromodulation techniques, such as repetitive Transcranial Magnetic Stimulation (rTMS) and transcranial Direct Current Stimulation (tDCS), have increasingly been investigated for their potential as treatments for neurological and psychiatric disorders. Despite widespread dissemination of these techniques, the underlying therapeutic mechanisms and the ideal stimulation site for a given disorder remain unknown. Increasing evidence support the possibility of non-invasive neuromodulation affecting a brain network rather than just the local stimulation target. In this article, we present evidence in a clinical setting to support the idea that non-invasive neuromodulation changes brain networks.

Method: This article addresses the idea that non-invasive neuromodulation modulates brain networks, rather than just the local stimulation target, using neuromodulation studies in tinnitus and major depression as examples. We present studies that support this hypothesis from different perspectives.

Main Results/Conclusion: Studies stimulating the same brain region, such as the dorsolateral prefrontal cortex (DLPFC), have shown to be effective for several disorders and studies using different stimulation sites for the same disorder have shown similar results. These findings, as well as results from studies investigating brain network connectivity on both macro and micro levels, suggest that non-invasive neuromodulation affects a brain network rather than just the local stimulation site targeted. We propose that non-invasive neuromodulation should be approached from a network perspective and emphasize the therapeutic potential of this approach through the modulation of targeted brain networks.

Efficacy Towards Negative Symptoms and Safety of Repetitive Transcranial Magnetic Stimulation Treatment for Patients with Schizophrenia: A Systematic Review

Background

Negative symptoms are one of the most difficult areas in the treatment of schizophrenia because antipsychotics are often less effective towards them. Repetitive transcranial magnetic stimulation (rTMS) is a new technique for cerebral cortex stimulation and is believed to be a safe and promising method for the treatment of mental disorders. As the clinical research and new treatment models have increased in recent years, the efficacy towards negative symptoms and safety evaluation of rTMS treatment should also be updated.

Aims

To explore the efficacy and safety of rTMS in the treatment of negative symptoms for patients with schizophrenia.

Methods

We searched for relevant controlled clinical trials from the following databases: PubMed, EMBASE, the Cochrane Library, EBSCO, Web of Science, China National Knowledge Infrastructure (CNKI), VIP, Wanfang Data, SINOMED, and Airiti Library. The retrieval time went up to January 2, 2017. The research literature was screened according to the predefined inclusion and exclusion criteria. After data extraction, statistical analysis was conducted by using RevMan 5.3 and Stata 14. Quality evaluation was done on the included research articles. The Cochrane risk of bias assessment tool was adopted for assessing risk of bias. The GRADE (Grades of Recommendation, Assessment, Development, and Evaluation) system recommendation grading method was used as the reference standard.

Results

A total of 3500 articles were retrieved. In the end, there were 29 articles included in the metaanalysis with a total sample size of 1440. After the meta-analysis, it was found that the use of antipsychotic treatment combined with rTMS could improve the negative symptoms of patients (SMD=-0.40, 95% CI= -0.62~-0.18). Based on the bias of the efficacy evaluation assessed by the Cochrane risk of bias assessment tool, there were 6 studies rated as having “high risk of bias” and the rest were rated as “unable to determine”. According to the assessment, development and evaluation criteria of the GRADE classification, the evidence quality for the efficacy evaluation index was “moderate”. The acceptability of rTMS treatment was better (RR= 0.75, 95% CI= 0.49~1.15, based on the 1492 samples from the 28 studies), however, the patients who received the rTMS treatment had a higher rate of mild adverse effects (RR= 2.20, 95% CI= 1.53~ 3.18, based on the 1296 samples from the 23 studies).

Conclusions

The use of the antipsychotic treatment incorporated with rTMS treatment can slightly improve the negative symptoms of patients with schizophrenia and has better acceptability and fewer adverse effects. Nevertheless, there is publication bias in this study and the heterogeneity of the study is relatively high. Therefore, we need to be cautious when interpreting the results

High frequency repetitive transcranial magnetic stimulation (rTMS) reduces EEG-hypofrontality in patients with schizophrenia

The reduced metabolic activity in the prefrontal brain lobes, so-called hypofrontality, is associated with increased electrophysiological delta-band activity. Schizophrenia inpatients (N=35) received sham-controlled 10Hz rTMS over the left dorsolateral prefrontal cortex in a randomised design. After treatment, the resting electroencephalography revealed a significant decrease in the delta-band activity, which originated in the right prefrontal cortex and correlated with improvements in facial affect recognition.

