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Neuroscience and Biobehavioral Reviews Sep 2023Whether remitted major depressive disorder (rMDD) and MDD present common or distinct neuropathological mechanisms remains unclear. We performed a meta-analysis of... (Meta-Analysis)
Meta-Analysis Review
Common and distinct patterns of task-related neural activation abnormalities in patients with remitted and current major depressive disorder: A systematic review and coordinate-based meta-analysis.
Whether remitted major depressive disorder (rMDD) and MDD present common or distinct neuropathological mechanisms remains unclear. We performed a meta-analysis of task-related whole-brain functional magnetic resonance imaging (fMRI) using anisotropic effect-size signed differential mapping software to compare brain activation between rMDD/MDD patients and healthy controls (HCs). We included 18 rMDD studies (458 patients and 476 HCs) and 120 MDD studies (3746 patients and 3863 HCs). The results showed that MDD and rMDD patients shared increased neural activation in the right temporal pole and right superior temporal gyrus. Several brain regions, including the right middle temporal gyrus, left inferior parietal, prefrontal cortex, left superior frontal gyrus and striatum, differed significantly between MDD and rMDD. Meta-regression analyses revealed that the percentage of females with MDD was positively associated with brain activity in the right lenticular nucleus/putamen. Our results provide valuable insights into the underlying neuropathology of brain dysfunction in MDD, developing more targeted and efficacious treatment and intervention strategies, and more importantly, providing potential neuroimaging targets for the early screening of MDD.
Topics: Female; Humans; Depressive Disorder, Major; Brain; Brain Mapping; Prefrontal Cortex; Temporal Lobe; Magnetic Resonance Imaging
PubMed: 37315658
DOI: 10.1016/j.neubiorev.2023.105284 -
Neuroscience and Biobehavioral Reviews Sep 2023This systematic review examined whether neural responses to visual food-cues measured by functional magnetic resonance imaging (fMRI) are influenced by physical... (Review)
Review
This systematic review examined whether neural responses to visual food-cues measured by functional magnetic resonance imaging (fMRI) are influenced by physical activity. Seven databases were searched up to February 2023 for human studies evaluating visual food-cue reactivity using fMRI alongside an assessment of habitual physical activity or structured exercise exposure. Eight studies (1 exercise training, 4 acute crossover, 3 cross-sectional) were included in a qualitative synthesis. Structured acute and chronic exercise appear to lower food-cue reactivity in several brain regions, including the insula, hippocampus, orbitofrontal cortex (OFC), postcentral gyrus and putamen, particularly when viewing high-energy-density food cues. Exercise, at least acutely, may enhance appeal of low-energy-density food-cues. Cross-sectional studies show higher self-reported physical activity is associated with lower reactivity to food-cues particularly of high-energy-density in the insula, OFC, postcentral gyrus and precuneus. This review shows that physical activity may influence brain food-cue reactivity in motivational, emotional, and reward-related processing regions, possibly indicative of a hedonic appetite-suppressing effect. Conclusions should be drawn cautiously given considerable methodological variability exists across limited evidence.
Topics: Humans; Cues; Cross-Sectional Studies; Food; Brain; Magnetic Resonance Imaging; Exercise
PubMed: 37236384
DOI: 10.1016/j.neubiorev.2023.105247 -
Behavioural Brain Research Oct 2023Social rewards (e.g., social feedback, praise, and social interactions) are fundamental to social learning and relationships across the life span. Exposure to social... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Social rewards (e.g., social feedback, praise, and social interactions) are fundamental to social learning and relationships across the life span. Exposure to social rewards is linked to activation in key brain regions, that are impaired in major depression. This is the first summary of neuroimaging literature on social reward processing in depressed and healthy individuals.
METHOD
We screened 409 studies and identified 25 investigating task-based fMRI activation during exposure to social stimuli in depressed and healthy populations across the lifespan. We conducted a systematic review followed by an Activation Likelihood Estimation (ALE) analysis of three main contrasts: a) positive social feedback vs. neutral stimuli; b) negative social feedback vs. neutral stimuli; c) positive vs. negative social feedback. We also compared activation patterns in depressed versus healthy controls.
RESULTS
Systematic review revealed that social rewards elicit increased activation in subcortical reward regions (NAcc, amygdala, ventral striatum, thalamus) in healthy and depressed individuals; and decreased activation in prefrontal reward regions (medial prefrontal cortex, orbitofrontal cortex) among depressed persons. Our meta-analysis showed, in both depressed and healthy individuals, increased cluster activation of the putamen and caudate in response to negative social stimuli vs. positive stimuli. We also found increased cluster activation in the inferior frontal gyrus (IFG) and the medial frontal gyrus (MFG) in healthy controls vs. depressed individuals, in response to negative social stimuli.
