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Clinical Radiology Oct 2019To test the network degeneration hypothesis in multiple sclerosis (MS) with a two-stage coordinate-based meta-analysis by: (1) characterising regional selectivity of... (Meta-Analysis)
Meta-Analysis
AIM
To test the network degeneration hypothesis in multiple sclerosis (MS) with a two-stage coordinate-based meta-analysis by: (1) characterising regional selectivity of grey matter (GM) atrophy and (2) testing for functional connectivity involving these regions.
MATERIALS AND METHODS
Meta-analytic sources included 33 journal articles (1,666 MS patients and 1,269 healthy controls) with coordinate-based results from voxel-based morphometry analysis demonstrating GM atrophy. Mass univariate and multivariate coordinate-based meta-analyses were performed to identify a convergent pattern of GM atrophy and determine inter-regional co-activation (as a surrogate of functional connectivity), with anatomical likelihood estimation and functional meta-analytic connectivity modelling, respectively.
RESULTS
Localised GM atrophy was demonstrated in the thalamus, putamen, caudate, sensorimotor cortex, insula, superior temporal gyrus, and cingulate gyrus. This convergent pattern of atrophy displayed significant inter-regional functional co-activations.
CONCLUSION
In MS, GM atrophy was regionally selective, and these regions were functionally connected. The meta-analytic model-based results of this study are intended to guide future development of quantitative neuroimaging markers for diagnosis, evaluating disease progression, and monitoring treatment response.
Topics: Atrophy; Brain; Gray Matter; Humans; Magnetic Resonance Imaging; Multiple Sclerosis; Neuroimaging
PubMed: 31421864
DOI: 10.1016/j.crad.2019.07.005 -
Psychiatry Research. Neuroimaging Jun 2020A systematic review was implemented according to PRISMA guidelines on Pubmed, Psychinfo, Medline, Embase to fill the existing literature gap on the effectiveness of...
A systematic review was implemented according to PRISMA guidelines on Pubmed, Psychinfo, Medline, Embase to fill the existing literature gap on the effectiveness of using Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT) in Anorexia Nervosa (AN), Bulimia Nervosa (BN) and Binge Eating Disorder (BED). Twenty-two articles were included. Four studies reported an increased density in 5-hydroxytryptamine receptor (5-HT) in fronto-temporo-parietal regions in both affected and recovered AN as well as in BN. The 5-HT transporter (5-HTT) binding was increased or diminished in different specific cortical areas and in relation to Eating Disorder (ED) subtypes. Some evidences of blunted Dopamine (DA) release in the putamen in BN patients suggest that their DA function might be impaired as in addictive behaviours. Studies estimating the regional Cerebral Blood Flow (rCBF) with SPECT demonstrated that temporal areas seem to play a key role in ED corroborating the hypothesis of a cingulate-temporal cortical dysfunction in AN. In addition, alterations of both parietal and prefrontal cortex provide a possible common neural substrate in AN. Studies included in this review are heterogeneous preventing robust conclusions, however, our findings add knowledge on some of the neurotransmitters involved in ED.
Topics: Anorexia Nervosa; Binge-Eating Disorder; Bulimia Nervosa; Cerebrovascular Circulation; Humans; Parietal Lobe; Positron-Emission Tomography; Prefrontal Cortex; Tomography, Emission-Computed, Single-Photon
PubMed: 32234640
DOI: 10.1016/j.pscychresns.2020.111065 -
Journal of Neuroscience Research Jul 2024Increasing neuroimaging studies have attempted to identify biomarkers of Huntington's disease (HD) progression. Here, we conducted voxel-based meta-analyses of... (Meta-Analysis)
Meta-Analysis Review
Increasing neuroimaging studies have attempted to identify biomarkers of Huntington's disease (HD) progression. Here, we conducted voxel-based meta-analyses of voxel-based morphometry (VBM) studies on HD to investigate the evolution of gray matter volume (GMV) alterations and explore the effects of genetic and clinical features on GMV changes. A systematic review was performed to identify the relevant studies. Meta-analyses of whole-brain VBM studies were performed to assess the regional GMV changes in all HD mutation carriers, in presymptomatic HD (pre-HD), and in symptomatic HD (sym-HD). A quantitative comparison was performed between pre-HD and sym-HD. Meta-regression analyses were used to explore the effects of genetic and clinical features on GMV changes. Twenty-eight studies were included, comparing a total of 1811 HD mutation carriers [including 1150 pre-HD and 560 sym-HD] and 969 healthy controls (HCs). Pre-HD showed decreased GMV in the bilateral caudate nuclei, putamen, insula, anterior cingulate/paracingulate gyri, middle temporal gyri, and left dorsolateral superior frontal gyrus compared with HCs. Compared with pre-HD, GMV decrease in sym-HD extended to the bilateral median cingulate/paracingulate gyri, Rolandic operculum and middle occipital gyri, left amygdala, and superior temporal gyrus. Meta-regression analyses found that age, mean lengths of CAG repeats, and disease burden were negatively associated with GMV atrophy of the bilateral caudate and right insula in all HD mutation carriers. This meta-analysis revealed the pattern of GMV changes from pre-HD to sym-HD, prompting the understanding of HD progression. The pattern of GMV changes may be biomarkers for disease progression in HD.
