Repetitive transcranial magnetic stimulation for treating the symptoms of schizophrenia: A PRISMA compliant meta-analysis

Non-invasive brain stimulation for treatment-resistant schizophrenia: protocol of a systematic review and network meta-analysis

BACKGROUND

Non-invasive brain stimulation (NIBS) is a promising intervention for treatment-resistant schizophrenia. However, there are multiple available techniques and a comprehensive synthesis of evidence is lacking. Thus, we will conduct a systematic review and network meta-analysis to investigate the comparative efficacy and safety of NIBS techniques as an add-on to antipsychotics for treatment-resistant schizophrenia.

METHODS

We will include single- and double-blind randomized-controlled trials (RCT) comparing any NIBS technique with each other or with a control intervention as an add-on to antipsychotics in adult patients with treatment-resistant schizophrenia. We will exclude studies focusing on predominant negative symptoms, maintenance treatment, and single sessions. The primary outcome will be a change in overall symptoms, and secondary outcomes will be a change in symptom domains, cognitive performance, quality of life, functioning, response, dropouts, and side effects. We will search for eligible studies in previous reviews, multiple electronic databases and clinical trial registries from inception onwards. At least two independent reviewers will perform the study selection, data extraction, and risk of bias assessment. We will measure the treatment differences using standardized mean difference (SMD) and odds ratio (OR) for continuous and dichotomous outcomes, respectively. We will conduct pairwise and network meta-analysis within a frequentist framework using a random-effects model, except for rare event outcomes where we will use a fixed-effects Mantel-Haenszel method. We will investigate potential sources of heterogeneity in subgroup analyses. Reporting bias will be assessed with funnel plots and the Risk of Bias due to Missing Evidence in Network meta-analysis (ROB-MEN) tool. The certainty in the evidence will be evaluated using the Confidence in Network Meta-analysis (CINeMA) approach.

DISCUSSION

Our network meta-analysis would provide an up-to-date synthesis of the evidence from all available RCTs on the comparative efficacy and safety of NIBS for treatment-resistant schizophrenia. This information could guide evidence-based clinical practice and improve the outcomes of patients.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO-ID CRD42023410645.

Assessing the impact of sex on high-frequency repetitive transcranial magnetic stimulation´s clinical response in schizophrenia - results from a secondary analysis

BACKGROUND

The evidence for repetitive transcranial magnetic stimulation (rTMS) to treat negative symptoms in schizophrenia (SCZ) is increasing, although variable response rates remain a challenge. Subject´s sex critically influences rTMS´ treatment outcomes. Females with major depressive disorder are more likely to respond to rTMS, while SCZ data is scarce.

METHODS

Using data from the 'rTMS for the Treatment of Negative Symptoms in Schizophrenia' (RESIS) trial we assessed the impact of sex on rTMS´ clinical response rate from screening up to 105 days after intervention among SCZ patients. The impact of resting motor threshold (RMT) on response rates was also assessed.

RESULTS

157 patients received either active or sham rTMS treatment. No significant group differences were observed. Linear mixed model showed no effects on response rates (all p > 0.519). Apart from a significant sex*time interaction for the positive subscale of the positive and negative syndrome scale (PANSS) scores (p = 0.032), no other significant effects of sex on continuous PANSS scores were observed. RMT had no effect on response rate.

CONCLUSION

In the largest rTMS trial on the treatment of SCZ negative symptoms we did not observe any significant effect of sex on treatment outcomes. Better assessments of sex-related differences could improve treatment individualisation.

Repetitive Transcranial Magnetic Stimulation for Working Memory Deficits in Schizophrenia: A Systematic Review of Randomized Controlled Trials

Working memory (WM) deficits are a significant component of neurocognitive impairment in individuals with schizophrenia (SCZ). Two previous meta-analyses, conducted on randomized controlled trials (RCTs), examined the effectiveness of repetitive transcranial magnetic stimulation (rTMS) in addressing WM deficits in individuals diagnosed with SCZ. However, the conclusions drawn from these analyses were inconsistent. Additionally, the commonly used random effects (RE) models might underestimate statistical errors, attributing a significant portion of perceived heterogeneity between studies to variations in study quality. Therefore, this review utilized both RE and quality effects (QE) models to assess relevant RCTs comparing TMS with sham intervention in terms of clinical outcomes. A comprehensive literature search was conducted using PubMed and Scopus databases, resulting in the inclusion of 13 studies for data synthesis. Overall, regardless of whether the RE or QE model was used, eligible RCTs suggested that the TMS and sham groups exhibited comparable therapeutic effects after treatment. The current state of research regarding the use of rTMS as a treatment for WM deficits in patients with SCZ remains in its preliminary phase. Furthermore, concerning the mechanism of action, the activation of brain regions focused on the dorsolateral prefrontal cortex and alterations in gamma oscillations may hold significant relevance in the therapeutic application of rTMS for addressing WM impairments. Finally, we believe that the application of closed-loop neuromodulation may contribute to the optimization of rTMS for WM impairment in patients with SCZ.

Efficacy of repetitive transcranial magnetic stimulation (rTMS) on negative symptoms and cognitive functioning in schizophrenia: An umbrella review of systematic reviews and meta-analyses

Negative symptoms and cognitive dysfunction are core characteristics of schizophrenia that profoundly impact daily function and quality of life. As a noninvasive brain stimulation, repetitive transcranial magnetic stimulation (rTMS) has been proposed as a relatively new treatment for ameliorating negative symptoms and cognitive dysfunction in schizophrenia. However, there is controversy over the treatment methods and efficacy. We aimed to provide a quantitative integration of the published evidence regarding the efficacy of rTMS and analyze the feasibility of rTMS for treating negative symptoms and cognitive dysfunction in schizophrenia. A total of twenty reviews were ultimately selected and divided into thirty-three latitudes. Twenty-six analyses showed that rTMS significantly decreased the negative symptom score, and seventeen analyses were performed. Six analyses showed that rTMS treatment can increase working memory scores, and two of them had significant effects. Two analyses from the same review showed that rTMS had a long-term significant effect on treating language function. Only one analysis showed that rTMS had a significant effect on treating executive function. The analyses showed that rTMS had no significant effect on attention function and processing speed. Most reviews indicate that rTMS has an effect on negative symptoms, executive function, working memory, and language function in patients with schizophrenia. Although the quality of evidence was not high, these results are still positive and worthwhile for further study.

