Structural Magnetic Resonance Imaging Studies Research Articles

Clinical and neuroimaging aspects of formal thought disorder in schizophrenia: a brief narrative review

Aim. To analyze current sources regarding the clinical and neuroimaging aspects of formal thought disorder (FTD) in patients with schizophrenia to create an up-to-date pathogenetic model of its main forms. Materials and methods. English-language publications in the Medline database (PubMed) were analyzed for this review. We analyzed only structural magnetic resonance imaging (MRI) studies in which a clear clinical assessment of FTD in schizophrenia is provided and the neuroimaging protocol meets generally accepted standards (as in the ENIGMA Schizophrenia Working Group). For the clinical division of FTD, positive and negative FTD were distinguished according to the positive and negative syndrome scale (PANSS). Results. From a clinical point of view, FTD includes at least 30 phenomena. For clinical and neuroimaging studies, division into positive and negative FTD is used according to the PANSS. Positive FTD is manifested by the disorganization of thinking processes and exhibits mainly in violations of its purposeful sequence. Negative FTD is manifested by violations of the abstract-symbolic way of thinking, lack of spontaneity, and stereotyping. According to morphometric MRI data, atrophic changes in brain regions related to neuronal networks of cognition and impulse control (prefrontal and anterior cingulate cortex), emotional processing (amygdala), abstract thinking, and imagination (lateral occipital cortex) are important for the development of both forms of FTD. Negative FTD is mainly associated with damage to the prefronto-cingulate circles, which are the anatomical and functional substrates of executive functions. A unique feature of positive FTD is atrophy of the structures of the left temporal lobe, which leads to language disorders at the semantic level. Using the method of virtual histology, it was established that both forms of FTD are associated with bilateral changes in astrocytes and dendritic spines in the involved anatomical regions. A positive FTD is also associated with pathological changes in microglia in two hemispheres, while with a negative FTD, microglial damages are present only in the right hemisphere. Conclusions. Positive FTD in schizophrenia is mainly associated with atrophic (astroglial-microglial) processes of cognitive control networks, negative – with the atrophy of networks of semantic processing of verbal information. In both forms, networks of emotional processing, abstract thinking, and imagination are involved. Treatment strategies for FTD should include effects on astroglial and microglial dysfunction.

The Association Between Chronic Tobacco Smoking and Brain Alterations in Schizophrenia: A Systematic Review of Magnetic Resonance Imaging Studies.

The high co-occurrence of tobacco smoking in patients with schizophrenia spectrum disorders (SSD) poses a serious health concern, linked to increased mortality and worse clinical outcomes. The mechanisms underlying this co-occurrence are not fully understood. Addressing the need for a comprehensive overview of the impact of tobacco use on SSD neurobiology, we conducted a systematic review of neuroimaging studies (including structural, functional, and neurochemical magnetic resonance imaging studies) that investigate the association between chronic tobacco smoking and brain alterations in patients with SSD. Eight structural and fourteen functional studies were included. Structural studies show widespread independent and additive reductions in gray matter in relation to smoking and SSD. The majority of functional studies suggest that smoking might be associated with improvements in connectivity deficits linked to SSD. However, the limited number of and high amount of cross-sectional studies, and high between-studies sample overlap prevent a conclusive determination of the nature and extent of the impact of smoking on brain functioning in patients with SSD. Overall, functional results imply a distinct neurobiological mechanism for tobacco addiction in patients with SSD, possibly attributed to differences at the nicotinic acetylcholine receptor level. Our findings highlight the need for more longitudinal and exposure-dependent studies to differentiate between inherent neurobiological differences and the (long-term) effects of smoking in SSD, and to unravel the complex interaction between smoking and schizophrenia at various disease stages. This could inform more effective strategies addressing smoking susceptibility in SSD, potentially improving clinical outcomes.

Abnormal Structure and Function of Parietal Lobe in Individuals With Attention Deficit Hyperactivity Disorder (ADHD): A Systematic Review Study

Introduction: Abnormal brain structure and function have been reported in individuals with attention deficit hyperactivity disorder (ADHD). This study investigated the parietal lobe structure and function alteration in individuals with ADHD. Methods: In this systematic review, we searched English papers in accordance with the PRISMA (the preferred reporting items for systematic reviews and meta-analyses) approach. Studies were published between January 2010 and May 2021. Our search was conducted in two parts. Our first search was in July 2020, and our final search was in June 2021. A literature search identified 20 empirical experiments. Results: Functional magnetic resonance imaging (MRI) studies generally reported low activity and poor connectivity; structural MRI studies reported less gray matter in this lobe, and an echo study reported atrophy. In addition, electroencephalographic studies reported less connectivity of the parietal lobes in ADHD. Furthermore, the transcranial direct current stimulation intervention has shown that activation of this lobe improves attention and executive functions in children with ADHD. Finally, a deep transcranial magnetic stimulation study has demonstrated that activation of this lobe improves working memory. Conclusion: Functional and structural alteration of the parietal cortex has been reported in ADHD, which has a causal relationship with cognitive impairments. In sum, all included studies reported abnormal structure, function, or connectivity of the parietal lobe or improvement of cognitive functions with parietal lobe stimulation.

