Voxel-based Morphometry Analysis Research Articles

Progressive loss of cortical gray matter in first episode psychosis patients with auditory hallucinations

BackgroundPrevious longitudinal magnetic resonance imaging studies have shown progressive gray matter (GM) reduction during the earliest phases of schizophrenia. It is unknown whether these progressive processes are homogeneous in all groups of patients. One way to obtain more valid findings is to focus on the symptoms. Auditory hallucinations (AHs) are frequent and reliable symptoms of psychosis. The present study aims to analyze whether longitudinal changes in structural abnormalities in cortical regions are related to the presence of AHs and the intensity of psychotic symptoms in a large sample. MethodsA Magnetic Resonance (MR) voxel-based morphometry analysis was applied to a group of 128 first episodes psychosis (FEP) patients (63 patients with AHs and 65 patients without AHs) and 78 matched healthy controls at baseline and at a 2-year follow-up. ResultsAt baseline, FEP patients exhibited significant GM volume reductions in the temporal, frontal and precentral regions. At follow-up, FEP patients exhibited GM volume changes in the temporal, Rolandic, frontal, precentral and insula regions. At baseline, no significant differences were found between FEP patients with and without AHs. At follow-up, while FEP patients with AHs showed less GM volume in temporal and frontal lobes, non-AH FEP patients showed reductions in the frontal, precentral and fusiform areas. PANSS scores showed statistically significant correlations with GM volume reductions at baseline and follow-up. ConclusionsBrain cortical loss in the early phases of psychosis is not associated with potentially transitory AHs; however, brain structural changes may emerge as AHs appear in chronic patients.

Volumetric and cognitive findings in transient global amnesia: results of the FORGOT cohort

AbstractBackgroundTransient global amnesia (TGA) is a sudden onset syndrome of episodic amnesia with unclear pathophysiology. Although expected to last less than 24 hours, different studies described persistent cognitive impairment primarily in memory and executive functions. We aim to analyze the cognitive performance and cortical volume of patients after a TGA as contributing factors to its pathophysiology.MethodCase‐control study of matched TGA subjects (n = 50) and normal controls (NC) (n = 50). All were studied with brain MRI with volumetric T1 sequences (in TGA subjects performed 1.4 months after the episode (SD±3.4)). Voxel‐based morphometry (VBM), region‐based morphometry (RBM) and surface‐based morphometry (SBM) steps were performed using an extension of the software package SPM12. All subjects were evaluated with a modified UDS3 neuropsychological battery. TGA patients were assesed 3 months after the event to avoid confusors. A deficit in each cognitive domain was diagnosed when individuals scored below ‐1.5 SD for normal values for age, sex and education. Anxiety, depression and cognitive complaints were also assessed. For VBM and RBM, a two‐sample independent t‐test was modeled and estimated with TIV, sex, and age as covariates. For SBM, a two‐sample independent t‐test without covariates was modeled and estimated. We applied the FDR method for multiple comparison corrections and defined a p<.05 threshold for statistical significance.ResultAmong 50 patients with TGA, 54% were female. Mean age was 66 (±9). No significant differences were found in VBM analysis. In the RBM test, we observed reduced volume in the left accumbens nucleus (figure 1) and in SBM, reduced cortical thickness on the right temporal pole and ventromedial visual area 2 (figure 2). No differences were found among cognitive performance between TGA and control patients (table 1).ConclusionThe absence of abnormalities in cortical volume and cognitive failure beyond three months of the event affirms the transient nature of the episode and dispells the association with a neurodegenerative disease as a predisposing factor. SBM abnormalities in distant regions may suggest a network disruption beyond the hippocampus.

Functional neuroanatomic validity of a novel, smartphone‐based remote assessment of processing speed in early Alzheimer’s Disease