The schizophrenia syndrome, circa 2024: What we know and how that informs its nature

With new data about different aspects of schizophrenia being continually generated, it becomes necessary to periodically revisit exactly what we know. Along with a need to review what we currently know about schizophrenia, there is an equal imperative to evaluate the construct itself. With these objectives, we undertook an iterative, multi-phase process involving fifty international experts in the field, with each step building on learnings from the prior one. This review assembles currently established findings about schizophrenia (construct, etiology, pathophysiology, clinical expression, treatment) and posits what they reveal about its nature. Schizophrenia is a heritable, complex, multi-dimensional syndrome with varying degrees of psychotic, negative, cognitive, mood, and motor manifestations. The illness exhibits a remitting and relapsing course, with varying degrees of recovery among affected individuals with most experiencing significant social and functional impairment. Genetic risk factors likely include thousands of common genetic variants that each have a small impact on an individual's risk and a plethora of rare gene variants that have a larger individual impact on risk. Their biological effects are concentrated in the brain and many of the same variants also increase the risk of other psychiatric disorders such as bipolar disorder, autism, and other neurodevelopmental conditions. Environmental risk factors include but are not limited to urban residence in childhood, migration, older paternal age at birth, cannabis use, childhood trauma, antenatal maternal infection, and perinatal hypoxia. Structural, functional, and neurochemical brain alterations implicate multiple regions and functional circuits. Dopamine D-2 receptor antagonists and partial agonists improve psychotic symptoms and reduce risk of relapse. Certain psychological and psychosocial interventions are beneficial. Early intervention can reduce treatment delay and improve outcomes. Schizophrenia is increasingly considered to be a heterogeneous syndrome and not a singular disease entity. There is no necessary or sufficient etiology, pathology, set of clinical features, or treatment that fully circumscribes this syndrome. A single, common pathophysiological pathway appears unlikely. The boundaries of schizophrenia remain fuzzy, suggesting the absence of a categorical fit and need to reconceptualize it as a broader, multi-dimensional and/or spectrum construct.

Low-frequency repetitive transcranial magnetic stimulation over the right orbitofrontal cortex for patients with first-episode schizophrenia: A randomized, double-blind, sham-controlled trial

Repetitive transcranial magnetic stimulation (rTMS) has been used in the treatment of patients with schizophrenia. The conventional targets of rTMS treatment are the dorsolateral prefrontal cortex (DLPFC) and temporoparietal cortex (TPC). However, the efficacy of these two treatment strategies was quite heterogeneous. Structural and functional abnormalities of the orbitofrontal cortex (OFC) in schizophrenia are closely related to negative symptoms. We sought to determine whether 1 Hz rTMS over the right OFC is effective in treating patients with first-episode schizophrenia. In this study, eighty-nine patients with drug-naïve, first-episode schizophrenia were randomly divided into the rTMS (n = 47) or sham stimulation (n = 42) groups, with both groups receiving twenty sessions of 1 Hz rTMS treatment. The PANSS was assessed at baseline, day 10, and day 20, and MATRICS Consensus Cognitive Battery (MCCB) was implemented to assess the cognitive impairment at baseline and day 20. Results showed that patients in the active rTMS group had more improvement in clinical symptoms and cognitive deficits than patients in sham group at day 20. In conclusion, 1 Hz rTMS over OFC can improve psychotic symptoms and cognitive functions in schizophrenic patients. Our study provides a new alternative for the treatment of negative symptoms and cognitive deficits in schizophrenia.

Rich-club reorganization of white matter structural network in schizophrenia patients with auditory verbal hallucinations following 1 Hz rTMS treatment

The human brain comprises a large-scale structural network of regions and interregional pathways, including a selectively defined set of highly central and interconnected hub regions, often referred to as the "rich club", which may play a pivotal role in the integrative processes of the brain. A quintessential symptom of schizophrenia, auditory verbal hallucinations (AVH) have shown a decrease in severity following low-frequency repetitive transcranial magnetic stimulation (rTMS). However, the underlying mechanism of rTMS in treating AVH remains elusive. This study investigated the effect of low-frequency rTMS on the rich-club organization within the brain in patients diagnosed with schizophrenia who experience AVH using diffusion tensor imaging data. Through by constructing structural connectivity networks, we identified several critical rich hub nodes, which constituted a rich-club subnetwork, predominantly located in the prefrontal cortices. Notably, our findings revealed enhanced connection strength and density within the rich-club subnetwork following rTMS treatment. Furthermore, we found that the decreased connectivity within the subnetwork components, including the rich-club subnetwork, was notably enhanced in patients following rTMS treatment. In particular, the increased connectivity strength of the right median superior frontal gyrus, which functions as a critical local bridge, with the right postcentral gyrus exhibited a significant correlation with improvements in both positive symptoms and AVH. These findings provide valuable insights into the role of rTMS in inducing reorganizational changes within the rich-club structural network in schizophrenia and shed light on potential mechanisms through which rTMS may alleviate AVH.

Alterations in brain connectivity patterns in schizophrenia patients with auditory verbal hallucinations during low frequency repetitive transcranial magnetic stimulation

OBJECTIVE

Auditory verbal hallucinations (AVH) are a characteristic symptom of schizophrenia. Although low-frequency repetitive transcranial magnetic stimulation (rTMS) has been demonstrated to alleviate the severity of AVH, its exact neurophysiological mechanisms remain unclear. This study aimed to elucidate the alterations in brain connectivity patterns in schizophrenia patients with AVH after low frequency rTMS. Furthermore, the relationship between these alterations and clinical outcomes was examined, thereby identifying potential biomarkers for rTMS treatment efficacy.

METHODS

A total of 30 schizophrenia patients with AVH and 33 healthy controls were recruited. The patients received 1 Hz rTMS applied to the left temporoparietal junction region over 15 days. Resting-state functional magnetic resonance imaging scans were conducted for all participants. Subsequently, degree centrality (DC) and seed-based functional connectivity (FC) analyses were employed to identify specific alterations in brain connectivity patterns after rTMS treatment.

RESULTS

At baseline, patients exhibited divergent DC patterns in the frontal, occipital, and limbic lobes compared to healthy controls. In addition, prior to treatment, patients demonstrated altered FC from the superior frontal gyrus seeds that linked to the frontal, temporal, and somatosensory regions. Following rTMS treatment, these abnormalities were notably reversed, correlating with improved clinical outcomes.

CONCLUSIONS

These findings demonstrate that schizophrenia patients with AVH exhibited atypical interactions within the frontal and temporal lobes. These alterations might be crucial biomarkers for predicting the efficacy of low frequency rTMS.

