Decreased grey matter volume in dorsolateral prefrontal cortex and thalamus accompanied by compensatory increases in middle cingulate gyrus of premature ejaculation patients

INTRODUCTION

The prefrontal-cingulate-thalamic areas are associated with ejaculation control. Functional abnormalities of these areas and decreased grey matter volume (GMV) in the subcortical areas have been confirmed in premature ejaculation (PE) patients. However, no study has explored the corresponding GMV changes in the prefrontal-cingulate-thalamic areas, which are considered as the important basis for functional abnormalities. This study aimed to investigated whether PE patients exhibited impaired GMV in the brain, especially the prefrontal-cingulate-thalamic areas, and whether these structural deficits were associated with declined ejaculatory control.

METHODS

T1-weighted structural magnetic resonance imaging (MRI) data were acquired from 50 lifelong PE patients and 50 age-, and education-matched healthy controls (HCs). The PE diagnostic tool (PEDT) was applied to assess the subjective symptoms of PE. Based on the method of voxel-based morphometry (VBM), GMV were measured and compared between groups. In addition, the correlations between GMV of brain regions showed differences between groups and PEDT scores were evaluated in the patient group.

RESULTS

PE patients showed decreased GMV in the right dorsolateral superior frontal gyrus (clusters = 13, peak T-values = -4.30) and left thalamus (clusters = 47, T = -4.33), and increased GMV in the left middle cingulate gyrus (clusters = 12, T = 4.02) when compared with HCs. In the patient group, GMV of the left thalamus were negatively associated with PEDT scores (r = -0.35; P = 0.01). Receiver operating characteristic (ROC) analysis showed that GMV of the right dorsolateral superior frontal gyrus (AUC = 0.71, P < 0.01, sensitivity = 60%, specificity = 78%), left thalamus (AUC = 0.72, P < 0.01, sensitivity = 92%, specificity = 46%) and middle cingulate gyrus (AUC = 0.69, P < 0.01, sensitivity = 50%, specificity = 90%), and the combined model (AUC = 0.84, P < 0.01, sensitivity = 78%, specificity = 80%) all had the ability to distinguish PE patients from HCs.

CONCLUSION

Disturbances in GMV were revealed in the prefrontal-cingulate-thalamic areas of PE patients. The findings implied that decreased GMV in the dorsolateral prefrontal cortex and thalamus might be associated with the central pathological neural mechanism underlying the declined ejaculatory control while increased GMV in the middle cingulate gyrus might be the compensatory mechanism underlying PE.

Functional and Structural Abnormalities in the Pain Network of Generalized Anxiety Disorder Patients with Pain Symptoms

Pain symptoms significantly impact the well-being and work capacity of individuals with generalized anxiety disorder (GAD), and hinder treatment and recovery. Despite existing literature focusing on the neural substrate of pain and anxiety separately, further exploration is needed to understand the possible neuroimaging mechanisms of the pain symptoms in GAD patients. We recruited 73 GAD patients and 75 matched healthy controls (HC) for clinical assessments, as well as resting-state functional and structural magnetic resonance imaging scans. We defined a pain-related network through a published meta-analysis, including the insula, thalamus, periaqueductal gray, prefrontal cortex, anterior cingulate cortex, amygdala, and hippocampus. Subsequently, we conducted the regional homogeneity (ReHo) and the gray matter volume (GMV) within the pain-related network. Correlation analysis was then employed to explore associations between abnormal regions and self-reported outcomes, assessed using the Patient Health Questionnaire-15 (PHQ-15) and pain scores. We observed significantly increased ReHo in the bilateral insula but decreased GMV in the bilateral thalamus of GAD compared to HC. Further correlation analysis revealed a positive correlation between ReHo of the left anterior insula and pain scores in GAD patients, while a respective negative correlation between GMV of the bilateral thalamus and PHQ-15 scores. In summary, GAD patients exhibit structural and functional abnormalities in pain-related networks. The enhanced ReHo in the left anterior insula is correlated with pain symptoms, which might be a crucial brain region of pain symptoms in GAD.

Structural and resting-state connection abnormalities of habenula in obsessive-compulsive disorder

BACKGROUND

Previous studies have suggested that the habenula (Hb) may be involved in the mechanism of obsessive-compulsive disorder (OCD). However, the specific role of Hb in OCD remains unclear. This study aimed to explore the structural and functional abnormalities of Hb in OCD and their relationship with the clinical symptoms.

METHODS

Eighty patients with OCD and 85 healthy controls (HCs) were recruited as the primary dataset. The grey matter volume, resting-state functional connectivity (FC), and effective connectivity (EC) of the Hb were calculated and compared between OCD group and HCs. An independent replication dataset was used to verify the stability and robustness of the results.

RESULTS

Patients with OCD exhibited smaller Hb volume and increased FC of right Hb-left hippocampus than HCs. Dynamic causal model revealed an increased EC from left hippocampus to right Hb and a less inhibitory causal influence from the right Hb to left hippocampus in the OCD group compared to HCs. Similar results were found in the replication dataset.

CONCLUSIONS

This study suggested that abnormal structure of Hb and hippocampus-Hb connectivity may contribute to the pathological basis of OCD.

Differences in resting-state brain activity in first-episode drug-naïve major depressive disorder patients with and without suicidal ideation

Despite altered brain activities being associated with suicidal ideation (SI), the neural correlates of SI in major depressive disorder (MDD) have remained elusive. We enrolled 82 first-episode drug-naïve MDD patients including 41 with SI and 41 without SI, as well as 41 healthy controls (HCs). Resting-state functional and structural MRI data were collected. The measures of fractional amplitude of low-frequency fluctuation (fALFF) and grey matter volume (GMV) were calculated and compared. Compared with HCs, patients with SI exhibited increased fALFF values in the right rectus gyrus and left medial superior frontal gyrus, middle frontal gyrus and precuneus. Decreased GMV in the right parahippocampal gyrus, insula and middle occipital gyrus and increased GMV in the left superior frontal gyrus were detected in patients with SI. In addition, patients without SI demonstrated increased fALFF values in the right superior frontal gyrus and decreased fALFF values in the right postcentral gyrus. Decreased GMV in the left superior frontal gyrus, right medial superior frontal gyrus, opercular part of inferior frontal gyrus, postcentral gyrus, fusiform gyrus and increased left supplementary motor area, superior occipital gyrus, right anterior cingulate gyrus and superior temporal gyrus were revealed in patients with SI. Moreover, in comparison with patients without SI, increased fALFF values were identified in the left precuneus of patients with SI. However, no significant differences were found in GMV between patients with and without SI. These findings might be helpful for finding neuroimaging markers predicting individual suicide risk and detecting targeted brain regions for effective early interventions.

Insular volumetry in severe alcohol use disorder and Korsakoff's syndrome through an anatomical parcellation: Let us go back to basics

Functional neuroimaging has demonstrated the key role played by the insula in severe alcohol use disorder (sAUD), notably through its involvement in craving and body signals processing. However, the anatomical counterpart of these functional modifications in sAUD patients with and without neurological complications remains largely unexplored, especially using state-of-the-art parcellation tools. We thus compared the grey matter volume of insular subregions (form anterior to posterior: anterior inferior cortex, anterior short gyrus, middle short gyrus, posterior short gyrus, anterior long gyrus, posterior long gyrus) in 50 recently detoxified patients with sAUD, 19 patients with Korsakoff's syndrome (KS) and 36 healthy controls (HC). We used a mixed linear model analysis to explore group differences in the six subregions grey matter volume and lateralization differences. Insular macrostructure was globally affected to the same extent in sAUD with and without KS, indicating that these brain abnormalities may be related to alcohol consumption per se, rather than to the presence of alcohol-related neurological complications. Insular atrophy showed a right-sided lateralization effect and was especially marked in the posterior insula, a region associated with visceral information processing and the embodiment effect of a substance, from which craving arises. Anatomical damages might thus underlie the previously reported altered insular activations and their behavioural counterparts.

