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American Journal of Human Biology : the... Dec 2023Resilience or the capacity to "bend but not break" refers to the ability to maintain or regain psychobiological equilibrium during or after exposure to stressful life... (Review)
Review
Resilience or the capacity to "bend but not break" refers to the ability to maintain or regain psychobiological equilibrium during or after exposure to stressful life events. Specifically, resilience has been proposed as a potential resource for staving off pathological states that often emerge after exposure to repeated stress and that are related to alterations in circulating cortisol. The aim of this systematic review of the literature was to gather evidence related to the relationship between psychological resilience and cortisol levels in adult humans. An extensive systematic search was carried out following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method in the PubMed and Web of Science databases. In total, 1256 articles were identified and, of these, 35 peer-reviewed articles were included in the systematic review. We categorized findings according to (1) the short and long-term secretion period covered by the cortisol matrices selected by studies and also according to (2) the differentiated diurnal, phasic (acute), and tonic (basal) components of the HPA output to which they refer and their relationships with resilience. Reported relationships between psychological resilience and distinct cortisol output parameters varied widely across studies, finding positive, negative, and null associations between the two variables. Notably, several of the studies that found no relationship between resilience and cortisol used a single morning saliva or plasma sample as their assessment of HPA axis activity. Despite limitations such as the great variability of the instruments and methods used by the studies to measure both resilience and cortisol, together with their high heterogeneity and small sample sizes, the evidence found in this systematic review points to the potential of resilience as a modifiable key factor to modulate the physiological response to stress. Therefore, further exploration of the interaction between the two variables is necessary for the eventual development of future interventions aimed at promoting resilience as an essential component of health prevention.
Topics: Adult; Humans; Resilience, Psychological; Hydrocortisone; Hypothalamo-Hypophyseal System; Pituitary-Adrenal System; Saliva; Stress, Psychological
PubMed: 37395446
DOI: 10.1002/ajhb.23954 -
Neuroscience and Biobehavioral Reviews Jan 2022Dissociative disorders (DD) and conversion disorders (CD) are frequent in general and psychiatric populations. Some evidence suggest that the hypothalamic-pituitary axis... (Review)
Review
Dissociative disorders (DD) and conversion disorders (CD) are frequent in general and psychiatric populations. Some evidence suggest that the hypothalamic-pituitary axis (HPA) and autonomic nervous system (ANS) are dysregulated in both disorders. We carried out a systematic review of the literature to summarize the existing knowledge on the stress response, via HPA and/or ANS, in patients with DD, CD, or dissociative symptoms. We systematically searched Medline and Web of Science using the Medical Subject Headings related to stress axis, CD, DD, and dissociative symptoms following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Results suggest that in participants without psychiatric history, high cortisol secretion is related to high dissociation scores. Conversely the stress system might be blunted in patients with post-traumatic stress disorder who develop dissociative symptoms. Stress response changes seem to be associated with the emergence and persistence of dissociative and conversion disorders. Hence, monitoring the stress response and examining closely the history of stress exposure in DD and CD should be encouraged in future larger studies.
Topics: Autonomic Nervous System; Conversion Disorder; Dissociative Disorders; Humans; Hypothalamo-Hypophyseal System; Pituitary-Adrenal System; Stress Disorders, Post-Traumatic
PubMed: 34740754
DOI: 10.1016/j.neubiorev.2021.10.049 -
Neuroscience and Biobehavioral Reviews Jun 2021An integrated view of the stress response requires consideration of both the emotional and hormonal sequelae of stress, which are regulated by the... (Meta-Analysis)
Meta-Analysis Review
An integrated view of the stress response requires consideration of both the emotional and hormonal sequelae of stress, which are regulated by the hypothalamic-pituitary-adrenal (HPA) axis. Understanding the extent of the association between emotions and cortisol at the momentary level can shed light on the biopsychological pathways linking stress to health. Research in this area has adopted heterogeneous approaches and produced mixed findings; thus, it is critical to conduct a systematic review and meta-analysis. Systematic searches in major databases identified 22 studies (negative emotions [k = 19; 38,418 momentary observations]; positive emotions [k = 15; 31,721 momentary observations]). Meta-analysis found a significant positive association between momentary negative emotions and cortisol (r = .06, p < .001) and a significant negative association between momentary positive emotions and cortisol (r = -.05, p = .003). No methodological differences moderated these associations. Our findings suggest that emotional states correlate with cortisol levels at the momentary level. We discuss the health implications of our findings and provide recommendations for advancing this area of research.
