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Epilepsia Mar 2022Deep brain stimulation (DBS) is a neuromodulatory treatment used in patients with drug-resistant epilepsy (DRE). The primary goal of this systematic review and... (Meta-Analysis)
Meta-Analysis Review
Deep brain stimulation (DBS) is a neuromodulatory treatment used in patients with drug-resistant epilepsy (DRE). The primary goal of this systematic review and meta-analysis is to describe recent advancements in the field of DBS for epilepsy, to compare the results of published trials, and to clarify the clinical utility of DBS in DRE. A systematic literature search was performed by two independent authors. Forty-four articles were included in the meta-analysis (23 for anterior thalamic nucleus [ANT], 8 for centromedian thalamic nucleus [CMT], and 13 for hippocampus) with a total of 527 patients. The mean seizure reduction after stimulation of the ANT, CMT, and hippocampus in our meta-analysis was 60.8%, 73.4%, and 67.8%, respectively. DBS is an effective and safe therapy in patients with DRE. Based on the results of randomized controlled trials and larger clinical series, the best evidence exists for DBS of the anterior thalamic nucleus. Further randomized trials are required to clarify the role of CMT and hippocampal stimulation. Our analysis suggests more efficient deep brain stimulation of ANT for focal seizures, wider use of CMT for generalized seizures, and hippocampal DBS for temporal lobe seizures. Factors associated with clinical outcome after DBS for epilepsy are electrode location, stimulation parameters, type of epilepsy, and longer time of stimulation. Recent advancements in anatomical targeting, functional neuroimaging, responsive neurostimulation, and sensing of local field potentials could potentially lead to improved outcomes after DBS for epilepsy and reduced sudden, unexpected death of patients with epilepsy. Biomarkers are needed for successful patient selection, targeting of electrodes and optimization of stimulation parameters.
Topics: Anterior Thalamic Nuclei; Death, Sudden; Deep Brain Stimulation; Drug Resistant Epilepsy; Epilepsy; Hippocampus; Humans; Intralaminar Thalamic Nuclei; Seizures
PubMed: 34981509
DOI: 10.1111/epi.17157 -
Journal of Psychiatry & Neuroscience :... Jan 2021Repetitive transcranial magnetic stimulation (rTMS) or transcranial direct current stimulation (tDCS) could provide treatment alternatives to stimulant medication for... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Repetitive transcranial magnetic stimulation (rTMS) or transcranial direct current stimulation (tDCS) could provide treatment alternatives to stimulant medication for attention-deficit/hyperactivity disorder (ADHD), given some evidence for improvements in cognition and clinical symptoms. However, despite a lack of solid evidence for their use, rTMS and tDCS are already offered clinically and commercially in ADHD. This systematic review and meta-analysis aimed to critically appraise rTMS and tDCS studies in ADHD to inform good research and clinical practice.
METHODS
A systematic search (up to February 2019) identified 18 studies (rTMS 4, tDCS 14; 311 children and adults with ADHD) stimulating mainly the dorsolateral prefrontal cortex (dlPFC). We included 12 anodal tDCS studies (232 children and adults with ADHD) in 3 random-effects meta-analyses of cognitive measures of attention, inhibition and processing speed.
RESULTS
The review of rTMS and tDCS showed positive effects in some functions but not others, and little evidence for clinical improvement. The meta-analyses of 1 to 5 sessions of anodal tDCS over mainly the left or bilateral dlPFC showed trend-level improvements in inhibition and processing speed, but not in attention.
LIMITATIONS
Heterogeneity in stimulation parameters, patient age and outcome measures limited the interpretation of findings.
CONCLUSION
The review and meta-analysis showed limited evidence that 1 to 5 sessions of rTMS and tDCS, mostly of the dlPFC, improved clinical or cognitive measures of ADHD. These findings did not support using rTMS or tDCS of the dlPFC as an alternative neurotherapy for ADHD as yet. Larger, multi-session stimulation studies identifying more optimal sites and stimulation parameters in combination with cognitive training could achieve larger effects.
