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Journal of Personalized Medicine Jul 2023COVID-19 affects brain function, as deduced by the "brain fog" that is often encountered in COVID-19 patients and some cognitive impairment that is observed in many a... (Review)
Review
COVID-19 affects brain function, as deduced by the "brain fog" that is often encountered in COVID-19 patients and some cognitive impairment that is observed in many a patient in the post-COVID-19 period. Approximately one-third of patients, even when they have recovered from the acute somatic disease, continue to show posttraumatic stress disorder (PTSD) symptoms. We hypothesized that the persistent changes induced by COVID-19 on brain structure would overlap with those associated with PTSD. We performed a thorough PubMed search on 25 April 2023 using the following strategy: ((posttraumatic OR PTSD) AND COVID-19 AND (neuroimaging OR voxel OR VBM OR freesurfer OR structural OR ROI OR whole-brain OR hippocamp* OR amygd* OR "deep gray matter" OR "cortical thickness" OR caudate OR striatum OR accumbens OR putamen OR "regions of interest" OR subcortical)) OR (COVID-19 AND brain AND (voxel[ti] OR VBM[ti] OR magnetic[ti] OR resonance[ti] OR imaging[ti] OR neuroimaging[ti] OR neuroimage[ti] OR positron[ti] OR photon*[ti] OR PET[ti] OR SPET[ti] OR SPECT[ti] OR spectroscop*[ti] OR MRS[ti])), which produced 486 records and two additional records from other sources, of which 36 were found to be eligible. Alterations were identified and described and plotted against the ordinary PTSD imaging findings. Common elements were hypometabolism in the insula and caudate nucleus, reduced hippocampal volumes, and subarachnoid hemorrhages, while white matter hyperintensities were widespread in both PTSD and post-COVID-19 brain infection. The comparison partly supported our initial hypothesis. These data may contribute to further investigation of the effects of long COVID on brain structure and function.
PubMed: 37511753
DOI: 10.3390/jpm13071140 -
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 -
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 -
Brain Research Aug 2020The progressive changes of brain structure in patients with Parkinson's disease (PD) remain controversial. To identify this controversy, a systematic review and... (Meta-Analysis)
Meta-Analysis
The progressive changes of brain structure in patients with Parkinson's disease (PD) remain controversial. To identify this controversy, a systematic review and meta-analysis of longitudinal magnetic resonance imaging studies in brain volume was performed. The percentage of volume change over time between patients with PD and healthy subjects of each brain region of interest was obtained. In total, 11 studies, comprising 833 cases (463 patients with PD and 370 healthy control subjects), were included for systematic review and meta-analysis. Ten brain regions were involved. Patients with PD in comparison with healthy controls showed significant progressive reductions in whole gray matter and caudate, putamen, accumbens, and amygdala volumes. Significant whole-brain atrophy from PD was also associated with cognitive dysfunction. The annual percentage of volume loss was -1.04% in whole-brain volume with cognitive decline, -1.16% in whole-brain volume in PD compared to PD with cognitive decline, -0.29% for whole gray matter, -0.62% for caudate, -0.97% for putamen, -3.55% for amygdala, and -5.40% for accumbens in patients with PD versus control subjects. Overall, our findings suggest that PD is related to progressive, regional brain atrophy, mainly affecting gray matter. However, due to existing confounding factors, the limited number of included studies, significant heterogeneity, and defective study design, the results should be interpreted with caution. Further confirmation is required by more studies with strict design, large samples, and unified paradigm.
Topics: Brain; Disease Progression; Humans; Magnetic Resonance Imaging; Parkinson Disease
PubMed: 32330518
DOI: 10.1016/j.brainres.2020.146847 -
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 Alzheimer's Disease : JAD 2022Affecting nearly half of the patients with Alzheimer's disease (AD), apathy is associated with higher morbidity and reduced quality of life. Basal ganglia and cortical... (Meta-Analysis)
Meta-Analysis
Cerebral Volumetric Correlates of Apathy in Alzheimer's Disease and Cognitively Normal Older Adults: Meta-Analysis, Label-Based Review, and Study of an Independent Cohort.
BACKGROUND
Affecting nearly half of the patients with Alzheimer's disease (AD), apathy is associated with higher morbidity and reduced quality of life. Basal ganglia and cortical atrophy have been implicated in apathy. However, the findings have varied across studies and left unclear whether subdomains of apathy may involve distinct neuroanatomical correlates.
OBJECTIVE
To identify neuroanatomical correlates of AD-associated apathy.
METHODS
We performed a meta-analysis and label-based review of the literature. Further, following published routines of voxel-based morphometry, we aimed to confirm the findings in an independent cohort of 19 patients with AD/mild cognitive impairment and 25 healthy controls assessed with the Apathy Evaluation Scale.
RESULTS
Meta-analysis of 167 AD and 56 healthy controls showed convergence toward smaller basal ganglia gray matter volume (GMV) in apathy. Label-based review showed anterior cingulate, putamen, insula, inferior frontal gyrus (IFG) and middle temporal gyrus (MTG) atrophy in AD apathy. In the independent cohort, with small-volume-correction, right putamen and MTG showed GMVs in negative correlation with Apathy Evaluation Scale total, behavioral, and emotional scores, and right IFG with emotional score (p < 0.05 family-wise error (FWE)-corrected), controlling for age, education, intracranial volume, and depression. With the Mini-Mental State Examination scores included as an additional covariate, the correlation of right putamen GMV with behavioral and emotional score, right MTG GMV with total and emotional score, and right IFG GMV with emotional score were significant.
CONCLUSION
The findings implicate putamen, MTG and IFG atrophy in AD associated apathy, potentially independent of cognitive impairment and depression, and suggest potentially distinct volumetric correlates of apathy.