Topics: Huntington Disease; Humans; Gray Matter; Neuroimaging; Brain; Magnetic Resonance Imaging
PubMed: 38953592
DOI: 10.1002/jnr.25366 -
Neurology India 2022Pain, a physiological protective mechanism, turns into a complex dynamic neural response when it becomes chronic. The role of neuroplastic brain changes is more evident... (Meta-Analysis)
Meta-Analysis
Pain, a physiological protective mechanism, turns into a complex dynamic neural response when it becomes chronic. The role of neuroplastic brain changes is more evident than the peripheral factors in the maintenance, modulation and amplification of chronic low back pain (cLBP). In this background, we summarise the brain changes in cLBP in a coordinate-based activation likelihood estimation (ALE) meta-analysis of previous functional magnetic resonance imaging (fMRI) studies. Databases ('PubMed', 'Scopus' and 'Sleuth') were searched till May 2022 and the activity pattern was noted under the 'without stimulation' and 'with stimulation' groups. A total of 312 studies were selected after removing duplicates. Seventeen (553 cLBP patients, 192 activation foci) studies were fulfilled the eligibility criteria and included in the 'without stimulation' group. Twelve statistically significant clusters are localized in the prefrontal cortex, primary somatosensory cortex, primary motor cortex, parietal cortex, anterior cingulate cortex, caudate, putamen, globus pallidus amygdala, occipital lobe, temporal lobe and associated white matter in this group. Ten studies (353 cLBP patients, 125 activation foci) were selected in the' with stimulation' groups. In this group, seven statistically significant clusters were found in the frontal cortex, orbitofrontal cortex, premotor cortex, parietal cortex, claustrum and insula. These statistically significant clusters indicate a probable imbalance in GABAergic modulation of brain circuits and dysfunction in the descending pain modulation system. This disparity in the pain neuro-matrix is the source of spontaneous and persisting pain in cLBP.
Topics: Brain; Brain Mapping; Humans; Low Back Pain; Magnetic Resonance Imaging; Pain Measurement
PubMed: 36076626
DOI: 10.4103/0028-3886.355137 -
Neuropsychopharmacology Reports Sep 2019Altered trafficking of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors has been reported in postmortem studies and suggested the involvement of...
BACKGROUND AND OBJECTIVES
Altered trafficking of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors has been reported in postmortem studies and suggested the involvement of AMPA receptors in the pathophysiology underpinning addictive disorders. However, these findings seemed mixed.
METHODS
A systematic literature search was conducted, using PubMed and Embase (last search, August 2018), to identify human postmortem studies that examined the expression of proteins and mRNA of AMPA receptor subunits in patients with addictive disorders in comparison with healthy controls.
RESULTS
Twelve (18 studies) out of 954 articles were identified to be relevant. Eight studies included alcohol use disorders, and four studies included heroin/cocaine abusers. The most frequently investigated regions were the hippocampus (three studies), amygdala (three studies), and putamen (three studies). In summary, two out of the three studies showed an increase in the expression of AMPA receptors in the hippocampus, while the other study found no change. Two studies to examine the amygdala demonstrated either a decreased or no change in receptor expression or binding. Concerning putamen, two studies showed no significant change whereas an overexpression of receptors was observed in the other.
CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE
The hippocampus and amygdala may be pertinent to addictive disorders through their functions on learning and memory, whereas findings in other regions were inconsistent across the studies. Human postmortem studies are prone to degenerative changes after death. Moreover, only qualitative assessment was conducted because of the limited, heterogenous data. These limitations emphasize the need to investigate AMPA receptors in the living human brains.
Topics: Adult; Aged; Amygdala; Autopsy; Female; Hippocampus; Humans; Male; Middle Aged; Protein Binding; Protein Subunits; Putamen; RNA, Messenger; Receptors, AMPA; Substance-Related Disorders
PubMed: 31070872
DOI: 10.1002/npr2.12058 -
Frontiers in Psychiatry 2020The use of modern neuroimaging approaches has demonstrated resting-state regional cerebral blood flow (rCBF) to be tightly coupled to resting cerebral glucose metabolism...
The use of modern neuroimaging approaches has demonstrated resting-state regional cerebral blood flow (rCBF) to be tightly coupled to resting cerebral glucose metabolism (rCMRglu) in healthy brains. In schizophrenia, several lines of evidence point toward aberrant neurovascular coupling, especially in the prefrontal regions. To investigate this, we used Signed Differential Mapping to undertake a voxel-based bimodal meta-analysis examining the relationship between rCBF and rCMRglu in schizophrenia, as measured by arterial spin labeling (ASL) and Flurodeoxyglucose positron emission tomography (FDG-PET) respectively. We used 19 studies comprised of data from 557 patients and 584 controls. Our results suggest that several key regions implicated in the pathophysiology of schizophrenia such as the frontoinsular cortex, dorsal ACC, putamen, and temporal pole show conjoint metabolic and perfusion abnormalities in patients. In contrast, discordance between metabolism and perfusion were seen in superior frontal gyrus and cerebellum, indicating that factors contributing to neurovascular uncoupling (e.g. inflammation, mitochondrial dysfunction, oxidative stress) are likely operates at these loci. Studies enrolling patients on high doses of antipsychotics had showed larger rCBF/rCMRglu effects in patients in the left dorsal striatum. Hybrid ASL-PET studies focusing on these regions could confirm our proposition regarding neurovascular uncoupling at superior frontal gyrus in schizophrenia.
PubMed: 32848931
DOI: 10.3389/fpsyt.2020.00754 -
Journal of Clinical Neuroscience :... May 2021Eyelid closing or opening disorders have been only sporadically described in patients with focal brain lesions over the last decades. Furthermore, the restricted number...
Eyelid closing or opening disorders have been only sporadically described in patients with focal brain lesions over the last decades. Furthermore, the restricted number of reports and the lack of uniform clinical assessment of affected individuals did not allow to define more in depth the clinical features and the underlying neural correlates of these uncommon clinical disorders. Here we report an 89-years old woman with a right hemispheric lesion who showed a contralesional defect of eyelid closure. We also include a video neuroimage of this case and a review of eyelid closing and opening disorders in patients with focal unilateral lesions. In this review we found a correlation between right hemisphere and eyelid motor control, particularly for apraxia of eyelid closure affecting only the contralesional eye. The right parietal lobe was most frequently affected in this unilateral form of eyelid closing disorders, whereas putamen and other subcortical structures were more involved in eyelid opening than in eyelid closing disorders. The relations between unilateral eyelid closing disorders and other forms of motor-intentional defects are shortly discussed.
Topics: Aged; Aged, 80 and over; Apraxias; Brain Injuries; Eyelid Diseases; Eyelids; Female; Humans; Male; Middle Aged; Parietal Lobe
PubMed: 33863537
DOI: 10.1016/j.jocn.2021.02.020 -
AJNR. American Journal of Neuroradiology Jul 2021Neurologic events have been reported in patients with coronavirus disease 2019 (COVID-19). However, a model-based evaluation of the spatial distribution of these events...
BACKGROUND
Neurologic events have been reported in patients with coronavirus disease 2019 (COVID-19). However, a model-based evaluation of the spatial distribution of these events is lacking.
PURPOSE
Our aim was to quantitatively evaluate whether a network diffusion model can explain the spread of small neurologic events.
DATA SOURCES
The MEDLINE, EMBASE, Scopus, and LitCovid data bases were searched from January 1, 2020, to July 19, 2020.
STUDY SELECTION
Thirty-five case series and case studies reported 317 small neurologic events in 123 unique patients with COVID-19.