Topics: Adolescent; Adult; Attention Deficit Disorder with Hyperactivity; Child; Humans; Outcome Assessment, Health Care; Prefrontal Cortex; Transcranial Direct Current Stimulation; Transcranial Magnetic Stimulation; Young Adult
PubMed: 33009906
DOI: 10.1503/jpn.190179 -
The Lancet. Psychiatry Apr 2023The left dorsolateral prefrontal cortex is a prime target for repetitive transcranial magnetic stimulation (TMS) to treat neuropsychiatric disorders; thus, abundant... (Meta-Analysis)
Meta-Analysis
Effects of repetitive transcranial magnetic stimulation of the left dorsolateral prefrontal cortex on symptom domains in neuropsychiatric disorders: a systematic review and cross-diagnostic meta-analysis.
BACKGROUND
The left dorsolateral prefrontal cortex is a prime target for repetitive transcranial magnetic stimulation (TMS) to treat neuropsychiatric disorders; thus, abundant efficacy data from controlled trials are available. A cross-diagnostic meta-analysis was conducted to identify the symptom domains susceptible to repetitive TMS to the left dorsolateral prefrontal cortex.
METHODS
This systematic review and meta-analysis investigated the effects of repetitive TMS to the left dorsolateral prefrontal cortex on neuropsychiatric symptoms presenting across diagnoses. We searched PubMed, MEDLINE, Embase, Web of Science, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, and WHO International Clinical Trials Registry Platform for randomised and sham controlled trials published from inception to Aug 17, 2022. Included studies assessed symptoms using clinical measures and reported sufficient data to calculate effect sizes pooled with a random effects model. Two independent reviewers conducted screening and used the Cochrane risk-of-bias tool for quality assessment. Summary data were extracted from published reports. The main outcome was the therapeutic effects of repetitive TMS of the left dorsolateral prefrontal cortex on distinct symptom domains. This study is registered with PROSPERO (CRD42021278458).
FINDINGS
Of 9056 studies identified (6704 from databases and 2352 from registers), 174 were included in the analysis including 7905 patients. 163 of 174 studies reported gender data; 3908 (52·35%) of 7465 patients were male individuals, and 3557 (47·65%) were female individuals. Mean age was 44·63 years (range 19·79-72·80). Ethnicity data were mostly not available. Effect size was large for craving (Hedges'g -0·803 [95% CI -1·099 to -0·507], p<0·0001; I=82·40%), medium for depressive symptoms (-0·725 [-0·889 to -0·561], p<0·0001; I=85·66%), small for anxiety, obsessions or compulsions, pain, global cognition, declarative memory, working memory, cognitive control, and motor coordination (Hedges'g -0·198 to -0·491), and non-significant for attention, suicidal ideation, language, walking ability, fatigue, and sleep.
INTERPRETATION
The cross-diagnostic meta-analysis shows the efficacy of repetitive TMS of the left dorsolateral prefrontal cortex on distinct symptom domains, providing a novel framework for assessing target or efficacy interactions of repetitive TMS, and informing personalised applications for conditions for which regular trials are uninformative.
FUNDING
The University Grants Committee of Hong Kong and the Mental Health Research Center, The Hong Kong Polytechnic University.
Topics: Humans; Male; Female; Young Adult; Adult; Middle Aged; Aged; Transcranial Magnetic Stimulation; Dorsolateral Prefrontal Cortex; Pain; Anxiety Disorders; Cognition
PubMed: 36898403
DOI: 10.1016/S2215-0366(23)00026-3 -
Journal of Affective Disorders Apr 2022Background We evaluated the efficacy and safety of repetitive transcranial magnetic stimulation (rTMS) for obsessive-compulsive disorder (OCD), and ranked the relative... (Meta-Analysis)
Meta-Analysis Review
Background We evaluated the efficacy and safety of repetitive transcranial magnetic stimulation (rTMS) for obsessive-compulsive disorder (OCD), and ranked the relative efficacy of different stimulation protocols. Methods We performed a search for randomised, sham-controlled trials of rTMS for OCD. The primary analysis included both a pairwise meta-analysis and a series of frequentist network meta-analyses (NMA) of OCD symptom severity. Secondary analyses were carried out on relevant clinical factors and safety. Results 21 studies involving 662 patients were included. The pairwise meta-analysis showed that rTMS for OCD is efficacious across all protocols (Hedges' g=-0.502 [95%CI= -0.708, -0.296]). The first NMA, with stimulation protocols clustered only by anatomical location, showed that both dorsolateral prefrontal cortex (dlPFC) stimulation and medial frontal cortex stimulation were efficacious. In the second NMA, considering each unique combination of frequency and location separately, low frequency (LF) pre-supplementary motor area (preSMA) stimulation, high frequency (HF) bilateral dlPFC stimulation, and LF right dlPFC stimulation were all efficacious . LF right dlPFC was ranked highest in terms of efficacy, although the corresponding confidence intervals overlapped with the other two protocols. Limitations Evidence base included mostly small studies, with only a few studies using similar protocols, giving a sparse network. Studies were heterogeneous, and a risk of publication bias was found. Conclusions rTMS for OCD was efficacious compared with sham stimulation. LF right dlPFC, HF bilateral dlPFC and LF preSMA stimulation were all efficacious protocols with significant and comparable clinical improvements. Future studies should further investigate the relative merits of these three protocols.