Morphological alterations of contralesional hemisphere relate to functional outcomes after stroke

The present study aimed to investigate poststroke morphological alterations contralesionally and correlations with functional outcomes. Structural magnetic resonance images were obtained from 27 poststroke patients (24 males, 50.21 ± 10.97 years) and 20 healthy controls (13 males, 46.63 ± 12.18 years). Voxel-based and surface-based morphometry analysis were conducted to detect alterations of contralesional grey matter volume (GMV), cortical thickness (CT), gyrification index (GI), sulcus depth (SD), and fractal dimension (FD) in poststroke patients. Partial correlation analysis was used to explore the relationship between regions with significant structural differences and scores of clinical assessments, including Modified Barthel Index (MBI), Berg Balance Scale (BBS), Fugl-Meyer Assessment of Upper Extremity (FMA-UE), Mini-Mental State Examination (MMSE), and Montreal Cognitive Assessment (MoCA). Correction for multiplicity was conducted within each parameter and for all tests. GMV significantly decreased in the contralesional motor-related, occipital and temporal cortex, limbic system, and cerebellum lobe (P < 0.01, family-wise error [FWE] correction). Lower CT was found in the contralesional precentral and lingual gyrus (P < 0.01, FWE correction), while lower GI found in the contralesional superior temporal gyrus and insula (P < 0.01, FWE correction). There were significant correlations between GMV of contralesional lingual gyrus and MBI (P = 0.031, r = 0.441), and BBS (P = 0.047, r = 0.409) scores, and GMV of contralesional hippocampus and FMA-UE scores (P = 0.048, r = 0.408). In conclusion, stroke patients exhibited wide grey matter loss and cortical morphological changes in the contralesional hemisphere, which correlated with sensorimotor functions and the ability of daily living.

Associations between sleep health and grey matter volume in the UK Biobank cohort (n = 33 356)

As suggested by previous research, sleep health is assumed to be a key determinant of future morbidity and mortality. In line with this, recent studies have found that poor sleep is associated with impaired cognitive function. However, to date, little is known about brain structural abnormalities underlying this association. Although recent findings link sleep health deficits to specific alterations in grey matter volume, evidence remains inconsistent and reliant on small sample sizes. Addressing this problem, the current preregistered study investigated associations between sleep health and grey matter volume (139 imaging-derived phenotypes) in the UK Biobank cohort (33 356 participants). Drawing on a large sample size and consistent data acquisition, sleep duration, insomnia symptoms, daytime sleepiness, chronotype, sleep medication and sleep apnoea were examined. Our main analyses revealed that long sleep duration was systematically associated with larger grey matter volume of basal ganglia substructures. Insomnia symptoms, sleep medication and sleep apnoea were not associated with any of the 139 imaging-derived phenotypes. Short sleep duration, daytime sleepiness as well as late and early chronotype were associated with solitary imaging-derived phenotypes (no recognizable pattern, small effect sizes). To our knowledge, this is the largest study to test associations between sleep health and grey matter volume. Clinical implications of the association between long sleep duration and larger grey matter volume of basal ganglia are discussed. Insomnia symptoms as operationalized in the UK Biobank do not translate into grey matter volume findings.

Neuroanatomical correlates of system-justifying ideologies: a pre-registered voxel-based morphometry study on right-wing authoritarianism and social dominance orientation

System-justifying ideologies are a cluster of ideals that perpetuate a hierarchical social system despite being fraught with inequalities. Right-wing authoritarianism (RWA) and social dominance orientation (SDO) are two ideologies that have received much attention in the literature separately and together. Given that these ideologies are considered to be stable individual differences that are likely to have an evolutionary basis, there has yet to be any examination for volumetric brain structures associated with these variables. Here, we proposed an investigation of overlapping and non-overlapping brain regions associated with RWA and SDO in a sample recruited in Singapore. Indeed, it will be interesting to determine how RWA and SDO correlate in a country that proactively promotes institutionalized multi-culturalism such as Singapore. RWA and SDO scores were collected via self-report measures from healthy individuals (39 males and 43 females; age 25.89 ± 5.68 years). Consequently, voxel-based morphometry (VBM) whole brain and region of interest (ROI) analyses were employed to identify neuroanatomical correlates of these system-justifying ideologies. RWA and SDO scores were strongly correlated despite the low ideological contrast in Singapore's sociopolitical context. The whole brain analysis did not reveal any significant clusters associated with either RWA or SDO. The ROI analyses revealed clusters in the bilateral amygdala and ventromedial prefrontal cortex (vmPFC) that were associated with both RWA and SDO scores, whereas two clusters in the left anterior insula were negatively associated with only SDO scores. The study corroborates the claim of RWA and SDO as stable individual differences with identifiable neuroanatomical correlates, but our exploratory analysis suggests evidence that precludes any definitive conclusion based on the present evidence.

Neuroanatomical correlates of system-justifying ideologies: a pre-registered voxel-based morphometry study on right-wing authoritarianism and social dominance orientation

System-justifying ideologies are a cluster of ideals that perpetuate a hierarchical social system despite being fraught with inequalities. Right-wing authoritarianism (RWA) and social dominance orientation (SDO) are two ideologies that have received much attention in the literature separately and together. Given that these ideologies are considered to be stable individual differences that are likely to have an evolutionary basis, there has yet to be any examination for volumetric brain structures associated with these variables. Here, we proposed an investigation of overlapping and non-overlapping brain regions associated with RWA and SDO in a sample recruited in Singapore. Indeed, it will be interesting to determine how RWA and SDO correlate in a country that proactively promotes institutionalized multi-culturalism such as Singapore. RWA and SDO scores were collected via self-report measures from healthy individuals (39 males and 43 females; age 25.89 ± 5.68 years). Consequently, voxel-based morphometry (VBM) whole brain and region of interest (ROI) analyses were employed to identify neuroanatomical correlates of these system-justifying ideologies. RWA and SDO scores were strongly correlated despite the low ideological contrast in Singapore's sociopolitical context. The whole brain analysis did not reveal any significant clusters associated with either RWA or SDO. The ROI analyses revealed clusters in the bilateral amygdala and ventromedial prefrontal cortex (vmPFC) that were associated with both RWA and SDO scores, whereas two clusters in the left anterior insula were negatively associated with only SDO scores. The study corroborates the claim of RWA and SDO as stable individual differences with identifiable neuroanatomical correlates, but our exploratory analysis suggests evidence that precludes any definitive conclusion based on the present evidence.

Morphological and Structural Network Analysis of Sporadic Alzheimer's Disease Brains Based on the APOE4 Gene

BACKGROUND

Alzheimer's disease (AD) is an increasingly common type of dementia. Apolipoprotein E (APOE) gene is a strong risk factor for AD.

OBJECTIVE

Here, we explored alterations in grey matter structure (GMV) and networks in AD, as well as the effects of the APOEɛ4 allele on neuroimaging regions based on structural magnetic resonance imaging (sMRI).

METHODS

All subjects underwent an sMRI scan. GMV and cortical thickness were calculated using voxel-based morphological analysis, and structural networks were constructed based on graph theory analysis to compare differences between AD and normal controls.

RESULTS

The volumes of grey matter in the bilateral inferior temporal gyrus, right middle temporal gyrus, right inferior parietal lobule, right limbic lobe, right frontal lobe, left anterior cingulate gyrus, and bilateral olfactory cortex of patients with AD were significantly decreased. The cortical thickness in patients with AD was significantly reduced in the left lateral occipital lobe, inferior parietal lobe, orbitofrontal region, precuneus, superior parietal gyrus, right precentral gyrus, middle temporal gyrus, pars opercularis gyrus, insular gyrus, superior marginal gyrus, bilateral fusiform gyrus, and superior frontal gyrus. In terms of local properties, there were significant differences between the AD and control groups in these areas, including the right bank, right temporalis pole, bilateral middle temporal gyrus, right transverse temporal gyrus, left postcentral gyrus, and left parahippocampal gyrus.

