High frequency repetitive transcranial magnetic stimulation of dorsomedial prefrontal cortex for negative symptoms in patients with schizophrenia: A double-blind, randomized controlled trial

Advancing post-stroke cognitive rehabilitation through high-frequency neurostimulation: A retrospective evaluation of cortical excitability and biomarker modulation

BackgroundPost-stroke cognitive impairment (PSCI) poses significant challenges to patient independence, yet technological interventions like high-frequency repetitive transcranial magnetic stimulation (rTMS) remain underexplored in clinical neurorehabilitation.ObjectiveThis study evaluates the integration of high-frequency rTMS into standard care, focusing on its technological efficacy in modulating neuroplasticity and serum biomarkers to enhance cognitive and functional recovery.MethodsA retrospective analysis of 80 PSCI patients (2021-2023) compared outcomes between a conventional care group (n = 30) and an rTMS group (n = 50) receiving 20 Hz stimulation (YRD-CCY-I device) targeting the dorsolateral prefrontal cortex. Key metrics included Montreal Cognitive Assessment (MoCA), Barthel Index (BI), cortical silent period (CL), central motor conduction time (CMCT), and serum neurotrophic factors (BDNF, VEGF, IGF-1).ResultsPost-intervention, the rTMS group demonstrated superior MoCA scores (19.25 vs. 15.24, p = 0.001), BI (76.36 vs. 70.13, p = 0.001), and IADL (20.38 vs. 18.13, p = 0.001) compared to controls. Neurophysiological markers revealed prolonged CL (25.30 vs. 24.02 ms, p = 0.001) and shortened CMCT (12.05 vs. 12.98 ms, p = 0.001), alongside elevated BDNF (9.56 vs. 7.34 ng/mL), VEGF (156.48 vs. 110.54 pg/mL), and IGF-1 (153.74 vs. 112.90 ng/mL, p = 0.001). Overall efficacy was 94% for rTMS versus 73.33% for conventional care (p = 0.047).ConclusionHigh-frequency rTMS, as a targeted neurostimulation technology, enhances cognitive recovery and cortical adaptability in PSCI by modulating neuroplasticity and upregulating neurotrophic biomarkers. These findings underscore its potential as a scalable adjunct in technology-driven neurorehabilitation programs.

An Update on the Use of Neuromodulation Strategies in the Treatment of Schizophrenia

The field of neuromodulation has evolved tremendously and now includes a vast array of interventions utilizing different technologies that span electrical, magnetic, and ultrasound forms of stimulation. The evolution of interventions holds the promise of fewer adverse effects and a noninvasive approach, increasing the scale at which these interventions may be offered in hospital and community settings. While the majority of neuromodulation studies have focused on patients with mood disorders, predominantly depression, there is an unmet need for patients with schizophrenia, who are in dire need of novel therapeutic options. Advances in neuroimaging and approaches for examining individual variability and transdiagnostic symptoms may lead to more effective neuromodulation treatments in this patient population. This overview explores the modern landscape of invasive and noninvasive neuromodulation treatments for patients with schizophrenia. It begins with approaches that involve diffuse stimulation of the cortex and subcortex and then reviews more focal stimulation approaches at the cortical and subcortical levels. The authors also reflect on the relationship between our understanding of the neurobiology of schizophrenia and neuromodulation interventions.

Intermittent theta burst stimulation for negative symptoms in schizophrenia patients with moderate to severe cognitive impairment: A randomized controlled trial

AIMS

This study aims to assess the therapeutic effects of intermittent theta burst stimulation (iTBS) targeting the bilateral dorsomedial prefrontal cortex (DMPFC) on negative symptoms in patients with schizophrenia, utilizing functional near-infrared spectroscopy for evaluation.

METHODS

Thirty-five schizophrenia patients with negative symptoms and moderate to severe cognitive impairment were randomly assigned to a treatment group (n = 18) or a control group (n = 17). The treatment group received iTBS via bilateral DMPFC. Negative symptoms, cognitive function, emotional state, and social function were assessed using Positive and Negative Syndrome Scale (PANSS), Scale for the Assessment of Negative Symptoms (SANS), Montreal Cognitive Assessment (MoCA), Calgary Depression Scale for Schizophrenia (CDSS), and Social Dysfunction Screening Questionnaire (SDSS) scales at pretreatment, posttreatment, and follow-up at 4, 8, and 12 weeks. Brain activation in regions of interest (ROIs) was evaluated through verbal fluency tasks.