Effects of electroconvulsive therapy on cortical thickness in depression: a systematic review.

Electroconvulsive therapy (ECT) is one of the most studied and validated available treatments for severe or treatment-resistant depression. However, little is known about the neural mechanisms underlying ECT. This systematic review aims to critically review all structural magnetic resonance imaging studies investigating longitudinal cortical thickness (CT) changes after ECT in patients with unipolar or bipolar depression. We performed a search on PubMed, Medline, and Embase to identify all available studies published before April 20, 2023. A total of 10 studies were included. The investigations showed widespread increases in CT after ECT in depressed patients, involving mainly the temporal, insular, and frontal regions. In five studies, CT increases in a non-overlapping set of brain areas correlated with the clinical efficacy of ECT. The small sample size, heterogeneity in terms of populations, comorbidities, and ECT protocols, and the lack of a control group in some investigations limit the generalisability of the results. Our findings support the idea that ECT can increase CT in patients with unipolar and bipolar depression. It remains unclear whether these changes are related to the clinical response. Future larger studies with longer follow-up are warranted to thoroughly address the potential role of CT as a biomarker of clinical response after ECT.

Aging, cingulate cortex, and cognition: insights from structural MRI, emotional recognition, and theory of mind.

The cingulate cortex is a limbic structure involved in multiple functions, including emotionalprocessing, pain, cognition, memory, and spatial orientation. The main goal of this structural Magnetic Resonance Imaging (MRI) study was to investigate whether age affects the cingulate cortex uniformly across its anteroposterior dimensions and determine if the effects of age differ based on sex, hemisphere, and regional cingulate anatomy, in a large cohort of healthy individuals across the adult lifespan. The second objective aimed to explore whether the decline in emotional recognition accuracy and Theory of Mind (ToM) is linked to the potential age-related reductions in the pregenual anterior cingulate (ACC) and anterior midcingulate (MCC) cortices. We recruited 126 healthy participants (18-85years) for this study. MRI datasets were acquired on a 4.7T system. The cingulate cortex was manually segmented into the pregenual ACC, anterior MCC, posterior MCC, and posterior cingulate cortex (PCC). We observed negative relationships between the presence and length of the superior cingulate gyrus and bilateral volumes of pregenual ACC and anterior MCC. Age showed negative effects on the volume of all cingulate cortical subregions bilaterally except for the right anterior MCC. Most of the associations between age and the cingulate subregional volumes were linear. We did not find a significant effect of sex on cingulate cortical volumes. However, stronger effects of age were observed in men compared to women. This study also demonstrated that performance on an emotional recognition task was linked to pregenual ACC volume, whist the ToM capabilities were related to the size of pregenual ACC and anterior MCC. These results suggest that the cingulate cortex contributes to emotional recognition ability and ToM across the adult lifespan.

Возрастные особенности показателей структурной МРТ головного мозга и методы их квантификации

Understanding the formation of the trajectories of the brain structural development in relation to emotional and cognitive functions is an important scientific task for identifying and predicting the stages of brain maturation. This review systematically examines structural magnetic resonance imaging studies of the brain anatomical development in children and adolescents. The literature reveals inconsistency due to the difference in participants demographic groups and methodological approaches. Nevertheless, some patterns have been identified, such as age-related changes in the ratios of white and gray matter, thickness and area of the cerebral cortex both total and regional. The most observable results underline that the brain maturation is a heterochronous processes. For instance, the frontal region of the cerebral cortex has a longer maturation trajectory compared to the occipital region. Gender differences reflected in higher values of volume indicators have been identified in many studies. This article also describes the methods of quantification of structural magnetic resonance imaging, which allowed us to determine the value of more than two hundred parameters. There are some explanations of the advantage of the surface-based morphometry by using the FreeSurfer software, developed by the Computational Neuroimaging Laboratory at the A. A. Martinos Biomedical Imaging Center at Harvard University. The authors substantiate the necessity of further experimental studies of age-related changes in surface-based morphometry parameters in relation to emotional and cognitive functions in children from 7 to 20 years old.

