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International Journal of Molecular... Apr 2022(1) Objective: Considering that current knowledge of mechanisms involved in the molecular pathogenesis of Social Anxiety Disorder (SAD) is limited, we conducted a... (Review)
Review
(1) Objective: Considering that current knowledge of mechanisms involved in the molecular pathogenesis of Social Anxiety Disorder (SAD) is limited, we conducted a systematic review to evaluate cumulative data obtained by Proton Magnetic Resonance Spectroscopic (H MRS) studies. (2) Methods: A computer-based literature search of Medline, EMBASE, PsycInfo, and ProQuest was performed. Only cross-sectional studies using H MRS techniques in participants with SAD and healthy controls (HCs) were selected. (3) Results: The search generated eight studies. The results indicated regional abnormalities in the 'fear neurocircuitry' in patients with SAD. The implicated regions included the anterior cingulate cortex (ACC), dorsomedial prefrontal cortex (dmPFC), dorsolateral prefrontal cortex (dlPFC), insula, occipital cortex (OC), as well as the subcortical regions, including the thalamus, caudate, and the putamen. (4) Conclusions: The evidence derived from eight studies suggests that possible pathophysiological mechanisms of SAD include impairments in the integrity and function of neurons and glial cells, including disturbances in energy metabolism, maintenance of phospholipid membranes, dysregulations of second messenger systems, and excitatory/inhibitory neurocircuitry. Conducting more cross-sectional studies with larger sample sizes is warranted given the limited evidence in this area of research.
Topics: Brain; Cross-Sectional Studies; Humans; Magnetic Resonance Imaging; Phobia, Social; Proton Magnetic Resonance Spectroscopy; Protons
PubMed: 35563145
DOI: 10.3390/ijms23094754 -
Drug and Alcohol Dependence Sep 2013Substance use disorders (SUDs) can be conceptualized as a form of risk-taking behavior with the potential for highly aversive outcomes such as health or legal problems.... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Substance use disorders (SUDs) can be conceptualized as a form of risk-taking behavior with the potential for highly aversive outcomes such as health or legal problems. Risky decision-making likely draws upon several related brain processes involved in estimations of value and risk, executive control, and emotional processing. SUDs may result from a dysfunction in one or more of these cognitive processes.
METHODS
We performed a systematic literature review of functional neuroimaging studies examining risk-related decision making in individuals with SUDs. A quantitative meta-analysis tool (GingerALE) and qualitative approach was used to summarize the imaging results.
RESULTS
Meta-analysis findings indicate that individuals with SUDs exhibit differences in neural activity relative to healthy controls during risk-taking in the anterior cingulate cortex, orbitofrontal cortex, dorsolateral prefrontal cortex, striatum, insula, and somatosensory cortex. In addition, a qualitative review of the literature suggests that individuals with SUDs may have altered function in the amygdala and ventromedial prefrontal cortex.
CONCLUSIONS
The neuroimaging literature reveals that several neural substrates involved in the computation of risk may function suboptimally in SUDs. Future research is warranted to elucidate which computational processes are affected, whether dysfunctional risk-related processing recovers with sobriety, and whether different drugs of abuse have specific effects on risk-taking.
Topics: Animals; Brain; Emotions; Humans; Likelihood Functions; Pain; Risk-Taking; Substance-Related Disorders
PubMed: 23623507
DOI: 10.1016/j.drugalcdep.2013.03.019 -
Frontiers in Human Neuroscience 2023Disorders of consciousness (DoC) commonly occurs secondary to severe neurological injury. A considerable volume of research has explored the effectiveness of different...
BACKGROUND
Disorders of consciousness (DoC) commonly occurs secondary to severe neurological injury. A considerable volume of research has explored the effectiveness of different non-invasive neuromodulation therapy (NINT) on awaking therapy, however, equivocal findings were reported.
OBJECTIVE
The aim of this study was to systematically investigate the effectiveness on level of consciousness of different NINT in patients with DoC and explore optimal stimulation parameters and characteristics of patients.
METHODS
PubMed, Embase, Web of Science, Scopus, and Cochrane central register of controlled trials were searched from their inception through November 2022. Randomized controlled trials, that investigated effectiveness on level of consciousness of NINT, were included. Mean difference (MD) with 95% confidence interval (CI) was evaluated as effect size. Risk of bias was assessed with revised Cochrane risk-of-bias tool.