RESULTS

Prior to treatment there was no significant difference in the two groups. After 20 iTBS sessions, a significant difference was observed in SANS total score, its related subscales, PANSS total score, and PANSS-negative symptoms (all P < 0.05). The group-by-time interaction showed statistical significance, indicating improvements in negative symptoms and related dimensions over time, with therapeutic effects persisting for at least 8 weeks posttreatment. Prior to treatment, there were no significant differences in activation across all ROIs between the two groups. Posttreatment, the activation of right inferior frontal gyrus (t = 2.19, P = 0.036) and right frontal eye field (t = 2.14, P = 0.04) in the treatment group was significantly higher than in the control group.

CONCLUSIONS

iTBS stimulation of bilateral DMPFC demonstrates therapeutic effects in improving negative symptoms in schizophrenia patients, and this treatment approach has the potential to enhance activation within the prefrontal cortex.

Intermittent theta burst stimulation for negative symptoms in schizophrenia patients with mild cognitive impairment: a randomized controlled trail

Background

This study aims to evaluate the intervention effect of intermittent Theta burst stimulation (iTBS) on bilateral dorsomedial prefrontal cortex (DMPFC) for negative symptoms in schizophrenia using functional near-infrared spectroscopy (fNIRS) to confirm the therapeutic significance of DMPFC in treating negative symptoms and provide new evidence for schizophrenia treatment and research.

Method

Thirty-nine schizophrenia patients with negative symptoms and mild cognitive impairment were randomly divided into a treatment group (n=20) and a control group (n=19). The treatment group received iTBS in bilateral DMPFC. The control group received the sham treatment. Negative symptoms, cognitive function, emotional state, and social function were assessed at pre-treatment, post-treatment, 4-, 8-, and 12-week follow-ups. Brain activation in regions of interest (ROIs) was evaluated through verbal fluency tasks. Changes in scale scores were analyzed by repeated measures ANOVA.

Result

After 20 sessions of iTBS, the Scale for the Assessment of Negative Symptoms (SANS) total and sub-scale scores significantly improved in the treatment group, with statistically significant differences. SANS scores differed significantly between pre- and post-treatment in both groups, with post-treatment scores markedly lower than pre-treatment and better efficacy in the treatment group. However, there was no significant difference in cognitive function, emotional state, and social function. ROIs did not differ significantly between groups before intervention. After treatment, prefrontal cortex activation was significantly higher in the treatment group than in controls, with a statistically significant difference. Regarding functional connectivity, the small-world properties Sigma and Gamma were enhanced.

Conclusion

iTBS on bilateral DMPFC can effectively alleviate negative symptoms and enhance prefrontal cortex activation and the small-world properties in patients of schizophrenia.

Exploring Cognitive Deficits and Neuromodulation in Schizophrenia: A Narrative Review

Cognitive deficits are emerging as critical targets for managing schizophrenia and enhancing clinical and functional outcomes. These deficits are pervasive among individuals with schizophrenia, affecting various cognitive domains. Traditional pharmacotherapy and cognitive behavioral therapy (CBT) have limitations in effectively addressing cognitive impairments in this population. Neuromodulation techniques show promise in improving certain cognitive domains among patients with schizophrenia spectrum disorders. Understanding the mechanisms of neural circuits that underlie cognitive enhancement is essential for elucidating the pathophysiological processes of the disorder, and these insights could significantly optimize strategies for managing schizophrenia. Meanwhile, although there is an increasing body of evidence demonstrating the therapeutic effects of neuromodulation in this area, further research is still needed, particularly regarding topics such as different treatment protocols and the long-term effects of treatment.

Mass Spectrometry Imaging of Two Neocortical Areas Reveals the Histological Selectivity of Schizophrenia-Associated Lipid Alterations

BACKGROUND

Schizophrenia is a psychiatric disorder known to affect brain structure and functionality. Structural changes in the brain at the level of gross anatomical structures have been fairly well studied, while microstructural changes, especially those associated with changes in the molecular composition of the brain, are still being investigated. Of special interest are lipids and metabolites, for which some previous studies have shown association with schizophrenia.

AIM

To utilize a spatially resolved analysis of the brain lipidome composition to investigate the degree and nature of schizophrenia-associated lipidome alterations in the gray and white matter structures of two neocortical regions - the dorsolateral prefrontal cortex (Brodmann area 9, BA9) and the posterior part of the superior temporal gyrus (Brodmann area 22, posterior part, BA22p), as well compare the distribution of the changes between the two regions and tissue types.