Topics: Humans; Motor Cortex; Network Meta-Analysis; Obsessive-Compulsive Disorder; Prefrontal Cortex; Transcranial Magnetic Stimulation; Treatment Outcome
PubMed: 35041869
DOI: 10.1016/j.jad.2022.01.048 -
PloS One 2023Binaural beats are an auditory phenomenon that occurs when two tones of different frequencies, which are presented separately to each ear, elicit the sensation of a...
Binaural beats to entrain the brain? A systematic review of the effects of binaural beat stimulation on brain oscillatory activity, and the implications for psychological research and intervention.
Binaural beats are an auditory phenomenon that occurs when two tones of different frequencies, which are presented separately to each ear, elicit the sensation of a third tone oscillating at the difference frequency of the two tones. Binaural beats can be perceived in the frequency range of about 1-30 Hz, a range that coincides with the main human EEG frequency bands. The brainwave entrainment hypothesis, which assumes that external stimulation at a certain frequency leads to the brain's electrocortical activity oscillating at the same frequency, provides the basis for research on the effects of binaural beat stimulation on cognitive and affective states. Studies, particularly in more applied fields, usually refer to neuroscientific research demonstrating that binaural beats elicit systematic changes in EEG parameters. At first glance, however, the available literature on brainwave entrainment effects due to binaural beat stimulation appears to be inconclusive at best. The aim of the present systematic review is, thus, to synthesize existing empirical research. A sample of fourteen published studies met our criteria for inclusion. The results corroborate the impression of an overall inconsistency of empirical outcomes, with five studies reporting results in line with the brainwave entrainment hypothesis, eight studies reporting contradictory, and one mixed results. What is to be noticed is that the fourteen studies included in this review were very heterogeneous regarding the implementation of the binaural beats, the experimental designs, and the EEG parameters and analyses. The methodological heterogeneity in this field of study ultimately limits the comparability of research outcomes. The results of the present systematic review emphasize the need for standardization in study approaches so as to allow for reliable insight into brainwave entrainment effects in the future.
Topics: Humans; Acoustic Stimulation; Brain; Auditory Cortex; Brain Waves
PubMed: 37205669
DOI: 10.1371/journal.pone.0286023 -
Neuropsychology Review Jun 2023Deep brain stimulation (DBS) of the subthalamic nucleus (STN) or globus pallidum internus (GPi) improves motor functions in patients with Parkinson's disease (PD) but... (Meta-Analysis)
Meta-Analysis Review
Deep brain stimulation (DBS) of the subthalamic nucleus (STN) or globus pallidum internus (GPi) improves motor functions in patients with Parkinson's disease (PD) but may cause a decline in specific cognitive domains. The aim of this systematic review and meta-analysis was to assess the long-term (1-3 years) effects of STN or GPi DBS on four cognitive functions: (i) memory (delayed recall, working memory, immediate recall), (ii) executive functions including inhibition control (Color-Word Stroop test) and flexibility (phonemic verbal fluency), (iii) language (semantic verbal fluency), and (iv) mood (anxiety and depression). Medline and Web of Science were searched, and studies published before July 2021 investigating long-term changes in PD patients following DBS were included. Random-effects model meta-analyses were performed using the R software to estimate the standardized mean difference (SMD) computed as Hedges' g with 95% CI. 2522 publications were identified, 48 of which satisfied the inclusion criteria. Fourteen meta-analyses were performed including 2039 adults with a clinical diagnosis of PD undergoing DBS surgery and 271 PD controls. Our findings add new information to the existing literature by demonstrating that, at a long follow-up interval (1-3 years), both positive effects, such as a mild improvement in anxiety and depression (STN, Hedges' g = 0,34, p = 0,02), and negative effects, such as a decrease of long-term memory (Hedges' g = -0,40, p = 0,02), verbal fluency such as phonemic fluency (Hedges' g = -0,56, p < 0,0001), and specific subdomains of executive functions such as Color-Word Stroop test (Hedges' g = -0,45, p = 0,003) were observed. The level of evidence as qualified with GRADE varied from low for the pre- verses post-analysis to medium when compared to a control group.
