-
CNS Neuroscience & Therapeutics Feb 2024Several studies have reported iron accumulation in the basal ganglia to be associated with the development of Parkinson's Disease (PD). Recently, a few trials have... (Meta-Analysis)
Meta-Analysis Review
INTRODUCTION
Several studies have reported iron accumulation in the basal ganglia to be associated with the development of Parkinson's Disease (PD). Recently, a few trials have examined the efficacy of using the iron-chelating agent Deferiprone (DFP) for patients with PD. We conducted this meta-analysis to summarize and synthesize evidence from published randomized controlled trials about the efficacy of DFP for PD patients.
METHODS
A comprehensive literature search of four electronic databases was performed, spanning until February 2023. Relevant RCTs were selected, and their data were extracted and analyzed using the RevMan software. The primary outcome was the change in the Unified Parkinson's Disease Rating Scale (UPDRS-III).
RESULTS
Three RCTs with 431 patients were included in this analysis. DFP did not significantly improve UPDRS-III score compared to placebo (Standardized mean difference -0.06, 95% CI [-0.69, 0.58], low certainty evidence). However, it significantly reduced iron accumulation in the substantia nigra, putamen, and caudate as measured by T2*-weighted MRI (with high certainty evidence).
CONCLUSION
Current evidence does not support the use of DFP in PD patients. Future disease-modification trials with better population selection, adjustment for concomitant medications, and long-term follow up are recommended.
Topics: Humans; Deferiprone; Parkinson Disease; Iron Chelating Agents; Iron; Substantia Nigra
PubMed: 38334258
DOI: 10.1111/cns.14607 -
Journal of Child and Adolescent... Aug 2019Addictive disorders start during adolescence for most individuals, and developmental differences in brain maturation and response to treatments are present. Recent... (Meta-Analysis)
Meta-Analysis
Addictive disorders start during adolescence for most individuals, and developmental differences in brain maturation and response to treatments are present. Recent studies in adults have identified associations between addiction treatment response and regional and circuit specific brain dysfunction, suggesting candidate neural treatment targets. The purpose of this systematic review and meta-analysis was to qualitatively and quantitatively summarize findings from structural and functional neuroimaging studies that examine neural correlates of treatment response in adolescents and young adults with addictive disorders. A systematic review and meta-analysis of peer-reviewed studies was conducted following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Studies were selected if they included individuals aged 13-26 with a DSM-IV or DSM-5 () addictive disorder diagnosis, used neuroimaging, administered a treatment/intervention, and reported within- or between-subject contrasts in brain structure or activity across treatment/intervention and a control condition or brain-behavior correlations with treatment-outcome variables. Quantitative meta-analyses used an activation-likelihood estimation (ALE) approach. Out of 3177 citations, 27 studies were included in the qualitative analysis. Qualitative analyses revealed anatomical, connectivity, and functional brain-behavior associations with response to addiction interventions across a broad array of cortical and subcortical brain regions and associated networks. Eighteen functional magnetic resonance imaging studies involving 354 participants and 88 brain foci were included in the ALE meta-analysis. Despite significant heterogeneity in study design and methods, six ALE activation clusters localized to the anterior cingulate cortex, inferior frontal gyrus, supramarginal gyrus, middle temporal gyrus, precuneus, and putamen showed consistent brain-behavior associations with treatment-outcome variables. Cortical and subcortical brain regions involved in cognition, emotion regulation, decision-making, reward, and self-reference are associated with treatment response in addicted youth. These results are consistent with findings in the adult literature and suggest overlapping neural treatment targets across developmental stages.
Topics: Adolescent; Adolescent Behavior; Behavior, Addictive; Brain; Cognition; Decision Making; Functional Neuroimaging; Humans; Reward; Substance-Related Disorders; Young Adult
PubMed: 31313938
DOI: 10.1089/cap.2019.0007 -
Progress in Neuro-psychopharmacology &... Mar 2022Abnormalities in spontaneous brain activity, measured with resting-state functional magnetic resonance imaging (rs-fMRI), may be key biomarkers for bipolar disorders....
OBJECTIVE
Abnormalities in spontaneous brain activity, measured with resting-state functional magnetic resonance imaging (rs-fMRI), may be key biomarkers for bipolar disorders. This systematic review compares rs-fMRI findings in people experiencing a bipolar depressive or (hypo)manic episode to bipolar euthymia and/or healthy participants.