Language abnormalities in schizophrenia: binding core symptoms through contemporary empirical evidence

Both the ability to speak and to infer complex linguistic messages from sounds have been claimed as uniquely human phenomena. In schizophrenia, formal thought disorder (FTD) and auditory verbal hallucinations (AVHs) are manifestations respectively relating to concrete disruptions of those abilities. From an evolutionary perspective, Crow (1997) proposed that "schizophrenia is the price that Homo sapiens pays for the faculty of language". Epidemiological and experimental evidence points to an overlap between FTD and AVHs, yet a thorough investigation examining their shared neural mechanism in schizophrenia is lacking. In this review, we synthesize observations from three key domains. First, neuroanatomical evidence indicates substantial shared abnormalities in language-processing regions between FTD and AVHs, even in the early phases of schizophrenia. Second, neurochemical studies point to a glutamate-related dysfunction in these language-processing brain regions, contributing to verbal production deficits. Third, genetic findings further show how genes that overlap between schizophrenia and language disorders influence neurodevelopment and neurotransmission. We argue that these observations converge into the possibility that a glutamatergic dysfunction in language-processing brain regions might be a shared neural basis of both FTD and AVHs. Investigations of language pathology in schizophrenia could facilitate the development of diagnostic tools and treatments, so we call for multilevel confirmatory analyses focused on modulations of the language network as a therapeutic goal in schizophrenia.

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.

Efficacy and safety of intermittent theta-burst stimulation in patients with schizophrenia: A meta-analysis of randomized sham-controlled trials

Theta-burst stimulation is a non-invasive brain stimulation technique that was introduced as a potential augmentation treatment for patients with schizophrenia. The purpose of this meta-analysis was to investigate the therapeutic efficacy and safety of intermittent theta-burst stimulation in patients with schizophrenia. Following the PRISMA guidelines, the MEDLINE, Embase, Cochrane, Scopus, Web of Science, and CNKI databases were searched for relevant studies from database inception to 9 January 2022. Change in symptom severity among patients with schizophrenia was the primary outcome, and changes in cognitive function and safety profiles, including the discontinuation rate and adverse events, were secondary outcomes. In total, 13 double-blind randomized sham-controlled trials with 524 patients were included. Intermittent theta-burst stimulation adjunct to antipsychotics was associated with significantly improved psychopathology in patients with schizophrenia, particularly for negative symptoms and general psychopathology but not for positive symptoms or cognitive function. The stimulation parameters influenced the effectiveness of intermittent theta-burst stimulation. A more favorable effect was observed in patients who received theta-burst stimulation at the left dorsolateral prefrontal cortex, with ≥1800 pulses per day, for ≥20 sessions, and using an inactive sham coil as a placebo comparison in the study. The intermittent theta-burst stimulation is well tolerated and safe in patients with schizophrenia. Intermittent theta-burst stimulation adjunct to antipsychotics treatment is associated with significant improvement in negative symptoms and favorable tolerability in patients with schizophrenia. This meta-analysis may provide insights into the use of intermittent theta-burst stimulation as an additional treatment to alleviate the negative symptoms of schizophrenia.

"Efficacy of intensive bilateral Temporo-Parietal Continuous theta-burst Stimulation for Auditory VErbal hallucinations (TPC-SAVE) in schizophrenia: A randomized sham-controlled trial"☆

Transcranial magnetic stimulation (TMS) is a non-invasive tool that moderates specific brain regions to ameliorate auditory verbal hallucinations (AVH) in schizophrenia. Citing the critical involvement of temporoparietal cortex (TPC) in AVH, our study aimed to evaluate the effect of continuous theta burst stimulation (cTBS) targeting bilateral TPC in schizophrenia subjects with AVH, on a randomized rater blinded placebo control trial. 59 patients were randomly allocated to active and sham groups. They received 20 cTBS sessions (2 per day: first right TPC, then left TPC) 5 days a week for 2 weeks. PANSS (Positive and Negative Syndrome Scale), AVHRS (Auditory vocal hallucination rating scale), PSYRAT-AH (Psychiatric symptoms rating scale- Auditory hallucinations scale), CDSS (Calgary depression scale for schizophrenia), SCoRS (Schizophrenia cognition rating scale) and CGI-S (Clinical global impression-severity) were rated at baseline, immediately post 20th session and 2 weeks post-TBS. 50 patients (25-active, 25-sham) completed the study. Conducting an intention to treat analysis, we found a significant group*time effect for PANSS, AVHRS, PSYRAT-AH, CDSS, SCoRS, CGI-S but when controlled for confounding variables and multiple comparisons, only PANSS-PS (F=26.617, p < 0.001), PANSS-TOTAL (F=23.671, p < 0.001), AVHRS (F=17.779, p < 0.001), PSYRAT-AH (F=11.385, p < 0.001) and CGI-S (F=28.462, p < 0.001) retained significance. We conclude that cTBS over TPC is safe and has efficacy in treating AVH in schizophrenia. Limited sample size and lack of integrity assessment for blinding in the study participants are major limitations of the study.

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.

Low-frequency rTMS treatment alters the topographical organization of functional brain networks in schizophrenia patients with auditory verbal hallucination

Auditory verbal hallucinations (AVH) are an important characteristic of schizophrenia. Repeated transcranial magnetic stimulation (rTMS) has been evidence to be effective in treating AVH. We evaluated the topological properties of resting-state functional brain networks in schizophrenia patients with AVH (n = 32) who received 1-Hz rTMS treatment and matched healthy controls (n = 33). The results showed that the psychotic symptoms and certain neurocognitive performances in patients were improved by rTMS treatment. Furthermore, the pretreatment patients showed abnormal global topological metrics compared with the controls, including lower global efficiency (E_glob, represents the relative quality of information transmission between all nodes in the network) and higher characteristic path length (L_p, characterizes the mean shortest distance between any two nodes in the network). The pretreament patients also showed decreased local topological metrics relative to the controls, including the nodal shortest path (NL_p, quantifies the mean distance between the given node and the other nodes in the network) and nodal efficiency (N_e, measures the information interchange among the neighbor nodes when one node is removed), mainly located in the prefrontal cortex, occipital cortex, and subcortical regions. While the abnormal global and local topological patterns were normalized in patients after rTMS treatment. The multiple linear regression analysis indicated that the baseline topological metrics could be associated with the clinical responses after treatment in the patient group. The results suggested that the topological organization of the functional brain network was globally and regionally altered in schizophrenia patients with AVH after rTMS treatment and may be a potential therapeutic effect for AVH in schizophrenia.