Topics: Adult; Humans; Parkinson Disease; Deep Brain Stimulation; Subthalamic Nucleus; Globus Pallidus; Cognition; Neuropsychological Tests
PubMed: 35318587
DOI: 10.1007/s11065-022-09540-9 -
Journal of Neurology Jan 2023To comprehensively summarize and meta-analyze the concurrence across voxel-based morphometric (VBM) neuroimaging studies of migraine. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
To comprehensively summarize and meta-analyze the concurrence across voxel-based morphometric (VBM) neuroimaging studies of migraine.
METHODS
Neuroimaging studies published from origin to August 1, 2021 were searched in six databases including PubMed, Web of Science, Excerpta Medica Database (EMBASE), China National Knowledge Infrastructure (CNKI), Wanfang Database, and Chongqing VIP. Study selection, quality assessment, and data extraction were conducted by two independent researchers. Anisotropic effect size-signed differential mapping (AES-SDM) and activation likelihood estimation (ALE) were used to perform the meta-analysis of available studies reporting whole-brain gray matter (GM) structural data in migraine patients. Clinical variables correlation analysis and migraine subgroup analysis were also conducted.
RESULTS
40 articles were included after the strict screening, containing 1616 migraine patients and 1681 matched healthy subjects (HS) in total. Using the method of AES-SDM, migraine patients showed GM increase in the bilateral amygdala, the bilateral parahippocampus, the bilateral temporal poles, the bilateral superior temporal gyri, the left hippocampus, the right superior frontal gyrus, and the left middle temporal gyrus, as well as GM decrease in the left insula, the bilateral cerebellum (hemispheric lobule IX), the right dorsal medulla, the bilateral rolandic operculum, the right middle frontal gyrus, and the right inferior parietal gyrus. Using the method of ALE, migraine patients showed GM increase in the left parahippocampus and GM decrease in the left insula. The results of correlation analysis showed that many of these brain regions were associated with migraine headache frequency and migraine disease duration. Migraine patients in different subtypes (such as migraine without aura (MwoA), migraine with aura (MwA), episodic migraine (EM), chronic migraine (CM), vestibular migraine (VM), etc.), and in different periods (in the ictal and interictal periods) presented not entirely consistent GM alterations.
CONCLUSION
Migraine patients have GM alterations in multiple brain regions associated with sensation, affection, cognition, and descending modulation aspects of pain. These changes might be a consequence of repeated migraine attacks. Further studies are required to determine how these GM changes can be used to diagnose, monitor disease progression, or exploit potential therapeutic interventions for migraine patients.
Topics: Humans; Brain; Gray Matter; Frontal Lobe; Prefrontal Cortex; Migraine without Aura; Magnetic Resonance Imaging
PubMed: 36098838
DOI: 10.1007/s00415-022-11363-w -
Journal of Anxiety Disorders Oct 2023Anxiety disorders are among the most prevalent psychiatric disorders. Neuroimaging findings remain uncertain, and resting state functional magnetic resonance (rs-fMRI)... (Meta-Analysis)
Meta-Analysis Review
Anxiety disorders are among the most prevalent psychiatric disorders. Neuroimaging findings remain uncertain, and resting state functional magnetic resonance (rs-fMRI) connectivity is of particular interest since it is a scalable functional imaging modality. Given heterogeneous past findings for rs-fMRI in anxious individuals, we characterize patterns across anxiety disorders by conducting a systematic review and meta-analysis. Studies were included if they contained at the time of scanning both a healthy group and a patient group. Due to insufficient study numbers, the quantitative meta-analysis only included seed-based studies. We performed an activation likelihood estimation (ALE) analysis that compared patients and healthy volunteers. All analyses were corrected for family-wise error with a cluster-level threshold of p < .05. Patients exhibited hypo-connectivity between the amygdala and the medial frontal gyrus, anterior cingulate cortex, and cingulate gyrus. This finding, however, was not robust to potential file-drawer effects. Though limited by strict inclusion criteria, our results highlight the heterogeneous nature of reported findings. This underscores the need for data sharing when attempting to detect reliable patterns of disruption in brain activity across anxiety disorders.