Transcranial magnetic stimulation (TMS) for schizophrenia

BACKGROUND

People with schizophrenia often experience symptoms which fail to fully respond to antipsychotic medication. Transcranial magnetic stimulation (TMS) has been proposed as a new treatment for people with schizophrenia, especially those who experience persistent auditory hallucinations.

OBJECTIVES

To estimate the effects of TMS alone, compared with sham TMS or with 'standard management' and any other comparison interventions in reducing psychotic symptoms associated with schizophrenia.

SEARCH METHODS

We searched the Cochrane Schizophrenia Group Trials Register (June 2006, June 2008, April 2013). This register is compiled by methodical searches of MEDLINE, EMBASE, BIOSIS, CINAHL, Dissertation abstracts, LILACS, PSYNDEX, PsycINFO, RUSSMED, and Sociofile, and is supplemented with handsearching of relevant journals and numerous conference proceedings.

SELECTION CRITERIA

We included all randomised controlled trials recruiting at least five participants and comparing TMS with sham TMS or any other treatment for people with schizophrenia.

DATA COLLECTION AND ANALYSIS

We extracted data independently. For dichotomous data we calculated relative risks (RRs) and their 95% confidence intervals (CIs). For continuous data, we calculated mean differences (MD) and 95% CI. We used a fixed-effect model. We assessed overall quality of the evidence using the GRADE approach.

MAIN RESULTS

We included 41 studies with 1473 participants in the review. We found significant differences in favour of temporoparietal TMS compared to sham TMS for global state measured on the CGI scale (7 RCTs, n = 224, MD -0.5, 95% CI -0.76 to -0.23, very low-quality evidence) and positive symptoms measured on the PANSS scale (5 RCTs, n = 127, MD -6.09, 95% CI -10.95 to -1.22, very low-quality evidence). Participants experienced significantly more headaches in the temporoparietal TMS group (10 RCTs, n = 392, RR 2.65, 95% CI 1.56 to 4.50, very low-quality evidence). However, no more participants left the study early from the TMS group than from the sham group (very low-quality evidence). Cognitive state was assessed using 39 different measures, and all were equivocal (very low-quality evidence).We included only two trials which compared temporoparietal TMS with standard treatment. In both trials the participants received first- and second-generation antipsychotic medication in both treatment groups, therefore TMS was used an adjunctive therapy to medication. We found no significant differences in the number of participants that showed clinical improvement in global state (1 RCT, n = 100, RR 1.19, 95% CI 0.91 to 1.57) or left the study early (2 RCTs, n = 140, RR 0.33, 95% CI 0.08 to 1.46) (both very low-quality evidence). No studies reported on global state score, mental state, cognitive state and adverse effects.For prefrontal TMS compared to sham TMS, global state was measured on three different scales, all of which presented equivocal results (very low quality evidence). We could not pool data for mental state on the PANSS scale due to high heterogeneity. Cognitive state was assessed using 19 different measures, with 15/19 being equivocal (very low-quality evidence). Prefrontal TMS caused more headaches (6 RCTs, n = 164, RR 2.77, 95% CI 1.22 to 6.26, very low-quality evidence) but there was no difference in the number of participants leaving the study early (very low-quality evidence). No studies reported data for clinical improvement.We found a significant difference in favour of prefrontal theta burst stimulation TMS compared to sham TMS for mental state on the PANNS scale (3 RCTs, n = 108, MD -5.71, 95% CI -9.32 to -2.10, very low evidence). We found no difference for clinical improvement, cognitive state, number of headaches, and leaving the study early (very low-quality evidence).None of the included studies reported satisfaction with care.

AUTHORS' CONCLUSIONS

Based on this review, there is insufficient evidence to support or refute the use of TMS to treat symptoms of schizophrenia. Although some evidence suggests that TMS, and in particular temporoparietal TMS, may improve certain symptoms (such as auditory hallucinations and positive symptoms of schizophrenia) compared to sham TMS, the results were not robust enough to be unequivocal across the assessment measures used. There was insufficient evidence to suggest any added benefit with TMS used as an adjunctive therapy to antipsychotic medication.The overall quality of evidence was graded as very low due to risk of bias, and this was accompanied by an imprecision in estimates due to the relatively small number of participants in the studies. Thus, consideration is required in improving the quality of trial processes, as well as the quality of reporting of ongoing and future TMS trials, so as to facilitate accurate future judgements in assessing risk of bias. Differences in TMS techniques in relation to stimulation intensity, stimulation length, brain areas stimulated and variations in the design of sham TMS all contributed to the heterogeneity of study findings and limited the interpretation and applicability of the results. In addition, the trials assessed their outcomes with a variety of scales, and usable data were limited. Therefore, to better evaluate the treatment effects of TMS in people with schizophrenia, we favour the use of standardised treatment protocols and outcome measures.