AbstractBackgroundThe quantification of information processing speed (IPS) and its changes over time is a cornerstone of neuropsychological assessment for early Alzheimer’s disease (eAD). Additionally, clinical practice and drug development increasingly require tools enabling the remote assessment of cognition. We previously reported the feasibility, reliability and clinical validity of a novel, smartphone‐based IPS test remotely self‐administered to healthy controls (HC) and individuals with subjective cognitive decline (SCD) and eAD. The present study performed whole‐brain voxel‐based morphometry (VBM) analyses to determine whether smartphone‐based IPS performance indeed correlated with atrophy of brain regions known to support processing speed.Method31 HC, 31 SCDn (amyloid‐PET negative), 31 SCDp (amyloid‐PET positive) and 30 eAD individuals participated in a Alzheimer’s Digital Assessment Suite (AD‐DAS) Proof‐of‐Concept study (https://www.isrctn.com/ISRCTN17035495). Participants performed 9 IPS assessments (90s digit‐symbol matching) over 28 days on provisioned smartphones. Each response sequence and digit‐symbol pairing was novel and matched for difficulty within/across sessions.High‐resolution anatomic, T1‐weighted MRI were submitted to whole‐brain VBM analyses (Computational Anatomy Toolbox, SPM12/Matlab 2021) testing whether performance (number correct) correlated with gray matter signal intensities (covariates: age, gender, years of education, study site, total intracranial volume). The statistical parametric map was thresholded at p<0.001 uncorrected (voxel‐level) and family‐wise error corrected p<0.05 (cluster‐level). Peak voxel MNI coordinates and t‐values, cluster‐level p‐values are reported.ResultPoor smartphone‐based IPS performance correlated with atrophy in five regions centered in: (1) right insula (57, ‐14, 15; t = 5.83; p<0.0001), (2) right lingual gyrus (14, ‐64, ‐8; t = 5.21; p = 0.006), (3) left hippocampus (‐36, ‐24, ‐16; t = 4.83; p = 0.021), (4) left precuneus (‐10, ‐57, 26; t = 4.73; p = 0.017), (5) right fusiform gyrus (27, ‐38, ‐15; t = 4.69; p = 0.043), replicating previous functional MRI findings with IPS (lingual gyrus, precuneus) and known neuroanatomical correlates of working memory (insula, hippocampus).ConclusionThese findings support the functional neuroanatomic validity of a novel smartphone‐based IPS task and thus remote, clinically meaningful characterization of preclinical/early AD individuals’ IPS impairments in clinical monitoring and drug trials.

A proposed scheme for comprehensive and systematic evaluation of normal pressure hydrocephalus

AbstractBackgroundAs ageing population continues to rise across the globe, age‐related conditions such as normal pressure hydrocephalus (NPH) are expected to become a prevalent health problem effecting gait and cognition in the elderly. Alas, the vague definition of NPH, coupled with the absence of standardized assessment protocols, can potentially result in unnecessary surgical interventions and complications. We aim to demonstrate the feasibility of our proposed objective scheme for a comprehensive and systematic evaluation of NPH, which we anticipate will be beneficial in guiding future management of this enigmatic disorder.MethodParticipants suspected of idiopathic NPH (iNPH) selected to undergo a trial of fluid diversion (i.e. large volume spinal tap) were enrolled to receive structured assessment with various biomarkers. This assessment includes pre‐fluid diversion evaluation of the following: iNPH grading scale (Kubo et al., 2008), voxel based morphometry analysis of the MRI, tablet‐based digitalized Montreal Cognitive Assessment, International Consultation on Incontinence Questionnaires, urodynamic studies. Tests that were conducted both pre‐ and post‐fluid diversion test included actigraphy, video gait analysis using Kinovea®, in‐house tablet‐based go/no‐go test and conjunction search test. During the fluid diversion trial, participants underwent an infusion test for objective quantification of cerebrospinal fluid dynamics. Cerebrospinal fluid was collected and analyzed for levels of Alzheimer’s disease biomarkers, specifically Aβ and tau species, using ELISA, as well as an α‐synuclein seeding assay. The decision to operate was made according to subjective improvement, which is the current standard of care, and subsequent assessments were repeated at 4‐month intervals for 1, 2, and 3 years postoperativelyResultBetween May 2022 and November 2022, six participants were recruited. Each test was completed by at least three out of the six participants. The participant who completed the most tests completed all but one of the tests. It is important to note that none of the participants recruited underwent shunt surgery.ConclusionThe proposed scheme for the assessment of NPH demonstrates feasibility, however, certain optimizations are necessary. Further research should be conducted to determine the correlation between these parameters and their performance in predicting long‐term responsiveness to shunt surgery.