The alternations of nucleus accumbent in schizophrenia patients with auditory verbal hallucinations during low-frequency rTMS treatment

Low-frequency repetitive transcranial magnetic stimulation (rTMS) has been shown to reduce the severity of auditory verbal hallucinations (AVH) and induce beneficial functional and structural alternations of the brain in schizophrenia patients with AVH. The nucleus accumbens (NAcc) as an important component of the ventral striatum is implicated with the pathology in AVH. However, the induced characteristic patterns of NAcc by low-frequency rTMS in schizophrenia with AVH are seldom explored. We investigated the functional and structural characteristic patterns of NAcc by using seed-based functional connectivity (FC) analysis and gray matter volume (GMV) measurement in schizophrenia patients with AVH during 1 Hz rTMS treatment. Although low-frequency rTMS treatment did not affect the volumetric changes of NAcc, the abnormal FC patterns of NAcc, including increased FC of NAcc with the temporal lobes and decreased FC of NAcc with the frontal cortices in the pretreatment patients compared to healthy controls, were normalized or reversed after treatment. These FC changes were associated with improvements in clinical symptoms and neurocognitive functions. Our findings may extend our understanding of the NAcc in the pathology of schizophrenia with AVH and might be a biomarker of clinical effect for low-frequency rTMS treatment in schizophrenia.

Intermittent theta burst stimulation of cerebellar vermis enhances fronto-cerebellar resting state functional connectivity in schizophrenia with predominant negative symptoms: A randomized controlled trial

OBJECTIVE

Negative symptoms of schizophrenia are substantially disabling and treatment resistant. Novel treatments like repetitive transcranial magnetic stimulation (TMS) need to be examined for the same using the experimental medicine approach that incorporates tests of mechanism of action in addition to clinical efficacy in trials.

METHODS

Study was a double-blind, parallel, randomized, sham-controlled trial recruiting schizophrenia with at least a moderate severity of negative symptoms. Participants were randomized to real or sham intermittent theta burst stimulation (iTBS) under MRI-guided neuro-navigation, targeting the cerebellar vermis area VII-B, at a stimulus intensity of 100% active motor threshold, two sessions/day for five days (total = 6000 pulses). Assessments were conducted at baseline (T0), day-6 (T1) and week-6 (T2) after initiation of intervention. Main outcomes were, a) Scale for the Assessment of Negative Symptoms (SANS) score (T0, T1, T2), b) fronto-cerebellar resting state functional connectivity (RSFC) (T0, T1).

RESULTS

Thirty participants were recruited in each arm. Negative symptoms improved in both arms (p < 0.001) but was not significantly different between the two arms (p = 0.602). RSFC significantly increased between the cerebellar vermis and the right inferior frontal gyrus (p_cluster-FWER = 0.033), right pallidum (p_cluster-FWER = 0.042) and right frontal pole (p_cluster-FWER = 0.047) in the real arm with no change in the sham arm.

CONCLUSION

Cerebellar vermal iTBS engaged a target belonging to the class of cerebello-subcortical-cortical networks, implicated in negative symptoms of schizophrenia. However, this did not translate to a superior clinical efficacy. Future trials should employ enhanced midline cerebellar TMS stimulation parameters for longer durations that can potentiate and translate biological changes into clinical effects.

Brazilian research on noninvasive brain stimulation applied to health conditions

BACKGROUND

Brazil has a top position regarding scientific production on noninvasive neuromodulation worldwide. Knowledge of scientometric phenomena involving Brazilian researchers who produce science on this theme may aid confidence in Brazilian clinical and research professionals.

OBJECTIVE

To investigate the scenario of research on the theme of noninvasive neuromodulation in Brazil.

METHODS

This was a scientometric study for mapping scientific production on this subject involving network phenomena, the professions of researchers, institutional affiliation, main research unit, total number of scientific articles on noninvasive neuromodulation published in journals, research sub-area and year of obtaining the PhD title. Public data from Lattes Platform curricula vitae and from VOSViewer© were used.

RESULTS

A total of 54 Brazilian researchers were identified, of whom 16 are research productivity fellows. Most of them are linked to institutions in southeastern Brazil, involving the professions of biology, biochemistry, physical education, physiotherapy, speech therapy, gerontology, medicine and psychology, with 1175 articles published in journals. These studies involve experimental animal and human models to account for mechanisms, observational studies, case reports, randomized clinical trials, systematic reviews, meta-analyses, product and process development, computer modeling and guidelines.

CONCLUSIONS

Brazil occupies a prominent place in the world scenario of research on noninvasive neuromodulation, which is used by different professions for treatment of brain dysfunctions, with a trend towards expansion to other fields.

Repetitive transcranial magnetic stimulation and transcranial direct current stimulation for auditory hallucinations in schizophrenia: Systematic review and meta-analysis

Through imaging studies, a significant increase in cerebral activity has been detected in fronto-temporal areas in patients experiencing auditory verbal hallucinations. Therefore, non-invasive neuromodulation, in particular transcranial direct current stimulation (tDCS) and repetitive transcranial magnetic stimulation (rTMS), has been considered as a therapeutic intervention for medication-resistant auditory verbal hallucinations in schizophrenia. We aimed to synthesize results from randomized trials on either rTMS or tDCS versus placebo in patients with schizophrenia by including five recently published trials in the field. A systematic review and meta-analysis of relevant literature was conducted. Studies were included on the basis of pre-defined selection criteria. The quality of the studies was assessed by the Cochrane Risk of Bias Tool for Randomized Controlled Trials. RevMan 5.3 was used to conduct the statistical analysis. Including 465 and 960 patients, respectively, 12 tDCS and 27 rTMS studies were included. Regarding treatment of medication refractory auditory verbal hallucinations, no significant effect of tDCS (-0.23 [-0.49, 0.02], p = 0.08) or rTMS (-0.19 [-0.50, 0,11], p = 0.21) was found compared to sham in this meta-analysis. The current study found that it cannot be concluded that rTMS and tDCS are efficacious in treating medication-resistant auditory verbal hallucinations. Larger randomized controlled tDCS trials of a higher quality should be conducted in the future to establish substantial evidence of tDCS. The interventions appear safe and may have beneficial effects on other outcomes.

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.

Dorsomedial prefrontal theta burst stimulation to treat anhedonia, avolition, and blunted affect in schizophrenia or depression - a randomized controlled trial

BACKGROUND

Intermittent theta burst stimulation (iTBS) over the dorsomedial prefrontal cortex (DMPFC) has shown promise in open-label trials of depression.

METHODS

In this randomized, double-blind, sham controlled trial we evaluate iTBS over the DMPFC for anhedonia, avolition, and blunted affect in patients with schizophrenia or depression. Active iTBS was delivered over the DMPFC with 1200 pulses per session, twice daily over ten weekdays at target intensity with an angled figure-of eight coil. Sham condition comprised the magnetically shielded side of the coil and simultaneous transcutaneous electrical nerve stimulation. Primary outcome was change on the Clinical Assessment Interview for Negative Symptoms (CAINS).