Topics: Ecological Momentary Assessment; Emotions; Humans; Hydrocortisone; Hypothalamo-Hypophyseal System; Pituitary-Adrenal System; Saliva; Stress, Psychological
PubMed: 33662445
DOI: 10.1016/j.neubiorev.2021.02.042 -
Behavioural Brain Research Oct 2023SARS-CoV-2 infection produces a wide range of symptoms. Some of the structural changes caused by the virus in the nervous system are found in the medial temporal lobe,... (Review)
Review
SARS-CoV-2 infection produces a wide range of symptoms. Some of the structural changes caused by the virus in the nervous system are found in the medial temporal lobe, and several neuropsychological sequelae of COVID-19 are related to the function of the hippocampus. The main objective of the systematic review is to update and further analyze the existing evidence of hippocampal and related cortices' structural and functional alterations due to SARS-CoV-2 infection. Both clinical and preclinical studies that used different methodologies to explore the effects of this disease at different stages and grades of severity were considered, besides exploring related cognitive and emotional symptomatology. A total of 24 studies were identified by searching in SCOPUS, Web Of Science (WOS), PubMed, and PsycInfo databases up to October 3rd, 2022. Thirteen studies were performed in clinical human samples, 9 included preclinical animal models, 3 were performed post-mortem, and 1 included both post-mortem and preclinical samples. Alterations in the hippocampus were detected in the acute stage and after several months of infection. Clinical studies revealed alterations in hippocampal connectivity and metabolism. Memory alterations correlated with altered metabolic profiles or changes in grey matter volumes. Hippocampal human postmortem and animal studies observed alterations in neurogenesis, dendrites, and immune response, besides high apoptosis and neuroinflammation. Preclinical studies reported the viral load in the hippocampus. Olfactory dysfunction was associated with alterations in brain functionality. Several clinical studies revealed cognitive complaints, neuropsychological alterations, and depressive and anxious symptomatology.
Topics: Animals; Humans; COVID-19; SARS-CoV-2; Hippocampus; Temporal Lobe
PubMed: 37703951
DOI: 10.1016/j.bbr.2023.114662 -
Neurosciences (Riyadh, Saudi Arabia) Jul 2015The relationship of the occipital lobe of the brain with schizophrenia is not commonly studied; however, this topic is considered an essential subject matter among... (Review)
Review
The relationship of the occipital lobe of the brain with schizophrenia is not commonly studied; however, this topic is considered an essential subject matter among clinicians and scientists. We conducted this systematic review to elaborate the relationship in depth. We found that most schizophrenic patients show normal occipital anatomy and physiology, a minority showed dwindled values, and some demonstrated augmented function and structure. The findings are laborious to incorporate within single disease models that present the involvement of the occipital lobe in schizophrenia. Schizophrenia progresses clinically in the mid-twenties and thirties and its prognosis is inadequate. Changes in the volume, the gray matter, and the white matter in the occipital lobe are quite evident; however, the mechanism behind this involvement is not yet fully understood. Therefore, we recommend further research to explore the occipital lobe functions and volumes across the different stages of schizophrenia.
Topics: Humans; Magnetic Resonance Imaging; Occipital Lobe; Schizophrenia
PubMed: 26166588
DOI: 10.17712/nsj.2015.3.20140757 -
Ageing Research Reviews Aug 2023Social health factors (e.g., social activities or social support) and cognitive activity engagement have been associated with dementia risk, but their neural substrates... (Meta-Analysis)
Meta-Analysis Review
Social health factors (e.g., social activities or social support) and cognitive activity engagement have been associated with dementia risk, but their neural substrates have not been well established. This systematic review and meta-analysis summarizes the available evidence regarding the association between these factors and cerebral macro- and micro-structure. A comprehensive literature search was conducted in various databases, following predefined criteria. Heterogeneity, risk of publication bias and overall certainty of evidence were assessed using standardized scales and, whenever appropriate, random effects meta-analysis was conducted. Of 6715 identified articles, 43 were included. Overall, consistency of findings was low and methodological heterogeneity high for all outcomes. However, in some studies cognitive and social activities were positively associated with total brain, global and cortical grey matter and hippocampal volume as well as white matter microstructural integrity. Furthermore, structural social network characteristics (e.g., social network size) were associated with regional grey matter volumes, while functional social network characteristics (e.g., social support) were additionally associated with total brain volume. Meta-analyses revealed small but significant partial correlations between cognitive and social activities and hippocampal (three studies; n = 892; r =0.07) and white matter hyperintensity volume (three studies; n = 2934; r =-0.04). More prospective studies are needed to assess temporal associations.
