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JAMA Network Open May 2024Noninvasive brain stimulation (NIBS) interventions have been shown to be efficacious in several mental disorders, but the optimal dose stimulation parameters for each... (Meta-Analysis)
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.
Topics: Humans; Transcranial Magnetic Stimulation; Transcranial Direct Current Stimulation; Mental Disorders; Adult; Male; Female; Middle Aged; Randomized Controlled Trials as Topic
PubMed: 38776083
DOI: 10.1001/jamanetworkopen.2024.12616 -
Neuroscience and Biobehavioral Reviews Jul 2024This study aimed to evaluate the association of the six parameters, namely stimulation intensity, stimulation frequency, pulses per session, treatment duration, number... (Meta-Analysis)
Meta-Analysis Review
This study aimed to evaluate the association of the six parameters, namely stimulation intensity, stimulation frequency, pulses per session, treatment duration, number of sessions, and total number of pulses with the efficacy of conventional transcranial magnetic stimulation (rTMS) over left dorsolateral prefrontal cortex for patients with treatment-resistant depression (TRD). A random-effects dose-response meta-analysis of blinded randomized controlled trials (RCTs) involving 2391 participants were conducted to examine the dose-effect relationship of six stimulation parameters. Any of the six parameters significantly individually predicted proportion of variance in efficacy: pulses per session (R²=52.7%), treatment duration (R²=51.2%), total sessions (R²=50.9%), frequency (R²=49.6%), total pulses (R²=49.5%), and intensity (R²= 40.4%). Besides, we identified frequency as a potential parameter interacting with the other five parameters, resulting in a significant increase in variance(ΔR) ranging from 5.0% to 16.7%. Finally, we found that RCTs using frequency > 10 Hz compared to those of 10 Hz showed better dose-effect relationships. We conclude that the six stimulation parameters significantly predict the dose-effect relationship of conventional rTMS on TRD. Besides, higher stimulation frequency, higher stimulation intensity, and adequate number of pulses were associated with treatment efficacy.
Topics: Humans; Transcranial Magnetic Stimulation; Depressive Disorder, Treatment-Resistant; Dorsolateral Prefrontal Cortex
PubMed: 38723735
DOI: 10.1016/j.neubiorev.2024.105704 -
Frontiers in Aging Neuroscience 2024With aging, dual task (DT) ability declines and is more cognitively demanding than single tasks. Rapidly declining DT performance is regarded as a predictor of...
INTRODUCTION
With aging, dual task (DT) ability declines and is more cognitively demanding than single tasks. Rapidly declining DT performance is regarded as a predictor of neurodegenerative disease. Task training and non-invasive transcranial electrical stimulation (tES) are methods applied to optimize the DT ability of the elderly.
METHODS
A systematic search was carried out in the PUBMED, TDCS (transcranial direct current stimulation) databases, as well as Web of Science, and a qualitative analysis was conducted in 56 included studies. Aiming to summarize the results of studies that implemented tES, task training, or the combination for improving DT ability and related performance changes in healthy elderly and geriatric patients. For different approaches, the training procedures, parameters, as well as outcomes were discussed.
RESULTS
Task training, particularly cognitive-motor DT training, has more notable effects on improving DT performance in the elderly when compared to the neuromodulation method.
DISCUSSION
Anodal transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (L-DLPFC), or its combination with task training could be promising tools. However, additional evidence is required from aged healthy people and patients, as well as further exploration of electrode montage.
PubMed: 38650865
DOI: 10.3389/fnagi.2024.1267307 -
NeuroImage Jun 2024This systematic review investigates how prefrontal transcranial magnetic stimulation (TMS) immediately influences neuronal excitability based on oxygenation changes... (Review)
Review
This systematic review investigates how prefrontal transcranial magnetic stimulation (TMS) immediately influences neuronal excitability based on oxygenation changes measured by functional magnetic resonance imaging (fMRI) or functional near-infrared spectroscopy (fNIRS). A thorough understanding of TMS-induced excitability changes may enable clinicians to adjust TMS parameters and optimize treatment plans proactively. Five databases were searched for human studies evaluating brain excitability using concurrent TMS/fMRI or TMS/fNIRS. Thirty-seven studies (13 concurrent TMS/fNIRS studies, 24 concurrent TMS/fMRI studies) were included in a qualitative synthesis. Despite methodological inconsistencies, a distinct pattern of activated nodes in the frontoparietal central executive network, the cingulo-opercular salience network, and the default-mode network emerged. The activated nodes included the prefrontal cortex (particularly dorsolateral prefrontal cortex), insula cortex, striatal regions (especially caudate, putamen), anterior cingulate cortex, and thalamus. High-frequency repetitive TMS most consistently induced expected facilitatory effects in these brain regions. However, varied stimulation parameters (e.g., intensity, coil orientation, target sites) and the inter- and intra-individual variability of brain state contribute to the observed heterogeneity of target excitability and co-activated regions. Given the considerable methodological and individual variability across the limited evidence, conclusions should be drawn with caution.
