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Psychoneuroendocrinology Feb 2022Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis has been implicated in the development of major depressive disorder (MDD) in adulthood. Less work has... (Meta-Analysis)
Meta-Analysis Review
INTRODUCTION
Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis has been implicated in the development of major depressive disorder (MDD) in adulthood. Less work has focused on the role of the HPA axis in depression in adolescence and young adulthood globally. The aim of this study was to conduct a systematic review and meta-analysis of worldwide research investigating the relationship between cortisol, a measure of HPA axis activity, and MDD in adolescence and young adulthood.
METHOD
We searched MEDLINE, PsycINFO, Cochrane Database of Systematic Reviews, Web of Science, Lilacs, African Journals Online, and Global Health for studies which examined the relationship between cortisol and MDD in global youth (10-24 years old).
RESULTS
Twenty-six studies were included in the systematic review and 14 were eligible for the meta-analysis, but only one study included young adults in their sample. Results from the meta-analysis demonstrated that elevated morning, but not evening, cortisol levels was prospectively associated with later MDD development in adolescence and young adulthood. However, morning cortisol levels did not significantly differ between healthy controls and individuals with MDD in cross-sectional studies. Afternoon cortisol and cortisol stress response also did not differ between adolescents with MDD and healthy controls. Qualitative synthesis of the three studies examining nocturnal cortisol showed higher nocturnal cortisol was both longitudinally and cross-sectionally associated with MDD in adolescence.
CONCLUSION
Our findings suggest elevated morning cortisol precedes depression in adolescence. Despite this, we did not find any differences in other cortisol measures in association with MDD in cross-sectional studies. Taken together, these findings suggest that elevated morning and nocturnal cortisol are risk factors for depression in adolescence rather than a biomarker of existing MDD. This supports a role for the hyperactivity of the HPA axis in the development of MDD in adolescence. Most of the studies were from high-income-countries (HICs) and thus further work would need to be conducted in low- and middle-income countries (LMICs) to understand if our findings are generalisable also to these populations.
Topics: Adolescent; Adult; Child; Cross-Sectional Studies; Depression; Depressive Disorder, Major; Humans; Hydrocortisone; Hypothalamo-Hypophyseal System; Pituitary-Adrenal System; Young Adult
PubMed: 34920399
DOI: 10.1016/j.psyneuen.2021.105625 -
Neurobiology of Aging Feb 2020Repetitive transcranial magnetic stimulation (rTMS), a noninvasive brain stimulation technique, has emerged as a promising treatment for mild cognitive impairment (MCI)... (Meta-Analysis)
Meta-Analysis
Repetitive transcranial magnetic stimulation (rTMS), a noninvasive brain stimulation technique, has emerged as a promising treatment for mild cognitive impairment (MCI) and Alzheimer's disease (AD). Currently, however, the effectiveness of this therapy is unclear because of the low statistical power and heterogeneity of previous trials. The purpose of the meta-analysis was to systematically characterize the effectiveness of various combinations of rTMS parameters on different cognitive domains in patients with MCI and AD. Thirteen studies comprising 293 patients with MCI or AD were included in this analysis. Random-effects analysis revealed an overall medium-to-large effect size (0.77) favoring active rTMS over sham rTMS in the improvement of cognitive functions. Subgroup analyses revealed that (1) high-frequency rTMS over the left dorsolateral prefrontal cortex and low-frequency rTMS at the right dorsolateral prefrontal cortex significantly improved memory functions; (2) high-frequency rTMS targeting the right inferior frontal gyrus significantly enhanced executive performance; and (3) the effects of 5-30 consecutive rTMS sessions could last for 4-12 weeks. Potential mechanisms of rTMS effects on cognitive functions are discussed.
