-
Journal of Magnetic Resonance Imaging :... Aug 2022Automated magnetic resonance imaging (MRI) volumetry is a promising tool to evaluate regional brain volumes in dementia and especially Alzheimer's disease (AD). (Meta-Analysis)
Meta-Analysis
BACKGROUND
Automated magnetic resonance imaging (MRI) volumetry is a promising tool to evaluate regional brain volumes in dementia and especially Alzheimer's disease (AD).
PURPOSE
To compare automated methods and the gold standard manual segmentation in measuring regional brain volumes on MRI across healthy controls, patients with mild cognitive impairment, and patients with dementia due to AD.
STUDY TYPE
Systematic review and meta-analysis.
DATA SOURCES
MEDLINE, Embase, and PsycINFO were searched through October 2021.
FIELD STRENGTH
1.0 T, 1.5 T, or 3.0 T.
ASSESSMENT
Two review authors independently identified studies for inclusion and extracted data. Methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2).
STATISTICAL TESTS
Standardized mean differences (SMD; Hedges' g) were pooled using random-effects meta-analysis with robust variance estimation. Subgroup analyses were undertaken to explore potential sources of heterogeneity. Sensitivity analyses were conducted to examine the impact of the within-study correlation between effect estimates on the meta-analysis results.
RESULTS
Seventeen studies provided sufficient data to evaluate the hippocampus, lateral ventricles, and parahippocampal gyrus. The pooled SMD for the hippocampus, lateral ventricles, and parahippocampal gyrus were 0.22 (95% CI -0.50 to 0.93), 0.12 (95% CI -0.13 to 0.37), and -0.48 (95% CI -1.37 to 0.41), respectively. For the hippocampal data, subgroup analyses suggested that the pooled SMD was invariant across clinical diagnosis and field strength. Subgroup analyses could not be conducted on the lateral ventricles data and the parahippocampal gyrus data due to insufficient data. The results were robust to the selected within-study correlation value.
DATA CONCLUSION
While automated methods are generally comparable to manual segmentation for measuring hippocampal, lateral ventricle, and parahippocampal gyrus volumes, wide 95% CIs and large heterogeneity suggest that there is substantial uncontrolled variance. Thus, automated methods may be used to measure these regions in patients with AD but should be used with caution.
EVIDENCE LEVEL
3 TECHNICAL EFFICACY: Stage 3.
Topics: Alzheimer Disease; Cognitive Dysfunction; Hippocampus; Humans; Lateral Ventricles; Magnetic Resonance Imaging
PubMed: 34964531
DOI: 10.1002/jmri.28037 -
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 -
The conscious processing of emotion in depression disorder: a meta-analysis of neuroimaging studies.Frontiers in Psychiatry 2023Depression is generally accompanied by a disturbed conscious processing of emotion, which manifests as a negative bias to facial/voice emotion information and a...
BACKGROUND
Depression is generally accompanied by a disturbed conscious processing of emotion, which manifests as a negative bias to facial/voice emotion information and a decreased accuracy in emotion recognition tasks. Several studies have proved that abnormal brain activation was responsible for the deficit function of conscious emotion recognition in depression. However, the altered brain activation related to the conscious processing of emotion in depression was incongruent among studies. Therefore, we conducted an activation likelihood estimation (ALE) analysis to better understand the underlying neurophysiological mechanism of conscious processing of emotion in depression.
METHOD
Electronic databases were searched using the search terms "depression," "emotion recognition," and "neuroimaging" from inceptions to April 10th, 2023. We retrieved trials which explored the neuro-responses of depressive patients to explicit emotion recognition tasks. Two investigators independently performed literature selection, data extraction, and risk of bias assessment. The spatial consistency of brain activation in conscious facial expressions recognition was calculated using ALE. The robustness of the results was examined by Jackknife sensitivity analysis.
RESULTS
We retrieved 11,365 articles in total, 28 of which were included. In the overall analysis, we found increased activity in the middle temporal gyrus, superior temporal gyrus, parahippocampal gyrus, and cuneus, and decreased activity in the superior temporal gyrus, inferior parietal lobule, insula, and superior frontal gyrus. In response to positive stimuli, depressive patients showed hyperactivity in the medial frontal gyrus, middle temporal gyrus, and insula (uncorrected < 0.001). When receiving negative stimuli, a higher activation was found in the precentral gyrus, middle frontal gyrus, precuneus, and superior temporal gyrus (uncorrected < 0.001).
CONCLUSION
Among depressive patients, a broad spectrum of brain areas was involved in a deficit of conscious emotion processing. The activation of brain regions was different in response to positive or negative stimuli. Due to potential clinical heterogeneity, the findings should be treated with caution.