Convergent and clinical validity of a remote smartphone‐based self‐assessment of cognition, function, and behavior in early Alzheimer’s disease

AbstractBackgroundTrials in early Alzheimer’s disease (eAD) require the quantification of cognitive and functional progression. Compared with traditional in‐clinic assessments, remote assessments via digital health technologies (DHT) enable the collection of a broader palette of cognitive and functional measures at higher frequency and in patients' home environments. However, these must demonstrate validity against standard clinical outcome measures and relevant biomarkers. To this end, the present study aims to determine the reliability, convergent clinical, and functional neuroanatomic validity of a novel DHT, the Alzheimer’s Disease Digital Assessment Suite (AD‐DAS), for individuals on the AD continuum.MethodsIn total, 123 participants from 2 countries across 5 sites (3 USA, 2 Spain) participated (https://www.isrctn.com/ISRCTN17035495): 32 healthy controls (HC), 31 amyloid‐PET negative and 30 amyloid‐PET positive subjective cognitive decline (SCDn, SCDP, respectively), and 30 eAD. All participants completed standard in‐clinic neuropsychological assessments and remotely performed the AD‐DAS tasks daily for 28 days without supervision. AD‐DAS comprised 9 active tasks of cognitive/motor functioning and 4 survey questionnaires. Convergent and clinical validity analysis were performed using linear and proportional odds logistic regression modeling with age, sex, education, and site as covariates, respectively. Functional neuroanatomic validity was tested with voxel‐based morphometry (VBM) analyses with anatomic MRIs.ResultsOutcome metrics from all AD‐DAS cognitive/motor tasks correlated with their corresponding clinical comparators (ρpartial (range) = 0.16 ‐ 0.52), supporting their convergent validity. Similarly, outcome metrics from all tasks significantly differentiated the eAD from all the other groups in the expected directions (odds ratio (range) = 0.01 ‐ 61), supporting their clinical validity. The reliability of the outcome metrics ranged from good to excellent (interclass correlation coefficient (range) = 0.71 ‐ 0.91). VBM analyses provided independent and largely confirmatory results, further validating the AD‐DAS.ConclusionsThe AD‐DAS remote, smartphone‐based assessments of cognition show good to excellent test‐retest reliability, and preliminary analyses indicate that they may show convergent, clinical and exploratory functional neuroanatomic validity. Thus, these results provide a foundation for building towards the overarching goals of remote screening, prediction of progression, and monitoring of cognitive decline for future clinical trials and clinical care for preclinical and eAD.

Convergent and clinical validity of a remote smartphone‐based self‐assessment of cognition, function, and behavior in early Alzheimer’s disease

AbstractBackgroundTrials in early Alzheimer’s disease (eAD) require the quantification of cognitive and functional progression. Compared with traditional in‐clinic assessments, remote assessments via digital health technologies (DHT) enable the collection of a broader palette of cognitive and functional measures at higher frequency and in patients' home environments. However, these must demonstrate validity against standard clinical outcome measures and relevant biomarkers. To this end, the present study aims to determine the reliability, convergent clinical, and functional neuroanatomic validity of a novel DHT, the Alzheimer’s Disease Digital Assessment Suite (AD‐DAS), for individuals on the AD continuum.MethodIn total, 123 participants from 2 countries across 5 sites (3 USA, 2 Spain) participated (https://www.isrctn.com/ISRCTN17035495): 32 healthy controls (HC), 31 amyloid‐PET negative and 30 amyloid‐PET positive subjective cognitive decline (SCDn, SCDP, respectively), and 30 eAD. All participants completed standard in‐clinic neuropsychological assessments and remotely performed the AD‐DAS tasks daily for 28 days without supervision. AD‐DAS comprised 9 active tasks of cognitive/motor functioning and 4 survey questionnaires. Convergent and clinical validity analysis were performed using linear and proportional odds logistic regression modeling with age, sex, education, and site as covariates, respectively. Functional neuroanatomic validity was tested with voxel‐based morphometry (VBM) analyses with anatomic MRIs.ResultOutcome metrics from all AD‐DAS cognitive/motor tasks correlated with their corresponding clinical comparators (ρpartial (range) = 0.16 ‐ 0.52), supporting their convergent validity. Similarly, outcome metrics from all tasks significantly differentiated the eAD from all the other groups in the expected directions (odds ratio (range) = 0.01 ‐ 61), supporting their clinical validity. The reliability of the outcome metrics ranged from good to excellent (interclass correlation coefficient (range) = 0.71 ‐ 0.91). VBM analyses provided independent and largely confirmatory results, further validating the AD‐DAS.ConclusionThe AD‐DAS remote, smartphone‐based assessments of cognition show good to excellent test‐retest reliability, and preliminary analyses indicate that they may show convergent, clinical and exploratory functional neuroanatomic validity. Thus, these results provide a foundation for building towards the overarching goals of remote screening, prediction of progression, and monitoring of cognitive decline for future clinical trials and clinical care for preclinical and eAD.