RESULTS
A total of 15 randomized controlled trials with 345 patients were included. Meta-analysis was performed on 13 out of 15 reviewed trials indicating that transcranial Direct Current Stimulation (tDCS), Transcranial Magnetic Stimulation (TMS), and median nerve stimulation (MNS) all had a small but significant effect (MD 0.71 [95% CI 0.28, 1.13]; MD 1.51 [95% CI 0.87, 2.15]; MD 3.20 [95%CI: 1.45, 4.96]) on level of consciousness. Subgroup analyses revealed that patients with traumatic brain injury, higher initial level of consciousness (minimally conscious state), and shorter duration of prolonged DoC (subacute phase of DoC) reserved better awaking ability after tDCS. TMS also showed encouraging awaking effect when stimulation was applied on dorsolateral prefrontal cortex in patients with prolonged DoC.
CONCLUSION
tDCS and TMS appear to be effective interventions for improving level of consciousness of patients with prolonged DoC. Subgroup analyses identified the key parameters required to enhance the effects of tDCS and TMS on level of consciousness. Etiology of DoC, initial level of consciousness, and phase of DoC could act as significant characteristics of patients related to the effectiveness of tDCS. Stimulation site could act as significant stimulation parameter related to the effectiveness of TMS. There is insufficient evidence to support the use of MNS in clinical practice to improve level of consciousness in patients with coma.
SYSTEMATIC REVIEW REGISTRATION
https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=337780, identifier: CRD42022337780.
PubMed: 37292582
DOI: 10.3389/fnhum.2023.1129254 -
Structural and functional neuroimaging studies in generalized anxiety disorder: a systematic review.Revista Brasileira de Psiquiatria (Sao... 2019Brain imaging studies carried out in patients suffering from generalized anxiety disorder (GAD) have contributed to better characterize the pathophysiological mechanisms...
OBJECTIVES
Brain imaging studies carried out in patients suffering from generalized anxiety disorder (GAD) have contributed to better characterize the pathophysiological mechanisms underlying this disorder. The present study reviews the available functional and structural brain imaging evidence on GAD, and suggests further strategies for investigations in this field.
METHODS
A systematic literature review was performed in PubMed, PsycINFO, and Google Scholar, aiming to identify original research evaluating GAD patients with the use of structural and functional magnetic resonance imaging as well as diffusion tensor imaging.
RESULTS
The available studies have shown impairments in ventrolateral and dorsolateral prefrontal cortex, anterior cingulate, posterior parietal regions, and amygdala in both pediatric and adult GAD patients, mostly in the right hemisphere. However, the literature is often tentative, given that most studies have employed small samples and included patients with comorbidities or in current use of various medications. Finally, different methodological aspects, such as the type of imaging equipment used, also complicate the generalizability of the findings.
CONCLUSIONS
Longitudinal neuroimaging studies with larger samples of both juvenile and adult GAD patients, as well as at risk individuals and unaffected relatives, should be carried out in order to shed light on the specific biological signature of GAD.
Topics: Anxiety Disorders; Brain; Functional Neuroimaging; Humans; Magnetic Resonance Imaging
PubMed: 31116259
DOI: 10.1590/1516-4446-2018-0108 -
CNS Neuroscience & Therapeutics Jul 2022Transcranial direct current stimulation (tDCS) is a promising method for migraine treatment. In this study, we investigated the efficacy and safety of tDCS for migraine... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Transcranial direct current stimulation (tDCS) is a promising method for migraine treatment. In this study, we investigated the efficacy and safety of tDCS for migraine by conducting a systematic review and meta-analysis of randomized controlled trials (RCTs).
METHODS
We searched PubMed, EMBASE, Cochrane Library, and Web of Science up to December 02, 2021 for RCTs reporting tDCS for migraine treatment. Two authors independently evaluated the eligibility of the retrieved trials and extracted relevant data. Outcomes for the quantitative synthesis were reduction in migraine days per month and adverse events.
RESULTS
Eleven RCTs that included 425 patients with migraine were evaluated in the meta-analysis. The efficacy and safety of anodal or cathodal stimulation targeting different brain areas, including primary motor cortex (M1), primary sensory cortex (S1), dorsolateral prefrontal cortex (DLPFC), and visual cortex (VC), were assessed in the RCTs enrolled. We found that tDCS with M1 and VC activation could reduce No. of migraine days per month in patients with migraine. Meanwhile, tDCS with VC inhibition could also reduce No. of migraine days per month in patients with migraine. However, there were no differences in the incidence of adverse events between the two groups.