Left prefrontal high-frequency repetitive transcranial magnetic stimulation for the treatment of schizophrenia with predominant negative symptoms: a sham-controlled, randomized multicenter trial

BACKGROUND

Investigators are urgently searching for options to treat negative symptoms in schizophrenia because these symptoms are disabling and do not respond adequately to antipsychotic or psychosocial treatment. Meta-analyses based on small proof-of-principle trials suggest efficacy of repetitive transcranial magnetic stimulation (rTMS) for the treatment of negative symptoms and call for adequately powered multicenter trials. This study evaluated the efficacy of 10-Hz rTMS applied to the left dorsolateral prefrontal cortex for the treatment of predominant negative symptoms in schizophrenia.

METHODS

A multicenter randomized, sham-controlled, rater-blinded and patient-blinded trial was conducted from 2007-2011. Investigators randomly assigned 175 patients with schizophrenia with predominant negative symptoms and a high-degree of illness severity into two treatment groups. After a 2-week pretreatment phase, 76 patients were treated with 10-Hz rTMS applied 5 days per week for 3 weeks to the left dorsolateral prefrontal cortex (added to the ongoing treatment), and 81 patients were subjected to sham rTMS applied similarly.

RESULTS

There was no statistically significant difference in improvement in negative symptoms between the two groups at day 21 (p = .53, effect size = .09) or subsequently through day 105. Also, symptoms of depression and cognitive function showed no differences in change between groups. There was a small, but statistically significant, improvement in positive symptoms in the active rTMS group (p = .047, effect size = .30), limited to day 21.

CONCLUSIONS

Application of active 10-Hz rTMS to the left dorsolateral prefrontal cortex was well tolerated but was not superior compared with sham rTMS in improving negative symptoms; this is in contrast to findings from three meta-analyses.

Efficacy of bilateral repetitive transcranial magnetic stimulation for negative symptoms of schizophrenia: results of a multicenter double-blind randomized controlled trial

BACKGROUND

Few studies have investigated the efficacy of repetitive transcranial magnetic stimulation (rTMS) treatment for negative symptoms of schizophrenia, reporting inconsistent results. We aimed to investigate whether 10 Hz stimulation of the bilateral dorsolateral prefrontal cortex during 3 weeks enhances treatment effects.

METHOD

A multicenter double-blind randomized controlled trial was performed in 32 patients with schizophrenia or schizo-affective disorder, and moderate to severe negative symptoms [Positive and Negative Syndrome Scale (PANSS) negative subscale ⩾15]. Patients were randomized to a 3-week course of active or sham rTMS. Primary outcome was severity of negative symptoms as measured with the Scale for the Assessment of Negative Symptoms (SANS) and the PANSS negative symptom score. Secondary outcome measures included cognition, insight, quality of life and mood. Subjects were followed up at 4 weeks and at 3 months. For analysis of the data a mixed-effects linear model was used.

RESULTS

A significant improvement of the SANS in the active group compared with sham up to 3 months follow-up (p = 0.03) was found. The PANSS negative symptom scores did not show a significant change (p = 0.19). Of the cognitive tests, only one showed a significant improvement after rTMS as compared with sham. Finally, a significant change of insight was found with better scores in the treatment group.

CONCLUSIONS

Bilateral 10 Hz prefrontal rTMS reduced negative symptoms, as measured with the SANS. More studies are needed to investigate optimal parameters for rTMS, the cognitive effects and the neural basis.

A systematic review and meta-analysis of the use of repetitive transcranial magnetic stimulation for auditory hallucinations treatment in refractory schizophrenic patients

BACKGROUND

The use of repetitive transcranial magnetic stimulation (rTMS) remains a promising therapeutic tool in the treatment of schizophrenia. Symptoms such as auditory hallucinations (AH) find contradictory results in many studies. Here we present an up-to-date systematic review and meta-analysis of rTMS in the treatment of AH in schizophrenia.

METHODS

We searched Pubmed-MEDLINE from 1999 to 2013 for double-blinded randomized sham-controlled trials that applied slow rTMS on the left temporoparietal cortex and assessed the outcome results using Hallucination Change Scale or Auditory Hallucination Rating Scale or Scale for Auditory Hallucinations (SAH). We identified 10 studies suitable for the meta-analysis.