Topics: Humans; Transcranial Magnetic Stimulation; Prefrontal Cortex; Magnetic Resonance Imaging; Spectroscopy, Near-Infrared; Oxygen; Brain Mapping; Brain
PubMed: 38636640
DOI: 10.1016/j.neuroimage.2024.120618 -
ENeuro Apr 2024This systematic review presented a comprehensive survey of studies that applied transcranial magnetic stimulation and transcranial electrical stimulation to parietal and... (Review)
Review
This systematic review presented a comprehensive survey of studies that applied transcranial magnetic stimulation and transcranial electrical stimulation to parietal and nonparietal areas to examine the neural basis of symbolic arithmetic processing. All findings were compiled with regard to the three assumptions of the triple-code model (TCM) of number processing. Thirty-seven eligible manuscripts were identified for review (33 with healthy participants and 4 with patients). Their results are broadly consistent with the first assumption of the TCM that intraparietal sulcus both hold a magnitude code and engage in operations requiring numerical manipulations such as subtraction. However, largely heterogeneous results conflicted with the second assumption of the TCM that the left angular gyrus subserves arithmetic fact retrieval, such as the retrieval of rote-learned multiplication results. Support is also limited for the third assumption of the TCM, namely, that the posterior superior parietal lobule engages in spatial operations on the mental number line. Furthermore, results from the stimulation of brain areas outside of those postulated by the TCM show that the bilateral supramarginal gyrus is involved in online calculation and retrieval, the left temporal cortex in retrieval, and the bilateral dorsolateral prefrontal cortex and cerebellum in online calculation of cognitively demanding arithmetic problems. The overall results indicate that multiple cortical areas subserve arithmetic skills.
Topics: Humans; Magnetic Resonance Imaging; Brain; Learning; Transcranial Magnetic Stimulation; Parietal Lobe; Brain Mapping
PubMed: 38580452
DOI: 10.1523/ENEURO.0318-23.2024 -
Neuroscience and Biobehavioral Reviews May 2024Predicting treatment outcome in internalizing mental disorders prior to treatment initiation is pivotal for precision mental healthcare. In this regard, resting-state... (Meta-Analysis)
Meta-Analysis Review
Predicting treatment outcome in internalizing mental disorders prior to treatment initiation is pivotal for precision mental healthcare. In this regard, resting-state functional connectivity (rs-FC) and machine learning have often shown promising prediction accuracies. This systematic review and meta-analysis evaluates these studies, considering their risk of bias through the Prediction Model Study Risk of Bias Assessment Tool (PROBAST). We examined the predictive performance of features derived from rs-FC, identified features with the highest predictive value, and assessed the employed machine learning pipelines. We searched the electronic databases Scopus, PubMed and PsycINFO on the 12th of December 2022, which resulted in 13 included studies. The mean balanced accuracy for predicting treatment outcome was 77% (95% CI: [72%- 83%]). rs-FC of the dorsolateral prefrontal cortex had high predictive value in most studies. However, a high risk of bias was identified in all studies, compromising interpretability. Methodological recommendations are provided based on a comprehensive exploration of the studies' machine learning pipelines, and potential fruitful developments are discussed.
Topics: Humans; Mental Disorders; Treatment Outcome
PubMed: 38548002
DOI: 10.1016/j.neubiorev.2024.105640 -
Neuropsychiatric Disease and Treatment 2024Working memory (WM) deficits are a significant component of neurocognitive impairment in individuals with schizophrenia (SCZ). Two previous meta-analyses, conducted on... (Review)
Review
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.
PubMed: 38528855
DOI: 10.2147/NDT.S450303 -
Neurophysiologie Clinique = Clinical... Feb 2024To update a systematic review of the efficacy and safety of transcranial direct current stimulation (tDCS) for analgesia, for antidepressant effects, and to reduce the... (Meta-Analysis)
Meta-Analysis
OBJECTIVES
To update a systematic review of the efficacy and safety of transcranial direct current stimulation (tDCS) for analgesia, for antidepressant effects, and to reduce the impact of fibromyalgia (FM), looking for optimal areas of stimulation.