Functional Connectivity Change Associated With Apolipoprotein E Allotypes Precedes Structural Connectivity and Neurodegeneration in Cognitive Normal Older Adults Without Cerebral Aβ Deposition.

Apolipoprotein E (APOE) gene is known to influence cerebral functional connectivity (FC) in Alzheimer's disease continuum. We investigated association between APOE allotypes and FC, structural connectivity, and cortical thickness in amyloid-PET negative cognitive normal older adults (CN). A total of 188 CN (37 had ε2/ε2 or ε2/ε3 [ε2 group], 113 had ε3/ε3 [ε3 group], and 38 had ε3/ε4 or ε4/ε4 [ε4 group]) were recruited. Voxel-based morphometry and cortical thickness analysis were used to investigate differences in cortical thickness between three APOE allotypes. To investigate integrity of structural connectivity, we analyzed diffusion weighted imaging using fractional anisotropy and mean diffusivity. In terms of FC, differences of FC in default mode network (DMN) among APOE allotypes were measured using functional magnetic resonance imaging. There were no significant differences in age, sex, education, cerebral beta-amyloid (Aβ) deposition severity, or neuropsychological profiles. No significant differences were found in cortical thickness and structural connectivity among the APOE allotypes. However, FC within the DMN was significantly lower in ε4 and ε2 carriers compared to ε3 homozygotes. This study suggests that both ε4 and ε2 exhibit APOE-associated DMN FC changes before Aβ deposition, structural changes, and neurodegeneration.

Changes in Multiparametric Magnetic Resonance Imaging and Plasma Amyloid-Beta Protein in Subjective Cognitive Decline.

The association between plasma amyloid-beta protein (Aβ) and subjective cognitive decline (SCD) remains controversial. We aimed to explore the correlation between neuroimaging findings, plasma Aβ, and neuropsychological scales using data from 53 SCD patients and 46 age- and sex-matched healthy controls (HCs). Magnetic resonance imaging (MRI) was used to obtain neuroimaging data for a whole-brain voxel-based morphometry analysis and cortical functional network topological features. The SCD group had slightly lower Montreal Cognitive Assessment (MoCA) scores than the HC group. The Aβ42 levels were significantly higher in the SCD group than in the HC group (p < 0.05). The SCD patients demonstrated reduced volumes in the left hippocampus, right rectal gyrus (REC.R), and right precentral gyrus (PreCG.R); an increased percentage fluctuation in the left thalamus (PerAF); and lower average small-world coefficient (aSigma) and average global efficiency (aEg) values. Correlation analyses with Aβ and neuropsychological scales revealed significant positive correlations between the volumes of the HIP.L, REC.R, PreCG.R, and MoCA scores. The HIP.L volume and Aβ42 were negatively correlated, as were the REC.R volume and Aβ42/40. PerAF and aSigma were negatively and positively correlated with the MoCA scores, respectively. The aEg was positively correlated with Aβ42/40. SCD patients may exhibit alterations in plasma biomarkers and multi-parameter MRI that resemble those observed in Alzheimer's disease, offering a theoretical foundation for early clinical intervention in SCD.

Clinical subtypes in patients with isolated REM sleep behaviour disorder

Patients with Parkinson’s disease (PD) show a broad heterogeneity in clinical presentation, and subtypes may already arise in prodromal disease stages. Isolated REM sleep behaviour disorder (iRBD) is the most specific marker of prodromal PD, but data on clinical subtyping of patients with iRBD remain scarce. Therefore, this study aimed to identify iRBD subtypes. We conducted comprehensive clinical assessments in 66 patients with polysomnography-proven iRBD, including motor and non-motor evaluations, and applied a two-step cluster analysis. Besides, we compared iRBD clusters to matched healthy controls and related the resulting cluster solution to cortical and subcortical grey matter volumes by voxel-based morphometry analysis. We identified two distinct subtypes of patients based on olfactory function, dominant electroencephalography frequency, amount of REM sleep without atonia, depressive symptoms, disease duration, and motor functions. One iRBD cluster (Cluster I, late onset—aggressive) was characterised by higher non-motor symptom burden despite shorter disease duration than the more benign subtype (Cluster II, early onset—benign). Motor functions were comparable between the clusters. Patients from Cluster I were significantly older at iRBD onset and exhibited a widespread reduction of cortical grey matter volume compared to patients from Cluster II. In conclusion, our findings suggest the existence of clinical subtypes already in the prodromal stage of PD. Future longitudinal studies are warranted that replicate these findings and investigate the risk of the more aggressive phenotype for earlier phenoconversion and dementia development.