Topics: Humans; Brain; Hippocampus; Prospective Studies; Cognition
PubMed: 37356551
DOI: 10.1016/j.arr.2023.101986 -
Molecular Autism Apr 2024This meta-analysis aimed to explore the most robust findings across numerous existing resting-state functional imaging and voxel-based morphometry (VBM) studies on the... (Meta-Analysis)
Meta-Analysis
BACKGROUND
This meta-analysis aimed to explore the most robust findings across numerous existing resting-state functional imaging and voxel-based morphometry (VBM) studies on the functional and structural brain alterations in individuals with autism spectrum disorder (ASD).
METHODS
A whole-brain voxel-wise meta-analysis was conducted to compare the differences in the intrinsic functional activity and gray matter volume (GMV) between individuals with ASD and typically developing individuals (TDs) using Seed-based d Mapping software.
RESULTS
A total of 23 functional imaging studies (786 ASD, 710 TDs) and 52 VBM studies (1728 ASD, 1747 TDs) were included. Compared with TDs, individuals with ASD displayed resting-state functional decreases in the left insula (extending to left superior temporal gyrus [STG]), bilateral anterior cingulate cortex/medial prefrontal cortex (ACC/mPFC), left angular gyrus and right inferior temporal gyrus, as well as increases in the right supplementary motor area and precuneus. For VBM meta-analysis, individuals with ASD displayed decreased GMV in the ACC/mPFC and left cerebellum, and increased GMV in the left middle temporal gyrus (extending to the left insula and STG), bilateral olfactory cortex, and right precentral gyrus. Further, individuals with ASD displayed decreased resting-state functional activity and increased GMV in the left insula after overlapping the functional and structural differences.
CONCLUSIONS
The present multimodal meta-analysis demonstrated that ASD exhibited similar alterations in both function and structure of the insula and ACC/mPFC, and functional or structural alterations in the default mode network (DMN), primary motor and sensory regions. These findings contribute to further understanding of the pathophysiology of ASD.
Topics: Humans; Autism Spectrum Disorder; Brain; Cerebral Cortex; Gray Matter; Gyrus Cinguli; Magnetic Resonance Imaging
PubMed: 38576034
DOI: 10.1186/s13229-024-00593-6 -
Brain Imaging and Behavior Dec 2023The hippocampus is a complex structure that consists of several subfields with distinct and specialized functions. Although numerous studies have been performed to... (Meta-Analysis)
Meta-Analysis Review
The hippocampus is a complex structure that consists of several subfields with distinct and specialized functions. Although numerous studies have been performed to explore hippocampal atrophy at the sub-regional level in mild cognitive impairment (MCI) and Alzheimer's disease (AD), the results have been inconsistent especially for whether and which subfields can be served as the most potential biomarkers in MCI and AD. Herein, we used a meta-analytic approach to synthesize the extant literatures on hippocampal subfields in MCI and AD through PubMed, Web of Science, and Embase (PROSPERO CRD42021257586). As a result, a total of twenty studies using Freesurfer 5 and Freesurfer 6 were included in this investigation. These studies revealed that at the sub-regional level, hippocampal subfield volume reductions in MCI and AD were not restricted to specific subfields, and subiculum and presubiculum had the largest z-scores across most comparisons. However, none of the subfield performed much better in discriminating MCI and HC, AD and MCI, AD and HC as compared to whole hippocampus volume. These results suggested that we should explore the changes in the hippocampal subfields in subtypes of MCI or even at an earlier stage, that is subjective cognitive impairment.