SYSTEMATIC REVIEW REGISTRATION
https://inplasy.com/inplasy-2022-11-0057/, identifier: 2022110057.
PubMed: 37448490
DOI: 10.3389/fpsyt.2023.1099426 -
Frontiers in Aging Neuroscience 2023Mild cognitive impairment (MCI) depicts a transitory phase between healthy elderly and the onset of Alzheimer's disease (AD) with worsening cognitive impairment. Some...
BACKGROUND
Mild cognitive impairment (MCI) depicts a transitory phase between healthy elderly and the onset of Alzheimer's disease (AD) with worsening cognitive impairment. Some functional MRI (fMRI) research indicated that the frontoparietal network (FPN) could be an essential part of the pathophysiological mechanism of MCI. However, damaged FPN regions were not consistently reported, especially their interactions with other brain networks. We assessed the fMRI-specific anomalies of the FPN in MCI by analyzing brain regions with functional alterations.
METHODS
PubMed, Embase, and Web of Science were searched to screen neuroimaging studies exploring brain function alterations in the FPN in MCI using fMRI-related indexes, including the amplitude of low-frequency fluctuation, regional homogeneity, and functional connectivity. We integrated distinctive coordinates by activating likelihood estimation, visualizing abnormal functional regions, and concluding functional alterations of the FPN.
RESULTS
We selected 29 studies and found specific changes in some brain regions of the FPN. These included the bilateral dorsolateral prefrontal cortex, insula, precuneus cortex, anterior cingulate cortex, inferior parietal lobule, middle temporal gyrus, superior frontal gyrus, and parahippocampal gyrus. Any abnormal alterations in these regions depicted interactions between the FPN and other networks.
CONCLUSION
The study demonstrates specific fMRI neuroimaging alterations in brain regions of the FPN in MCI patients. This could provide a new perspective on identifying early-stage patients with targeted treatment programs.
SYSTEMATIC REVIEW REGISTRATION
https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023432042, identifier: CRD42023432042.
PubMed: 37448688
DOI: 10.3389/fnagi.2023.1165908 -
Neuropsychologia Nov 2014Social Anxiety Disorder (SAD) and Williams-Beuren Syndrome (WS) are two conditions which seem to be at opposite ends in the continuum of social fear but show compromised... (Meta-Analysis)
Meta-Analysis Review
Common and distinct neural correlates of facial emotion processing in social anxiety disorder and Williams syndrome: A systematic review and voxel-based meta-analysis of functional resonance imaging studies.
BACKGROUND
Social Anxiety Disorder (SAD) and Williams-Beuren Syndrome (WS) are two conditions which seem to be at opposite ends in the continuum of social fear but show compromised abilities in some overlapping areas, including some social interactions, gaze contact and processing of facial emotional cues. The increase in the number of neuroimaging studies has greatly expanded our knowledge of the neural bases of facial emotion processing in both conditions. However, to date, SAD and WS have not been compared.
METHODS
We conducted a systematic review of functional magnetic resonance imaging (fMRI) studies comparing SAD and WS cases to healthy control participants (HC) using facial emotion processing paradigms. Two researchers conducted comprehensive PubMed/Medline searches to identify all fMRI studies of facial emotion processing in SAD and WS. The following search key-words were used: "emotion processing"; "facial emotion"; "social anxiety"; "social phobia"; "Williams syndrome"; "neuroimaging"; "functional magnetic resonance"; "fMRI" and their combinations, as well as terms specifying individual facial emotions. We extracted spatial coordinates from each study and conducted two separate voxel-wise activation likelihood estimation meta-analyses, one for SAD and one for WS.
RESULTS
Twenty-two studies met the inclusion criteria: 17 studies of SAD and five of WS. We found evidence for both common and distinct patterns of neural activation. Limbic engagement was common to SAD and WS during facial emotion processing, although we observed opposite patterns of activation for each disorder. Compared to HC, SAD cases showed hyperactivation of the amygdala, the parahippocampal gyrus and the globus pallidus. Compared to controls, participants with WS showed hypoactivation of these regions. Differential activation in a number of regions specific to either condition was also identified: SAD cases exhibited greater activation of the insula, putamen, the superior temporal gyrus, medial frontal regions and the cuneus, while WS subjects showed decreased activation in the inferior region of the parietal lobule.
CONCLUSIONS
The identification of limbic structures as a shared correlate and the patterns of activation observed for each condition may reflect the aberrant patterns of facial emotion processing that the two conditions share, and may contribute to explaining part of the underlying neural substrate of exaggerated/diminished fear responses to social cues that characterize SAD and WS respectively. We believe that insights from WS and the inclusion of this syndrome as a control group in future experimental studies may improve our understanding of the neural correlates of social fear in general, and of SAD in particular.