CONCLUSION

There were significant differences in the morphological and structural covariate networks between AD patients and healthy controls under APOEɛ4 allele effects.

Identification of Attention-Deficit-Hyperactivity Disorder Subtypes based on Structural MRI Grey Matter Volume and Phenotypic Information

BACKGROUND

One of the neurodevelopment disorders widely affecting school-aged children in recent years is attention deficit hyperactivity disorder (ADHD). In many neurodevelopmental disorders, grey matter can be used as a clinical indicator by looking at MRIs.

OBJECTIVE

The study aimed to segment grey matter from brain MRI using a proposed fuzzy c-means clustering-based technique for the detection of ADHD and its subtypes (ADHD-Inattentive, ADHD-Hyperactive, and ADHD-Combined). The grey matter volume, age, gender, and medication status of the subjects were investigated to identify ADHD subtypes.

METHOD

A modified fuzzy c-means with an elbow approach has been proposed to overcome the drawbacks of previous fuzzy c-means methods and improve segmentation performance. The volume of segmented grey matter was included with the phenotypic information of the ADHD-200 dataset for data analysis of typically developing (TD) and ADHD subtypes.

RESULTS

The proposed segmentation exhibited a dice similarity index of 95%. ADHD-Inattentive exhibited a loss of grey matter in the prefrontal cortex, while ADHD-hyperactive exhibited a loss of grey matter in the cerebellum when compared to TD. The analysis of ADHD subtypes based on age and gender showed that children transitioning to adolescence are mostly affected by ADHD-inattentive and female kids are less prone to ADHD-hyperactive. The whole grey matter volume of ADHD-inattentive children, on average, was found to be approximately 4% less than ADHD-combined. Furthermore, the whole grey matter volume was less in non-medication naive children.

CONCLUSION

This study can support healthcare providers in giving appropriate occupational therapy based on the identification of different ADHD subtypes.

Association between stressful life events and grey matter volume in the medial prefrontal cortex: A 2-year longitudinal study

Stressful life events (SLEs) in adulthood are a risk factor for various disorders such as depression, cancer or infections. Part of this risk is mediated through pathways altering brain physiology and structure. There is a lack of longitudinal studies examining associations between SLEs and brain structural changes. High-resolution structural magnetic resonance imaging data of 212 healthy subjects were acquired at baseline and after 2 years. Voxel-based morphometry was used to identify associations between SLEs using the Life Events Questionnaire and grey matter volume (GMV) changes during the 2-year period in an ROI approach. Furthermore, we assessed adverse childhood experiences as a possible moderator of SLEs-GMV change associations. SLEs were negatively associated with GMV changes in the left medial prefrontal cortex. This association was stronger when subjects had experienced adverse childhood experiences. The medial prefrontal cortex has previously been associated with stress-related disorders. The present findings represent a potential neural basis of the diathesis-stress model of various disorders.

Multimodal MRI data fusion reveals distinct structural, functional and neurochemical correlates of heavy cannabis use

Heavy cannabis use (HCU) is frequently associated with a plethora of cognitive, psychopathological and sensorimotor phenomena. Although HCU is frequent, specific patterns of abnormal brain structure and function underlying HCU in individuals presenting without cannabis-use disorder or other current and life-time major mental disorders are unclear at present. This multimodal magnetic resonance imaging (MRI) study examined resting-state functional MRI (rs-fMRI) and structural MRI (sMRI) data from 24 persons with HCU and 16 controls. Parallel independent component analysis (p-ICA) was used to examine covarying components among grey matter volume (GMV) maps computed from sMRI and intrinsic neural activity (INA), as derived from amplitude of low-frequency fluctuations (ALFF) maps computed from rs-fMRI data. Further, we used JuSpace toolbox for cross-modal correlations between MRI-based modalities with nuclear imaging derived estimates, to examine specific neurotransmitter system changes underlying HCU. We identified two transmodal components, which significantly differed between the HCU and controls (GMV: p = 0.01, ALFF p = 0.03, respectively). The GMV component comprised predominantly cerebello-temporo-thalamic regions, whereas the INA component included fronto-parietal regions. Across HCU, loading parameters of both components were significantly associated with distinct HCU behavior. Finally, significant associations between GMV and the serotonergic system as well as between INA and the serotonergic, dopaminergic and μ-opioid receptor system were detected. This study provides novel multimodal neuromechanistic insights into HCU suggesting co-altered structure/function-interactions in neural systems subserving cognitive and sensorimotor functions.

Preliminary evidence on the neural correlates of timing deficit in post-traumatic stress disorder

It has recently been suggested that a deficit in time processing may be considered a cognitive marker of Post-Traumatic Stress Disorder (PTSD). However, the neural correlates of this cognitive deficit in PTSD remain unknown. Voxel-based morphometry and supra-second perceptual time processing data from 8 participants with PTSD and 19 healthy controls have been examined. In line with previous investigations, PTSD patients overestimated the duration of the displayed stimuli. Moreover, their time estimation was more variable than that of controls. Critically, compared to controls, a higher grey matter volume was reported in most of neural regions of PTSD canonically associated with supra-second perceptual timing. These data provide preliminary evidence that the abnormal neuroplasticity of this neural network may be responsible for the altered experience of time in PTSD.

The Relationship Between Grey Matter Volume and Clinical and Functional Outcomes in People at Clinical High Risk for Psychosis

Objective

To examine the association between baseline alterations in grey matter volume (GMV) and clinical and functional outcomes in people at clinical high risk (CHR) for psychosis.

Methods

265 CHR individuals and 92 healthy controls were recruited as part of a prospective multi-center study. After a baseline assessment using magnetic resonance imaging (MRI), participants were followed for at least two years to determine clinical and functional outcomes, including transition to psychosis (according to the Comprehensive Assessment of an At Risk Mental State, CAARMS), level of functioning (according to the Global Assessment of Functioning), and symptomatic remission (according to the CAARMS). GMV was measured in selected cortical and subcortical regions of interest (ROI) based on previous studies (ie orbitofrontal gyrus, cingulate gyrus, gyrus rectus, inferior temporal gyrus, parahippocampal gyrus, striatum, and hippocampus). Using voxel-based morphometry, we analysed the relationship between GMV and clinical and functional outcomes.

Results

Within the CHR sample, a poor functional outcome (GAF < 65) was associated with relatively lower GMV in the right striatum at baseline (P < .047 after Family Wise Error correction). There were no significant associations between baseline GMV and either subsequent remission or transition to psychosis.

Conclusions

In CHR individuals, lower striatal GMV was associated with a poor level of overall functioning at follow-up. This finding was not related to effects of antipsychotic or antidepressant medication. The failure to replicate previous associations between GMV and later psychosis onset, despite studying a relatively large sample, is consistent with the findings of recent large-scale multi-center studies.

Relationship between depression, prefrontal creatine and grey matter volume

BACKGROUND

Depression and low mood are leading contributors to disability worldwide. Research indicates that clinical depression may be associated with low creatine concentrations in the brain and low prefrontal grey matter volume. Because subclinical depression also contributes to difficulties in day-to-day life, understanding the neural mechanisms of depressive symptoms in all individuals, even at a subclinical level, may aid public health.

METHODS

Eighty-four young adult participants completed the Depression, Anxiety and Stress Scale (DASS) to quantify severity of depression, anxiety and stress, and underwent 1H-Magnetic Resonance Spectroscopy of the medial prefrontal cortex and structural magnetic resonance imaging (MRI) to determine whole-brain grey matter volume.

RESULTS/OUTCOMES

DASS depression scores were negatively associated (a) with concentrations of creatine (but not other metabolites) in the prefrontal cortex and (b) with grey matter volume in the right superior medial frontal gyrus. Medial prefrontal creatine concentrations and right superior medial frontal grey matter volume were positively correlated. DASS anxiety and DASS stress scores were not related to prefrontal metabolite concentrations or whole-brain grey matter volume.