RESULTS

Twenty-eight patients were randomized to active iTBS and 28 to sham. Mean (standard deviation) change in CAINS score from baseline to the day after last treatment was -5.3 (8.1) in active iTBS and -2.1 (7.1) in sham. A linear model showed no significant effect of treatment, accounting for baseline scores p=.088. Sub analyses per diagnostic group showed a significant effect in patients with depression, p=.038, but not in the schizophrenia group, p=.850. However, overall depressive symptoms did not change significantly in patients with depression. There were three serious adverse events, all in the sham group.

LIMITATIONS

Possibly too short treatment course and few patients with schizophrenia.

CONCLUSION

In this first transdiagnostic randomized controlled trial of iTBS over DMPFC for anhedonia, avolition, and blunted affect it can be concluded that it was generally tolerable and safe but only more effective than sham in the subgroup of patients with depression.

Examining and Modulating Neural Circuits in Psychiatric Disorders With Transcranial Magnetic Stimulation and Electroencephalography: Present Practices and Future Developments

Transcranial magnetic stimulation (TMS) is a noninvasive brain stimulation technique uniquely equipped to both examine and modulate neural systems and related cognitive and behavioral functions in humans. As an examination tool, TMS can be used in combination with EEG (TMS-EEG) to elucidate directly, objectively, and noninvasively the intrinsic properties of a specific cortical region, including excitation, inhibition, reactivity, and oscillatory activity, irrespective of the individual's conscious effort. Additionally, when applied in repetitive patterns, TMS has been shown to modulate brain networks in healthy individuals, as well as ameliorate symptoms in individuals with psychiatric disorders. The key role of TMS in assessing and modulating neural dysfunctions and associated clinical and cognitive deficits in psychiatric populations is therefore becoming increasingly evident. In this article, the authors review TMS-EEG studies in schizophrenia and mood disorders, as most TMS-EEG studies to date have focused on individuals with these disorders. The authors present the evidence on the efficacy of repetitive TMS (rTMS) and theta burst stimulation (TBS), when targeting specific cortical areas, in modulating neural circuits and ameliorating symptoms and abnormal behaviors in individuals with psychiatric disorders, especially when informed by resting-state and task-related neuroimaging measures. Examples of how the combination of TMS-EEG assessments and rTMS and TBS paradigms can be utilized to both characterize and modulate neural circuit alterations in individuals with psychiatric disorders are also provided. This approach, along with the evaluation of the behavioral effects of TMS-related neuromodulation, has the potential to lead to the development of more effective and personalized interventions for individuals with psychiatric disorders.

Current clinical practice of electroconvulsive therapy and repetitive transcranial magnetic stimulation in psychiatry, a German sample

The purpose of the study was to evaluate the current clinical practice of Electroconvulsive Therapy and Repetitive Transcranial Magnetic Stimulation in German psychiatry. Case-based data (> 1.000.000 cases) were collected according to §21 of the German hospital remuneration law from January 2015 to December 2017. The study cohort comprises approximately 35-40% of the annual psychiatric cases and hospitals in Germany. Frequency of ECT and rTMS cases were investigated considering main diagnoses according to ICD-10 and treatment settings (inpatient vs. day-care). ECT cases with short-term hospitalization (≤ 4 days) were supposed to be maintenance ECT cases. A linear regression analysis was conducted to estimate trends in the use of ECT and rTMS. Different groups were compared using Chi-square tests. ECT and rTMS cases appear to increase in total during the observation period possibly due to facilities newly introducing ECT and rTMS but also to increased frequency of treatments. Both treatments were rarely performed in day-care settings (0.89% and 11.25%). ECT was performed in 1.72% of all cases with affective disorders and in 1.48% with major depressions, respectively. Age ≥ 65 years, females, severe and psychotic depression were significantly associated with a higher rate of ECT cases. > 40% of all ECT cases were possibly maintenance ECT cases. Only 0.60% of these were performed in day- care settings. rTMS was primarily performed in major depression (86,7% of all rTMS cases). This study suggests a growing demand for ECT and rTMS. Nevertheless, the use of ECT is still low compared to the high prevalence of treatment resistant depression. The use of rTMS is even lower and seems to be restricted to specialized institutions. Maintenance ECT is frequently carried out in an inpatient setting. Limitations of this study are the case- and group-based analysis, missing data on outpatient services and treatment sessions per case. Therefore, the database is not necessarily representative for the entire German healthcare system. Further studies are needed to verify the presented findings and should address the feasibility of ambulatory and day-care ECT services.

Functional MRI in the effect of transcranial magnetic stimulation therapy for patients with schizophrenia: a meta-analysis protocol

INTRODUCTION

Schizophrenia is a psychiatric illness associated with brain function alterations and varying degree of treatment resistance, often leading to severe social malfunctioning. In recent decades, numerous studies have been investigating the therapeutic potential of transcranial magnetic stimulation (TMS) as a non-invasive therapy for schizophrenia. However, its clinical efficacy remains controversial, as a number of clinical trials indicated moderate therapeutic effect while others failed to reproduce the positive result. Moreover, the neurobiological mechanism of action remains unclear, possibly constricting the application of TMS in clinical practice. The present protocol of meta-analysis aims to investigate the TMS-related functional neuroimaging (ie, functional MRI) features and alterations in subjects with schizophrenia, and to discuss the potential of functional MRI in TMS researches.

METHODS AND ANALYSIS

The study selection process will follow the Preferred Reporting Items for Meta-Analyses guideline and quality assessment will be conducted with a customised checklist. We plan to search in the following databases: PubMed, Embase, OVID, China National Knowledge Infrastructure and Wanfang Data, from their respective dates of inception to 1 May 2020, with language restricted to English and Chinese. Studies focusing on the brain functional alterations in patients with schizophrenia treated by TMS will be retrieved.

ETHICS AND DISSEMINATION

This work does not require ethics approval as it will be based on published studies. This systematic review will be publicly disseminated in peer-reviewed journals.

PROSPERO REGISTRATION NUMBER

CRD42020166288.