RESULTS

We found a positive sized effect in favor of rTMS [random-effects model Hedges' g = 0.011, I-squared = 58.1%]. There was some variability between study effect sizes, but the sensitivity analysis concluded that none of them had sufficient weight to singularly alter the results of our meta-analysis.

DISCUSSION

rTMS appears to be an effective treatment for AH. The left temporoparietal cortex seems to be the area in which rTMS is effective. Although meta-analysis is a powerful analytical tool, more studies must be conducted in order to obtain a more expressive sample size to perform a more accurate analytical approach.

The effects of high-frequency repetitive transcranial magnetic stimulation (rTMS) on negative symptoms of schizophrenia and the follow-up study

In this double-blind, randomized controlled study, we assessed the therapeutic effects of high-frequency left dorsolateral prefrontal cortex (DLPFC) repetitive transcranial magnetic stimulation (rTMS) on negative symptoms of schizophrenia. For the study, 117 patients with prominent negative symptoms were randomized to a 20-day course of either active rTMS applied to the left DLPFC (n = 78) or sham rTMS (n = 39). The primary outcome measures were the Positive and Negative Symptom Scale (PANSS) and the Scale for the Assessment of Negative Symptoms (SANS). Secondary outcomes included the Clinical Global Impressions Scale (CGI) and the Udvalg for Kliniske Under sogelser (UKU) Side Effect Rating Scale. We found that treatment with high-frequency rTMS for 6 weeks significantly improved negative symptoms in the active group as compared to the sham group. However, active rTMS was not correlated with significant improvement in the CGI severity of illness scale (CGI-S). The improvement of negative symptoms persisted to the 24-week follow-up assessment. These results indicate that there is a lasting beneficial effect of rTMS on negative symptoms in absence of decrease in CGI scores. We conclude that rTMS may serve as a relatively noninvasive treatment that alleviates negative symptoms in patients with schizophrenia.

Evidence-based guidelines on the therapeutic use of repetitive transcranial magnetic stimulation (rTMS)

A group of European experts was commissioned to establish guidelines on the therapeutic use of repetitive transcranial magnetic stimulation (rTMS) from evidence published up until March 2014, regarding pain, movement disorders, stroke, amyotrophic lateral sclerosis, multiple sclerosis, epilepsy, consciousness disorders, tinnitus, depression, anxiety disorders, obsessive-compulsive disorder, schizophrenia, craving/addiction, and conversion. Despite unavoidable inhomogeneities, there is a sufficient body of evidence to accept with level A (definite efficacy) the analgesic effect of high-frequency (HF) rTMS of the primary motor cortex (M1) contralateral to the pain and the antidepressant effect of HF-rTMS of the left dorsolateral prefrontal cortex (DLPFC). A Level B recommendation (probable efficacy) is proposed for the antidepressant effect of low-frequency (LF) rTMS of the right DLPFC, HF-rTMS of the left DLPFC for the negative symptoms of schizophrenia, and LF-rTMS of contralesional M1 in chronic motor stroke. The effects of rTMS in a number of indications reach level C (possible efficacy), including LF-rTMS of the left temporoparietal cortex in tinnitus and auditory hallucinations. It remains to determine how to optimize rTMS protocols and techniques to give them relevance in routine clinical practice. In addition, professionals carrying out rTMS protocols should undergo rigorous training to ensure the quality of the technical realization, guarantee the proper care of patients, and maximize the chances of success. Under these conditions, the therapeutic use of rTMS should be able to develop in the coming years.

Revisiting the therapeutic effect of rTMS on negative symptoms in schizophrenia: a meta-analysis

This study sought to determine the moderators in the treatment effect of repetitive transcranial magnetic stimulation (rTMS) on negative symptoms in schizophrenia. We performed a meta-analysis of prospective studies on the therapeutic application of rTMS in schizophrenia assessing the effects of both low-frequency and high-frequency rTMS on negative symptoms. Results indicate that rTMS is effective in alleviating negative symptoms in schizophrenia. The effect size was moderate (0.63 and 0.53, respectively). The effect size of rTMS on negative symptoms in sham-controlled trials was 0.80 as measured by the SANS and 0.41 as measured by the PANSS. A longer duration of illness was associated with poorer efficacy of rTMS on negative symptoms. A 10 Hz setting, at least 3 consecutive weeks of treatment, treatment site at the left dorsolateral prefrontal cortex (DLPFC) and a 110% motor threshold (MT) were found to be the best rTMS parameters for the treatment of negative symptoms. The results of our meta-analysis suggest that rTMS is an effective treatment option for negative symptoms in schizophrenia. The moderators of rTMS on negative symptoms included duration of illness, stimulus frequency, duration of illness, position and intensity of treatment as well as the type of outcome measures used.