Topics: Humans; Alzheimer Disease; Magnetic Resonance Imaging; Cognitive Dysfunction; Hippocampus; Atrophy
PubMed: 37768441
DOI: 10.1007/s11682-023-00804-3 -
World Neurosurgery Mar 2021Lesioning the Forel field or the subthalamic region is considered a possible treatment for tremoric patients with Parkinson disease, essential tremor, and other...
BACKGROUND
Lesioning the Forel field or the subthalamic region is considered a possible treatment for tremoric patients with Parkinson disease, essential tremor, and other diseases. This surgical treatment was performed in the 1960s to 1970s and was an alternative to thalamotomy. Recently, there has been increasing interest in the reappraisal of stimulating and/or lesioning these targets, partly as a result of innovations in imaging and noninvasive ablative technologies, such as magnetic resonance-guided focused ultrasonography.
OBJECTIVE
We wanted to perform a thorough review of the subthalamic region, both from an anatomic and a surgical standpoint, to offer a comprehensive and updated analysis of the techniques and results reported for patients with tremor treated with different techniques.
METHODS
We performed a systematic review of the literature, gathering articles that included patients who underwent ablative or stimulation surgical techniques, targeting the pallidothalamic pathways (pallidothalamic tractotomy), cerebellothalamic pathway (cerebellothalamic tractotomy), or subthalamic area.
RESULTS
Pallidothalamic tractotomy consists of a reduced area that includes pallidofugal pathways. It may be considered an interesting target, given the benefit/risk ratio and the clinical effect, which, compared with pallidotomy, involves a lower risk of injury or involvement of vital structures such as the internal capsule or optic tract. Cerebellothalamic tractotomy and/or posterior subthalamic area are other alternative targets to thalamic stimulation or ablative surgery.
CONCLUSIONS
Based on the significant breakthrough that magnetic resonance-guided focused ultrasonography has meant in the neurosurgical world, some classic targets such as the pallidothalamic tract, Forel field, and posterior subthalamic area may be reconsidered as surgical alternatives for patients with movement disorders.
Topics: Cerebellum; Deep Brain Stimulation; Essential Tremor; Globus Pallidus; Humans; Implantable Neurostimulators; Neural Pathways; Parkinson Disease; Prosthesis Implantation; Radiofrequency Ablation; Subthalamus; Thalamus; Tremor; Ultrasonic Surgical Procedures
PubMed: 33276174
DOI: 10.1016/j.wneu.2020.11.143 -
Psychoneuroendocrinology Nov 2022Childhood exposure to violence has been consistently linked to externalizing behaviors like delinquency and aggression. Growing evidence indicates that physiological... (Review)
Review
Childhood exposure to violence has been consistently linked to externalizing behaviors like delinquency and aggression. Growing evidence indicates that physiological biomarkers from the parasympathetic and sympathetic nervous systems (PNS and SNS) and hypothalamic-pituitary-adrenal (HPA) axis may moderate or mediate the relation between childhood violence exposure and externalizing behaviors. We conducted a systematic review to synthesize recent findings on physiological biomarkers as mediators and/or moderators of this association across the life course, using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Our search yielded 3878 articles, of which 44 met inclusion criteria (describing a total of 46 independent studies). We found consistent evidence for blunted HPA-axis reactivity as a mediator of the relation between childhood violence exposure and subsequent externalizing behaviors, and for non-reciprocal PNS/SNS activation as moderators exacerbating this relation. However, the results of the majority of included studies that demonstrated significant moderating effects of physiological biomarkers varied by participant sex, type of childhood violence exposure, and type of stimuli used to induce physiological reactivity. The observed mixed findings are consistent with some theories that emphasize that both high and low stress reactivity can be adaptive depending on one's early environment. These findings highlight the need for systematic explorations of heterogeneity, theory-driven research questions, and longitudinal studies that span multiple developmental periods and multiple biological systems. Clinical implications include the need to assess physiological biomarkers in treatment and intervention studies and the potential to target interventions based on both autonomic functioning and environmental contexts.
Topics: Aggression; Biomarkers; Exposure to Violence; Humans; Hypothalamo-Hypophyseal System; Pituitary-Adrenal System; Stress, Psychological
PubMed: 36087419
DOI: 10.1016/j.psyneuen.2022.105898