Topics: Brain; Emotions; Facial Recognition; Humans; Magnetic Resonance Imaging; Phobia, Social
PubMed: 25194208
DOI: 10.1016/j.neuropsychologia.2014.08.027 -
Human Brain Mapping Apr 2023Specific subfields within the hippocampus have shown vulnerability to chronic stress, highlighting the importance of looking regionally within the hippocampus to...
Specific subfields within the hippocampus have shown vulnerability to chronic stress, highlighting the importance of looking regionally within the hippocampus to understand the role of psychosocial factors in the development of neurodegenerative diseases. A systematic review on psychosocial factors and hippocampal subfield volumes was performed and showed inconsistent results, highlighting the need for future studies to explore this relationship. The current study aimed to explore the association of psychosocial factors with hippocampal (subfield) volumes, using high-field 7T MRI. Data were from the Memory Depression and Aging (Medea)-7T study, which included 333 participants without dementia. Hippocampal subfields were automatically segmented from T2-weighted images using ASHS software. Generalized linear models accounting for correlated outcomes were used to assess the association between subfields (i.e., entorhinal cortex, subiculum, Cornu Ammonis [CA]1, CA2, CA3, dentate gyrus, and tail) and each psychosocial factor (i.e., depressive symptoms, anxiety symptoms, childhood maltreatment, recent stressful life events, and social support), adjusted for age, sex, and intracranial volume. Neither depression nor anxiety was associated with specific hippocampal (subfield) volumes. A trend for lower total hippocampal volume was found in those reporting childhood maltreatment, and a trend for higher total hippocampal volume was found in those who experienced a recent stressful life event. Among subfields, low social support was associated with lower volume in the CA3 (B = -0.43, 95% CI: -0.72; -0.15). This study suggests possible differential effects among hippocampal (subfield) volumes and psychosocial factors.
Topics: Humans; Organ Size; Hippocampus; CA1 Region, Hippocampal; Aging; Entorhinal Cortex; Magnetic Resonance Imaging
PubMed: 36583397
DOI: 10.1002/hbm.26185 -
Brain Sciences Aug 2022Deficits in social cognition and function are characteristic of dementia, commonly accompanied by a loss of awareness of the presence or extent of these deficits. This... (Review)
Review
Deficits in social cognition and function are characteristic of dementia, commonly accompanied by a loss of awareness of the presence or extent of these deficits. This lack of awareness can impair social relationships, increase patients' and carers' burden, and contribute to increased rates of institutionalization. Despite clinical importance, neural correlates of this complex phenomenon remain unclear. We conducted a systematic search of five electronic databases to identify functional and structural neuroimaging studies investigating the neural correlates of impaired awareness of social cognition and function in any dementia type. We rated study quality and conducted a narrative synthesis of the results of the eight studies that met the predefined eligibility criteria. Across these studies, deficits in awareness of impairments in social cognition and function were associated with structural or functional abnormalities in the frontal pole, orbitofrontal cortex, temporal pole, middle temporal gyrus, inferior temporal gyrus, fusiform gyrus, amygdala, hippocampus, parahippocampal gyrus, and insula. Several identified regions overlap with established neural correlates of social cognition. More research is needed to understand awareness of social cognition and function and how this becomes impaired in dementia to improve neuroscientific understanding, aid the identification of this problematic symptom, and target interventions to reduce burden and improve care.
PubMed: 36138872
DOI: 10.3390/brainsci12091136 -
PCN Reports : Psychiatry and Clinical... Mar 2023There are many neuroimaging studies of mild behavioral impairment (MBI), but the results have been somewhat inconsistent. Moreover, it remains unclear whether MBI is a... (Review)
Review
There are many neuroimaging studies of mild behavioral impairment (MBI), but the results have been somewhat inconsistent. Moreover, it remains unclear whether MBI is a risk factor or prodromal symptom of dementia. Therefore, a systematic review was conducted to summarize the results of neuroimaging studies of MBI and consider whether MBI is a prodromal symptom of dementia in terms of its neural correlates. A systematic review supported by a JSPS Grant-in-Aid for Scientific Research (C) was conducted using MBI neuroimaging studies identified using PubMed, PsycINFO, CINAHL, and Google Scholar on November 1, 2022. The inclusion criteria were (i) neuroimaging study; (ii) research on human subjects; (iii) papers written in English; and (iv) not a case study, review, book, comments, or abstract only. Joanna Briggs Institute critical appraisal checklists were used to assess the quality of selected studies, and 23 structural and functional imaging studies were ultimately included in the systematic review. The structural studies suggested an association of MBI with atrophy in the hippocampus, parahippocampal gyrus, entorhinal cortex, and temporal lobe, whereas the functional studies indicated involvement of an altered default mode network, frontoparietal control network, and salience network in MBI. A limitation in many studies was the use of region-of-interest analysis. The brain areas detected as neural correlates of MBI are considered to be alterations in the early stage of each dementia. Therefore, MBI may emerge against a background of pathological changes in dementia.
