-
Frontiers in Neurology 2022Transcranial direct current stimulation (tDCS) has been widely studied for treatment of patients with prolonged disorders of consciousness (PDOC). The dorsolateral...
Effectiveness of transcranial direct current stimulation over dorsolateral prefrontal cortex in patients with prolonged disorders of consciousness: A systematic review and meta-analysis.
BACKGROUND
Transcranial direct current stimulation (tDCS) has been widely studied for treatment of patients with prolonged disorders of consciousness (PDOC). The dorsolateral prefrontal cortex (DLPFC) is a hot target for intervention, but some controversies remain.
PURPOSE
This review aimed to systematically investigate the therapeutic effects of DLPFC-anodal-tDCS for patients with PDOC through a meta-analysis approach.
DATA SOURCES
Searches for relevant articles available in English were conducted using EMBASE, Medline, Web of Science, EBSCO, and Cochrane Central Register of Controlled Trials from inception until March 26, 2022.
STUDY SELECTION
All randomized parallel or cross-over controlled trials comparing the effect of intervention with active-tDCS and Sham-tDCS on Coma Recovery Scale Revised (CRS-R) score in individuals with PDOC were included.
DATA EXTRACTION
Two authors independently extracted data, assessed the methodological quality, and rated each study.
DATA SYNTHESIS
Ten randomized parallel or cross-over controlled trials were eligible for systematic review, and eight of the studies involving 165 individuals were identified as eligible for meta-analysis. Compared with Sham-tDCS, the use of anode-tDCS over DLPFC improved the CRS-R score (SMD = 0.71; 95% CI: 0.47-0.95, = 10%). Patients with PDOC classified as MCS and clinically diagnosed as CVA or TBI may benefit from anode-tDCS.
LIMITATIONS
Failure to evaluate the long-term effects and lack of quantitative analysis of neurological examination are the main limitations for the application of anode-tDCS.
CONCLUSIONS
Anodal-tDCS over the left DLPFC may be advantageous to the recovery of patients with MCS and clinically diagnosed with CVA or TBI. There is a lack of evidence to support the duration of the disease course will limit the performance of the treatment. Further studies are needed to explore the diversity of stimulation targets and help to improve the mesocircuit model.
SYSTEMATIC REVIEW REGISTRATION
https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=279391, identifier: CRD42022279391.
PubMed: 36226076
DOI: 10.3389/fneur.2022.998953 -
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 -
Revista de Psiquiatria Y Salud Mental 2022The neural correlates of the cognitive dysfunction in first-episode psychosis (FEP) are still unclear. The present review and meta-analysis provide an update of the... (Meta-Analysis)
Meta-Analysis Review
INTRODUCTION
The neural correlates of the cognitive dysfunction in first-episode psychosis (FEP) are still unclear. The present review and meta-analysis provide an update of the location of the abnormalities in the fMRI-measured brain response to cognitive processes in individuals with FEP.
METHODS
Systematic review and voxel-based meta-analysis of cross-sectional fMRI studies comparing neural responses to cognitive tasks between individuals with FEP and healthy controls (HC) according to PRISMA guidelines.
RESULTS
Twenty-six studies were included, comprising 598 individuals with FEP and 567 HC. Individual studies reported statistically significant hypoactivation in the dorsolateral prefrontal cortex (6 studies), frontal lobe (8 studies), cingulate (6 studies) and insula (5 studies). The meta-analysis showed statistically significant hypoactivation in the left anterior insula, precuneus and bilateral striatum.
CONCLUSIONS
While the studies tend to highlight frontal hypoactivation during cognitive tasks in FEP, our meta-analytic results show that the left precuneus and insula primarily display aberrant activation in FEP that may be associated with salience attribution to external stimuli and related to deficits in perception and regulation.
