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

The therapeutic effects of theta burst stimulation on negative symptoms in chronic schizophrenia using functional near-infrared spectroscopy

BACKGROUND

To explore the efficacy of theta burst stimulation (TBS) on the negative symptoms in patients with chronic schizophrenia, and to investigate the alterations of local brain activity using functional near-infrared spectroscopy (fNIRS).

METHODS

100 patients with chronic schizophrenia were enrolled and divided into the real group (50 subjects) and sham group (50 subjects). The real group was given real stimulation of TBS for 4 weeks, and the sham group was sham-stimulated with the same site. The Positive and Negative Symptom Scale (PANSS) and the Scale for Assessment of Negative Symptoms (SANS) were used to assess the clinical symptoms. fNIRS was used to detect the amplitude of low frequency fluctuation (ALFF) of cortical hemoglobin before and after TBS. Repeated analysis of variance (ANOVA) was used to compare the changes in clinical features between the two groups. Correlation analysis was used to explore the associations between altered ALFF and clinical features.

RESULTS

Repeated ANOVA revealed that the interaction effect of group∗time showed significant influence on the scores of PANSS-total, PANSS-negative, and SANS in the two groups of patients. Test of within-subjects effects showed that significant reductions in scores of PANSS-total, PANSS-negative, and SANS were found between the real group and sham group after TBS, as well as in the real group before and after TBS. fNIRS revealed that the normalized ALFF (zALFF) of deoxyhemoglobin in the left dorsolateral prefrontal cortex was decreased in the real group after TBS. Furthermore, the zALFF of oxyhemoglobin was increased in the right and left frontal pole regions, and decreased in the right superior temporal gyrus in the real group compared to the sham group after TBS. Correlation analysis showed that the alterations of zALFF in frontal regions after treatment were associated with the improvement of negative symptoms in chronic schizophrenia patients.

CONCLUSIONS

Short-term TBS is effective in the improvement of negative symptoms of chronic schizophrenia. fNIRS could reveal the changes in brain activity after TBS treatment, providing an effective technique for exploring the efficacy of TBS in schizophrenia.

Efficacy and safety of transcranial magnetic stimulation on cognition in mild cognitive impairment, Alzheimer's disease, Alzheimer's disease-related dementias, and other cognitive disorders: a systematic review and meta-analysis

OBJECTIVE

We aim to analyze the efficacy and safety of TMS on cognition in mild cognitive impairment (MCI), Alzheimer's disease (AD), AD-related dementias, and nondementia conditions with comorbid cognitive impairment.

DESIGN

Systematic review, Meta-Analysis.

SETTING

We searched MEDLINE, Embase, Cochrane database, APA PsycINFO, Web of Science, and Scopus from January 1, 2000, to February 9, 2023.

PARTICIPANTS AND INTERVENTIONS

RCTs, open-label, and case series studies reporting cognitive outcomes following TMS intervention were included.

MEASUREMENT

Cognitive and safety outcomes were measured. Cochrane Risk of Bias for RCTs and MINORS (Methodological Index for Non-Randomized Studies) criteria were used to evaluate study quality. This study was registered with PROSPERO (CRD42022326423).

RESULTS

The systematic review included 143 studies (n = 5,800 participants) worldwide, encompassing 94 RCTs, 43 open-label prospective, 3 open-label retrospective, and 3 case series. The meta-analysis included 25 RCTs in MCI and AD. Collectively, these studies provide evidence of improved global and specific cognitive measures with TMS across diagnostic groups. Only 2 studies (among 143) reported 4 adverse events of seizures: 3 were deemed TMS unrelated and another resolved with coil repositioning. Meta-analysis showed large effect sizes on global cognition (Mini-Mental State Examination (SMD = 0.80 [0.26, 1.33], p = 0.003), Montreal Cognitive Assessment (SMD = 0.85 [0.26, 1.44], p = 0.005), Alzheimer's Disease Assessment Scale-Cognitive Subscale (SMD = -0.96 [-1.32, -0.60], p < 0.001)) in MCI and AD, although with significant heterogeneity.

CONCLUSION

The reviewed studies provide favorable evidence of improved cognition with TMS across all groups with cognitive impairment. TMS was safe and well tolerated with infrequent serious adverse events.

Aberrant brain functional connectivity mediates the effects of negative symptoms on cognitive function in schizophrenia: A structural equation model

BACKGROUND

Schizophrenia is a severe psychiatric disorder, characterized by positive symptoms, negative symptoms, and cognitive deficits. Elucidating the mechanism of negative symptom and cognitive deficits could contribute to the treatment and prognosis of schizophrenia. We hypothesized that abnormal functional connectivity would be involved in the indirect effects of negative symptoms on cognitive function.