Synaptic plasticity in neurodegenerative diseases evaluated and modulated by in vivo neurophysiological techniques

Several studies demonstrated in experimental models and in humans synaptic plasticity impairment in some neurodegenerative and neuropsychiatric diseases such as Parkinson's disease, Alzheimer's disease, Huntington's disease, and schizophrenia. Recently new neurophysiological tools, such as repetitive transcranial magnetic stimulation and transcranial direct current stimulation, have been introduced in experimental and clinical settings for studying physiology of the brain and modulating cortical activity. These techniques use noninvasive transcranial electrical or magnetic stimulation to modulate neurons activity in the human brain. Cortical stimulation might enhance or inhibit the activity of cortico-subcortical networks, depending on stimulus frequency and intensity, current polarity, and other stimulation parameters such as the configuration of the induced electric field and stimulation protocols. On this basis, in the last two decades, these techniques have rapidly become valuable tools to investigate physiology of the human brain and have been applied to treat drug-resistant neurological and psychiatric diseases. Here we describe these techniques and discuss the mechanisms that may explain these effects.

[French guidelines on the use of repetitive transcranial magnetic stimulation (rTMS): safety and therapeutic indications]

During the past decade, a large amount of work on transcranial magnetic stimulation (TMS) has been performed, including the development of new paradigms of stimulation, the integration of imaging data, and the coupling of TMS techniques with electroencephalography or neuroimaging. These accumulating data being difficult to synthesize, several French scientific societies commissioned a group of experts to conduct a comprehensive review of the literature on TMS. This text contains all the consensual findings of the expert group on the mechanisms of action, safety rules and indications of TMS, including repetitive TMS (rTMS). TMS sessions have been conducted in thousands of healthy subjects or patients with various neurological or psychiatric diseases, allowing a better assessment of risks associated with this technique. The number of reported side effects is extremely low, the most serious complication being the occurrence of seizures. In most reported seizures, the stimulation parameters did not follow the previously published recommendations (Wassermann, 1998) [430] and rTMS was associated to medication that could lower the seizure threshold. Recommendations on the safe use of TMS / rTMS were recently updated (Rossi et al., 2009) [348], establishing new limits for stimulation parameters and fixing the contraindications. The recommendations we propose regarding safety are largely based on this previous report with some modifications. By contrast, the issue of therapeutic indications of rTMS has never been addressed before, the present work being the first attempt of a synthesis and expert consensus on this topic. The use of TMS/rTMS is discussed in the context of chronic pain, movement disorders, stroke, epilepsy, tinnitus and psychiatric disorders. There is already a sufficient level of evidence of published data to retain a therapeutic indication of rTMS in clinical practice (grade A) in chronic neuropathic pain, major depressive episodes, and auditory hallucinations. The number of therapeutic indications of rTMS is expected to increase in coming years, in parallel with the optimisation of stimulation parameters.

Repetitive transcranial magnetic stimulation for the treatment of negative symptoms in residual schizophrenia: rationale and design of a sham-controlled, randomized multicenter study

Current meta-analysis revealed small, but significant effects of repetitive transcranial magnetic stimulation (rTMS) on negative symptoms in patients with schizophrenia. There is a need for further controlled, multicenter trials to assess the clinical efficacy of rTMS on negative symptoms in schizophrenia in a larger sample of patients. The objective of this multicenter, randomized, sham-controlled, rater- and patient-blind clinical trial is to investigate the efficacy of 3-week 10-Hz high frequency rTMS add on to antipsychotic therapy, 15 sessions per 3 weeks, 1,000 stimuli per session, stimulation intensity 110% of the individual motor threshold) of the left dorsolateral prefrontal cortex for treating negative symptoms in schizophrenia, and to evaluate the effect during a 12 weeks of follow-up. The primary efficacy endpoint is a reduction of negative symptoms as assessed by the negative sum score of the positive and negative symptom score (PANSS). A sample size of 63 in each group will have 80% power to detect an effect size of 0.50. Data analysis will be based on the intention to treat population. The study will be conducted at three university hospitals in Germany. This study will provide information about the efficacy of rTMS in the treatment of negative symptoms. In addition to psychopathology, other outcome measures such as neurocognition, social functioning, quality of life and neurobiological parameters will be assessed to investigate basic mechanisms of rTMS in schizophrenia. Main limitations of the trial are the potential influence of antipsychotic dosage changes and the difficulty to ensure adequate blinding.