CONCLUSIONS/INTERPRETATIONS

This study provides preliminary evidence from a representative group of individuals who exhibit a range of depression levels that prefrontal creatine and grey matter volume are negatively associated with depression. While future research is needed to fully understand this relationship, these results provide support for previous findings, which indicate that increasing creatine concentrations in the prefrontal cortex may improve mood and well-being.

Grey matter volume abnormalities in the first depressive episode of medication-naïve adult individuals: a systematic review of voxel based morphometric studies

BACKGROUND

To identify the reliable and consistent grey matter volume (GMV) abnormalities associated with major depressive disorder (MDD), we excluded the influence of confounding clinical characteristics, comorbidities and brain degeneration on brain morphological abnormalities by inclusion of non-comorbid and non-geriatric drug-naïve MDD individuals experiencing first episode depressive.

METHODS

The PubMed, Scopus, Web of Science, Science Direct and Google scholar databases were searched for papers published in English up to April 2020.

RESULTS

A total of 21 voxel based morphometric (VBM) studies comparing 845 individuals in the first depressive episode and medication-naïve with 940 healthy control subjects were included. The results showed a grey matter volumes reductions in the orbitofrontal cortex (OFC), prefrontal cortex (PFC), frontal and temporal gyri, temporal pole, insular lobe, thalamus, basal ganglia, cerebellum, hippocampus, cingulate cortex, and amygdala. In addition, increased grey matter volumes in the postcentral gyrus, superior frontal gyrus, insula, basal ganglia, thalamus, amygdala, cuneus, and precuneus differentiated the first depressive episode in medication-naïve individuals from healthy subjects.

CONCLUSION

The present systematic review provided additional support for the involvement of grey matter structural abnormalities in limbic-cortical circuits as possibly specific structural abnormalities in the early stage of MDD.Key pointsDistinct brain regions in MDD patients might be associated with the early stages of illness, and thus it is critical to study the causal relationship between brain structures and the onset of the disease to improve the evaluation in clinic.Grey matter alterations in the fronto-limbic networks in the first episode, medication-naïve MDD might suggest that these abnormalities may play an important role in the neuropathophysiology of MDD at its onset.First episode, medically naïve depressive patients show grey matter volume alterations in brain regions mainly associated with emotion regulation including parietal-temporal regions, PFC, insular lobe, thalamus, basal ganglia, cerebellum and limbic structures that may be specific changes in early stage of MDD.Genotype-diagnosis interaction effects on brain morphology in the cortico-limbic-striatal circuits, including the PFC, amygdala, hippocampus and striatum that might be implicated in the dysfunctional regulation of emotion in first-episode MDD patients.Future longitudinal and prospective studies should be conducted to identify the core structural brain changes in people at-risk for MDD and explore the association of their brain volumes with symptom onset.

Grey and White Matter Volume Changes after Preterm Birth: A Meta-Analytic Approach

Cross-sectional studies have reported lower brain grey matter volumes (GMV) and white matter volumes (WMV) in preterm (PT) born individuals. While large MRI studies in the normative population have led to a better understanding of brain growth trajectories across the lifespan, such results remain elusive for PT born individuals since large, aggregated datasets of PT born individuals do not exist. To close this gap, we investigated GMV and WMV in PT born individuals as reported in the literature and contrasted it against individual volumetric data and trajectories from the general population. Systematic database search of PubMed and Web of Science in March 2021, and extraction of outcome measures were conducted by two independent reviewers. Individual data on full-term (FT) controls was extracted from freely available databases. Mean GMV, WMV, total intracranial volume (TIV), and mean age at scan were the main outcome measures. Of 532 identified records, nine studies were included with 538 PT born subjects between 1.1 and 28.5 years of age. Reference data was generated from 880 FT controls between 1 and 30 years of age. GMV was consistently lower in PT born individuals from infancy to early adulthood with no evidence for catch-up growth. While GMV changes followed a similar trajectory as FT controls, WMV was particularly low in adolescence after PT birth. Results demonstrate altered brain volumes after PT birth across the first half of lifespan. Future studies should address this issue in large aggregated datasets of PT born individuals.

Lithium prevents grey matter atrophy in patients with bipolar disorder: an international multicenter study

BACKGROUND

Lithium (Li) is the gold standard treatment for bipolar disorder (BD). However, its mechanisms of action remain unknown but include neurotrophic effects. We here investigated the influence of Li on cortical and local grey matter (GM) volumes in a large international sample of patients with BD and healthy controls (HC).

METHODS

We analyzed high-resolution T1-weighted structural magnetic resonance imaging scans of 271 patients with BD type I (120 undergoing Li) and 316 HC. Cortical and local GM volumes were compared using voxel-wise approaches with voxel-based morphometry and SIENAX using FSL. We used multiple linear regression models to test the influence of Li on cortical and local GM volumes, taking into account potential confounding factors such as a history of alcohol misuse.

RESULTS

Patients taking Li had greater cortical GM volume than patients without. Patients undergoing Li had greater regional GM volumes in the right middle frontal gyrus, the right anterior cingulate gyrus, and the left fusiform gyrus in comparison with patients not taking Li.

CONCLUSIONS

Our results in a large multicentric sample support the hypothesis that Li could exert neurotrophic and neuroprotective effects limiting pathological GM atrophy in key brain regions associated with BD.

Examining volumetric gradients based on the frustum surface ratio in the brain in autism spectrum disorder

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder that is accompanied by neurodevelopmental differences in regional cortical volume (CV), and a potential layer‐specific pathology. Conventional measures of CV, however, do not indicate how volume is distributed across cortical layers. In a sample of 92 typically developing (TD) controls and 92 adult individuals with ASD (aged 18–52 years), we examined volumetric gradients by quantifying the degree to which CV is weighted from the pial to the white surface of the brain. Overall, the spatial distribution of Frustum Surface Ratio (FSR) followed the gyral and sulcal pattern of the cortex and approximated a bimodal Gaussian distribution caused by a linear mixture of vertices on gyri and sulci. Measures of FSR were highly correlated with vertex‐wise estimates of mean curvature, sulcal depth, and pial surface area, although none of these features explained more than 76% variability in FSR on their own. Moreover, in ASD, we observed a pattern of predominant increases in the degree of FSR relative to TD controls, with an atypical neurodevelopmental trajectory. Our findings suggest a more outward‐weighted gradient of CV in ASD, which may indicate a larger contribution of supragranular layers to regional differences in CV.

Nucleus accumbens volume is related to obesity measures in an age-dependent fashion

Motivation theories of obesity suggest that one of the brain mechanisms underlying pathological eating and weight gain is the dysregulation of dopaminergic circuits. Although these dysregulations likely occur at the microscopic level, studies on grey matter volume report macroscopic differences associated with obesity. One region suggested to play a key role in the pathophysiology of obesity is the nucleus accumbens (NAcc). We performed a meta-analysis of findings regarding NAcc volume and overweight/obesity. We additionally examined whether grey matter volume in the NAcc and other mesolimbic areas depends on the longitudinal trajectory of obesity, using the UK Biobank dataset. To this end, we analysed the data using a latent growth model, which identifies whether a certain variable of interest (eg, NAcc volume) is related to another variable's (body mass index [BMI]) initial values or longitudinal trajectories. Our meta-analysis showed that, overall, NAcc volume is positively related to BMI. However, further analyses revealed that the relationship between NAcc volume and BMI is dependent on age. For younger individuals, such a relationship is positive, whereas, for older adults, it is negative. This was corroborated by our analysis in the UK Biobank dataset, which includes older adults, where we found that a higher BMI was associated with a lower NAcc and thalamus volume. Overall, the present study suggests that increased NAcc volume at a young age might be a vulnerability factor for obesity, whereas, at an older age, decreased NAcc volume with increased BMI might be an effect of prolonged influences of neuroinflammation on the brain.