The functional connectivity between right parahippocampal gyrus and precuneus underlying the association between reward sensitivity and procrastination

Procrastination has adverse effects on personal growth and social development. Behavior research has found reward sensitivity is positively correlated with procrastination. However, it remains unclear that the neural substrates underlie the relationship between reward sensitivity and procrastination. To address this issue, the present study used voxel-based morphometry (VBM) and resting-state functional connectivity (RSFC) analyses to investigate the neural substrates underlying the association with reward sensitivity and procrastination in two independent samples (N1 = 388, N2 = 330). In Sample 1, the behavioral result indicated reward sensitivity was positively correlated with procrastination. Moreover, the VBM analysis showed that reward sensitivity was positively associated with the gray matter volume (GMV) of the right parahippocampal gyrus. Furthermore, the RSFC result found reward sensitivity was negatively associated with the functional connectivity of the right parahippocampal gyrus-precuneus. Crucially, the mediation analysis revealed that functional connectivity of the right parahippocampal gyrus-precuneus mediated the relationship between reward sensitivity and procrastination. To verify the robustness of the results, confirmatory analysis was carried out in Sample 2. The results of Sample 1 (i.e., the behavioral, VBM, RSFC, and mediation results) can be verified in Sample 2. In brief, these findings suggested that the functional connectivity of the right parahippocampal gyrus-precuneus involved in reward impulsive control could modulate the relationship between reward sensitivity and procrastination, which is the first to reveal the neural underpinning of the association between reward sensitivity and procrastination.

Low bone mineral density is associated with gray matter volume decrease in UK Biobank.

Previous research has found an association of low bone mineral density (BMD) and regional gray matter (GM) volume loss in Alzheimer's disease (AD). We were interested whether BMD is associated with GM volume decrease in brains of a healthy elderly population from the UK Biobank. T1-weighted images from 5,518 women (MAge = 70.20, SD = 3.54; age range: 65-82 years) and 7,595 men (MAge = 70.84, SD = 3.68; age range: 65-82 years) without neurological or psychiatric impairments were included in voxel-based morphometry (VBM) analysis in CAT12 with threshold-free-cluster-enhancement (TFCE) across the whole brain. We found a significant decrease of GM volume in women in the superior frontal gyri, middle temporal gyri, fusiform gyri, temporal poles, cingulate gyri, precunei, right parahippocampal gyrus and right hippocampus, right ventral diencephalon, and right pre- and postcentral gyrus. Only small effects were found in men in subcallosal area, left basal forebrain and entorhinal area. BMD is associated with low GM volume in women but less in men in regions afflicted in the early-stages of AD even in a sample without neurodegenerative diseases.

Neuroanatomical differences in Latinx children from rural farmworker families and urban non-farmworker families and related associations with pesticide exposure