Topics: Cognition; Cross-Sectional Studies; Humans; Magnetic Resonance Imaging; Parietal Lobe; Psychotic Disorders
PubMed: 35840277
DOI: 10.1016/j.rpsmen.2022.06.004 -
Cognitive, Affective & Behavioral... Feb 2024All experiences preserved within episodic memory contain information on the space and time of events. The hippocampus is the main brain region involved in processing... (Meta-Analysis)
Meta-Analysis Review
All experiences preserved within episodic memory contain information on the space and time of events. The hippocampus is the main brain region involved in processing spatial and temporal information for incorporation within episodic memory representations. However, the other brain regions involved in the encoding and retrieval of spatial and temporal information within episodic memory are unclear, because a systematic review of related studies is lacking and the findings are scattered. The present study was designed to integrate the results of functional magnetic resonance imaging and positron emission tomography studies by means of a systematic review and meta-analysis to provide converging evidence. In particular, we focused on identifying the brain regions involved in the retrieval of spatial and temporal information. We identified a spatial retrieval network consisting of the inferior temporal gyrus, parahippocampal gyrus, superior parietal lobule, angular gyrus, and precuneus. Temporal context retrieval was supported by the dorsolateral prefrontal cortex. Thus, the retrieval of spatial and temporal information is supported by different brain regions, highlighting their different natures within episodic memory.
Topics: Humans; Memory, Episodic; Brain Mapping; Brain; Temporal Lobe; Parietal Lobe; Magnetic Resonance Imaging; Mental Recall
PubMed: 38030912
DOI: 10.3758/s13415-023-01140-1 -
Neuroscience and Biobehavioral Reviews Apr 2018We systematically reviewed research on cognitive training and neuromodulation interventions for reducing food craving/intake, unhealthy diet and weight, and discussed...
We systematically reviewed research on cognitive training and neuromodulation interventions for reducing food craving/intake, unhealthy diet and weight, and discussed their mechanisms of action. We reviewed 50 studies involving six cognitive trainings: Approach and Attentional Bias Modification, Implementation Intentions, Response Inhibition, Episodic Future Thinking and Working Memory; and four neuromodulation approaches: Transcranial Magnetic Stimulation (TMS), transcranial Direct Current Stimulation (tDCS), Deep Brain Stimulation (DBS) and Neurofeedback. Response Inhibition and Implementation Intentions have shown to reduce unhealthy diet and weight in people with overweight/obesity. Attentional Bias Modification has shown promising results in healthy-weight participants. Brain stimulation of the Dorsolateral Prefrontal Cortex via tDCS and the Hypothalamus via DBS showed benefits for reducing food craving and weight in people with overweight/obesity. Studies quality was generally high, but most trials were short-term and many conducted in healthy-weight samples. Modification of cognitive control and motivational processes/circuits are common mechanisms of beneficial training and neuromodulation interventions, and thus a promising approach for overweight/obesity treatment. Longer duration trials in clinical populations are needed to confirm benefits.
Topics: Attention; Brain; Cognitive Behavioral Therapy; Craving; Deep Brain Stimulation; Eating; Electric Stimulation Therapy; Humans; Neurofeedback; Obesity; Treatment Outcome
PubMed: 29432784
DOI: 10.1016/j.neubiorev.2018.02.003 -
Journal of Psychiatry & Neuroscience :... May 2014Several current theories emphasize the role of cognitive control in addiction. The present review evaluates neural deficits in the domains of inhibitory control and... (Review)
Review
BACKGROUND
Several current theories emphasize the role of cognitive control in addiction. The present review evaluates neural deficits in the domains of inhibitory control and error processing in individuals with substance dependence and in those showing excessive addiction-like behaviours. The combined evaluation of event-related potential (ERP) and functional magnetic resonance imaging (fMRI) findings in the present review offers unique information on neural deficits in addicted individuals.
METHODS
We selected 19 ERP and 22 fMRI studies using stop-signal, go/no-go or Flanker paradigms based on a search of PubMed and Embase.
RESULTS
The most consistent findings in addicted individuals relative to healthy controls were lower N2, error-related negativity and error positivity amplitudes as well as hypoactivation in the anterior cingulate cortex (ACC), inferior frontal gyrus and dorsolateral prefrontal cortex. These neural deficits, however, were not always associated with impaired task performance. With regard to behavioural addictions, some evidence has been found for similar neural deficits; however, studies are scarce and results are not yet conclusive. Differences among the major classes of substances of abuse were identified and involve stronger neural responses to errors in individuals with alcohol dependence versus weaker neural responses to errors in other substance-dependent populations.
LIMITATIONS
Task design and analysis techniques vary across studies, thereby reducing comparability among studies and the potential of clinical use of these measures.