Cognitive Enhancing Effect of High-Frequency Neuronavigated rTMS in Chronic Schizophrenia Patients With Predominant Negative Symptoms: A Double-Blind Controlled 32-Week Follow-up Study

Accumulating studies have shown that high-frequency (HF) repetitive transcranial magnetic stimulation (rTMS) may improve cognitive dysfunction of the patients with schizophrenia (SCZ), but with inconsistent results. The present study aims to assess the efficacy of different frequencies of neuronavigated rTMS in ameliorating cognitive impairments and alleviating the psychotic symptoms. A total of 120 patients were randomly assigned to 3 groups: 20 Hz rTMS (n = 40), 10 Hz rTMS (n = 40), or sham stimulation (n = 40) for 8 weeks, and then followed up at week 32. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was performed to assess the cognitive functions of the patients at baseline, at the end of week 8, and week 32 follow-up. Psychotic symptoms were assessed with the Positive and Negative Syndrome Scale (PANSS) at baseline and at the end of week 2, week 4, week 6, week 8, and week 32 follow-up. Our results demonstrated that 20 Hz rTMS treatment produced an effective therapeutic benefit on immediate memory of patients with chronic SCZ at week 8, but not in the 10 Hz group. Interestingly, both 10 Hz and 20 Hz rTMS treatments produced delayed effects on cognitive functions at the 6-month follow-up. Moreover, in both 10 Hz rTMS and 20 Hz rTMS, the improvements in RBANS total score were positively correlated with the reduction of PANSS positive subscore at the 6-month follow-up. Stepwise regression analysis identified that the visuospatial/constructional index, immediate memory index, and prolactin at baseline were predictors for the improvement of cognitive impairments in the patients. Our results suggest that add-on HF rTMS could be an effective treatment for cognitive impairments in patients with chronic SCZ, with a delayed effect. Trial registration: clinicaltrials.gov identifier-NCT03774927.

Efficacy of repetitive transcranial magnetic stimulation on auditory hallucinations in schizophrenia: A meta-analysis

To evaluate the efficacy of repetitive transcranial magnetic stimulation (rTMS) on auditory hallucinations (AH) in schizophrenia, we conducted a meta-analysis of currently available randomized control studies (RCTs). Electronic databases were searched to identify relevant literatures. Only RCTs that met the inclusion criteria were enrolled for further analysis. Standard mean difference (SMD) and 95% confidence interval (CI) values were used to evaluate the effects of rTMS. The overall robustness of the results was assessed by analyzing the influence of single studies. Publication bias was analyzed using funnel plots. Eleven eligible studies were included in this meta-analysis. Auditory hallucinations improved more in the rTMS group than in the sham group (SMD = -0.27, 95%CI = -0.51 to -0.03). However, this result was not stable after sensitivity analysis. Despite a moderate effect for rTMS on AH, future definitive trials of rTMS with rigorous processes and high-quality reporting are needed.

Clozapine Combination and Augmentation Strategies in Patients With Schizophrenia -Recommendations From an International Expert Survey Among the Treatment Response and Resistance in Psychosis (TRRIP) Working Group

BACKGROUND

Evidence for the management of inadequate clinical response to clozapine in treatment-resistant schizophrenia is sparse. Accordingly, an international initiative was undertaken with the aim of developing consensus recommendations for treatment strategies for clozapine-refractory patients with schizophrenia.

METHODS

We conducted an online survey among members of the Treatment Response and Resistance in Psychosis (TRRIP) working group. An agreement threshold of ≥75% (responses "agree" + "strongly agree") was set to define a first-round consensus. Questions achieving agreement or disagreement proportions of >50% in the first round, were re-presented to develop second-round final consensus recommendations.

RESULTS

Forty-four (first round) and 49 (second round) of 63 TRRIP members participated. Expert recommendations at ≥75% agreement included raising clozapine plasma levels to ≥350 ng/ml for refractory positive, negative, and mixed symptoms. Where plasma level-guided dose escalation was ineffective for persistent positive symptoms, waiting for a delayed response was recommended. For clozapine-refractory positive symptoms, combination with a second antipsychotic (amisulpride and oral aripiprazole) and augmentation with ECT achieved consensus. For negative symptoms, waiting for a delayed response was recommended, and as an intervention for clozapine-refractory negative symptoms, clozapine augmentation with an antidepressant reached consensus. For clozapine-refractory suicidality, augmentation with antidepressants or mood-stabilizers, and ECT met consensus criteria. For clozapine-refractory aggression, augmentation with a mood-stabilizer or antipsychotic medication achieved consensus. Generally, cognitive-behavioral therapy and psychosocial interventions reached consensus.

CONCLUSIONS

Given the limited evidence from randomized trials of treatment strategies for clozapine-resistant schizophrenia (CRS), this consensus-based series of recommendations provides a framework for decision making to manage this challenging clinical situation.

High-frequency neuronavigated rTMS effect on clinical symptoms and cognitive dysfunction: a pilot double-blind, randomized controlled study in Veterans with schizophrenia

Cognitive impairment is a central aspect of schizophrenia (SCZ) that occurs at the onset of the disease and is related to poor social function and outcome in patients with SCZ. Recent literatures have revealed repetitive transcranial magnetic stimulation (rTMS) to be one of the efficient medical interventions for cognitive impairments. However, no study has been conducted to investigate the treatment effectiveness of 20 Hz rTMS with neuronavigation system administered to the left dorsolateral prefrontal cortex (DLPFC) in patients with schizophrenia. In this randomized, double-blind and sham-controlled study, 56 patients were enrolled in 20 Hz rTMS (n = 28) or sham stimulation (n = 28) over left DLPFC for 8 weeks. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was performed to measure the cognitive function at baseline and after 8 weeks of rTMS treatment. The positive and negative syndrome scales (PANSS) was performed to assess the clinical symptoms at baseline, after 2-week treatment, 4-week treatment, 6-week treatment, and 8-week treatment. Totally, 15 subjects (seven in active group and eight in sham group) dropped out during the trial and the main findings were from completed 41 patients. At 2 weeks, 4 weeks, and 6 weeks, there were no significant differences in PANSS total score and subscores between the sham and treatment groups. At 8 weeks, the 20 Hz rTMS significantly increased the immediate memory score compared with the sham. Furthermore, the improvement in the immediate memory score was correlated with the decrease in the excitement factor score of the patients with SCZ. Our results suggest that 20 Hz rTMS appears to be an effective treatment for improving the cognitive performance and reducing the clinical symptoms of patients with SCZ.

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.