Exposure to pesticides in humans may lead to changes in brain structure and function and increase the likelihood of experiencing neurodevelopmental disorders. Despite the potential risks, there is limited neuroimaging research on the effects of pesticide exposure on children, particularly during the critical period of brain development. Here we used voxel-based morphometry (VBM) and diffusion tensor imaging (DTI) from magnetic resonance images (MRI) to investigate neuroanatomical differences between Latinx children (n = 71) from rural, farmworker families (FW; n = 48) and urban, non-farmworker families (NFW; n = 23). Data presented here serves as a baseline for our ongoing study examining the longitudinal effects of living in a rural environment on neurodevelopment and cognition in children. The VBM analysis revealed that NFW children had higher volume in several distinct regions of white matter compared to FW children. Tract-based spatial statistics (TBSS) of DTI data also indicated NFW children had higher fractional anisotropy (FA) in several key white matter tracts. Although the difference was not as pronounced as white matter, the VBM analysis also found higher gray matter volume in selected regions of the frontal lobe in NFW children. Notably, white matter and gray matter findings demonstrated a high degree of overlap in the medial frontal lobe, a brain region predominantly linked to decision-making, error processing, and attention functions. To gain further insights into the underlying causes of the observed differences in brain structure between the two groups, we examined the association of organochlorine (OC) and organophosphate (OP) exposure collected from passive dosimeter wristbands with brain structure. Based on our previous findings within this data set, demonstrating higher OC exposure in children from non-farmworker families, we hypothesized OC might play a critical role in structural differences between NFW and FW children. We discovered a significant positive correlation between the number of types of OC exposure and the structure of white matter. The regions with significant association with OC exposure were in agreement with the findings from the FW-NFW groups comparison analysis. In contrast, OPs did not have a statistically significant association with brain structure. This study is among the first multimodal neuroimaging studies examining the brain structure of children exposed to agricultural pesticides, specifically OC. These findings suggest OC pesticide exposure may disrupt normal brain development in children, highlighting the need for further neuroimaging studies within this vulnerable population.

Production of emotions conveyed by voice in Parkinson's disease: Association between variability of fundamental frequency and gray matter volumes of regions involved in emotional prosody.

Parkinson's disease (PD) is associated with impairment in producing emotions conveyed by voice which could depend on motor limitations of the vocal apparatus and/or alterations in emotional processing. This study explores the relationship between the standard deviation of fundamental frequency (F0SD) of emotional speech and the volume of specific gray matter regions. Fifteen PD patients and 15 healthy controls (HC) were asked to produce different emotions vocally elicited by reading short stories. For each vocal track, the F0SD was calculated as index of variability. All subjects underwent a structural magnetic resonance imaging and a voxel-based morphometry analysis. An ad hoc mask of brain regions implicated in emotional prosody was constructed to test the relationship between F0SD and the level of brain atrophy. PD patients showed lower F0SD values than HC in the expression of anger. Neuroimaging results showed brain atrophy in PD patients in a widespread bilateral network, including frontal areas, left cingulate cortex, parietal areas as well as occipital cortices. In the PD group, a positive correlation was observed between F0SD values of anger and volumes of the bilateral supramarginal gyrus, left thalamus, right inferior frontal gyrus, and amygdala. The lower F0SD values observed in PD patients in anger production are consistent with their lower ability to express anger effectively through voice compared to HC. Our data demonstrated the involvement of right-lateralized areas, such as the inferior frontal gyrus and amygdala, which are typically involved in emotional prosody. Disturbances in emotion processing might contribute to speech production deficits in PD, probably in addition to the motor impairment of the articulatory system. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Neuroanatomical Correlates of Cognitive Tests in Young-onset MCI.

Mild Cognitive Impairment (MCI) is a heterogeneous condition characterised by cognitive changes that do not affect everyday functioning and may represent a predementia phase. Research on the neuroanatomical correlates of cognitive tests used to diagnose MCI is heterogeneous and has mainly focused on elderly populations of patients with MCI, usually well above the age of 65. However, the effect of ageing on brain structure is known to be substantial and to affect brain-behaviour associations in older people. We explored the brain correlates of different cognitive tests in a group of young-onset MCI (i.e., with symptoms onset before the age of 65) to minimise the effect of ageing on brain-behaviour associations. Patients with a clinical diagnosis of young-onset MCI underwent extensive cognitive assessment and multimodal Magnetic Resonance Imaging (MRI) including high-resolution T1-weighted and Diffusion Tensor Imaging (DTI) sequences. Their scores on cognitive tests were related to measures of grey matter (GM) density and white matter (WM) integrity using, respectively, Voxel Based Morphometry (VBM) and Tract-Based Spatial Statistics (TBSS). 104 young-onset MCI were recruited. VBM and TBSS whole-brain correlational analyses showed that between-subject variability in cognitive performance was significantly associated with regional variability in GM density and WM integrity. While associations between cognitive scores and focal GM density in our young-onset MCI group reflected the well-known lateralization of verbal and visuo-spatial abilities on the left and right hemispheres respectively, the associations between cognitive scores and WM microstructural integrity were widespread and diffusely involved most of the WM tracts in both hemispheres. We investigated the structural neuroanatomical correlates of cognitive tests in young-onset MCI in order to minimise the effect of ageing on brain-behaviour associations.