METHODS

We employed Matrix-Assisted Laser Desorption/Ionization Mass Spectrometric Imaging (MALDI-MSI), supplemented by a statistical analysis, to examine the lipid composition of brain sections. A total of 24 neocortical sections from schizophrenia patients (n=2) and a healthy control group (n=2), representing the two aforementioned neocortical areas, were studied, yielding data for 131 lipid compounds measured across more than a million MALDI-MSI pixels.

RESULTS

Our findings revealed an uneven distribution of schizophrenia-related lipid alterations across the two neocortical regions. The BA22p showed double the differences in its subcortical white matter structures compared to BA9, while less bias was detected in the gray matter layers. While the schizophrenia-associated lipid differences generally showed good agreement between brain regions at the lipid class level for both gray and white matter, there were consistently more discrepancies for white matter structures.

CONCLUSION

Our study found a consistent yet differential association of schizophrenia with the brain lipidome composition of distinct neocortical areas, particularly subcortical white matter. These findings highlight the need for broader brain coverage in future schizophrenia research and underscore the potential of spatially resolved molecular analysis methods in identifying structure-specific effects.

A new era of current and future treatment applications of transcranial magnetic stimulation

Background

Transcranial magnetic stimulation (TMS) equipment has advanced dramatically over the years thanks to considerable advancements in signal motors, coils, placement devices, and modeling, optimization, and treatment scheduling programs. In this review, a primary assessment of the impact of transcranial magnetic stimulation (TMS) on seizure course in people with and without epilepsy has been done through search in the Embase, PubMed, Scopus, and Web of Science databases. Other proposed roles of TMS in various studies has been reported. The features of TMS protocols for several potential disorders was assessed and the key TMS findings has been documented starting from 1985 until 2023.

Results

More than 500 papers were found that describe various research populations, TMS techniques, and TMS functions in 16 various medical conditions.

Conclusion

After reviewing recent updates in TMS, further researches are needed to improve the technical part of the used TMS protocols and to have definitive results not experimental one with regard to TMS usage in various psychiatric and neurological disorders.

The effect of noninvasive brain stimulation on anhedonia in patients with schizophrenia and depression: A systematic review and meta-analysis

Anhedonia is a transdiagnostic symptom found in patients with schizophrenia and depression. Current pharmacological interventions for anhedonia are unsatisfactory in a considerable proportion of patients. There has been growing interest in applying noninvasive brain stimulation (NIBS) to patients with anhedonia. However, evidence for the efficacy of NIBS for anhedonia remain inconsistent. This study systematically identified all studies that measured anhedonia and applied NIBS in patients with schizophrenia or depression. We conducted a search using the various databases in English (PubMed, EBSCOHost (PsycInfo/PsycArticles), Web of Science) and Chinese (China National Knowledge Infrastructure, Wanfang Data Knowledge Service Platform) languages, and reviewed original research articles on NIBS published from January 1989 to July 2023. Our search had identified 15 articles for quantitative synthesis, with three concerning schizophrenia samples, 11 concerning samples with depression, and one concerning both clinical samples. We conducted a meta-analysis based on the 15 included studies, and the results suggested that NIBS could improve anhedonia symptoms in schizophrenia patients and patients with depression, with a medium-to-large effect size. Our findings are preliminary, given the limited number of included studies. Future NIBS research should measure anhedonia as a primary outcome and should recruit transdiagnostic samples.

Is it more effective for anhedonia and avolition? A systematic review and meta-analysis of non-invasive brain stimulation interventions for negative symptoms in schizophrenia

BACKGROUND

Noninvasive brain stimulation (NIBS) techniques are a promising tool for treating the negative symptoms of schizophrenia. Growing evidence suggests that different dimensions of negative symptoms have partly distinct underlying pathophysiological mechanisms. Previous randomized controlled trials (RCTs) have shown inconsistent impacts of NIBS across dimensions.

OBJECTIVE

This systematic review and meta-analysis evaluated the effects of NIBS on general negative symptoms, and on specific domains, including blunted affect, alogia, asociality, anhedonia, and avolition.

DATA SOURCES

PubMed, Web of Science, Embase, Cochrane CENTRAL, PsycINFO, OpenGrey, and Clinicaltrials.gov from the first date available to October, 2023.