Topics: Humans; Magnetic Resonance Imaging; Gyrus Cinguli; Anxiety Disorders; Anxiety; Brain
PubMed: 37741177
DOI: 10.1016/j.janxdis.2023.102773 -
World Neurosurgery May 2018To present a systematic review and meta-analysis to establish the relation between cerebral autoregulation (CA) and intracranial hypertension. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To present a systematic review and meta-analysis to establish the relation between cerebral autoregulation (CA) and intracranial hypertension.
METHODS
An electronic search using the term "Cerebral autoregulation and intracranial hypertension" was designed to identify studies that analyzed cerebral blood flow autoregulation in patients undergoing intracranial pressure (ICP) monitoring. The data were used in meta-analyses and sensitivity analyses.
RESULTS
A static CA technique was applied in 10 studies (26.3%), a dynamic technique was applied in 25 studies (65.8%), and both techniques were used in 3 studies (7.9%). Static CA studies using the cerebral blood flow technique revealed impaired CA in patients with an ICP ≥20 (standardized mean difference [SMD] 5.44%, 95% confidence interval [CI] 0.25-10.65, P = 0.04); static CA studies with transcranial Doppler revealed a tendency toward impaired CA in patients with ICP ≥20 (SMD -7.83%, 95% CI -17.52 to 1.85, P = 0.11). Moving correlation studies reported impaired CA in patients with ICP ≥20 (SMD 0.06, 95% CI 0.07-0.14, P < 0.00001). A comparison of CA values and mean ICP revealed a correlation between greater ICP and impaired CA (SMD 5.47, 95% CI 1.39-10.1, P = 0.01). Patients with ICP ≥20 had an elevated risk of impaired CA (OR 2.27, 95% CI 1.20-4.31, P = 0.01).
CONCLUSIONS
A clear tendency toward CA impairment was observed in patients with increased ICP.
Topics: Cerebral Cortex; Homeostasis; Humans; Intracranial Hypertension; Intracranial Pressure
PubMed: 29421451
DOI: 10.1016/j.wneu.2018.01.194 -
Ageing Research Reviews Dec 2023In aging, olfactory deficits have been associated with lower cognition and motor function. Olfactory dysfunction is also one of the earliest features of... (Review)
Review
In aging, olfactory deficits have been associated with lower cognition and motor function. Olfactory dysfunction is also one of the earliest features of neurodegenerative disease. A comprehensive review of the neural correlates of olfactive function may reveal mechanisms underlying the associations among olfaction, cognition, motor function, and neurodegenerative diseases. Here, we summarize existing knowledge on the relationship between brain structural and functional measures and olfaction in older adults without and with cognitive impairment, including Alzheimer's disease. We identified 33 eligible studies (30 MRI/DTI,3 fMRI); 31 were cross-sectional, most assessed odor identification, and few examined multiple brain areas. Lower olfactory function was associated with smaller volumes in the temporal lobe (hippocampus,parahippocampal gyrus,fusiform gyrus), olfactory-related regions (piriform cortex,amygdala,entorhinal cortex), pre- and postcentral gyri, and globus pallidus. During aging, olfactory impairment may be associated with pathology in brain areas important for motor function and cognition, especially memory. Future longitudinal studies that include neuroimaging across different brain areas are warranted to determine the neurobiological changes underlying olfactory changes in the aging brain and the progression of neurodegeneration.
Topics: Humans; Aged; Neurodegenerative Diseases; Brain; Entorhinal Cortex; Hippocampus; Temporal Lobe; Magnetic Resonance Imaging; Cognitive Dysfunction
PubMed: 37913831
DOI: 10.1016/j.arr.2023.102095