METHODS

A total of 150 schizophrenia male patients and 108 healthy controls matched for age, education and gender were enrolled in the study. The scores of Brief Negative Symptom Scale were divided into two factors: motivation and pleasure deficits (MAP) and diminished expression (EXP). Subsequently, a series of classic neurocognitive tests were used to evaluate cognitive functions. Resting-state fMRI data was collected from all participants. The Anatomical Automatic Labeling template was employed to establish regions of interest, thereby constructing the functional connectivity network across the entire brain. Eventually, scores of patients' negative symptoms scale, cognitive function, and strengths of abnormal functional connectivity were incorporated into a structural equation model to explore the interactions among variables.

RESULTS

MAP exhibited a distinctly and significantly negative impact on cognitive function. The functional connectivity between the left insula and left precuneus, along with that between the left precuneus and right angular gyrus, collectively served as intermediaries, contributing to the indirect effects of MAP and EXP on cognitive function.

CONCLUSIONS

Our findings demonstrated the moderating role of aberrant brain functional connectivity between negative symptoms and cognitive function, providing clues about the neural correlates of negative symptoms and cognitive deficits in schizophrenia.

Placebo effects of repetitive transcranial magnetic stimulation on negative symptoms and cognition in patients with schizophrenia spectrum disorders: a systematic review and meta-analysis

Background

Negative symptoms and cognitive impairments are highly frequent in schizophrenia spectrum disorders (SSD), associated with adverse functional outcomes and quality of life. Repetitive transcranial magnetic stimulation (rTMS) has been considered a promising therapeutic option in SSD. However, placebo effects of rTMS on these symptoms remained unclear.

Objective

To investigate placebo effects of rTMS on alleviating negative symptoms and cognitive impairment in patients with SSD and to explore potential moderators.

Methods

We systematically searched five electronic databases up to 15 July 2023. Randomized, double-blind, sham-controlled trials investigating effects of rTMS on negative symptoms or cognition in patients with SSD were included. The pooled placebo effect sizes, represented by Hedges' g, were estimated using the random-effects model. Potential moderators were explored through subgroup analysis and meta-regression.

Results

Forty-four randomized controlled trials with 961 patients (mean age 37.53 years; 28.1% female) in the sham group were included. Significant low-to-moderate pooled placebo effect sizes were observed for negative symptoms (g=0.44, p<0.001), memory (g=0.31, p=0.010), executive function (g=0.35, p<0.001), working memory (g=0.26, p=0.004), and processing speed (g=0.36, p=0.004). Subgroup analysis indicated that placebo effects were affected by sham stimulation methods, rTMS targeting approaches, and stimulation frequency.

Conclusions

Placebo effects of rTMS on negative symptoms and cognition in patients with SSD are significant in a small-to-moderate magnitude, which might be mediated by rTMS parameters. Our findings will provide new insights for practitioners to further optimize and establish standardized rTMS protocols for future RCTs tackling cardinal symptoms in SSD.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023390138.

Fractional amplitude of low-frequency fluctuations in sensory-motor networks and limbic system as a potential predictor of treatment response in patients with schizophrenia

BACKGROUND

Previous investigations have revealed substantial differences in neuroimaging characteristics between healthy controls (HCs) and individuals diagnosed with schizophrenia (SCZ). However, we are not entirely sure how brain activity links to symptoms in schizophrenia, and there is a need for reliable brain imaging markers for treatment prediction.

METHODS

In this longitudinal study, we examined 56 individuals diagnosed with 56 SCZ and 51 HCs. The SCZ patients underwent a three-month course of antipsychotic treatment. We employed resting-state functional magnetic resonance imaging (fMRI) along with fractional Amplitude of Low Frequency Fluctuations (fALFF) and support vector regression (SVR) methods for data acquisition and subsequent analysis.

RESULTS

In this study, we initially noted lower fALFF values in the right postcentral/precentral gyrus and left postcentral gyrus, coupled with higher fALFF values in the left hippocampus and right putamen in SCZ patients compared to the HCs at baseline. However, when comparing fALFF values in brain regions with abnormal baseline fALFF values for SCZ patients who completed the follow-up, no significant differences in fALFF values were observed after 3 months of treatment compared to baseline data. The fALFF values in the right postcentral/precentral gyrus and left postcentral gyrus, and the left postcentral gyrus were useful in predicting treatment effects.

CONCLUSION

Our findings suggest that reduced fALFF values in the sensory-motor networks and increased fALFF values in the limbic system may constitute distinctive neurobiological features in SCZ patients. These findings may serve as potential neuroimaging markers for the prognosis of SCZ patients.