Topics: Alzheimer Disease; Cognition; Cognitive Dysfunction; Humans; Memory; Prefrontal Cortex; Transcranial Magnetic Stimulation
PubMed: 31783330
DOI: 10.1016/j.neurobiolaging.2019.08.020 -
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 -
Movement Disorders : Official Journal... Feb 2021The aim of this systematic review was (1) to identify the brain regions involved in anxiety in Parkinson's disease (PD) based on neuroimaging studies and (2) to... (Review)
Review
BACKGROUND
The aim of this systematic review was (1) to identify the brain regions involved in anxiety in Parkinson's disease (PD) based on neuroimaging studies and (2) to interpret the findings against the background of dysfunction of the fear circuit and limbic cortico-striato-thalamocortical circuit.
METHODS
Studies assessing anxiety symptoms in PD patients and studies using magnetic resonance imaging, positron emission tomography, or single-photon emission computed tomography were included.
RESULTS
The severity of anxiety was associated with changes in the fear circuit and the cortico-striato-thalamocortical limbic circuit. In the fear circuit, a reduced gray-matter volume of the amygdala and the anterior cingulate cortex (ACC); an increased functional connectivity (FC) between the amygdala and orbitofrontal cortex (OFC) and hippocampus and between the striatum and the medial prefrontal cortex (PFC), temporal cortex, and insula; and a reduced FC between the lateral PFC and the OFC, hippocampus, and amygdala were reported. In the cortico-striato-thalamocortical limbic circuit, a reduced FC between the striatum and ACC; a reduced dopaminergic and noradrenergic activity in striatum, thalamus, and locus coeruleus; and a reduced serotoninergic activity in the thalamus were reported.
CONCLUSION
To conclude, anxiety is associated with structural and functional changes in both the hypothesized fear and the limbic cortico-striato-thalamocortical circuits. These circuits overlap and may well constitute parts of a more extensive pathway, of which different parts play different roles in anxiety. The neuropathology of PD may affect these circuits in different ways, explaining the high prevalence of anxiety in PD and also the associated cognitive, motor, and psychiatric symptoms. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Topics: Amygdala; Anxiety; Anxiety Disorders; Humans; Magnetic Resonance Imaging; Neuroimaging; Parkinson Disease
PubMed: 33289195
DOI: 10.1002/mds.28404 -
Neural Plasticity 2022Aphasia is a common symptom in stroke patients, presenting with the impairment of spontaneous speech, repetition, naming, auditory comprehension, reading, and writing... (Review)
Review
BACKGROUND
Aphasia is a common symptom in stroke patients, presenting with the impairment of spontaneous speech, repetition, naming, auditory comprehension, reading, and writing function. Multiple rehabilitation methods have been suggested for the recovery of poststroke aphasia, including medication treatment, behavioral therapy, and stimulation approach. Acupuncture has been proven to have a beneficial effect on improving speech functions in repetition, oral speech, reading, comprehension, and writing ability. Neuroimaging technology provides a visualized way to explore cerebral neural activity, which helps reveal the therapeutic effect of acupuncture therapy. In this systematic review, we aim to reveal and summarize the neuroimaging mechanism of acupuncture therapy on poststroke aphasia to provide the foundation for further study.
METHODS
Seven electronic databases were searched including PubMed, Web of Science, Embase, Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, the Wanfang databases, and the Chinese Scientific Journal Database. After screening the studies according to the inclusion and exclusion criteria, we summarized the neuroimaging mechanism of acupuncture on poststroke aphasia, as well as the utilization of acupuncture therapy and the methodological characteristics.
RESULT
After searching, 885 articles were retrieved. After removing the literature studies, animal studies, and case reports, 16 studies were included in the final analysis. For the acupuncture type, 10 studies used manual acupuncture and 5 studies used electroacupuncture, while body acupuncture (10 studies), scalp acupuncture (7 studies), and tongue acupuncture (8 studies) were applied for poststroke aphasia patients. Based on blood oxygen level-dependent (BOLD) and diffusion tensor imaging (DTI) technologies, 4 neuroimaging analysis methods were used including amplitude of low-frequency fluctuation (ALFF), regional homogeneity (ReHo), seed-based analysis, and independent component analysis (ICA). Two studies reported the instant acupuncture effect, and 14 studies reported the constant acupuncture's effect on poststroke aphasia patients. 5 studies analyzed the correlation between the neuroimaging outcomes and the clinical language scales.