CONCLUSION
Current addiction theories were supported by identifying consistent abnormalities in prefrontal brain function in individuals with addiction. An integrative model is proposed, suggesting that neural deficits in the dorsal ACC may constitute a hallmark neurocognitive deficit under lying addictive behaviours, such as loss of control.
Topics: Behavior, Addictive; Brain; Evoked Potentials; Executive Function; Humans; Inhibition, Psychological; Magnetic Resonance Imaging; Models, Neurological; Psychomotor Performance; Substance-Related Disorders
PubMed: 24359877
DOI: 10.1503/jpn.130052 -
Brain Sciences Sep 2023Traumatic brain injury, cardiac arrest, intracerebral hemorrhage, and ischemic stroke may cause disorders of consciousness (DoC). Repetitive transcranial magnetic... (Review)
Review
Traumatic brain injury, cardiac arrest, intracerebral hemorrhage, and ischemic stroke may cause disorders of consciousness (DoC). Repetitive transcranial magnetic stimulation (rTMS) has been used to promote the recovery of disorders of consciousness (DoC) patients. In this meta-analysis, we examined whether rTMS can relieve DoC patient symptoms. We searched through journal articles indexed in PubMed, the Web of Science, Embase, Scopus, and the Cochrane Library until 20 April 2023. We assessed whether studies used rTMS as an intervention and reported the pre- and post-rTMS coma recovery scale-revised (CRS-R) scores. A total of 207 patients from seven trials were included. rTMS significantly improved the recovery degree of patients; the weighted mean difference (WMD) of the change in the CRS-R score was 1.89 (95% confidence interval (CI): 1.39-2.39; < 0.00001) in comparison with controls. The subgroup analysis showed a significant improvement in CRS-R scores in rTMS over the dorsolateral prefrontal cortex (WMD = 2.24; 95% CI: 1.55-2.92; < 0.00001; = 31%) and the primary motor cortex (WMD = 1.63; 95% CI: 0.69-2.57; = 0.0007; = 14%). Twenty-hertz rTMS significantly improved CRS-R scores in patients with DoC (WMD = 1.61; 95% CI: 0.39-2.83; = 0.010; = 31%). Furthermore, CRS-R scores in rTMS over 20 sessions significantly improved (WMD = 1.75; 95% CI: 0.95-2.55; < 0.0001; = 12%). rTMS improved the symptoms of DoC patients; however, the available evidence remains limited and inadequate.
PubMed: 37891731
DOI: 10.3390/brainsci13101362 -
Neuropsychopharmacology : Official... Oct 2021Loneliness is associated with increased morbidity and mortality. Deeper understanding of neurobiological mechanisms underlying loneliness is needed to identify potential...
Loneliness is associated with increased morbidity and mortality. Deeper understanding of neurobiological mechanisms underlying loneliness is needed to identify potential intervention targets. We did not find any systematic review of neurobiology of loneliness. Using MEDLINE and PsycINFO online databases, we conducted a search for peer-reviewed publications examining loneliness and neurobiology. We identified 41 studies (n = 16,771 participants) that had employed various methods including computer tomography (CT), structural magnetic resonance imaging (MRI), functional MRI (fMRI), electroencephalography (EEG), diffusion tensor imaging (DTI), single-photon emission computed tomography (SPECT), positron emission tomography (PET), and post-mortem brain tissue RNA analysis or pathological analysis. Our synthesis of the published findings shows abnormal structure (gray matter volume or white matter integrity) and/or activity (response to pleasant versus stressful images in social versus nonsocial contexts) in the prefrontal cortex (especially medial and dorsolateral), insula (particularly anterior), amygdala, hippocampus, and posterior superior temporal cortex. The findings related to ventral striatum and cerebellum were mixed. fMRI studies reported links between loneliness and differential activation of attentional networks, visual networks, and default mode network. Loneliness was also related to biological markers associated with Alzheimer's disease (e.g., amyloid and tau burden). Although the published investigations have limitations, this review suggests relationships of loneliness with altered structure and function in specific brain regions and networks. We found a notable overlap in the regions involved in loneliness and compassion, the two personality traits that are inversely correlated in previous studies. We have offered recommendations for future research studies of neurobiology of loneliness.