CONCLUSIONS
Processing of social stimuli elicits activation of key brain regions involved in affective and social information processing. Interventions for depression can increase social reward responsivity to improve outcomes.
Topics: Humans; Longevity; Magnetic Resonance Imaging; Neuroimaging; Depressive Disorder, Major; Reward
PubMed: 37598904
DOI: 10.1016/j.bbr.2023.114632 -
International Journal of General... 2023Diabetic chorea is a rare complication of diabetes mellitus for which head MRI is the most common diagnostic imaging modality. Cases have been reported where CT and/or... (Review)
Review
BACKGROUND
Diabetic chorea is a rare complication of diabetes mellitus for which head MRI is the most common diagnostic imaging modality. Cases have been reported where CT and/or MRI findings are inconsistent or clinical symptoms and imaging findings do not appear simultaneously. We aimed to compile the cases in which imaging findings appeared on MRI retests and to examine in a systematic review whether temporal differences in the appearance of imaging findings correlate with clinical characteristics.
CASE PRESENTATION
An 80-year-old man with type 2 diabetes mellitus came to a hospital with abnormal movements of the left upper and lower extremities. Two days after the first visit, his symptoms flared up, and his head MRI showed an old cerebral infarction and no new lesion. On day 14, he retested T1-weighted imaging and showed a high signal in the right putamen, which was considered diabetic chorea. Blood glucose was controlled with insulin, and the involuntary movements disappeared.
METHODS
PubMed and ICHUSHI were searched to identify patients with diabetic chorea who had undergone MRI retests. Patients grouped by the temporal change in the presence/absence of imaging findings were compared on age, sex, duration of diabetes mellitus, blood glucose level, HbA1c level, side of involuntary movement, time to first MRI, and follow-up MRI.
RESULTS
Of the 64 cases analyzed, 43 (67.2%) were female. The mean age was 69.0 years. 16 (25.0%) had worsening findings upon MRI retesting, 37 (57.8%) had improvement, and 10 (15.6%) had unchanged findings. There were no significant differences in age, sex, mean blood glucose level or HbA1c at onset among the groups.
CONCLUSION
There was no association between the pattern of appearance of imaging findings over time and clinical characteristics, including glucose levels. If initial MRI findings are negative, MRI retesting after a certain time may help diagnose diabetic chorea.
PubMed: 37808208
DOI: 10.2147/IJGM.S423400 -
NeuroImage. Clinical 2024Changes in eating behaviour including reductions in appetite and food intake, and healthier food cue reactivity, reward, hedonics and potentially also preference,... (Review)
Review
Changes in eating behaviour including reductions in appetite and food intake, and healthier food cue reactivity, reward, hedonics and potentially also preference, contribute to weight loss and its health benefits after obesity surgery. Functional magnetic resonance imaging (fMRI) has been increasingly used to interrogate the neural correlates of eating behaviour in obesity, including brain reward-cognitive systems, changes after obesity surgery, and links with alterations in the gut-hormone-brain axis. Neural responses to food cues can be measured by changes in blood oxygen level dependent (BOLD) signal in brain regions involved in reward processing, including caudate, putamen, nucleus accumbens, insula, amygdala, orbitofrontal cortex, and top-down inhibitory control, including dorsolateral prefrontal cortex (dlPFC). This systematic review aimed to examine: (i) results of human fMRI studies involving obesity surgery, (ii) important methodological differences in study design across studies, and (iii) correlations and associations of fMRI findings with clinical outcomes, other eating behaviour measures and mechanistic measures. Of 741 articles identified, 23 were eligible for inclusion: 16 (69.6%) longitudinal, two (8.7%) predictive, and five (21.7%) cross-sectional studies. Seventeen studies (77.3%) included patients having Roux-en-Y gastric bypass (RYGB) surgery, six (26.1%) vertical sleeve gastrectomy (VSG), and five (21.7%) laparoscopic adjustable gastric banding (LAGB). The majority of studies (86.0%) were identified as having a very low risk of bias, though only six (27.3%) were controlled interventional studies, with none including randomisation to surgical and control interventions. The remaining studies (14.0%) had a low risk of bias driven by their control groups not having an active treatment. After RYGB surgery, food cue reactivity often decreased or was unchanged in brain reward systems, and there were inconsistent findings as to whether reductions in food cue reactivity was greater for high-energy than low-energy foods. There was minimal evidence from studies of VSG and LAGB surgeries for changes in food cue reactivity in brain reward systems, though effects of VSG surgery on food cue reactivity in the dlPFC were more consistently found. There was consistent evidence for post-operative increases in satiety gut hormones glucagon-like-peptide 1 (GLP-1) and peptide YY (PYY) mediating reduced food cue reactivity after RYGB surgery, including two interventional studies. Methodological heterogeneity across studies, including nutritional state, nature of food cues, post-operative timing, lack of control groups for order effects and weight loss or dietary/psychological advice, and often small sample sizes, limited the conclusions that could be drawn, especially for correlational analyses with clinical outcomes, other eating behaviour measures and potential mediators. This systematic review provides a detailed data resource for those performing or analysing fMRI studies of obesity surgery and makes suggestions to help improve reporting and design of such studies, as well as future directions.