Topics: Aged; Alzheimer Disease; Apathy; Atrophy; Basal Ganglia; Brain; Cognitive Dysfunction; Cohort Studies; Gray Matter; Gyrus Cinguli; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Prefrontal Cortex
PubMed: 34924392
DOI: 10.3233/JAD-215316 -
Frontiers in Psychiatry 2022Obsessive-compulsive disorder (OCD) is characterized by recurrent distressing thoughts and repetitive behaviors, or mental rituals performed to reduce anxiety. Recent...
INTRODUCTION
Obsessive-compulsive disorder (OCD) is characterized by recurrent distressing thoughts and repetitive behaviors, or mental rituals performed to reduce anxiety. Recent neurobiological techniques have been particularly convincing in suggesting that cortico-striatal-thalamic-cortico (CSTC) circuits, including orbitofrontal cortex (OFC) and striatum regions (caudate nucleus and putamen), are responsible for mediation of OCD symptoms. However, it is still unclear how these regions are affected by OCD treatments in adult patients. To address this yet open question, we conducted a systematic review of all studies examining neurobiological changes before and after first-line psychological OCD treatment, i.e., cognitive-behavioral therapy (CBT).
METHODS
Studies were included if they were conducted in adults with OCD and they assessed the neurobiological effects of CBT before and after treatment. Two databases were searched: PsycINFO and PubMed for the time frame up to May 2022.
RESULTS
We obtained 26 pre-post CBT treatment studies performed using different neurobiological techniques, namely functional magnetic resonance imaging (fMRI), Positron emission tomography (PET), regional cerebral blood flow (rCBF), 5-HT concentration, magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), Electroencephalography (EEG). Neurobiological data show the following after CBT intervention: (i) reduced activations in OFC across fMRI, EEG, and rCBF; (ii) decreased activity in striatum regions across fMRI, rCBF, PET, and MRI; (iii) increased activations in cerebellum (CER) across fMRI and MRI; (iv) enhanced neurochemical concentrations in MRS studies in OFC, anterior cingulate cortex (ACC) and striatum regions. Most of these neurobiological changes are also accompanied by an improvement in symptom severity as assessed by a reduction in the Y-BOCS scores.
CONCLUSION
Cognitive-behavioral therapy seems to be able to restructure, modify, and transform the neurobiological component of OCD, in addition to the clinical symptoms. Nevertheless, further studies are necessary to frame the OCD spectrum in a dimensional way.
PubMed: 36569616
DOI: 10.3389/fpsyt.2022.1063116 -
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 -
Frontiers in Neuroscience 2023Neuroimaging studies have identified aberrant activity patterns in multiple brain regions in functional dyspepsia (FD) patients. However, due to the differences in study...
BACKGROUND
Neuroimaging studies have identified aberrant activity patterns in multiple brain regions in functional dyspepsia (FD) patients. However, due to the differences in study design, these previous findings are inconsistent, and the underlying neuropathological characteristics of FD remain unclear.
METHODS
Eight databases were systematically searched for literature from inception to October 2022 with the keywords "Functional dyspepsia" and "Neuroimaging." Thereafter, the anisotropic effect size signed the differential mapping (AES-SDM) approach that was applied to meta-analyze the aberrant brain activity pattern of FD patients.
RESULTS
A total of 11 articles with 260 FD patients and 202 healthy controls (HCs) were included. The AES-SDM meta-analysis demonstrated that FD patients manifested increased activity in the bilateral insula, left anterior cingulate gyrus, bilateral thalamus, right precentral gyrus, left supplementary motor area, right putamen, and left rectus gyrus and decreased functional activity in the right cerebellum compared to the HCs. Sensitivity analysis showed that all these above regions were highly reproducible, and no significant publication bias was detected.
CONCLUSION
The current study demonstrated that FD patients had significantly abnormal activity patterns in several brain regions involved in visceral sensation perception, pain modulation, and emotion regulation, which provided an integrated insight into the neuropathological characteristics of FD.
PubMed: 37250423
DOI: 10.3389/fnins.2023.1174287 -
PloS One 2020Iron is involved in many processes in the brain including, myelin generation, mitochondrial function, synthesis of ATP and DNA and the cycling of neurotransmitters....
Iron is involved in many processes in the brain including, myelin generation, mitochondrial function, synthesis of ATP and DNA and the cycling of neurotransmitters. Disruption of normal iron homeostasis can result in iron accumulation in the brain, which in turn can partake in interactions which amplify oxidative damage. The development of MRI techniques for quantifying brain iron has allowed for the characterisation of the impact that brain iron has on cognition and neurodegeneration. This review uses a systematic approach to collate and evaluate the current literature which explores the relationship between brain iron and cognition. The following databases were searched in keeping with a predetermined inclusion criterion: Embase Ovid, PubMed and PsychInfo (from inception to 31st March 2020). The included studies were assessed for study characteristics and quality and their results were extracted and summarised. This review identified 41 human studies of varying design, which statistically assessed the relationship between brain iron and cognition. The most consistently reported interactions were in the Caudate nuclei, where increasing iron correlated poorer memory and general cognitive performance in adulthood. There were also consistent reports of a correlation between increased Hippocampal and Thalamic iron and poorer memory performance, as well as, between iron in the Putamen and Globus Pallidus and general cognition. We conclude that there is consistent evidence that brain iron is detrimental to cognitive health, however, more longitudinal studies will be required to fully understand this relationship and to determine whether iron occurs as a primary cause or secondary effect of cognitive decline.
Topics: Adult; Aged; Aged, 80 and over; Brain; Child; Cognition; Female; Humans; Iron; Male; Middle Aged
PubMed: 33057378
DOI: 10.1371/journal.pone.0240697