Evidence-based guidelines on the therapeutic use of repetitive transcranial magnetic stimulation (rTMS): An update (2014-2018)

A group of European experts reappraised the guidelines on the therapeutic efficacy of repetitive transcranial magnetic stimulation (rTMS) previously published in 2014 [Lefaucheur et al., Clin Neurophysiol 2014;125:2150-206]. These updated recommendations take into account all rTMS publications, including data prior to 2014, as well as currently reviewed literature until the end of 2018. Level A evidence (definite efficacy) was reached for: high-frequency (HF) rTMS of the primary motor cortex (M1) contralateral to the painful side for neuropathic pain; HF-rTMS of the left dorsolateral prefrontal cortex (DLPFC) using a figure-of-8 or a H1-coil for depression; low-frequency (LF) rTMS of contralesional M1 for hand motor recovery in the post-acute stage of stroke. Level B evidence (probable efficacy) was reached for: HF-rTMS of the left M1 or DLPFC for improving quality of life or pain, respectively, in fibromyalgia; HF-rTMS of bilateral M1 regions or the left DLPFC for improving motor impairment or depression, respectively, in Parkinson's disease; HF-rTMS of ipsilesional M1 for promoting motor recovery at the post-acute stage of stroke; intermittent theta burst stimulation targeted to the leg motor cortex for lower limb spasticity in multiple sclerosis; HF-rTMS of the right DLPFC in posttraumatic stress disorder; LF-rTMS of the right inferior frontal gyrus in chronic post-stroke non-fluent aphasia; LF-rTMS of the right DLPFC in depression; and bihemispheric stimulation of the DLPFC combining right-sided LF-rTMS (or continuous theta burst stimulation) and left-sided HF-rTMS (or intermittent theta burst stimulation) in depression. Level A/B evidence is not reached concerning efficacy of rTMS in any other condition. The current recommendations are based on the differences reached in therapeutic efficacy of real vs. sham rTMS protocols, replicated in a sufficient number of independent studies. This does not mean that the benefit produced by rTMS inevitably reaches a level of clinical relevance.

Investigational and Therapeutic Applications of Transcranial Magnetic Stimulation in Schizophrenia

PURPOSE OF REVIEW

This current review summarizes the investigational and therapeutic applications of transcranial magnetic stimulation (TMS) in schizophrenia.

RECENT FINDINGS

Fairly consistent findings of an impaired cortical excitation-inhibition balance, cortical plasticity, and motor resonance have been reported in schizophrenia. Cortical connectivity impairments have also been demonstrated in motor and prefrontal brain regions. In terms of treatment, the best support is for 1-Hz TMS to the left temporoparietal cortex for the short-term treatment of persistent auditory hallucinations. High-frequency TMS to the left prefrontal cortex improves negative and cognitive symptoms, but with inconsistent and small effects. TMS combined with diverse brain mapping techniques and clinical evaluation can unravel critical brain-behavior relationships relevant to schizophrenia. These provide critical support to the conceptualization of schizophrenia as a connectopathy with anomalous cortical plasticity. Adaptive modulation of these aberrant brain networks in a neuroscience-informed manner drives short-term therapeutic gains in difficult-to-treat symptoms of schizophrenia.

Efficacy of high-frequency repetitive transcranial magnetic stimulation in schizophrenia patients with treatment-resistant negative symptoms treated with clozapine

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) is a promising augmentation treatment for schizophrenia, however there are few controlled studies of rTMS augmentation of clozapine.

METHODS

Using data from the 'rTMS for the Treatment of Negative Symptoms in Schizophrenia' (RESIS) trial we examined the impact of rTMS on PANSS total, general, positive and negative symptoms among participants on clozapine. rTMS was applied to the left dorsolateral prefrontal cortex (DLPFC) for five treatment sessions/week for 3-weeks as augmentation for patients with a predominant negative syndrome of schizophrenia, as rated on PANSS.

RESULTS

26 participants from the RESIS trial were on clozapine, receiving active (N=12) or sham (N=14) rTMS treatment. In our Linear Mixed Model (LMM) analysis, time×group interactions were significant in the PANSS positive subscale (p=0.003) (not being the corresponding behavioral output for DLPFC stimulation), the PANSS general subscale (p<0.001), the PANSS total scale (p=0.015), but not the PANSS negative subscale (p=0.301) (primary endpoint of the RESIS trial), when all PANSS measurements from screening to day 105 were included. Descriptive data suggests that in the active group the improvement was more pronounced compared to the sham rTMS group.

CONCLUSIONS

In this largest available clozapine cohort, active rTMS may be more effective than sham rTMS when added to clozapine for positive and total psychotic symptoms. These findings should be interpreted with caution given this is a secondary analysis with a limited number of participants.

Top 100 cited noninvasive neuromodulation clinical trials

INTRODUCTION

Introduction: Transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS) are noninvasive neuromodulation techniques used as therapeutic and research tools for several neuropsychiatric conditions. Given the exponential scientific growth of this field, we aimed to systematically review the most cited clinical trials using TMS or tDCS.

AREAS COVERED

A de-novo keyword search strategy identified and characterized the 100 most-cited trials. Total citation count for the most cited trials was 13,204. Articles were published between 2008 and 2014 in 50 different journals with a median impact factor of 6.52 (IQR 3.37). Almost half of the top cited papers were investigating mechanisms of action in healthy subjects. Most studies were feasibility trials and only five were pivotal trials, including the ones used for recent FDA approval. Seven articles were interlinked with another article by at least 25 citations and eight authors had collaborated with at least one other author.

EXPERT OPINION

Although there has been a significant increase in interest for rTMS and tDCS, most of the cited clinical trials are still small feasibility studies, what reinforced the need for more robust clinical trials (larger samples sizes and effects sizes) to better define clinical effectiveness.

Structural and functional brain biomarkers of clinical response to rTMS of medication-resistant auditory hallucinations in schizophrenia patients: study protocol for a randomized sham-controlled double-blind clinical trial

BACKGROUND

The potential of non-invasive repetitive transcranial magnetic stimulation (rTMS) to improve auditory verbal hallucinations (AVH) in schizophrenia patients has been increasingly explored over the past decade. Despite highly promising results, high inter-individual variability of clinical response and ineffective outcomes in a significant number of patients underscored the need to identify factors associated with the clinical response to rTMS. It should help improve the efficacy of rTMS in patients with medication-resistant AVH, and allow a better understanding of its neural impact. Here, we describe an exploratory study protocol which aims to identify structural and functional brain biomarkers associated with clinical response after an rTMS treatment for medication-resistant AVH in schizophrenia.

METHODS

Forty-five schizophrenia patients with medication-resistant AVH will be enrolled in a double-blind randomized sham-controlled monocentric clinical trial. Patients will be assigned to a regime of 20 sessions of active or sham 1 Hz rTMS delivered twice a day, 5 days a week for 2 weeks over the left temporo-parietal junction. Response will be assessed after rTMS and patients will be classified in responders or non-responders to treatment. Magnetic resonance imaging (MRI) sessions including diffusion weighted imaging and resting-state functional MRI sequences will be recorded before the onset of the rTMS treatment and 3 days following its discontinuation. The primary outcome measure is difference in fractional anisotropy between responder and non-responder patients at baseline. Differences in resting-state functional MRI data at baseline will be also investigated between responder and non-responder groups. Clinical, neuropsychological, neurophysiological, and blood serum BDNF assessments will be performed at baseline, 3 days, 1 month, and 3 months following rTMS.