DATA ANALYSIS
Neurologic events were localized to gray or white matter regions of the Illinois Institute of Technology (gray-matter and white matter) Human Brain Atlas using radiologic images and descriptions. The total proportion of events was calculated for each region. A network diffusion model was implemented, and any brain regions showing a significant association (< .05, family-wise error-corrected) between predicted and measured events were considered epicenters.
DATA SYNTHESIS
Within gray matter, neurologic events were widely distributed, with the largest number of events (∼10%) observed in the bilateral superior temporal, precentral, and lateral occipital cortices, respectively. Network diffusion modeling showed a significant association between predicted and measured gray matter events when the spread of pathology was seeded from the bilateral cerebellum (=0.51, < .001, corrected) and putamen (=0.4, = .02, corrected). In white matter, most events (∼26%) were observed within the bilateral corticospinal tracts.
LIMITATIONS
The risk of bias was not considered because all studies were either case series or case studies.
CONCLUSIONS
Transconnectome diffusion of pathology via the structural network of the brain may contribute to the spread of neurologic events in patients with COVID-19.
Topics: Brain; COVID-19; Cerebral Cortex; Gray Matter; Humans; Magnetic Resonance Imaging; White Matter
PubMed: 33888458
DOI: 10.3174/ajnr.A7113 -
Frontiers in Human Neuroscience 2020Many studies have revealed the structural or functional brain changes induced by occupational factors. However, it remains largely unknown how occupation-related...
Many studies have revealed the structural or functional brain changes induced by occupational factors. However, it remains largely unknown how occupation-related connectivity shapes the brain. In this paper, we denote occupational neuroplasticity as the neuroplasticity that takes place to satisfy the occupational requirements by extensively professional training and to accommodate the long-term, professional work of daily life, and a critical review of occupational neuroplasticity related to the changes in brain structure and functional networks has been primarily presented. Furthermore, meta-analysis revealed a neurophysiological mechanism of occupational neuroplasticity caused by professional experience. This meta-analysis of functional neuroimaging studies showed that experts displayed stronger activation in the left precentral gyrus [Brodmann area (BA)6], left middle frontal gyrus (BA6), and right inferior frontal gyrus (BA9) than novices, while meta-analysis of structural studies suggested that experts had a greater gray matter volume in the bilateral superior temporal gyrus (BA22) and right putamen than novices. Together, these findings not only expand the current understanding of the common neurophysiological basis of occupational neuroplasticity across different occupations and highlight some possible targets for neural modulation of occupational neuroplasticity but also provide a new perspective for occupational science research.
PubMed: 32760257
DOI: 10.3389/fnhum.2020.00215 -
Neurology India 2020The incidence and prevalence of Parkinson's (PD) are increasing rapidly in developing countries. PD is difficult to diagnose based on clinical assessment. Presently,...
The incidence and prevalence of Parkinson's (PD) are increasing rapidly in developing countries. PD is difficult to diagnose based on clinical assessment. Presently, magnetic resonance imaging (MRI) methods such as R2* and Quantitative Susceptibility Mapping (QSM) were found to be useful in diagnosing the PD based on the iron deposition in different regions of the brain. The objective of this review was to evaluate the efficacy of QSM over R2* in assessment of PD. A comprehensive literature search was made on PubMed-Medline, CINAHL, Science Direct, Scopus, Web of Science, and the Cochrane library databases for original research articles published between 2000 and 2018. Original articles that reported the efficacy of QSM and R2* in assessment of PD were included. A total of 327 studies were identified in the literature search. However, only ten studies were eligible for analysis. Of the ten studies, five studies compared the accuracy of QSM over R2* in measuring the iron deposition in different regions of brain in PD. Our review found that QSM has better accuracy in identifying iron deposition in PD patients compared to R2*. However, there is discrepancy in the results between MRI Imaging methods and Postmortem studies. Additional longitudinal research studies are needed to provide a strong evidence base for the use of MRI imaging methods such as R2*and QSM in accurately measuring iron deposition in different regions of brain and serve as biomarkers in PD.
Topics: Brain; Caudate Nucleus; Globus Pallidus; Humans; Iron; Magnetic Resonance Imaging; Parkinson Disease; Putamen; Red Nucleus; Sensitivity and Specificity; Substantia Nigra; Thalamus
PubMed: 32415005
DOI: 10.4103/0028-3886.284377