Vitamin D Levels, APOE Allele, and MRI Volumetry Assessed by NeuroQuant in Norwegian Adults with Cognitive Symptoms

BACKGROUND

Allele ɛ4 of the apolipoprotein (APOE∈4) gene is the strongest known genetic risk factor for late-onset sporadic Alzheimer's disease. A possible relationship between vitamin D and APOE is not yet clear.

OBJECTIVE

In this exploratory, cross-sectional study, we examined the association between serum levels of 25-hydroxyvitamin D [25(OH)D] and brain volumes and the associations of both serum levels of 25(OH)D and APOE polymorphism to brain volumes in 127 persons (mean age 66 years) with cognitive symptoms.

METHODS

All subjects were examined with fully automated software for MRI volumetry, NeuroQuant.

RESULTS

After adjustment for relevant covariates, higher serum 25(OH)D levels were associated with greater volumes of cortical gray matter on both left (p = 0.02) and right (p = 0.04) sides. When both 25(OH)D levels and APOE genotype were used as the main covariates, no significant associations were found between vitamin D level and brain volume in any of the 11 brain regions. In adjusted models, only homozygous but not heterozygous APOE∈4 allele carriers had significantly larger inferior lateral ventricles (p = 0.003) and smaller hippocampal volume (p = 0.035) than those without ɛ4. Homozygous APOE∈4 carriers also had significantly higher vitamin D levels (p = 0.009) compared to persons without the APOE∈4 allele.

CONCLUSION

Higher vitamin D levels might have a preserving effect on cortical grey matter volume.

Polygenic effects of schizophrenia on hippocampal grey matter volume and hippocampus-medial prefrontal cortex functional connectivity

BACKGROUND

Schizophrenia is a complex mental disorder with high heritability and polygenic inheritance. Multimodal neuroimaging studies have also indicated that abnormalities of brain structure and function are a plausible neurobiological characterisation of schizophrenia. However, the polygenic effects of schizophrenia on these imaging endophenotypes have not yet been fully elucidated.

AIMS

To investigate the effects of polygenic risk for schizophrenia on the brain grey matter volume and functional connectivity, which are disrupted in schizophrenia.

METHOD

Genomic and neuroimaging data from a large sample of Han Chinese patients with schizophrenia (N = 509) and healthy controls (N = 502) were included in this study. We examined grey matter volume and functional connectivity via structural and functional magnetic resonance imaging, respectively. Using the data from a recent meta-analysis of a genome-wide association study that comprised a large number of Chinese people, we calculated a polygenic risk score (PGRS) for each participant.

RESULTS

The imaging genetic analysis revealed that the individual PGRS showed a significantly negative correlation with the hippocampal grey matter volume and hippocampus-medial prefrontal cortex functional connectivity, both of which were lower in the people with schizophrenia than in the controls. We also found that the observed neuroimaging measures showed weak but similar changes in unaffected first-degree relatives of patients with schizophrenia.

CONCLUSIONS

These findings suggested that genetically influenced brain grey matter volume and functional connectivity may provide important clues for understanding the pathological mechanisms of schizophrenia and for the early diagnosis of schizophrenia.

Altered heartbeat perception sensitivity associated with brain structural alterations in generalised anxiety disorder

Background

Palpitation is a common complaint in generalised anxiety disorder (GAD). Brain imaging studies have investigated the neural mechanism of heartbeat perception in healthy volunteers. This study explored the neuroanatomical differences of altered heartbeat perception in patients with GAD using structural MRI.

Aims

Based on the strong somatic-interoceptive symptoms in GAD, we explored the regional structural brain abnormalities involved in heartbeat perception in patients with GAD.

Methods

This study was applied to the a priori regions using neuroanatomical theories of heartbeat perception, including the insula, anterior cingulate cortex, supplementary motor area and prefrontal cortex. A total of 19 patients with GAD and 19 healthy control subjects were enrolled. We used the FMRIB Software Library voxel-based morphometry software for estimating the grey matter volume of these regions of interest and analysed the correlation between heartbeat perception sensitivity and the volume of abnormal grey matter.

Results

Patients with GAD showed a significantly decreased volume of grey matter in their left medial prefrontal cortex, right orbital frontal cortex and anterior cingulate cortex. The grey matter volume of the left medial prefrontal cortex negatively correlated with heartbeat perception sensitivity in patients with GAD.

Conclusions

It should be the first study that shows heartbeat perception is associated with brain structure in GAD. Our findings suggest that the frontal region may play an important role in aberrant heartbeat perception processing in patients with GAD, and this may be an underlying mechanism resulting in the abnormal cardiovascular complaints in GAD. This is hypothesised as a ‘top-down’ deficiency, especially in the medial prefrontal cortex. This will provide the foundation for a more targeted region for neuromodulation intervention in the future.

Structural brain changes with lifetime trauma and re-experiencing symptoms is 5-HTTLPR genotype-dependent

Background: Findings on structural brain alterations following trauma are inconsistent due probably to heterogeneity in imaging studies and population, clinical presentations, genetic vulnerability, and selection of controls. This study examines whether trauma and re-experiencing symptoms are associated with specific alterations in grey matter volumes and if this varies according to 5-HTTLPR genotype. Methods: Structural MRI was used to acquire anatomical scans from 377 community-dwelling older adults. Quantitative regional estimates of 22 subregional volumes were derived using FreeSurfer software. Lifetime trauma was assessed using the validated Watson's PTSD inventory, which evaluates the most severe trauma experienced according to DSM criteria. Analyses adjusted for age, sex, total brain volume, head injury, and comorbidities. Results: Of the 212 participants reporting lifetime trauma, 35.4% reported re-experiencing symptoms and for 1.9%, this was severe enough to meet criteria for full threshold PTSD. In participants with the SS 5-HTTLPR genotype only, re-experiencing symptoms were associated with smaller volumes in middle and superior temporal, frontal (lateral orbital, rostral and caudal middle) and parietal (precuneus, inferior and superior) regions. The trauma-exposed participants without re-experiencing symptoms were not significantly different from the non-trauma-exposed participants except for smaller precuneus and superior parietal region in traumatized participants and a larger amygdala in traumatized women specifically. Conclusions: In the non-clinical sample, lifetime trauma and re-experiencing symptoms were associated with smaller volume in prefrontal, temporal and parietal cortex subregions, and this varied according to serotonergic genetic vulnerability, 5-HTTLPR SS individuals being most susceptible.

Reduced grey matter volume in frontal and temporal areas in depression: contributions from voxel-based morphometry study

OBJECTIVE

The aim of the current study was to examine whether and to what extent mood disorders, comprising major depression and bipolar disorder, are accompanied by structural changes in the brain as measured using voxel-based morphometry (VBM).

METHODS

We performed a VBM study using a 3Т MRI system (GE Discovery 750w) in patients with mood disorders (n=50), namely, 39 with major depression and 11 with bipolar disorder compared to 42 age-, sex- and education-matched healthy controls.

RESULTS

Our results show that depression was associated with significant decreases in grey matter (GM) volume of the regions located within the medial frontal and anterior cingulate cortex on the left side and middle frontal gyrus, medial orbital gyrus, inferior frontal gyrus (triangular and orbital parts) and middle temporal gyrus (extending to the superior temporal gyrus) on the right side. When the patient group was separated into bipolar disorder and major depression, the reductions remained significant only for patients with major depressive disorder.

CONCLUSIONS

Using VBM the present study was able to replicate decreases in GM volume restricted to frontal and temporal regions in patients with mood disorders, mainly major depression, compared with healthy controls.