DISCUSSION

The aim of this research project is to identify and assess the biomarker value of MRI-based structural and functional biomarkers predicting clinical response to rTMS for AVH in schizophrenia patients. The outcome of the trial should improve patient care by offering them a novel suitable therapy and deepen our understanding on how rTMS may impact AVH and develop more effective therapies adapted to individual patient needs.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02755623 . Registered on 22 April 2016.

Personalized TMS: role of RNA genotyping

Purpose

Noninvasive brain stimulation (NIBS) such a transcranial magnetic stimulation, intermittent theta burst stimulation, transcranial direct current stimulation and electroconvulsive therapy have emerged as an efficacious and well-tolerated therapy for treatment-resistant psychiatric disorders. While novel NIBS techniques are an exciting addition to the current repertoire of neuropsychiatric therapies, their success is somewhat limited by the wide range of treatment responses seen among treated patients.

Design/methodology/approach

In this study, the authors will review the studies on relevant genetic polymorphisms and discuss the role of RNA genotyping in personalizing NIBS.

Findings

Genome studies have revealed several genetic polymorphisms that may contribute for the heterogeneity of treatment response to NIBS where the presence of certain single nucleotide polymorphisms (SNPs) are associated with responders versus nonresponders.

Originality/value

Historically, mental illnesses have been arguably some of the most challenging disorders to study and to treat because of the degree of biological variability across affected individuals, the role of genetic and epigenetic modifications, the diversity of clinical symptomatology and presentations and the interplay with environmental factors. In lieu of these challenges, there has been a push for personalized medicine in psychiatry that aims to optimize treatment response based on one's unique characteristics.

Treating auditory hallucinations with transcranial direct current stimulation in a double-blind, randomized trial

OBJECTIVE

Transcranial direct current stimulation (tDCS) could be a treatment option for medication-resistant auditory hallucinations (AH), but so far results have been inconclusive, and large sample trials have been missing. This study used tDCS as a treatment method for these hallucinations in a double-blind, placebo-controlled study with a relatively large sample size.

METHODS

Fifty-four patients of several diagnostic categories with medication-resistant AH were randomized and treated during 10 sessions of 20 min each, with either 2 mA tDCS or placebo, administered on five consecutive days (i.e., two sessions per day). Anodal stimulation was targeted at the left dorsolateral prefrontal cortex, cathodal stimulation at the left temporoparietal junction. AH severity was assessed using the Auditory Hallucination Rating Scale (AHRS). Other outcome measures were assessed with the Positive and Negative Syndrome Scale (PANSS), the Stroop, and the Trail Making Test.

RESULTS

AH frequency and severity decreased significantly over time, as did the scores on the total and general subscales of the PANSS. However, there was no significant interaction effect with the treatment group on any of the main outcome measures.

CONCLUSIONS

We found no evidence that tDCS is more effective for medication-resistant AH than placebo, even though AH frequency and severity decreased in both groups. An alternative strategy may be to offer tDCS at an earlier stage of illness. In the light of recent investigations into the neurophysiological mechanisms behind tDCS, we may also have to consider the possibility that tDCS is not able to induce any long-lasting brain changes.

Efficacy of high-frequency repetitive transcranial magnetic stimulation on PANSS factors in schizophrenia with predominant negative symptoms - Results from an exploratory re-analysis

Repetitive transcranial magnetic stimulation (rTMS) applied to the left frontal lobe is discussed to be a promising add-on treatment for negative symptoms in schizophrenia. The Positive and Negative Syndrome Scale (PANSS) has been used as outcome parameter in several previous rTMS trials, but studies focusing on PANSS factor analyses are lacking. For this purpose, we used the available PANSS data of the 'rTMS for the Treatment of Negative Symptoms in Schizophrenia' (RESIS) trial to calculate different literature-based PANSS factors and to re-evaluate the impact of rTMS on negative symptoms in this trial. In an exploratory re-analysis of published data from the RESIS study (Wobrock et al. 2015), we tested the impact of rTMS applied to the left dorsolateral prefrontal cortex on two PANSS factors for negative symptoms in psychotic disorders as well as on a PANSS five-factor consensus model intending to show that active rTMS treatment improves PANSS negative symptom subscores. In accordance to the original analysis, all PANSS factors showed an improvement over time in the active and, to a considerable extent, also in the sham rTMS group. However, comparing the data before and directly after the rTMS intervention, the PANSS excitement factor improved in the active rTMS group significantly more than in the sham group, but this finding did not persist if follow-up data were taken into account. These additional analyses extend the previously reported RESIS trial results showing unspecific improvements in the PANSS positive subscale in the active rTMS group. Our PANSS factor-based approach to investigate the impact of prefrontal rTMS on different negative symptom domains confirmed no overall beneficial effect of the active compared to sham rTMS.

Low Field Magnetic Stimulation Ameliorates Schizophrenia-Like Behavior and Up-Regulates Neuregulin-1 Expression in a Mouse Model of Cuprizone-Induced Demyelination

White matter and myelin sheath integrity are disrupted in schizophrenia, and non-invasive magnetic brain stimulation targeting these tracts is a promising new therapeutic approach. In particular, deep-brain reachable low field magnetic stimulation (DMS) could alleviate cognitive impairment and depressive-like behaviors in animal models. In this study, we sought to assess the effects of DMS on myelin sheath damage and schizophrenia-like behaviors in the cuprizone-induced demyelination mouse model. Mice were fed cuprizone (copper ion chelating agent, 0.2% w/w mixed with food) for 6 weeks to induce demyelination. During these 6 weeks, mice were stimulated with either sham, low-frequency (LFS, delta frequency) DMS or high-frequency (HFS, gamma Hz) DMS for 20 min each day. Behavioral tests were conducted 24 h after the final DMS session. The myelin sheath was examined by immunohistochemistry and the expression of neuregulin-1 (NRG1)/ErbB4 in the prefrontal cortex was measured with Western blotting. Six weeks of HFS significantly alleviated schizophrenia-like behaviors in cuprizone mice, including improved nesting, social interaction and sensorimotor gating, while LFS improved sensorimotor gating only. HFS and LFS both repaired the myelin sheath and increased the expression of neuregulin-1 and its receptor ErbB4, in the prefrontal cortex of demyelinated mice. Our findings show that DMS is a potential effective neuromodulation technique for the treatment of schizophrenia. One possible mechanism underlying these therapeutic effects could involve the up-regulation of NRG1/ErbB4 signaling in the prefrontal cortex.