METHODS
We searched five databases to identify randomized controlled trials comparing active and sham tDCS for FM. The primary outcome was pain intensity, and secondary outcome measures included FM Impact Questionnaire (FIQ) and depression score. Meta-analysis was conducted using standardized mean difference (SMD). Subgroup analysis was performed to determine the effects of different regional stimulation, over the primary motor cortex (M1), dorsolateral prefrontal cortex (DLPFC), opercular-insular cortex (OIC), and occipital nerve (ON) regions. We analyzed the minimal clinically important difference (MCID) by the value of the mean difference (MD) for an 11-point scale for pain, the Beck Depressive Inventory-II (BDI-II), and the Fibromyalgia Impact Questionnaire (FIQ) score. We described the certainty of the evidence (COE) using the tool GRADE profile.
RESULTS
Twenty studies were included in the analysis. Active tDCS had a positive effect on pain (SMD= -1.04; 95 % CI -1.38 to -0.69), depression (SMD= -0.46; 95 % CI -0.64 to -0.29), FIQ (SMD= -0.73; 95 % CI -1.09 to -0.36), COE is moderate. Only group M1 (SD=-1.57) and DLPFC (SD=-1.44) could achieve MCID for analgesia; For BDI-II, only group DLPFC (SD=-5.36) could achieve an MCID change. Adverse events were mild.
CONCLUSION
tDCS is a safe intervention that relieves pain intensity, reduces depression, and reduces the impact of FM on life. Achieving an MCID is related to the stimulation site and the target symptom.
Topics: Humans; Fibromyalgia; Pain; Pain Management; Transcranial Direct Current Stimulation
PubMed: 38387108
DOI: 10.1016/j.neucli.2024.102944 -
General Hospital Psychiatry 2024Several types of neuromodulation have been investigated for the treatment of fibromyalgia, but they show varied efficacy on pain, functioning, comorbid depression and... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
Several types of neuromodulation have been investigated for the treatment of fibromyalgia, but they show varied efficacy on pain, functioning, comorbid depression and comorbid anxiety. Whether some types of neuromodulation or some factors are associated with a better response also awaits clarification.
METHODS
We conducted a systematic review and network meta-analysis of randomized controlled trials to evaluate the efficacy of neuromodulation in patients with fibromyalgia. We searched PubMed, EMBASE, the Cochrane Central Register of Controlled Trials and PsycINFO before March 2022. We employed a frequentist random-effects network meta-analysis.
RESULTS
Forty trials involving 1541 participants were included. Compared with sham control interventions, several types of transcranial direct current stimulation (tDCS), transcranial random noise stimulation (tRNS), and high-frequency repetitive transcranial magnetic stimulation (rTMS) were associated with significant reduction of pain, depression, anxiety, and improvement in functioning. Many significantly effective treatment options involve stimulation of the primary motor cortex or dorsolateral prefrontal cortex.
CONCLUSION
We concluded that several types of rTMS, tDCS and tRNS may have the potential to be applied for clinical purposes.
Topics: Humans; Fibromyalgia; Transcranial Direct Current Stimulation; Network Meta-Analysis; Transcranial Magnetic Stimulation; Pain; Treatment Outcome
PubMed: 38382420
DOI: 10.1016/j.genhosppsych.2024.01.007 -
Frontiers in Neuroscience 2024Olfaction is understudied in neuroimaging research compared to other senses, but there is growing evidence of its therapeutic benefits on mood and well-being. Olfactory... (Review)
Review
Olfaction is understudied in neuroimaging research compared to other senses, but there is growing evidence of its therapeutic benefits on mood and well-being. Olfactory imagery can provide similar health benefits as olfactory interventions. Harnessing crossmodal visual-olfactory interactions can facilitate olfactory imagery. Understanding and employing these cross-modal interactions between visual and olfactory stimuli could aid in the research and applications of olfaction and olfactory imagery interventions for health and wellbeing. This review examines current knowledge, debates, and research on olfaction, olfactive imagery, and crossmodal visual-olfactory integration. A total of 56 papers, identified using the PRISMA method, were evaluated to identify key brain regions, research themes and methods used to determine the suitability of fNIRS as a tool for studying these topics. The review identified fNIRS-compatible protocols and brain regions within the fNIRS recording depth of approximately 1.5 cm associated with olfactory imagery and crossmodal visual-olfactory integration. Commonly cited regions include the orbitofrontal cortex, inferior frontal gyrus and dorsolateral prefrontal cortex. The findings of this review indicate that fNIRS would be a suitable tool for research into these processes. Additionally, fNIRS suitability for use in naturalistic settings may lead to the development of new research approaches with greater ecological validity compared to existing neuroimaging techniques.
PubMed: 38356646
DOI: 10.3389/fnins.2024.1266664