CONCLUSION
tDCS activates M1 or activates/inhibits VC which could improve migraine symptoms. tDCS is an effective, preventive, and safe treatment for migraine.
Topics: Brain; Dorsolateral Prefrontal Cortex; Humans; Migraine Disorders; Randomized Controlled Trials as Topic; Transcranial Direct Current Stimulation
PubMed: 35437933
DOI: 10.1111/cns.13843 -
Neurologia Oct 2020Fibromyalgia syndrome (FM) is a chronic pathology characterized by widespread pain commonly associated with psychological distress affecting quality of life. In recent... (Review)
Review
INTRODUCTION
Fibromyalgia syndrome (FM) is a chronic pathology characterized by widespread pain commonly associated with psychological distress affecting quality of life. In recent years, transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS) have been investigated to treat chronic pain. The aim of the current review is to determine the effects of tDCS and TMS on the main symptoms of patients with FM.
DEVELOPMENT
A systematic review based on PRISMA guidelines was carried out. The search strategy was performed in Medline, Scopus, PEDro and Cochrane Library. Randomized controlled trials based on the effects of tDCS and TMS on pain, pressure pain threshold, fatigue, anxiety and depression, catastrophizing and quality of life in patients with FM were analysed. Fourteen studies were included.
CONCLUSIONS
The application of tDCS to the motor cortex is the only intervention shown to decrease pain in the short and medium-term in patients with FM. The application of both interventions showed improvements in pressure pain threshold, catastrophizing and quality of life when applied to the motor cortex, and in fatigue when applied to the dorsolateral prefrontal cortex. The effects of these interventions on anxiety and depression are unclear.
PubMed: 33071017
DOI: 10.1016/j.nrl.2020.07.024 -
Neuropsychopharmacology : Official... Mar 2013Clinical trials on low-frequency repetitive transcranial magnetic stimulation (LF-rTMS) over the right dorsolateral prefrontal cortex have yielded conflicting evidence... (Meta-Analysis)
Meta-Analysis Review
Clinically meaningful efficacy and acceptability of low-frequency repetitive transcranial magnetic stimulation (rTMS) for treating primary major depression: a meta-analysis of randomized, double-blind and sham-controlled trials.
Clinical trials on low-frequency repetitive transcranial magnetic stimulation (LF-rTMS) over the right dorsolateral prefrontal cortex have yielded conflicting evidence concerning its overall efficacy for treating major depression (MD). As this may have been the result of limited statistical power of individual trials, we have carried the present systematic review and meta-analysis to examine this issue. We searched the literature for English language randomized, double-blind and sham-controlled trials (RCTs) on LF-rTMS for treating MD from 1995 through July 2012 using EMBASE, PsycINFO, Cochrane Central Register of Controlled Trials, SCOPUS, and ProQuest Dissertations & Theses, and from October 2008 until July 2012 using MEDLINE. The main outcome measures were response and remission rates as well as overall dropout rates at study end. We used a random-effects model, odds ratios (ORs) and number needed to treat (NNT). Data were obtained from eight RCTs, totaling 263 subjects with MD. After an average of 12.6±3.9 rTMS sessions, 38.2% (50/131) and 15.1% (20/132) of subjects receiving active LF-rTMS and sham rTMS were classified as responders (OR=3.35; 95% CI=1.4-8.02; p=0.007). Also, 34.6% (35/101) and 9.7% (10/103) of subjects receiving active LF-rTMS and sham rTMS were classified as remitters (OR=4.76; 95% CI=2.13-10.64; p<0.0001). The associated NNT for both response and remission rates was 5. Sensitivity analyses have shown that protocols delivering >1200 magnetic pulses in total as well as those offering rTMS as a monotherapy for MD were associated with higher rates of response to treatment. No differences on mean baseline depression scores and dropout rates for active and sham rTMS groups were found. Finally, the risk of publication bias was low. In conclusion, LF-rTMS is a promising treatment for MD, as it provides clinically meaningful benefits that are comparable to those of standard antidepressants and high-frequency rTMS. Furthermore, LF-rTMS seems to be an acceptable intervention for depressed subjects.
Topics: Depressive Disorder, Major; Double-Blind Method; Humans; Patient Acceptance of Health Care; Randomized Controlled Trials as Topic; Transcranial Magnetic Stimulation; Treatment Outcome
PubMed: 23249815
DOI: 10.1038/npp.2012.237 -
Frontiers in Human Neuroscience 2020Mild traumatic brain injury (mTBI) results from an external force to the head or body causing neurophysiological changes within the brain. The number and severity of...