PubMed: 38868411
DOI: 10.1002/pcn5.81 -
Amyotrophic Lateral Sclerosis &... Jul 2023Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder associated with cognitive and behavioral impairments and motor symptoms. Magnetic resonance imaging... (Review)
Review
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder associated with cognitive and behavioral impairments and motor symptoms. Magnetic resonance imaging (MRI) biomarkers have been investigated as potential tools for detecting and monitoring memory-related impairment in ALS. Our objective was to examine the importance of identifying MRI biomarkers for memory-related impairment in ALS, motor neuron disease (MND), and ALS frontotemporal dementia (FTD) (ALS-FTD) patients. PubMed and Scopus databases were searched. Keywords covering magnetic resonance imaging, ALS, MND, and memory impairments were searched. There were a total of 25 studies included in our work here. The structural MRI (sMRI) studies reported gray matter (GM) atrophy in the regions associated with memory processing, such as the hippocampus and parahippocampal gyrus (PhG), in ALS patients. The diffusion tensor imaging (DTI) studies showed white matter (WM) alterations in the corticospinal tract (CST) and other tracts that are related to motor and extra-motor functions, and these alterations were associated with memory and executive function impairments in ALS. The functional MRI (fMRI) studies also demonstrated an altered activation in the prefrontal cortex, limbic system, and other brain regions involved in memory and emotional processing in ALS patients. MRI biomarkers show promise in uncovering the neural mechanisms of memory-related impairment in ALS. Nonetheless, addressing challenges such as sample sizes, imaging protocols, and longitudinal studies is crucial for future research. Ultimately, MRI biomarkers have the potential to be a tool for detecting and monitoring memory-related impairments in ALS.
PubMed: 37469125
DOI: 10.1080/21678421.2023.2236651 -
Progress in Neuro-psychopharmacology &... Dec 2022Reactive aggression in response to perceived threat or provocation is part of humans' adaptive behavioral repertoire. However, high levels of aggression can lead to the... (Meta-Analysis)
Meta-Analysis
Brain responses in aggression-prone individuals: A systematic review and meta-analysis of functional magnetic resonance imaging (fMRI) studies of anger- and aggression-eliciting tasks.
Reactive aggression in response to perceived threat or provocation is part of humans' adaptive behavioral repertoire. However, high levels of aggression can lead to the violation of social and legal norms. Understanding brain function in individuals with high levels of aggression as they process anger- and aggression-eliciting stimuli is critical for refining explanatory models of aggression and thereby improving interventions. Three neurobiological models of reactive aggression - the limbic hyperactivity, prefrontal hypoactivity, and dysregulated limbic-prefrontal connectivity models - have been proposed. However, these models are based on neuroimaging studies involving mainly non-aggressive individuals, leaving it unclear which model best describes brain function in those with a history of aggression. We conducted a systematic literature search (PubMed and Psycinfo) and Multilevel Kernel Density meta-analysis (MKDA) of nine functional magnetic resonance imaging (fMRI) studies (eight included in the between-group analysis [i.e., aggression vs. control groups], five in the within-group analysis). Studies examined brain responses to tasks putatively eliciting anger and aggression in individuals with a history of aggression alone and relative to controls. Individuals with a history of aggression exhibited greater activity in the superior temporal gyrus and in regions comprising the cognitive control and default mode networks (right posterior cingulate cortex, precentral gyrus, precuneus, right inferior frontal gyrus) during reactive aggression relative to baseline conditions. Compared to controls, individuals with a history of aggression exhibited increased activity in limbic regions (left hippocampus, left amygdala, left parahippocampal gyrus) and temporal regions (superior, middle, inferior temporal gyrus), and reduced activity in occipital regions (left occipital cortex, left calcarine cortex). These findings lend support to the limbic hyperactivity model in individuals with a history of aggression, and further indicate altered temporal and occipital activity in anger- and aggression-eliciting conditions involving face and speech processing.
Topics: Aggression; Anger; Brain; Brain Mapping; Humans; Magnetic Resonance Imaging; Prefrontal Cortex
PubMed: 35803398
DOI: 10.1016/j.pnpbp.2022.110596