RESULTS

Among 1049 studies, we identified eight high-quality RCTs. NIBS significantly affects general negative symptoms (SMD = -0.54, 95% CI [-0.88, -0.21]) and all five domains (SMD = -0.32 to -0.63). Among dimensions, better effects have been shown for improvement of avolition (SMD = -0.47, 95% CI [-0.81, -0.13]) and anhedonia (SMD = -0.63, 95% CI [-0.98, -0.28]). Subgroup analyses of studies that applied once daily stimulation or >10 sessions showed significantly reduced negative symptom severity.

CONCLUSION

NIBS exerts distinct effects across multiple dimensions of negative symptom, with treatment effects related to stimulation frequency and total sessions. These results need to be confirmed in dedicated studies.

Prefrontal cortical dopamine deficit may cause impaired glucose metabolism in schizophrenia

The brain neurotramsmitter dopamine may play an important role in modulating systemic glucose homeostasis. In seven hundred and four drug- naïve patients with first-episode schizophrenia, we provide robust evidence of positive associations between negative symptoms of schizophrenia and high fasting blood glucose. We then show that glucose metabolism and negative symptoms are improved when intermittent theta burst stimulation (iTBS) on prefrontal cortex (PFC) is performed in patients with predominantly negative symptoms of schizophrenia. These findings led us to hypothesize that the prefrontal cortical dopamine deficit, which is known to be associated with negative symptoms, may be responsible for abnormal glucose metabolism in schizophrenia. To explore this, we optogenetically and chemogenetically inhibited the ventral tegmental area (VTA)-medial prefrontal cortex (mPFC) dopamine projection in mice and found both procedures caused glucose intolerance. Moreover, microinjection of dopamine two receptor (D2R) neuron antagonists into mPFC in mice significantly impaired glucose tolerance. Finally, a transgenic mouse model of psychosis named Disc1tr exhibited depressive-like symptoms, impaired glucose homeostasis, and compared to wild type littermates reduced D2R expression in prefrontal cortex.

Devices and Technology in Transcranial Magnetic Stimulation: A Systematic Review

The technology for transcranial magnetic stimulation (TMS) has significantly changed over the years, with important improvements in the signal generators, the coils, the positioning systems, and the software for modeling, optimization, and therapy planning. In this systematic literature review (SLR), the evolution of each component of TMS technology is presented and analyzed to assess the limitations to overcome. This SLR was carried out following the PRISMA 2020 statement. Published articles of TMS were searched for in four databases (Web of Science, PubMed, Scopus, IEEE). Conference papers and other reviews were excluded. Records were filtered using terms about TMS technology with a semi-automatic software; articles that did not present new technology developments were excluded manually. After this screening, 101 records were included, with 19 articles proposing new stimulator designs (18.8%), 46 presenting or adapting coils (45.5%), 18 proposing systems for coil placement (17.8%), and 43 implementing algorithms for coil optimization (42.6%). The articles were blindly classified by the authors to reduce the risk of bias. However, our results could have been influenced by our research interests, which would affect conclusions for applications in psychiatric and neurological diseases. Our analysis indicates that more emphasis should be placed on optimizing the current technology with a special focus on the experimental validation of models. With this review, we expect to establish the base for future TMS technological developments.

Recent advances in noninvasive brain stimulation for schizophrenia

PURPOSE OF REVIEW

Noninvasive brain stimulation has emerged in the last three decades as a promising treatment for patients with antipsychotic-resistant symptoms of schizophrenia. This review updates the latest progress in the use of noninvasive brain stimulation to treat schizophrenia symptoms.

RECENT FINDINGS

Several recently published randomized-controlled trials support a long-lasting clinical effect of stimulation techniques on schizophrenia symptoms. In addition, efforts have been made in recent months to improve efficacy through several optimization strategies. Studies have tested new parameters of stimulation, such as theta burst stimulation, and alternative cortical or subcortical targets and have reported encouraging results. New forms of electrical stimulations such as alternating and random noise stimulation, have also been studied and have shown clinical and cognitive usefulness for patients. Accelerated stimulation protocols, and prospects could arise with deeper stimulation strategies.

SUMMARY

Using brain stimulation to treat symptoms of schizophrenia seems promising and the great flexibility of the stimulation parameters leaves much room for developing optimization strategies and improving its effectiveness. Further studies need to identify the optimal parameters to maximize response rate.