METHODS
Medline, Web of Science and Embase were searched up until April 2021. Studies without control group, or including minors, neurological co-morbidities or mixed episodes, were excluded. Qualitative synthesis was used to report results and risk of bias was assessed using the National Heart, Lung and Blood Institute tool for case-control studies.
RESULTS
Seventy-one studies were included (3167 bipolar depressed/706 (hypo)manic). In bipolar depression, studies demonstrated default-mode (DMN) and frontoparietal network (FPN) dysfunction, altered baseline activity in the precuneus, insula, striatum, cingulate, frontal and temporal cortex, and disturbed regional homogeneity in parietal, temporal and pericentral areas. Functional connectivity was altered in thalamocortical circuits and between the cingulate cortex and precuneus. In (hypo)mania, studies reported altered functional connectivity in the amygdala, frontal and cingulate cortex. Finally, rs-fMRI disturbances in the insula and putamen correlate with depressive symptoms, cerebellar resting-state alterations could evolve with disease progression and altered amygdala connectivity might mediate lithium effects.
CONCLUSIONS
Our results suggest DMN and FPN dysfunction in bipolar depression, whereas local rs-fMRI alterations might differentiate mood states. Future studies should consider controlling rs-fMRI findings for potential clinical confounding factors such as medication. Considerable heterogeneity of methodology between studies limits conclusions. Standardised clinical reporting and consistent analysis approaches would increase coherence in this promising field.
Topics: Amygdala; Biomarkers; Bipolar Disorder; Brain; Default Mode Network; Gyrus Cinguli; Humans; Magnetic Resonance Imaging; Mania; Neostriatum; Parietal Lobe; Temporal Lobe
PubMed: 34736998
DOI: 10.1016/j.pnpbp.2021.110465 -
NeuroImage. Clinical 2024Quantitative susceptibility mapping (QSM) is a quantitative measure based on magnetic resonance imaging sensitive to iron and myelin content. This makes QSM a promising... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Quantitative susceptibility mapping (QSM) is a quantitative measure based on magnetic resonance imaging sensitive to iron and myelin content. This makes QSM a promising non-invasive tool for multiple sclerosis (MS) in research and clinical practice.
OBJECTIVE
We performed a systematic review and meta-analysis on the use of QSM in MS.
METHODS
Our review was prospectively registered on PROSPERO (CRD42022309563). We searched five databases for studies published between inception and 30th April 2023. We identified 83 English peer-reviewed studies that applied QSM images on MS cohorts. Fifty-five included studies had at least one of the following outcome measures: deep grey matter QSM values in MS, either compared to healthy controls (HC) (k = 13) or correlated with the score on the Expanded Disability Status Scale (EDSS) (k = 7), QSM lesion characteristics (k = 22) and their clinical correlates (k = 17), longitudinal correlates (k = 11), histological correlates (k = 7), or correlates with other imaging techniques (k = 12). Two meta-analyses on deep grey matter (DGM) susceptibility data were performed, while the remaining findings could only be analyzed descriptively.
RESULTS
After outlier removal, meta-analyses demonstrated a significant increase in the basal ganglia susceptibility (QSM values) in MS compared to HC, caudate (k = 9, standardized mean difference (SDM) = 0.54, 95 % CI = 0.39-0.70, I = 46 %), putamen (k = 9, SDM = 0.38, 95 % CI = 0.19-0.57, I = 59 %), and globus pallidus (k = 9, SDM = 0.48, 95 % CI = 0.28-0.67, I = 60 %), whereas thalamic QSM values exhibited a significant reduction (k = 12, SDM = -0.39, 95 % CI = -0.66--0.12, I = 84 %); these susceptibility differences in MS were independent of age. Further, putamen QSM values positively correlated with EDSS (k = 4, r = 0.36, 95 % CI = 0.16-0.53, I = 0 %). Regarding rim lesions, four out of seven studies, representing 73 % of all patients, reported rim lesions to be associated with more severe disability. Moreover, lesion development from initial detection to the inactive stage is paralleled by increasing, plateauing (after about two years), and gradually decreasing QSM values, respectively. Only one longitudinal study provided clinical outcome measures and found no association. Histological data suggest iron content to be the primary source of QSM values in DGM and at the edges of rim lesions; further, when also considering data from myelin water imaging, the decrease of myelin is likely to drive the increase of QSM values within WM lesions.