Mild traumatic brain injury (mTBI) results from an external force to the head or body causing neurophysiological changes within the brain. The number and severity of symptoms can vary, with some individuals experiencing rapid recovery, and others having persistent symptoms for months to years, impacting their quality of life. Current rehabilitation is limited in its ability to treat persistent symptoms and novel approaches are being sought to improve outcomes following mTBI. Neuromodulation is one technique used to encourage adaptive neuroplasticity within the brain. To systematically review the literature on the efficacy of neuromodulation in the mTBI population. A systematic review was conducted using Medline, Embase, PsycINFO, PsycARTICLES and EBM Review. Preferred Reporting Items for Systematic Reviews and the Synthesis Without Meta-analysis reporting guidelines were used and a narrative review of the selected studies was completed. Fourteen articles fulfilled the inclusion criteria which were published in English, investigating an adult sample and using a pre- and post-intervention design. Studies were excluded if they included non-mild TBI severities, pediatric or older adult populations. Thirteen of fourteen studies reported positive reductions in mTBI symptomatology following neuromodulation. Specifically, improvements were reported in post-concussion symptom ratings, headaches, dizziness, depression, anxiety, sleep disturbance, general disability, cognition, return to work and quality of life. Normalization of working memory activation patterns, vestibular field potentials, hemodynamics of the dorsolateral prefrontal cortex and excessive delta wave activity were also seen. The studies reviewed had several methodological limitations including small, heterogenous samples and varied intervention protocols, limiting generalisability. Further research is required to understand the context in which neuromodulation may be beneficial. While these positive effects are observed, limitations included unequal representation of neuromodulation modalities in the literature, and lack of literature describing the efficacy of neuromodulation on the development or duration of persistent mTBI symptoms. Better clarity regarding neuromodulation efficacy could have a significant impact on mTBI patients, researchers, clinicians, and policy makers, facilitating a more productive post-mTBI population. Despite the limitations, the literature indicates that neuromodulation warrants further investigation. PROSPERO registration number: CRD42020161279.
PubMed: 33362494
DOI: 10.3389/fnhum.2020.598208 -
The Cochrane Database of Systematic... Sep 2014Panic disorder (PD) is a common type of anxiety disorder, characterized by unexpected and repeated panic attacks or fear of future panic attacks, or both. Individuals... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Panic disorder (PD) is a common type of anxiety disorder, characterized by unexpected and repeated panic attacks or fear of future panic attacks, or both. Individuals with PD are often resistant to pharmacological or psychological treatments and this can lead to the disorder becoming a chronic and disabling illness. Repetitive transcranial magnetic stimulation (rTMS) can deliver sustained and spatially selective current to suppress or induce cortical excitability, and its therapeutic effect on pathological neuronal activity in people with PD has already been examined in case studies and clinical trials. However, a systematic review is necessary to assess the efficacy and safety of rTMS for PD.
OBJECTIVES
To assess the effects of repetitive transcranial magnetic stimulation (rTMS) for panic disorder (PD) in adults aged 18 to 65 years, either as a monotherapy or as an augmentation strategy.
SEARCH METHODS
An electronic search of the Cochrane Depression, Anxiety and Neurosis Review Group Controlled Trials Register (CCDANCTR) was conducted to 19 February 2014. The CCDANCTR includes reports of relevant randomised controlled trials (RCTs) from MEDLINE (1950 to date), EMBASE (1974 to date), PsycINFO (1967 to date) and the Cochrane Central Register of Controlled Trials (CENTRAL) (all years). Additional searches were conducted in Psyndex and the main Chinese medical databases.
SELECTION CRITERIA
RCTs or quasi-randomised trials evaluating rTMS for PD in people aged between 18 and 65 years, either as a monotherapy or as an augmentation strategy.
DATA COLLECTION AND ANALYSIS
Two review authors independently selected studies and extracted data and verified the data by cross-checking. Disagreements were resolved by discussion. For binary data, we calculated fixed-effect model risk ratio (RR) and its 95% confidence interval (CI). For continuous data, we calculated fixed-effect model standardized mean difference (SMD) and its 95% CI.