Multi-scale analysis of schizophrenia risk genes, brain structure, and clinical symptoms reveals integrative clues for subtyping schizophrenia patients

Analysis linking directly genomics, neuroimaging phenotypes and clinical measurements is crucial for understanding psychiatric disorders, but remains rare. Here, we describe a multi-scale analysis using genome-wide SNPs, gene expression, grey matter volume (GMV), and the positive and negative syndrome scale scores (PANSS) to explore the etiology of schizophrenia. With 72 drug-naive schizophrenic first episode patients (FEPs) and 73 matched heathy controls, we identified 108 genes, from schizophrenia risk genes, that correlated significantly with GMV, which are highly co-expressed in the brain during development. Among these 108 candidates, 19 distinct genes were found associated with 16 brain regions referred to as hot clusters (HCs), primarily in the frontal cortex, sensory-motor regions and temporal and parietal regions. The patients were subtyped into three groups with distinguishable PANSS scores by the GMV of the identified HCs. Furthermore, we found that HCs with common GMV among patient groups are related to genes that mostly mapped to pathways relevant to neural signaling, which are associated with the risk for schizophrenia. Our results provide an integrated view of how genetic variants may affect brain structures that lead to distinct disease phenotypes. The method of multi-scale analysis that was described in this research, may help to advance the understanding of the etiology of schizophrenia.

Androgen deprivation therapy increases brain ageing

BACKGROUND

Prostate cancer (PC) is the most frequent neoplasia in the male population and androgen deprivation therapy (ADT) is frequently used in the management of the disease.

AIM

To evaluate the effect of ADT exposure on cognitive status, grey matter volume (GMV) and white matter lesion (WML) load.

METHODS

Fifty ADT patients and fifteen PC-non-ADT (control) patients were included in the study. A neuropsychological evaluation was performed and a magnetic resonance imaging (MRI), with anatomical T1 and FLAIR sequences, was performed to evaluate the GMV and the WML burden.

RESULTS

Most of the patients included in the study presented a significant cognitive impairment (CI). No significant differences were identified in the cognitive assessment between the studied groups, but when considering the educational background intragroup differences were found.No significant difference of GMV and WML volume were identified between groups, but a negative relationship between the ADT period and the GMV was identified. Furthermore, a significant positive association between the age and the lesion volume was found in the ADT group (β=.406; p=.004).

CONCLUSION

PC patients exposed to ADT present an acceleration of age-related brain changes, such as WML development and GMV loss.

A Neuroanatomical Substrate Linking Perceptual Stability to Cognitive Rigidity in Autism

Overly stable visual perception seen in individuals with autism spectrum disorder (ASD) is related to higher-order core symptoms of the condition. However, the neural basis by which these seemingly different symptoms are simultaneously observed in individuals with ASD remains unclear. Here, we aimed to identify such a neuroanatomical substrate linking perceptual stability to autistic cognitive rigidity, a part of core restricted, repetitive behaviors (RRBs). First, using a bistable visual perception test, we measured the perceptual stability of 22 high-functioning adults with ASD and 22 age-, IQ-, and sex-matched typically developing human individuals and confirmed overstable visual perception in autism. Next, using a spontaneous task-switching (TS) test, we showed that the individuals with ASD were more likely to repeat the same task voluntarily and spontaneously, and such rigid TS behavior was associated with the severity of their RRB symptoms. We then compared these perceptual and cognitive behaviors and found a significant correlation between them for individuals with ASD. Finally, we found that this behavioral link was supported by a smaller gray matter volume (GMV) of the posterior superior parietal lobule (pSPL) in individuals with ASD. Moreover, this smaller GMV in the pSPL was also associated with the RRB symptoms and replicated in two independent datasets. Our findings suggest that the pSPL could be one of the neuroanatomical mediators of cognitive and perceptual inflexibility in autism, which could help a unified biological understanding of the mechanisms underpinning diverse symptoms of this developmental disorder.SIGNIFICANCE STATEMENT Behavioral studies show perceptual overstability in autism spectrum disorder (ASD). However, the neural mechanisms by which such sensory symptoms can coexist and often correlate with seemingly separate core symptoms remain unknown. Here, we have identified such a key neuroanatomical substrate. We have revealed that overstable sensory perception of individuals with ASD is linked with their cognitive rigidity, a part of core restricted, repetitive behavior symptoms, and such a behavioral link is underpinned by a smaller gray matter volume in the posterior superior parietal lobule in autism. These findings uncover a key neuroanatomical mediator of autistic perceptual and cognitive inflexibility and would ignite future studies on how the core symptoms of ASD interact with its unique sensory perception.

Atypical intrinsic neural timescale in autism

How long neural information is stored in a local brain area reflects functions of that region and is often estimated by the magnitude of the autocorrelation of intrinsic neural signals in the area. Here, we investigated such intrinsic neural timescales in high-functioning adults with autism and examined whether local brain dynamics reflected their atypical behaviours. By analysing resting-state fMRI data, we identified shorter neural timescales in the sensory/visual cortices and a longer timescale in the right caudate in autism. The shorter intrinsic timescales in the sensory/visual areas were correlated with the severity of autism, whereas the longer timescale in the caudate was associated with cognitive rigidity. These observations were confirmed from neurodevelopmental perspectives and replicated in two independent cross-sectional datasets. Moreover, the intrinsic timescale was correlated with local grey matter volume. This study shows that functional and structural atypicality in local brain areas is linked to higher-order cognitive symptoms in autism.

Autism is a brain disorder that affects how people interact with others. It occupies a spectrum, with severe autism at one end and high-functioning autism at the other. People with severe autism usually have intellectual impairments and little spoken language. Those with high-functioning autism have average or above average IQ, but struggle with more subtle aspects of communication, such as body language. As well as social difficulties, many individuals with autism show repetitive behaviors and have narrow interests.

The brains of people with autism process information differently to those of people without autism. The brain as a whole shows less coordinated activity in autism, for example. But whether individual brain regions themselves also work differently in autism is unclear. Watanabe et al. set out to answer this question by using a brain scanner to compare the resting brain activity of high-functioning people with autism to that of people without autism.

In both groups, networks of brain regions increased and decreased their activity in predictable patterns. But in individuals with autism, sensory areas of the brain showed more random activity than in individuals without autism. The most random activity occurred in those with the most severe autism. This suggests that the brains of people with autism cannot hold onto and process sensory input for as long as those of neurotypical people. By contrast, a brain region called the caudate showed the opposite pattern, being more predictable in individuals with autism. The most predictable caudate activity occurred in those individuals with the most inflexible, repetitive behaviors. These differences in this neural randomness appear to result from changes in the structure of the individual brain regions.

The findings of Watanabe et al. suggest that changes in the structure and activity of small brain regions give rise to complex symptoms in autism. If these differences also exist in young children, they could help doctors diagnose autism earlier. Future studies should investigate whether the differences in brain activity cause the symptoms of autism. If so, it may be possible to treat the symptoms by changing brain activity, for example, by applying magnetic stimulation to the scalp.

Increased intrinsic connectivity for structural atrophy and functional maintenance after acute ischaemic stroke

BACKGROUND AND PURPOSE

Significant clinical recovery has commonly been observed in ischaemic stroke patients with irreversible brain structural damage. However, brain mechanisms that help to maintain clinical function remain unclear.

METHODS

Sixty-two patients with acute ischaemic stroke underwent longitudinal clinical assessments and magnetic resonance scanning. The clinical recovery trajectory was evaluated using a hierarchical linear model and intrinsic connectivity was analysed with a seed-based approach to examine its changing pattern based on the regional volume changes calculated using voxel-wise analysis.

RESULTS

It was observed that clinical outcome measures improved mainly in the short-term period (baseline versus 3 weeks) and then remained stable. Grey matter volume was reduced significantly in the bilateral caudate over the entire 3-year long-term period. Significant intrinsic connectivity increases were observed in the caudate-middle cingulum over the short-term period and in the caudate-precuneus and caudate-calcarine over the long-term period. Finally, it was found that increased caudate-calcarine connectivity was associated with reduced right caudate volume, and a positive correlation was found between increased caudate-middle cingulum connectivity and the amount of modified Rankin score changes.