CONCLUSIONS
We could provide meta-analytic evidence for DGM susceptibility changes in MS compared to HC; basal ganglia susceptibility is increased and, in the putamen, associated with disability, while thalamic susceptibility is decreased. Beyond these findings, further investigations are necessary to establish the role of QSM in MS for research or even clinical routine.
Topics: Humans; Multiple Sclerosis; Magnetic Resonance Imaging; Gray Matter; Brain
PubMed: 38582068
DOI: 10.1016/j.nicl.2024.103598 -
Reviews in Endocrine & Metabolic... Aug 2022Obesity is the second most common cause of preventable morbidity worldwide. Resting-state functional magnetic resonance imaging (fMRI) has been used extensively to... (Review)
Review
Obesity is the second most common cause of preventable morbidity worldwide. Resting-state functional magnetic resonance imaging (fMRI) has been used extensively to characterise altered communication between brain regions in individuals with obesity, though findings from this research have not yet been systematically evaluated within the context of prominent neurobiological frameworks. This systematic review aggregated resting-state fMRI findings in individuals with obesity and evaluated the contribution of these findings to current neurobiological models. Findings were considered in relation to a triadic model of problematic eating, outlining disrupted communication between reward, inhibitory, and homeostatic systems. We identified a pattern of consistently increased orbitofrontal and decreased insula cortex resting-state functional connectivity in individuals with obesity in comparison to healthy weight controls. BOLD signal amplitude was also increased in people with obesity across studies, predominantly confined to subcortical regions, including the hippocampus, amygdala, and putamen. We posit that altered orbitofrontal cortex connectivity may be indicative of a shift in the valuation of food-based rewards and that dysfunctional insula connectivity likely contributes to altered homeostatic signal processing. Homeostatic violation signals in obesity may be maintained despite satiety, thereby 'hijacking' the executive system and promoting further food intake. Moving forward, we provide a roadmap for more reliable resting-state and task-based functional connectivity experiments, which must be reconciled within a common framework if we are to uncover the interplay between psychological and biological factors within current theoretical frameworks.
Topics: Brain; Brain Mapping; Humans; Magnetic Resonance Imaging; Obesity; Reward
PubMed: 34159504
DOI: 10.1007/s11154-021-09665-x -
Journal of Neurology Jun 2022Neuroimaging studies have reported gray matter changes in patients with idiopathic dystonia but with considerable variations. Here, we aimed to investigate the... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Neuroimaging studies have reported gray matter changes in patients with idiopathic dystonia but with considerable variations. Here, we aimed to investigate the convergence of dystonia-related gray matter changes across studies.
METHODS
The whole brain voxel-based morphometry studies comparing idiopathic dystonia and healthy controls were systematically searched in the PubMed, Web of Science and Embase. Meta-analysis of gray matter changes was performed using the anisotropic effect size-based signed differential mapping.
RESULTS
Twenty-eight studies comparing 701 idiopathic dystonia patients and 712 healthy controls were included in the meta-analysis. Compared to healthy controls, idiopathic dystonia patients showed increased gray matter in bilateral precentral and postcentral gyri, bilateral putamen and pallidum, right insula, and left supramarginal gyrus, while decreased gray matter in bilateral temporal poles, bilateral supplementary motor areas, right angular gyrus, inferior parietal gyrus and precuneus, left insula and inferior frontal gyrus. These findings remained robust in the jackknife sensitivity analysis, and no significant heterogeneity was detected. Subgroup analyses of different phenotypes of dystonia were performed to further confirm the above findings.
CONCLUSION
The meta-analysis showed that consistent widespread gray matter abnormalities were shared in different subtypes of idiopathic dystonia and were not restricted to the corticostriatal circuits.