CONCLUSION
In this systematic review, we found that the mechanism of acupuncture's effect might be associated with the activation and functional connectivity of language-related brain areas, such as brain areas around Broca's area and Wernicke's area in the left inferior temporal gyrus, supramarginal gyrus, middle frontal gyrus, and inferior frontal gyrus. However, these studies were still in the preliminary stage. Multicenter randomized controlled trials (RCT) with large sample sizes were needed to verify current evidence, as well as to explore deeply the neuroimaging mechanisms of acupuncture's effects.
Topics: Acupuncture Therapy; Animals; Aphasia; Broca Area; Diffusion Tensor Imaging; Humans; Multicenter Studies as Topic; Stroke
PubMed: 35494482
DOI: 10.1155/2022/5635596 -
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 -
Brain and Behavior Sep 2022Among the target groups in child and adolescent psychiatry, transcranial direct current stimulation (tDCS) has been more applied in neurodevelopmental disorders... (Review)
Review
A systematic review of randomized controlled trials on efficacy and safety of transcranial direct current stimulation in major neurodevelopmental disorders: ADHD, autism, and dyslexia.
OBJECTIVE
Among the target groups in child and adolescent psychiatry, transcranial direct current stimulation (tDCS) has been more applied in neurodevelopmental disorders specifically, attention-deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and dyslexia. This systematic review aims to provide the latest update on published randomized-controlled trials applying tDCS in these disorders for evaluating its efficacy and safety.
METHODS
Based on a pre-registered protocol (PROSPERO: CRD42022321430) and using the PRISMA approach, a literature search identified 35 randomized controlled trials investigating the effects of tDCS on children and adolescents with ADHD (n = 17), ASD (n = 11), and dyslexia (n = 7).
RESULTS
In ADHD, prefrontal anodal tDCS is reported more effective compared to stimulation of the right inferior frontal gyrus. Similarly in ASD, prefrontal anodal tDCS was found effective for improving behavioral problems. In dyslexia, stimulating temporoparietal regions was the most common and effective protocol. In ASD and dyslexia, all tDCS studies found an improvement in at least one of the outcome variables while 64.7% of studies (11 of 17) in ADHD found a similar effect. About 88% of all tDCS studies with a multi-session design in 3 disorders (16 of 18) reported a significant improvement in one or all outcome variables after the intervention. Randomized, double-blind, controlled trials consisted of around 70.5%, 36.3%, and 57.1% of tDCS studies in ADHD, ASD, and dyslexia, respectively. tDCS was found safe with no reported serious side effects in 6587 sessions conducted on 745 children and adolescents across 35 studies.
CONCLUSION
tDCS was found safe and partially effective. For evaluation of clinical utility, larger randomized controlled trials with a double-blind design and follow-up measurements are required. Titration studies that systematically evaluate different stimulation intensities, duration, and electrode placement are lacking.
Topics: Adolescent; Attention Deficit Disorder with Hyperactivity; Autism Spectrum Disorder; Autistic Disorder; Child; Dyslexia; Humans; Prefrontal Cortex; Randomized Controlled Trials as Topic; Transcranial Direct Current Stimulation
PubMed: 35938945
DOI: 10.1002/brb3.2724 -
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 -
Journal of Neuroengineering and... Feb 2022Transcranial magnetic stimulation (TMS) has attracted plenty of attention as it has been proved to be effective in facilitating motor recovery in patients with stroke.... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Transcranial magnetic stimulation (TMS) has attracted plenty of attention as it has been proved to be effective in facilitating motor recovery in patients with stroke. The aim of this study was to systematically review the effects of repetitive TMS (rTMS) and theta burst stimulation (TBS) protocols in modulating cortical excitability after stroke.