CONCLUSIONS

The increased intrinsic connectivity found in this study tends to be a compensatory mechanism for post-stroke structural damage, associated with clinical recovery. The study helps in understanding the significance of enhanced intrinsic connectivity in post-stroke long-term assessment and rehabilitation.

Neurological soft signs and grey matter abnormalities in individuals with ultra-high risk for psychosis

Neurological soft signs (NSSs), conventionally defined as subtle neurological abnormalities, are frequently found in individuals with schizophrenia. Many neuroimaging studies have also reported that NSSs are associated with grey matter changes in patients with schizophrenia at different stages of the illness. However, these findings may be confounded by the effect of antipsychotic medications, chronicity, and duration of untreated psychosis. Examining NSSs in individuals with ultra-high risk (UHR) for psychosis may help to identify the neuroanatomical substrates of NSSs related to the illness itself and to avoid these potential confounding effects. A sample of 21 individuals with UHR were included in the present study. NSSs were rated using the abridged version of the Cambridge Neurological Inventory. Grey matter volume was assessed using optimized voxel-based morphometry on images acquired by a high-resolution 3-T magnetic resonance imaging scanner. We found that higher NSS scores in individuals with UHR were associated with decreased grey matter volume at the superior and medial frontal cortex, the rectal cortex, the pre- and post-central cortex, the insula, the caudate, and the cerebellum. Our results suggest that these brain structural characteristics may represent the neuroanatomical substrate of NSSs in individuals with UHR. These findings contribute to the understanding of the intrinsic features of psychosis associated with NSSs and may provide insights into pre-schizophrenia pathophysiology.

Regional structural impairments outside lesions are associated with verbal short-term memory deficits in chronic subcortical stroke

Background and Purpose

We aimed to explore the neural mechanisms of verbal short-term memory (VSTM) impairment in subcortical stroke by evaluating the contributions of lesion and remote grey matter volume (GMV) reduction.

Results

There was no significant correlation between lesions and VSTM. In stroke patients with left lesions, GMV reductions in the right middle frontal gyrus and in the left inferior frontal gyrus were positively correlated with VSTM impairment. In patients with right lesions, GMV reduction in the right dorsal posterior cingulate cortex was positively correlated with VSTM impairment.

Materials and Methods

Ninety-seven patients with chronic subcortical ischemic stroke and seventy-nine healthy controls underwent VSTM and structural MRI examinations. Voxel-based lesion symptom mapping was used to identify correlations between lesions and VSTM. Voxel-wise comparisons were used to identify brain regions with significant GMV reduction in patients with left and right lesions. These regions were used in correlation analyses between GMV and VSTM in each patient subgroup.

Conclusions

These findings suggest that VSTM impairment in subcortical stroke is associated with secondary regional structural damage in non-lesion regions, rather than with the lesion itself. Moreover, different neural substrates may underlie VSTM impairment in stroke patients with left and right lesions.

Extrastriatal dopamine D2/3 receptors and cortical grey matter volumes in antipsychotic-naïve schizophrenia patients before and after initial antipsychotic treatment

OBJECTIVES

Long-term dopamine D_2/3 receptor blockade, common to all antipsychotics, may underlie progressive brain volume changes observed in patients with chronic schizophrenia. In the present study, we examined associations between cortical volume changes and extrastriatal dopamine D_2/3 receptor binding potentials (BP_ND) in first-episode schizophrenia patents at baseline and after antipsychotic treatment.

METHODS

Twenty-two initially antipsychotic-naïve patients underwent magnetic resonance imaging (MRI), [¹²³I]epidepride single-photon emission computerised tomography (SPECT), and psychopathology assessments before and after 3 months of treatment with either risperidone (N = 13) or zuclopenthixol (N = 9). Twenty healthy controls matched on age, gender and parental socioeconomic status underwent baseline MRI and SPECT.

RESULTS

Neither extrastriatal D_2/3 receptor BP_ND at baseline, nor blockade at follow-up, was related to regional cortical volume changes. In post-hoc analyses excluding three patients with cannabis use we found that higher D_2/3 receptor occupancy was significantly associated with an increase in right frontal grey matter volume.

CONCLUSIONS

The present data do not support an association between extrastriatal D_2/3 receptor blockade and extrastriatal grey matter loss in the early phases of schizophrenia. Although inconclusive, our exclusion of patients tested positive for cannabis use speaks to keeping attention to potential confounding factors in imaging studies.

Aberrant brain grey matter volume patterns differ among Chinese Han drug-naïve depression patients with acute and chronic stress

Chronic or acute stress can induce structural changes and brain alterations associated with the neural mechanisms of depression. Aimed to investigate the GMV alterations in the drug-naïve depression patients with chronic and acute stress experience,we enrolled fifty depression patients with acute stress experience, fifty five depression patients with chronic stress experience and forty seven healthy controls(HC) to participant in the present study. We used voxel-based morphometry to analyze the brain grey matter volume (GMV) alterations. Compared with the HC, the patients with acute stress and those with chronic stress exhibited a distinct GMV impairment pattern. Widespread, decreased GMV was detected in most of the cerebral cortex in all the depression patients. Importantly, the greatest finding in our study is that the decreased GMV in the depression patients with chronic stress was more widespread than that in the patients with acute stress. All brain regions with decreased GMV participated in the regulation of emotions, memory, and executive function processing, which is consistent with previous findings. There was no significant difference between the major depression disorder patients with acute stressful life events and those with chronic stressful life events, and this finding largely weakens the support of our current conclusion. Thus, we cannot confirm this postulation. However, our findings probably indicate that GMV may be more sensitive to major depression disorder patients when compared to healthy controls, it did not sensitive when in the comparison of patient's group. Overall, our findings provide important information for the use of appropriate treatment methods to address acute stress and alleviate chronic stress in patients with depression, and such treatments can delay the deterioration of the affected brain regions and improve remission rates. More importantly, all the inexplicable findings in the present study encourage us to conduct a follow-up study to describe the developmental trajectory of the pathological brain features of depression patients and explore therapeutic targets for future personalized treatment.

Distinct patterns of reduced prefrontal and limbic grey matter volume in childhood general and internalizing psychopathology

Reduced grey matter volume (GMV) is widely implicated in psychopathology, but studies have found mostly overlapping areas of GMV reduction across disorders rather than unique neural signatures, potentially due to pervasive comorbidity. GMV reductions may be associated with broader psychopathology dimensions rather than specific disorders. We used an empirically supported bifactor model consisting of common psychopathology and internalizing- and externalizing-specific factors to evaluate whether latent psychopathology dimensions yield a clearer, more parsimonious pattern of GMV reduction in prefrontal and limbic/paralimbic areas implicated in individual disorders. A community sample of children (n=254, ages 6-10) was used to to evaluate whether GMV reductions could constitute early neural risk factors. The common psychopathology factor was associated with reduced GMV in prefrontal areas (dorsal, orbitofrontal, ventrolateral). The internalizing-specific factor was related to reduced GMV in limbic/paralimbic areas (hippocampus, amygdala, insula). No significant associations were found between GMV and the externalizing-specific factor after accounting for common psychopathology.

Abnormal functional connectivity and cortical integrity influence dominant hand motor disability in multiple sclerosis: a multimodal analysis

Functional reorganization and structural damage occur in the brains of people with multiple sclerosis (MS) throughout the disease course. However, the relationship between resting-state functional connectivity (FC) reorganization in the sensorimotor network and motor disability in MS is not well understood. This study used resting-state fMRI, T1-weighted and T2-weighted, and magnetization transfer (MT) imaging to investigate the relationship between abnormal FC in the sensorimotor network and upper limb motor disability in people with MS, as well as the impact of disease-related structural abnormalities within this network. Specifically, the differences in FC of the left hemisphere hand motor region between MS participants with preserved (n = 17) and impaired (n = 26) right hand function, compared with healthy controls (n = 20) was investigated. Differences in brain atrophy and MT ratio measured at the global and regional levels were also investigated between the three groups. Motor preserved MS participants had stronger FC in structurally intact visual information processing regions relative to motor impaired MS participants. Motor impaired MS participants showed weaker FC in the sensorimotor and somatosensory association cortices and more severe structural damage throughout the brain compared with the other groups. Logistic regression analysis showed that regional MTR predicted motor disability beyond the impact of global atrophy whereas regional grey matter volume did not. More importantly, as the first multimodal analysis combining resting-state fMRI, T1-weighted, T2-weighted and MTR images in MS, we demonstrate how a combination of structural and functional changes may contribute to motor impairment or preservation in MS. Hum Brain Mapp 37:4262-4275, 2016. © 2016 Wiley Periodicals, Inc.