Topics: Brain; Cerebral Cortex; Dystonia; Gray Matter; Humans; Magnetic Resonance Imaging; Neuroimaging
PubMed: 35013788
DOI: 10.1007/s00415-022-10961-y -
Pediatric Neurology Jan 2016Dyskinetic cerebral palsy affects 15%-20% of patients with cerebral palsy. Basal ganglia injury is associated with dyskinetic cerebral palsy, but the patterns of injury... (Review)
Review
BACKGROUND
Dyskinetic cerebral palsy affects 15%-20% of patients with cerebral palsy. Basal ganglia injury is associated with dyskinetic cerebral palsy, but the patterns of injury within the basal ganglia predisposing to dyskinetic cerebral palsy are unknown, making treatment difficult. For example, deep brain stimulation of the globus pallidus interna improves dystonia in only 40% of patients with dyskinetic cerebral palsy. Basal ganglia injury heterogeneity may explain this variability.
METHODS
To investigate this, we conducted a qualitative systematic review of basal ganglia and thalamic damage in dyskinetic cerebral palsy. Reviews and articles primarily addressing genetic or toxic causes of cerebral palsy were excluded yielding 22 studies (304 subjects).
RESULTS
Thirteen studies specified the involved basal ganglia nuclei (subthalamic nucleus, caudate, putamen, globus pallidus, or lentiform nuclei, comprised by the putamen and globus pallidus). Studies investigating the lentiform nuclei (without distinguishing between the putamen and globus pallidus) showed that all subjects (19 of 19) had lentiform nuclei damage. Studies simultaneously but independently investigating the putamen and globus pallidus also showed that all subjects (35 of 35) had lentiform nuclei damage (i.e., putamen or globus pallidus damage); this was followed in frequency by damage to the putamen alone (70 of 101, 69%), the subthalamic nucleus (17 of 25, 68%), the thalamus (88 of 142, 62%), the globus pallidus (7/35, 20%), and the caudate (6 of 47, 13%). Globus pallidus damage was almost always coincident with putaminal damage.
CONCLUSIONS
Noting consistent involvement of the lentiform nuclei in dyskinetic cerebral palsy, these results could suggest two groups of patients with dyskinetic cerebral palsy: those with putamen-predominant damage and those with panlenticular damage involving both the putamen and the globus pallidus. Differentiating between these groups could help predict response to therapies such as deep brain stimulation.
Topics: Animals; Basal Ganglia; Cerebral Palsy; Humans; Thalamus
PubMed: 26706479
DOI: 10.1016/j.pediatrneurol.2015.10.005 -
Sleep Medicine Reviews Aug 2021Sleep disturbances are commonly reported in patients with chronic liver disease (CLD). Changes in quality of sleep in patients with CLD could be related to multiple... (Meta-Analysis)
Meta-Analysis Review
Sleep disturbances are commonly reported in patients with chronic liver disease (CLD). Changes in quality of sleep in patients with CLD could be related to multiple factors viz., elevated levels of tryptophan, histamine, and increased turnover of dopamine in caudate-putamen and cingulate cortex. Also, iron metabolism disturbances are reported in patients with CLD. These changes may result in restless legs syndrome (RLS) that worsens sleep-quality. There have been reports suggesting an increased prevalence of RLS among patients with CLD. Literature was searched in PubMed, EMBASE, and Google Scholar. A total of twenty-two relevant articles were found. Out of these, nine studies have assessed the prevalence of RLS among patients with chronic liver disease or cirrhosis in the clinical population. Population prevalence reported from various studies was used to calculate odds ratio. Having included studies using various methods for diagnosis (clinical as well as questionnaires) pooled odds-ratio for the RLS was 8.62. It remains unaffected by study-method, gender, age, and geographical-area. However, studies using clinical diagnosis for RLS had lower odds compared to questionnaire based diagnosis. Studies varied with regards to diagnostic methods, age, gender, etiology, and severity of liver dysfunction. The severity and etiology of CLD and biochemical correlate of CLD were not found to be associated with RLS. Possible pathophysiological mechanisms are discussed for the occurrence of RLS in this population. In conclusion, the prevalence of RLS is higher among patients with CLD, however, the correlates are unknown.
Topics: Humans; Liver Diseases; Prevalence; Restless Legs Syndrome; Sleep Wake Disorders; Surveys and Questionnaires
PubMed: 33836477
DOI: 10.1016/j.smrv.2021.101463 -
Frontiers in Neurology 2018Around 30% Parkinson's disease (PD) patients develop impulse control disorders (ICDs) to D dopamine agonists and, to a lesser extent, levodopa. We aim to investigate...