Transcranial Magnetic Stimulation and Transcranial Direct Current Stimulation Across Mental Disorders: A Systematic Review and Dose-Response Meta-Analysis

Importance

Noninvasive brain stimulation (NIBS) interventions have been shown to be efficacious in several mental disorders, but the optimal dose stimulation parameters for each disorder are unknown.

Objective

To define NIBS dose stimulation parameters associated with the greatest efficacy in symptom improvement across mental disorders.

Data Sources

Studies were drawn from an updated (to April 30, 2023) previous systematic review based on a search of PubMed, OVID, and Web of Knowledge.

Study Selection

Randomized clinical trials were selected that tested transcranial magnetic stimulation (TMS) or transcranial direct current stimulation (tDCS) for any mental disorder in adults aged 18 years or older.

Data Extraction and Synthesis

Two authors independently extracted the data. A 1-stage dose-response meta-analysis using a random-effects model was performed. Sensitivity analyses were conducted to test robustness of the findings. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline.

Main Outcomes and Measures

The main outcome was the near-maximal effective doses of total pulses received for TMS and total current dose in coulombs for tDCS.

Results

A total of 110 studies with 4820 participants (2659 men [61.4%]; mean [SD] age, 42.3 [8.8] years) were included. The following significant dose-response associations emerged with bell-shaped curves: (1) in schizophrenia, high-frequency (HF) TMS on the left dorsolateral prefrontal cortex (LDLPFC) for negative symptoms (χ2 = 9.35; df = 2; P = .009) and TMS on the left temporoparietal junction for resistant hallucinations (χ2 = 36.52; df = 2; P < .001); (2) in depression, HF-DLPFC TMS (χ2 = 14.49; df = 2; P < .001); (3) in treatment-resistant depression, LDLPFC tDCS (χ2 = 14.56; df = 2; P < .001); and (4) in substance use disorder, LDLPFC tDCS (χ2 = 33.63; df = 2; P < .001). The following significant dose-response associations emerged with plateaued or ascending curves: (1) in depression, low-frequency (LF) TMS on the right DLPFC (RDLPFC) with ascending curve (χ2 = 25.67; df = 2; P = .001); (2) for treatment-resistant depression, LF TMS on the bilateral DLPFC with ascending curve (χ2 = 5.86; df = 2; P = .004); (3) in obsessive-compulsive disorder, LF-RDLPFC TMS with ascending curve (χ2 = 20.65; df = 2; P < .001) and LF TMS on the orbitofrontal cortex with a plateaued curve (χ2 = 15.19; df = 2; P < .001); and (4) in posttraumatic stress disorder, LF-RDLPFC TMS with ascending curve (χ2 = 54.15; df = 2; P < .001). Sensitivity analyses confirmed the main findings.

Conclusions and Relevance

The study findings suggest that NIBS yields specific outcomes based on dose parameters across various mental disorders and brain regions. Clinicians should consider these dose parameters when prescribing NIBS. Additional research is needed to prospectively validate the findings in randomized, sham-controlled trials and explore how other parameters contribute to the observed dose-response association.

Combining transcranial magnetic stimulation with training to improve social cognition impairment in schizophrenia: a pilot randomized controlled trial

Schizophrenia is a severe, chronic mental disorder that profoundly impacts patients' everyday lives. The illness's core features include positive and negative symptoms and cognitive impairments. In particular, deficits in the social cognition domain showed a tighter connection to patients' everyday functioning than the other symptoms. Social remediation interventions have been developed, providing heterogeneous results considering the possibility of generalizing the acquired improvements in patients' daily activities. In this pilot randomized controlled trial, we investigated the feasibility of combining fifteen daily cognitive and social training sessions with non-invasive brain stimulation to boost the effectiveness of the two interventions. We delivered intermittent theta burst stimulation (iTBS) over the left dorsolateral prefrontal cortex (DLPFC). Twenty-one patients were randomized into four groups, varying for the assigned stimulation condition (real vs. sham iTBS) and the type of cognitive intervention (training vs. no training). Clinical symptoms and social cognition tests were administered at five time points, i.e., before and after the treatment, and at three follow-ups at one, three, and six months after the treatments' end. Preliminary data show a trend in improving the competence in managing emotion in participants performing the training. Conversely, no differences were found in pre and post-treatment scores for emotion recognition, theory of mind, and attribution of intentions scores. The iTBS intervention did not induce additional effects on individuals' performance. The methodological approach's novelty and limitations of the present study are discussed.