Large-scale brain network abnormalities in Huntington's disease revealed by structural covariance

Huntington's disease (HD) is a progressive neurodegenerative disorder that can be diagnosed with certainty decades before symptom onset. Studies using structural MRI have identified grey matter (GM) loss predominantly in the striatum, but also involving various cortical areas. So far, voxel-based morphometric studies have examined each brain region in isolation and are thus unable to assess the changes in the interrelation of brain regions. Here, we examined the structural covariance in GM volumes in pre-specified motor, working memory, cognitive flexibility, and social-affective networks in 99 patients with manifest HD (mHD), 106 presymptomatic gene mutation carriers (pre-HD), and 108 healthy controls (HC). After correction for global differences in brain volume, we found that increased GM volume in one region was associated with increased GM volume in another. When statistically comparing the groups, no differences between HC and pre-HD were observed, but increased positive correlations were evident for mHD, relative to pre-HD and HC. These findings could be explained by a HD-related neuronal loss heterogeneously affecting the examined network at the pre-HD stage, which starts to dominate structural covariance globally at the manifest stage. Follow-up analyses identified structural connections between frontoparietal motor regions to be linearly modified by disease burden score (DBS). Moderator effects of disease load burden became significant at a DBS level typically associated with the onset of unequivocal HD motor signs. Together with existing findings from functional connectivity analyses, our data indicates a critical role of these frontoparietal regions for the onset of HD motor signs.

Psychopathic traits are associated with cortical and subcortical volume alterations in healthy individuals

Research suggests psychopathy is associated with structural brain alterations that may contribute to the affective and interpersonal deficits frequently observed in individuals with high psychopathic traits. However, the regional alterations related to different components of psychopathy are still unclear. We used voxel-based morphometry to characterize the structural correlates of psychopathy in a sample of 35 healthy adults assessed with the Triarchic Psychopathy Measure. Furthermore, we examined the regional grey matter alterations associated with the components described by the triarchic model. Our results showed that, after accounting for variation in total intracranial volume, age and IQ, overall psychopathy was negatively associated with grey matter volume in the left putamen and amygdala. Additional regression analysis with anatomical regions of interests revealed total triPM score was also associated with increased lateral orbitofrontal cortex (OFC) and caudate volume. Boldness was positively associated with volume in the right insula. Meanness was positively associated with lateral OFC and striatum volume, and negatively associated with amygdala volume. Finally, disinhibition was negatively associated with amygdala volume. Results highlight the contribution of both subcortical and cortical brain alterations for subclinical psychopathy and are discussed in light of prior research and theoretical accounts about the neurobiological bases of psychopathic traits.

Characterizing early Alzheimer's disease and disease progression using hippocampal volume and arterial spin labeling perfusion MRI

Searching for biomarkers sensitive to early Alzheimer's disease (AD) and its progression has been a research priority for two decades. MRI has been increasingly used for this endeavor because of its capability of detecting both structural and functional brain patterns without injecting external contrast agent or radioactive tracers. Recent work has shown sensitivity of hippocampal volume and regional cerebral blood flow for differentiating prodromal AD from normal controls as well as AD. This review provides a summary for the existing literature describing the applications of either or both modalities in early AD studies as well as disease progression assessment. The various findings in the reviewed studies lead to a conclusion of assessing hippocampal volume and arterial spin labeling cerebral blood flow as potential markers for disease detection, and progression monitoring though longitudinal studies are still lacking to fully examine their sensitivity and specificity.

Source-based morphometry reveals distinct patterns of aberrant brain volume in delusional infestation

Little is known about the neural correlates of delusional infestation (DI), the delusional belief to be infested with pathogens. So far, evidence comes mainly from case reports and case series. We investigated brain morphology in 16 DI patients and 16 healthy controls using structural magnetic resonance imaging and a multivariate data analysis technique, i.e. source-based morphometry (SBM). In addition, we explored differences in brain structure in patient subgroups based on disease aetiology. SBM revealed two patterns exhibiting significantly (p<0.05, Bonferroni-corrected) lower grey and higher white matter volume in DI patients compared to controls. Lower grey matter volume was found in medial prefrontal cortex, anterior cingulate cortex, medial temporal lobe structures (parahippocampus and hippocampus), sensorimotor cortices, bilateral insula and thalamus and inferior parietal regions. Higher white matter volume was found in medial and middle frontal and temporal cortices, left insula and lentiform nucleus. Grey matter volume was abnormal in both "psychiatric" (primary DI and DI associated with an affective disorder) and "organic" DI (DI due to a medical condition). In contrast, aberrant white matter volume was only confirmed for the "organic" DI patient subgroup. These results suggest prefrontal, temporal, parietal, insular, thalamic and striatal dysfunction underlying DI. Moreover, the data suggest that aetiologically distinct presentations of DI share similar patterns of abnormal grey matter volume, whereas aberrant white matter volume appears to be restricted to organic cases.

Interleukin-6 covaries inversely with hippocampal grey matter volume in middle-aged adults

BACKGROUND

Converging animal findings suggest that higher peripheral levels of inflammation are associated with activation of central inflammatory mechanisms that result in hippocampal neurodegeneration and related impairment of memory function. We have recently shown, consistent with animal findings, an inverse association between peripheral levels of interleukin-6 (IL-6), a relatively stable marker of systemic inflammation, and memory function in mid-life adults. In the current study, we extend this work to test whether systemic inflammation is associated with reduced grey matter volume of the hippocampus.

METHODS

For this purpose, we used a computational structural neuroimaging method (optimized voxel-based morphometry) to evaluate the relationship between plasma IL-6 levels and hippocampal grey matter volume in a sample of 76 relatively healthy community volunteers ages 30-54.

RESULTS

Peripheral levels of IL-6 covaried inversely with hippocampal grey matter volume, and this relationship persisted after accounting for several possible confounders, including age, gender, race, years of education, percent body fat, blood pressure, smoking, physical activity, hours of sleep, alcohol use, and total grey matter volume.

CONCLUSIONS

To our knowledge, this is the first report of a relationship between a peripheral marker of IL-6 and hippocampal grey matter volume, raising the possibility that low-grade systemic inflammation could plausibly presage subclinical cognitive decline in part via structural neural pathways.

No change to grey and white matter volumes in bipolar I disorder patients

BACKGROUND

Structural brain imaging is assumed to be a key method to elucidate the underlying neuropathology of bipolar disorder. However, magnetic resonance imaging studies using region of interest analysis and voxel-based morphometry (VBM) revealed quite inconsistent findings. Hence, there is no clear evidence so far for core regions of cortical or subcortical structural abnormalities in bipolar disorder. The aim of this study was to investigate grey and white matter volumes in a large sample of patients with bipolar I disorder.

METHODS

Thirty-five patients with bipolar I disorder and 32 healthy controls matched with respect to gender, handedness and education participated in the study. MRI scanning was performed and an optimized VBM analysis was conducted.

RESULTS

We could not observe any significant differences of grey or white matter volumes between patients with bipolar disorder and healthy control subjects. Additional analyses did not reveal significant correlations between grey or white matter volume with number of manic or depressive episodes, duration of illness, existence of psychotic symptoms, and treatment with lithium or antipsychotics.

CONCLUSIONS

With this VBM study we were not able to identify core regions of structural abnormalities in bipolar disorder.