Topics: Alzheimer Disease; Brain; Diffusion Tensor Imaging; Humans; Loneliness; Magnetic Resonance Imaging
PubMed: 34230607
DOI: 10.1038/s41386-021-01058-7 -
Journal of Rehabilitation Medicine Jan 2017To evaluate the effectiveness and safety of transcranial direct current stimulation for fibro-myalgia. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To evaluate the effectiveness and safety of transcranial direct current stimulation for fibro-myalgia.
METHODS
Databases, conference records and registered trials were searched for articles published from the date of establishment of the database through to October 2015. Six randomized controlled trials (n=192) of transcranial direct current stimulation for fibromyalgia were included in the current study.
DATA EXTRACTION
Two researchers independently screened the literature, assessed methodological quality using the Cochrane Collaboration's tool, and extracted data.
DATA SYNTHESIS
Studies were divided into 3 groups for meta-analysis according to stimulation site and polarity. Significant improvement in pain and general fibromyalgia-related function was seen with anodal transcranial direct current stimulation over the primary motor cortex (p<0.05). However, the pressure pain threshold did not improve (p>0.05). Anodal transcranial direct current stimulation over the left dorsolateral prefrontal cortex did not significantly reduce pain or improve general fibromyalgia-related function compared with sham stimulation (p>0.05). Cathodal transcranial direct current stimulation over the primary motor cortex did not improve the pressure pain threshold compared with sham stimulation (p>0.05). No significant adverse effects were seen.
CONCLUSION
Anodal transcranial direct current stimulation over the primary motor cortex is more likely than sham transcranial direct current stimulation to relieve pain and improve general fibromyalgia-related function.
Topics: Adult; Female; Fibromyalgia; Humans; Male; Pain Management; Transcranial Direct Current Stimulation
PubMed: 27983739
DOI: 10.2340/16501977-2179 -
Pain Physician Jul 2016Offset analgesia (OA) is an increasingly described phenomenon to measure endogenous pain inhibition, in which a greater decrease in pain intensity is experienced than... (Review)
Review
BACKGROUND
Offset analgesia (OA) is an increasingly described phenomenon to measure endogenous pain inhibition, in which a greater decrease in pain intensity is experienced than would be predicted by the decrease in painful stimulation. The temporal filtering in this OA phenomenon differs from the spatial filtering in the commonly described conditioned pain modulation (CPM). Yet, the knowledge on the efficacy of OA in chronic pain patients is scarce, compared to CPM efficacy.
OBJECTIVE
This systematic review has been conducted to provide an overview of the current knowledge regarding OA, and to compare it to CPM.
STUDY DESIGN
A systematic review of research studies that investigated the application or mechanisms of OA.
SETTING
The present study took place at Ghent University and the University of Antwerp.
METHODS
This systematic review follows the PRISMA guidelines. The electronic databases Pubmed and Web of Science were searched in January 2015. Full text clinical reports addressing OA were included. The checklists for randomized controlled trials, case-control studies, and cohort-studies provided by the Dutch Institute for Healthcare Improvement and the Dutch Cochrane Centre were used to assess methodological quality. The articles received a level of evidence A1, A2, B, C, or D, based on study design and risk of bias. These levels were used to determine the strength of conclusion (level 1 to 4).
RESULTS
Seventeen articles met the inclusion criteria. Sixteen studies used quantitative sensory testing to provoke OA; however, differences in protocols are present. OA can function as a non-opioid mediated assessment tool for endogenous pain inhibition, and activates brain regions such as periaqueductal gray (PAG), dorsolateral prefontral cortex, insula, medulla, pons and cerebellum, indicating strong brain derived pain modulation. The primary somatosensory cortex is, conversely, less activated during OA. OA is decreased in neuropathic patients. Nonetheless, evidence for the influence of individual factors on OA is limited. OA and CPM seem to rely on different mechanisms.
LIMITATIONS
Search strategy was taken wide, wherefore a large variety of research perspectives were included.
CONCLUSIONS
This systematic review displays OA as a temporal filtering mechanisms that is more brain-derived compared to the spatial assessment method CPM. There is strong evidence for reduced OA in neuropathic patients, however, evidence regarding OA in (sub)acute and central sensitization patients, and the influence of personal factors on OA is currently scarce and needs further investigation.
Topics: Analgesia; Central Nervous System Sensitization; Chronic Pain; Humans; Pain Management; Pain Measurement
PubMed: 27454261
DOI: No ID Found