Efficacy and safety of non-invasive brain stimulation on cognitive function for cognitive impairment associated with schizophrenia: A systematic review and meta-analysis

Based on existing evidence of the effects of the most commonly used non-invasive brain stimulation (NIBS), which includes transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS), we conducted a meta-analysis to investigate the cognitive improvement and safety of NIBS on schizophrenia-related cognitive impairment. PubMed, EMBASE, Cochrane Library, and Web of Science were searched. The Cochrane Risk of Bias tool was used to assess the risk of bias of the included RCTs; Review Manager, version 5.4.1, was used to perform the statistical analysis. Twenty double-blind, randomized, sham-controlled trials involving 997 patients were included. As a result, no significant improvement in cognitive function was observed after NIBS treatment. However, the overall treatment effect of the two main NIBS modes (i.e., rTMS and tDCS) was associated with significantly larger improvements in negative symptoms and good tolerability in patients with schizophrenia compared to sham-controls (SMD = -0.56, 95% CI [-1.03, -0.08], p = 0.02, I2 = 88%). NIBS model and stimulus parameters influenced the effect of NIBS. More favorable effects were observed in patients who received rTMS stimulation (SMD = 0.25, 95% CI [0.01, 0.49], p = 0.04, I2 = 0%) in the left dorsolateral prefrontal cortex with a stimulation intensity of 20 Hz (p = 0.004) for a period longer than 1 month (p < 0.05). Yet, due to the limited number of included studies and heterogeneity in both study design and target population, the results of this analysis need to be interpreted with caution.

The Role of Two Factors of Negative Symptoms and Cognition on Social Functioning in Male Patients with Schizophrenia: A Mediator Model

OBJECTIVE

This study aims to compare the cognitive function and social functioning in male patients with deficit syndrome (DS) and non-DS, and to explore whether cognitive function serves as a mediator in the relationship between the two factors of negative symptoms (motivation and pleasure (MAP) and expressivity (EXP) deficits, and social functioning in schizophrenia patients.

METHODS

One hundred and fifty-six male patients with schizophrenia and 109 age- and education-matched normal controls were enrolled in the current study. The Chinese version of a Schedule for Deficit Syndrome (SDS) was used for DS and non-DS categorization. The Brief Psychiatric Rating Scale (BPRS) and the Brief Negative Symptoms Scale (BNSS) were used to assess psychotic and negative symptoms in patients. The Social-Adaptive Functioning Evaluation (SAFE) was adopted to evaluate patients' social functioning, and a battery of classical neurocognitive tests was used to assess cognition, including sustained vigilance/attention, cognitive flexibility, ideation fluency, and visuospatial memory.

RESULTS

We found that male patients with DS performed worse in all four cognitive domains and social functioning compared to non-DS patients. Both total negative symptoms and its two factors were significantly associated with all four domains of cognition and social functioning in male patients. Interestingly, our results indicate that only cognitive flexibility mediates the relationship between negative symptoms and social functioning in schizophrenia patients, but there were no differences between EXP and MAP negative factors in this model.

CONCLUSION

Our findings suggest that DS patients may represent a unique clinical subgroup of schizophrenia, and the integrated interventions targeting both negative symptoms and cognition, especially cognitive flexibility, may optimally improve functional outcomes in schizophrenia patients.

Differences in inflammatory marker profiles and cognitive functioning between deficit and nondeficit schizophrenia

Deficit schizophrenia (DS) patient is a homogenous subtype of schizophrenia that includes primary and enduring negative symptoms. This study aimed to compare the differences in cognitive functioning and plasma levels of C-reactive protein (CRP) and inflammatory cytokines among DS patients, nondeficit schizophrenia (NDS) patients, and healthy controls (HCs). A total of 141 schizophrenia patients and 67 HCs were included in this study. The schizophrenia patients were divided into DS (N= 51) and NDS (N=90) groups based on the Proxy for the Deficit Syndrome Scale (PDS). The Positive and Negative Syndrome Scale (PANSS) and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) were used to evaluate the clinical symptoms and cognitive performances, respectively. The plasma level of CRP, IL-1β, Il-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-17, TNF-α, and IFN-γ were measured using enzyme-linked immunosorbent assays (ELISAs). Our results showed that DS patients had the worst cognitive performance, especially in the immediate memory, attention, and language dimensions, compared to the NDS and HC groups. Compared to the HCs group, DS patients had higher levels of CRP, IL-1β, IL-6, IL-8, IFN-γ, and total proinflammatory cytokines, and NDS patients had higher levels of IL-1β, IFN-γ, and proinflammatory cytokines. We also found that CRP levels were significantly increased in DS patients compared to NDS patients. Moreover, stepwise logistic regression analysis revealed that CRP is an independent risk factor for DS. Sex stratification analysis showed significant differences in almost all cytokines in female samples but not in male samples. The significant differences in cognitive performance and inflammatory components among groups suggest that deficit syndrome is an independent endophenotype of schizophrenia patients with unique immune-inflammatory features, but may have sex characteristics.

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.