METHODS
A literature search was carried out using PubMed, Medline, EMBASE, CINAHL, and PEDro, to identify studies that investigated the effects of four rTMS protocols-low and high frequency rTMS, intermittent and continuous TBS, on TMS measures of cortical excitability in stroke. A random-effects model was used for all meta-analyses.
RESULTS
Sixty-one studies were included in the current review. Low frequency rTMS was effective in decreasing individuals' resting motor threshold and increasing the motor-evoked potential of the non-stimulated M1 (affected M1), while opposite effects occurred in the stimulated M1 (unaffected M1). High frequency rTMS enhanced the cortical excitability of the affected M1 alone. Intermittent TBS also showed superior effects in rebalancing bilateral excitability through increasing and decreasing excitability within the affected and unaffected M1, respectively. Due to the limited number of studies found, the effects of continuous TBS remained inconclusive. Motor impairment was significantly correlated with various forms of TMS measures.
CONCLUSIONS
Except for continuous TBS, it is evident that these protocols are effective in modulating cortical excitability in stroke. Current evidence does support the effects of inhibitory stimulation in enhancing the cortical excitability of the affected M1.
Topics: Cortical Excitability; Evoked Potentials, Motor; Humans; Motor Cortex; Stroke; Transcranial Magnetic Stimulation
PubMed: 35193624
DOI: 10.1186/s12984-022-00999-4 -
Psychological Medicine Apr 2020People with attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) have abnormalities in frontal, temporal, parietal and striato-thalamic... (Comparative Study)
Comparative Study Meta-Analysis
Comparative meta-analyses of brain structural and functional abnormalities during cognitive control in attention-deficit/hyperactivity disorder and autism spectrum disorder.
BACKGROUND
People with attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) have abnormalities in frontal, temporal, parietal and striato-thalamic networks. It is unclear to what extent these abnormalities are distinctive or shared. This comparative meta-analysis aimed to identify the most consistent disorder-differentiating and shared structural and functional abnormalities.
METHODS
Systematic literature search was conducted for whole-brain voxel-based morphometry (VBM) and functional magnetic resonance imaging (fMRI) studies of cognitive control comparing people with ASD or ADHD with typically developing controls. Regional gray matter volume (GMV) and fMRI abnormalities during cognitive control were compared in the overall sample and in age-, sex- and IQ-matched subgroups with seed-based d mapping meta-analytic methods.
RESULTS
Eighty-six independent VBM (1533 ADHD and 1295 controls; 1445 ASD and 1477 controls) and 60 fMRI datasets (1001 ADHD and 1004 controls; 335 ASD and 353 controls) were identified. The VBM meta-analyses revealed ADHD-differentiating decreased ventromedial orbitofrontal (z = 2.22, p < 0.0001) but ASD-differentiating increased bilateral temporal and right dorsolateral prefrontal GMV (zs ⩾ 1.64, ps ⩽ 0.002). The fMRI meta-analyses of cognitive control revealed ASD-differentiating medial prefrontal underactivation but overactivation in bilateral ventrolateral prefrontal cortices and precuneus (zs ⩾ 1.04, ps ⩽ 0.003). During motor response inhibition specifically, ADHD relative to ASD showed right inferior fronto-striatal underactivation (zs ⩾ 1.14, ps ⩽ 0.003) but shared right anterior insula underactivation.
CONCLUSIONS
People with ADHD and ASD have mostly distinct structural abnormalities, with enlarged fronto-temporal GMV in ASD and reduced orbitofrontal GMV in ADHD; and mostly distinct functional abnormalities, which were more pronounced in ASD.
Topics: Adolescent; Adult; Attention Deficit Disorder with Hyperactivity; Autism Spectrum Disorder; Brain; Cerebral Cortex; Child; Cognition; Female; Gray Matter; Humans; Magnetic Resonance Imaging; Male; Parietal Lobe; Thalamus; Young Adult
PubMed: 32216846
DOI: 10.1017/S0033291720000574