MAIN RESULTS
Two RCTs (n = 40) were included in this review. The included trials compared rTMS with sham rTMS; no trials comparing rTMS with active treatments (electroconvulsive therapy (ECT), pharmacotherapy, psychotherapy) met our inclusion criteria. Both included studies used 1 Hz rTMS over the right dorso-lateral prefrontal cortex (DLPFC) for two or four weeks as an augmentation treatment for PD. However, in both studies the data for the primary outcome, panic symptoms as measured by the Panic Disorder Severity Scale (PDSS), were skewed and could not be pooled for a quantitative analysis. For this primary outcome one trial with 25 participants reported a superior effect of rTMS in reducing panic symptoms compared with sham rTMS (t = 3.04, df = 16.57, P = 0.007), but this trial had a 16% dropout rate and so was deemed as having a high risk of attrition bias. The other trial found that all 15 participants exhibited a reduction in panic symptoms but there was no significant difference between rTMS and sham rTMS (Mann Whitney U test, P > 0.05). Regarding the acceptability of rTMS, no significant difference was found between rTMS and sham rTMS in dropout rates or in reports of side effects. The quality of evidence contributing to this review was assessed as very low. Assessments of the risk of bias for the two studies were hampered by the lack of information provided in the reports, especially on methods of sequence generation and whether allocation concealment had been applied. Of the remaining sources of bias, we considered one of the studies to have been at risk of attrition bias.
AUTHORS' CONCLUSIONS
Only two RCTs of rTMS were available and their sample sizes were small. The available data were insufficient for us to draw any conclusions about the efficacy of rTMS for PD. Further trials with large sample sizes and adequate methodology are needed to confirm the effectiveness of rTMS for PD.
Topics: Adult; Humans; Panic Disorder; Patient Dropouts; Prefrontal Cortex; Randomized Controlled Trials as Topic; Transcranial Magnetic Stimulation
PubMed: 25230088
DOI: 10.1002/14651858.CD009083.pub2 -
Diagnostics (Basel, Switzerland) Mar 2021In recent years, the potential of non-invasive brain stimulation (NIBS) for therapeutic effects on cognitive functions has been explored for populations with traumatic... (Review)
Review
The Effect of Non-Invasive Brain Stimulation (NIBS) on Executive Functioning, Attention and Memory in Rehabilitation Patients with Traumatic Brain Injury: A Systematic Review.
In recent years, the potential of non-invasive brain stimulation (NIBS) for therapeutic effects on cognitive functions has been explored for populations with traumatic brain injury (TBI). However, there is no systematic NIBS review of TBI cognitive impairment with a focus on stimulation sites and stimulation parameters. The purpose of this study was to conduct a systematic review examining the effectiveness and safety of NIBS for cognitive impairment after a TBI. This study was prospectively registered with the PROSPERO database of systematic reviews (CRD42020183298). All English articles from the following databases were searched from inception up to 31 December 2020: Pubmed/MEDLINE, Scopus, CINAHL, Embase, PsycINFO and CENTRAL. Randomized and prospective controlled trials, including cross-over studies, were included for analysis. Studies with at least five individuals with TBI, whereby at least five sessions of NIBS were provided and used standardized neuropsychological measurement of cognition, were included. A total of five studies met eligibility criteria. Two studies used repetitive transcranial magnetic stimulation (rTMS) and three studies used transcranial direct current stimulation (tDCS). The pooled sample size was 44 individuals for rTMS and 91 for tDCS. Three of five studies combined cognitive training or additional therapy (computer assisted) with NIBS. Regarding rTMS, target symptoms included attention ( = 2), memory ( = 1), and executive function ( = 2); only one study showing significant improvement compared than control group with respect to attention. In tDCS studies, target symptoms included cognition ( = 2), attention ( = 3), memory ( = 3), working memory (WM) ( = 3), and executive function ( = 1); two of three studies showed significant improvement compared to the control group with respect to attention and memory. The evidence for NIBS effectiveness in rehabilitation of cognitive function in TBI is still in its infancy, more studies are needed. In all studies, dorsolateral prefrontal cortex (DLPFC) was selected as the stimulation site, along with the stimulation pattern promoting the activation of the left DLPFC. In some studies, there was a significant improvement compared to the control group, but neither rTMS nor tDCS had sufficient evidence of effectiveness. To the establishment of evidence we need the evaluation of brain activity at the stimulation site and related areas using neuroimaging on how NIBS acts on the neural network.
PubMed: 33807188
DOI: 10.3390/diagnostics11040627