Around 30% Parkinson's disease (PD) patients develop impulse control disorders (ICDs) to D dopamine agonists and, to a lesser extent, levodopa. We aim to investigate striatal dopaminergic function in PD patients with and without ICD. PubMed, Science Direct, EBSCO, and ISI Web of Science databases were searched (from inception to March 7, 2018) to identify PET or SPECT studies reporting striatal dopaminergic function in PD patients with ICD (ICD+) compared to those without ICD (ICD-). Studies which included drug naïve patients, explored non-pharmacological procedures (e.g., deep brain stimulation), and those using brain blood perfusion or non-dopaminergic markers were excluded. Standardized mean difference (SDM) was used and random-effect models were applied. Separate meta-analyses were performed for dopamine transporter level, dopamine release, and dopamine receptors availability in the putamen, caudate, dorsal, and ventral striatum. A total of 238 studies were title and abstract screened, of which 19 full-texts were assessed. Nine studies (ICD+: = 117; ICD-: = 175 patients) were included in the analysis. ICD+ showed a significant reduction of dopamine transporter binding in the putamen (SDM = -0.46; 95% CI: -0.80, -0.11; = 2.61; = 0.009), caudate (SDM = -0.38; 95% CI: -0.73, -0.04; = 2.18; = 0.03) and dorsal striatum (SDM = -0.45; 95% CI: -0.77, -0.13; = 2.76; = 0.006), and increased dopamine release to reward-related stimuli/gambling tasks in the ventral striatum (SDM = -1.04; 95% CI: -1.73, -0.35; = 2.95; = 0.003). Dopamine receptors availability did not differ between groups. Heterogeneity was low for dopamine transporter in the dorsal striatum ( = 0%), putamen ( = 0%) and caudate ( = 0%), and pre-synaptic dopamine release in the dorsal ( = 0%) and ventral striatum ( = 0%); heterogeneity was high for dopamine transporter levels in the ventral striatum ( = 80%), and for dopamine receptors availability in the ventral ( = 89%) and dorsal ( = 86%) striatum, putamen ( = 93%), and caudate ( = 71%). ICD+ patients show lower dopaminergic transporter levels in the dorsal striatum and increased dopamine release in the ventral striatum when engaged in reward-related stimuli/gambling tasks. This dopaminergic imbalance might represent a biological substrate for ICD in PD. Adequately powered longitudinal studies with drug naïve patients are needed to understand whether these changes may represent biomarkers of premorbid vulnerability to ICD.
PubMed: 30568628
DOI: 10.3389/fneur.2018.01018 -
Journal of Parkinson's Disease 2021The hallmark of Parkinson's disease is depletion of dopamine in the basal ganglia. Models of Parkinson's disease include dopamine as a contributor to disease... (Meta-Analysis)
Meta-Analysis
BACKGROUND
The hallmark of Parkinson's disease is depletion of dopamine in the basal ganglia. Models of Parkinson's disease include dopamine as a contributor to disease progression. However, intraneuronal levels of dopamine have not been reported.
OBJECTIVE
Meta-analytic methods were utilized to determine intracellular dopamine levels in Parkinson's disease.
METHODS
A systematic review of the literature and frequentist meta-analyses were performed. Dopamine levels were scaled for cell and axon numbers as well as VMAT2 protein levels.
RESULTS
Reduced tissue dopamine, dopaminergic cell bodies and VMAT2 protein were confirmed. The ratio of Parkinson's to normal brain intracellular dopamine scaled for either cell or axon number, each with VMAT2 level in the caudate ranged from 1.49 to 1.87 (p = 0.51 and p = 0.12, respectively) and in the putamen from 0.75 to 4.61 (p = 0.40 and 0.001, respectively).
CONCLUSION
Free, intracellular dopamine levels are not reduced in Parkinson's disease compared to normals to a similar degree as are total tissue concentrations, supporting the relevance of modulating VMAT2, neuromelanin and/or dopamine synthesis as rational neuroprotective strategies.
Topics: Basal Ganglia; Dopamine; Dopaminergic Neurons; Humans; Parkinson Disease; Putamen
PubMed: 34024786
DOI: 10.3233/JPD-212715