Topics: Humans; Cross-Sectional Studies; Obesity; Feeding Behavior; Magnetic Resonance Imaging; Weight Loss
PubMed: 38237270
DOI: 10.1016/j.nicl.2024.103563 -
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 -
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 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 -
International Journal of Developmental... Jun 2024Grey matter, a crucial component of the brain, has been found altered in generalized anxiety disorder (GAD) of several voxel-based morphometry studies. The conclusive... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
Grey matter, a crucial component of the brain, has been found altered in generalized anxiety disorder (GAD) of several voxel-based morphometry studies. The conclusive and consistent grey matter alterations in GAD have not been confirmed.
METHOD
Eleven voxel-based morphometry studies of GAD patients were included in the current systematic review and meta-analysis. The linear model of anxiety severity scores was applied to explore the relationship of grey matter alterations and anxiety severity. The subgroup analysis of adult GAD and adolescent GAD was also performed.
RESULTS
Significantly modest grey matter alterations in the left superior temporal gyrus of patients with GAD were found. The anxiety severity score was significantly correlated with grey matter alterations in the right insula, lenticular nucleus, putamen and striatum. The subgroup analysis of adult GAD and adolescent GAD all failed to show significant grey matter alterations. However, in the adult GAD subgroup, anxiety severity score was significantly correlated with grey matter alterations in the right insula.
CONCLUSION
GAD might have the modest grey matter alterations in the left superior temporal gyrus. Anxiety severity might be related to the grey matter alterations in the limbic regions, such as the right insula, lenticular nucleus, putamen and striatum. This kind of correlation might be related to the effects of adult GAD. Future studies with adequate sample sizes and sophisticated GAD categories will be needed.
Topics: Humans; Gray Matter; Anxiety Disorders; Magnetic Resonance Imaging; Brain; Adult; Image Processing, Computer-Assisted; Adolescent
PubMed: 38638086
DOI: 10.1002/jdn.10330 -
Brain and Behavior Dec 2023Posttraumatic stress disorder (PTSD) is a complex and heterogeneous mental health condition that can develop after exposure to a traumatic event. Clinical trials have... (Review)
Review
BACKGROUND
Posttraumatic stress disorder (PTSD) is a complex and heterogeneous mental health condition that can develop after exposure to a traumatic event. Clinical trials have used alternative pharmacological agents to treat PTSD, but their associated neural correlates remain unclear. The present systematic review aims to summarize the changes in brain function associated with the use of these alternative pharmacological agents in PTSD.
METHODS
Clinical trials using functional magnetic resonance imaging, either at rest or during the performance of tasks, were included if they compared the effects of alternative pharmacological agents between PTSD patients and either trauma-exposed controls or never-exposed healthy controls.
RESULTS
Sixteen studies were included, of which 11 used intranasal oxytocin, 2 used hydrocortisone, and 3 used delta-9-tetrahydrocannabinol (THC). Oxytocin administration was associated with the normalization of functional connectivity between the ventromedial prefrontal cortex and amygdala as well as enhanced the function of brain regions specifically involved in emotion processing (e.g., amygdala), working memory (e.g., dorsolateral prefrontal cortex), and reward (e.g., putamen). Hydrocortisone did not influence brain function at rest or during the performance of an autobiographical memory task, whereas THC was associated with the reduction of the amygdala and increased medial prefrontal cortex activation.
CONCLUSIONS
This systematic review identified preliminary evidence for normalizing brain function after the use of alternative pharmacological agents. Importantly, sex-specific differences were noted, in particular when using oxytocin, that will require further investigation.
Topics: Female; Humans; Male; Brain; Emotions; Hydrocortisone; Magnetic Resonance Imaging; Oxytocin; Stress Disorders, Post-Traumatic; Clinical Trials as Topic
PubMed: 37864378
DOI: 10.1002/brb3.3292