Cognitive empathy mediates the relationship between gray matter volume size of dorsomedial prefrontal cortex and social network size: A voxel-based morphometry study

Social networks are an important factor in developing and maintaining social relationships. The social brain network comprises brain regions that differ in terms of their location, structure, and functioning, and these differences tend to vary among individuals with different social network sizes. However, it remains unknown how social cognitive abilities such as empathy can affect social network size. The goal of our study was to examine the relationship between brain regions in the social brain network, empathy, and individual social network size by using the Social Network Index, which measures social network diversity, size, and complexity by assessing 12 different types of relationships. We performed voxel-based morphometry and mediation analyses using data from questionnaires and structural magnetic resonance imaging data in a sample of 204 young adults. Our findings showed that the gray matter volume of the dorsomedial prefrontal cortex (dmPFC) was inversely associated with social network size and cognitive empathy mediated this association, suggesting that decreased gray matter volume in the dmPFC is associated with greater utilization of cognitive empathy, which, in turn, seems to increase social network size. A potential mechanism explaining this inverse relationship could be cognitive pruning, a phenomenon that occurs in the brain between early adolescence and adulthood, but future longitudinal studies are needed. In conclusion, our findings provide information about the neurocognitive mechanisms involved in the formation and maintenance of social networks.

Structural and Functional Alterations of Motor-Thalamus in Different Motor Subtype of Parkinson’s Disease: An Individual Study

This study aimed to investigate the structural and functional alterations occurring within bilateral premotor thalamus (mPMtha) in motor subtypes of Parkinson's disease (PD). Sixty-one individuals with instability and gait difficulty (PIGD) subtype, 60individuals with tremor-dominant (TD) subtype and 66healthy controls (HCs) participated in the study. All participants underwent resting-state functional magnetic resonance imaging (rs-fMRI) and 3D T1-weighted (3DT1) scans. Functional connectivity (FC) analysis and Voxel-based morphometry (VBM) analysis were performed to evaluate the function and volume of mPMtha. Additionally, correlations between motor performance and FC values, volumes were examined separately. Support vector machine (SVM) model based on FC values and thalamic volumes was conducted to assist in the clinical diagnosis of PD motor subtype. Compared toHCs and PIGD, TD subtype showed increased FC between the bilateral mPMtha and left middle occipital gyrus, left inferior parietal lobule (IPL). While PIGD subtype demonstrated decreased FC between right mPMtha and precentral gyrus (PreCG), supramarginal, IPL and superior parietal lobule. FC of bilateral mPMtha with the identified regions were significantly correlated with motor performance scores in PD patients. The SVM classification based on FC values demonstrated a high level of efficiency (AUC=0.874). The volumes of the bilateral mPMtha were indifferent among three groups. We noted distinct FC alterations of mPMtha in TD and PIGD subtypes, and these changes were correlated with motor performance. Furthermore, the machine learning based on statistically significant FC might be served as an alternative approach for automatically classifying PD motor subtypes individually.

Cognitive impairment associated with cerebellar volume loss in spinocerebellar ataxia type 3.

Many neuroscience and neurology studies have forced a reconsideration of the traditional motor-related scope of cerebellar function, which has now expanded to include various cognitive functions. Spinocerebellar ataxia type 3 (SCA3; the most common hereditary ataxia) is neuropathologically characterized by cerebellar atrophy and frequently presents with cognitive impairment. To characterize cognitive impairment in SCA3 and investigate the cerebellum-cognition associations. This prospective, cross-sectional cohort study recruited 126 SCA3 patients and 41 healthy control individuals (HCs). Participants underwent a brain 3D T1-weighted images as well as neuropsychological tests. Voxel-based morphometry (VBM) and region of interest (ROI) approaches were performed on the 3D T1-weighted images. CERES was used to automatically segment cerebellums. Patients were grouped into cognitively impaired (CI) and cognitively preserved (CP), and clinical and MRI parameters were compared. Multivariable regression models were fitted to examine associations between cerebellar microstructural alterations and cognitive domain impairments. Compared to HCs, SCA3 patients showed cognitive domain impairments in information processing speed, verbal memory, executive function, and visuospatial perception. Between CI and CP subgroups, the CI subgroup was older and had lower education, as well as higher severity scores. VBM and ROI analyses revealed volume loss in cerebellar bilateral lobule VI, right lobule Crus I, and right lobule IV of the CI subgroup, and all these cerebellar lobules were associated with the above cognitive domain impairments. Our findings demonstrate the multiple cognitive domain impairments in SCA3 patients and indicate the responsible cerebellar lobules for the impaired cognitive domain(s).