Reconfiguration of Functional Dynamics in Cortico-Thalamo-Cerebellar Circuit in Schizophrenia Following High-Frequency Repeated Transcranial Magnetic Stimulation

Schizophrenia is a serious mental illness characterized by a disconnection between brain regions. Transcranial magnetic stimulation is a non-invasive brain intervention technique that can be used as a new and safe treatment option for patients with schizophrenia with drug-refractory symptoms, such as negative symptoms and cognitive impairment. However, the therapeutic effects of transcranial magnetic stimulation remain unclear and would be investigated using non-invasive tools, such as functional connectivity (FC). A longitudinal design was adopted to investigate the alteration in FC dynamics using a dynamic functional connectivity (dFC) approach in patients with schizophrenia following high-frequency repeated transcranial magnetic stimulation (rTMS) with the target at the left dorsolateral prefrontal cortex (DLPFC). Two groups of schizophrenia inpatients were recruited. One group received a 4-week high-frequency rTMS together with antipsychotic drugs (TSZ, n = 27), while the other group only received antipsychotic drugs (DSZ, n = 26). Resting-state functional magnetic resonance imaging (fMRI) and psychiatric symptoms were obtained from the patients with schizophrenia twice at baseline (t1) and after 4-week treatment (t2). The dynamics was evaluated using voxel- and region-wise FC temporal variability resulting from fMRI data. The pattern classification technique was used to verify the clinical application value of FC temporal variability. For the voxel-wise FC temporary variability, the repeated measures ANCOVA analysis showed significant treatment × time interaction effects on the FC temporary variability between the left DLPFC and several regions, including the thalamus, cerebellum, precuneus, and precentral gyrus, which are mainly located within the cortico-thalamo-cerebellar circuit (CTCC). For the ROI-wise FC temporary variability, our results found a significant interaction effect on the FC among CTCC. rTMS intervention led to a reduced FC temporary variability. In addition, higher alteration in FC temporal variability between left DLPFC and right posterior parietal thalamus predicted a higher remission ratio of negative symptom scores, indicating that the decrease of FC temporal variability between the brain regions was associated with the remission of schizophrenia severity. The support vector regression (SVR) results suggested that the baseline pattern of FC temporary variability between the regions in CTCC could predict the efficacy of high-frequency rTMS intervention on negative symptoms in schizophrenia. These findings confirm the potential relationship between the reduction in whole-brain functional dynamics induced by high-frequency rTMS and the improvement in psychiatric scores, suggesting that high-frequency rTMS affects psychiatric symptoms by coordinating the heterogeneity of activity between the brain regions. Future studies would examine the clinical utility of using functional dynamics patterns between specific brain regions as a biomarker to predict the treatment response of high-frequency rTMS.

Increased Prefrontal Activation During Verbal Fluency Task After Repetitive Transcranial Magnetic Stimulation Treatment in Depression: A Functional Near-Infrared Spectroscopy Study

BACKGROUND

Previous studies have shown the clinical effect of 2 Hz repetitive transcranial magnetic stimulation (rTMS) for depression; however, its underlying neural mechanisms are poorly understood. The aim of this study was to examine the effects of rTMS on the activity of the prefrontal cortex in patients with depression, using functional near-infrared spectroscopy (fNIRS).

METHODS

Forty patients with major depressive disorder (MDD) and 40 healthy controls were enrolled in this study. Patients underwent 4 weeks of 2 Hz TMS delivered to the right dorsolateral prefrontal cortex (DLPFC). fNIRS was used to measure the changes in the concentration of oxygenated hemoglobin ([oxy-Hb]) in the prefrontal cortex during a verbal fluency task (VFT) in depressed patients before and after rTMS treatment. The severity of depression was assessed using the Hamilton Rating Scale for Depression-24 item (HAMD-24).

RESULTS

Prior to rTMS, depressed patients exhibited significantly smaller [oxy-Hb] values in the bilateral prefrontal cortex during the VFT compared with the healthy controls. After 4 weeks of 2 Hz right DLPFC rTMS treatment, increased [oxy-Hb] values in the bilateral frontopolar prefrontal cortex (FPPFC), ventrolateral prefrontal cortex (VLPFC) and left DLPFC during the VFT were observed in depressed patients. The increased [oxy-Hb] values from baseline to post-treatment in the right VLPFC in depressed patients were positively related to the reduction of HAMD score following rTMS.

CONCLUSION

These findings suggest that the function of the prefrontal cortex in depressed patients was impaired and could be recovered by 2 Hz rTMS. The fNIRS-measured prefrontal activation during a cognitive task is a potential biomarker for monitoring depressed patients' treatment response to 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.