Gray matter volume abnormalities in obsessive-compulsive disorder correlate with molecular and transcriptional profiles

Neuroimaging studies have consistently established altered brain structure in obsessive-compulsive disorder (OCD). However, the molecular and genetic mechanisms underlying structural brain abnormalities remain unclear. In this study, we aimed to investigate altered gray matter volume and its underlying molecular and genetic mechanisms in patients with OCD. Gray matter morphological abnormalities measured with voxel based morphometry analysis were identified in patients with OCD in comparison to sex- and age-matched healthy controls (HCs). Spatial correlations between gray matter morphological abnormalities and neurotransmitter maps were calculated to identify neurotransmitters relating to structural abnormalities. Structural abnormalities related genes were identified by conducting transcriptome-neuroimaging spatial correlations. Compared with HCs, patients with OCD demonstrated significant morphological abnormalities in distributed brain areas, including gray matter atrophy in the anterior cingulate and increased gray matter volume in the thalamus, caudate and precentral and postcentral gyrus. The morphological abnormalities were significantly associated with dopamine synthesis capacity and expression profiles of 1110 genes enriched for trans-synaptic signaling, regulation of membrane potential, modulation of chemical synaptic transmission, brain development, synapse organization and regulation of neurotransmitter levels. These results elucidate the molecular and transcriptional basis of altered gray matter morphology and build linking between molecular, transcriptional and neuroimaging information facilitating an integrative understanding of OCD.

Association between internet addiction, brain structure, and social capital in adolescents

ABSTRACTOf late, internet addiction among adolescents has become a serious problem, with increased internet use. Previous research suggests that the more people become addicted to the internet, the more they isolate themselves from society. Conversely, it has been suggested that abundant social capital (the networks of relationships among people who live and work in a particular society) protects people from becoming addicted to the internet. This study focused on the brain structure of typical adolescents (10–18 years of age) and hypothesized that the size of the left dorsolateral prefrontal cortex (DLPFC), which is thought to be associated with self-control ability, is associated with both internet addiction and social capital. Voxel-based morphometry analysis indicated that left DLPFC volume was negatively correlated with the severity of internet addiction and positively correlated with social capital. Furthermore, correlation analysis demonstrated that the severity of internet addiction and social capital were negatively correlated. The statistical association between them was no longer significant when left DLPFC volume was used as a control variable. These results suggest that the left DLPFC may mediate the relationship between social capital and internet addiction in adolescents.

Comparison of two corticosteroid regimens on brain volumetrics in patients with Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is a neuromuscular disorder in which many patients also have neurobehavioral problems. Corticosteroids, the primary pharmacological treatment for DMD, have been shown to affect brain morphology in other conditions, but data in DMD are lacking. This study aimed to investigate the impact of two corticosteroid regimens on brain volumetrics in DMD using magnetic resonance imaging (MRI). In a cross-sectional, two-center study, T1-weighted MRI scans were obtained from three age-matched groups (9-18 years): DMD patients treated daily with deflazacort (DMDd, n = 20, scan site: Leuven), DMD patients treated intermittently with prednisone (DMDi, n = 20, scan site: Leiden), and healthy controls (n = 40, both scan sites). FSL was used to perform voxel-based morphometry analyses and to calculate intracranial, total brain, gray matter, white matter, and cerebrospinal fluid volumes. A MANCOVA was employed to compare global volumetrics between groups, with site as covariate. Both patient groups displayed regional differences in gray matter volumes compared to the control group. The DMDd group showed a wider extent of brain regions affected and a greater difference overall. This was substantiated by the global volume quantification: the DMDd group, but not the DMDi group, showed significant differences in gray matter, white matter, and cerebrospinal fluid volumes compared to the control group, after correction for intracranial volume. Volumetric differences in the brain are considered part of the DMD phenotype. This study suggests an additional impact of corticosteroid treatment showing a contrast between pronounced alterations seen in patients receiving daily corticosteroid treatment and more subtle differences in those treated intermittently.