Psychomotor slowing in schizophrenia is associated with cortical thinning of primary motor cortex: A three cohort structural magnetic resonance imaging study

Psychomotor slowing (PS) is characterized by slowed movements and lower activity levels. PS is frequently observed in schizophrenia (SZ) and distressing because it impairs performance of everyday tasks and social activities. Studying brain topography contributing to PS in SZ can help to understand the underlying neurobiological mechanisms as well as help to develop more effective treatments that specifically target affected brain areas. Here, we conducted structural magnetic resonance imaging (sMRI) of three independent cohorts of right-handed SZ patients (SZ#1: n = 72, SZ#2: n = 37, SZ#3: n = 25) and age, gender and education matched healthy controls (HC) (HC#1: n = 40, HC#2: n = 37, HC#3: n = 38). PS severity in the three SZ cohorts was determined using the Positive and Negative Syndrome Scale (PANSS) item #G7 (motor retardation) and Trail-Making-Test B (TMT-B). FreeSurfer v7.2 was used for automated parcellation and segmentation of cortical and subcortical regions. SZ#1 patients showed reduced cortical thickness in right precentral gyrus (M1; p = 0.04; Benjamini-Hochberg [BH] corr.). In SZ#1, cortical thinning in right M1 was associated with PANSS item #G7 (p = 0.04; BH corr.) and TMT-B performance (p = 0.002; BH corr.). In SZ#1, we found a significant correlation between PANSS item #G7 and TMT-B (p = 0.005, ρ=0.326). In conclusion, PANSS G#7 and TMT-B might have a surrogate value for predicting PS in SZ. Cortical thinning of M1 rather than alterations of subcortical structures may point towards cortical pathomechanism underlying PS in SZ.

Internalizing and externalizing behaviors in school-aged children are related to state anxiety during magnetic resonance imaging

Magnetic resonance imaging (MRI) procedures often evoke anxiety in children. Further, anxious children may be less likely to participate in MRI research, leading to a possible selection bias, and may be more likely to move during image acquisition, resulting in lower image quality and possible information bias. Therefore, state anxiety is problematic for functional and structural MRI studies. Children with behavioral problems, such as internalizing and externalizing behaviors, may be more likely to experience state anxiety prior to and during MRI scanning. Therefore, our first aim was to investigate the relationship between internalizing/externalizing behavior and children’s MRI-related state anxiety. Our second aim was to investigate the relationship between internalizing and externalizing behaviors and MRI research participation. Our final aim was to investigate the effect of internalizing and externalizing behaviors as well as MRI-related anxiety on image quality in children. We included 1,241 six- to ten-year-old children who underwent a mock MRI. Afterward, if not too anxious, these children were scanned using a 3-Tesla GE Discovery MRI system (n = 1,070). Internalizing and externalizing behaviors were assessed with the child behavior checklist. State anxiety was assessed with a visual analog scale. Internalizing behaviors were positively associated with child state anxiety, as reported by the child, parent, and researcher. For state anxiety reported by the parent and researcher, this relationship was independent of externalizing behaviors. Externalizing behaviors were related to state anxiety as reported by the child, parent, and researcher, but this difference was not independent of internalizing behaviors, pointing toward a relationship via the shared variance with internalizing behaviors. Further, children with more internalizing and externalizing behaviors were less likely to participate in the actual MRI-scanning procedure. Lastly, MRI-related state anxiety, reported by the child and the researcher, was associated with worse image quality. These results underscore the potential for biases and methodological issues related to MRI-related state anxiety in children.

APOEε4 genotype boosts neurodegenerative structural changes in medial temporal lobe areas in adults with Mild Cognitive Impairment

AbstractBackgroundApolipoprotein E ε4 allele (APOEε4) is considered the major genetic risk factor of Alzheimer´s Disease (AD). Structural magnetic resonance imaging (sMRI) studies demonstrated that, compared to APOEε4 non‐carriers, APOEε4 carriers display structural changes in lateral and medial temporal lobe (MTL). However, the knowledge about the impact of this genotype on hippocampal subfields is still limited. The present sMRI study aimed to evaluate volumetric and cortical thickness differences between adults with mild cognitive impairment (MCI) APOEε4 non‐carriers compared with MCI‐APOEε4 carriers.MethodTwelve MCI‐APOEε4 non‐carriers (mean age: 70.33 years, SD: 5.12) and ten MCI‐APOEε4 carriers (mean age: 72.70 years, SD: 6.38), diagnosed as MCI according Petersen criteria (Petersen, 2004; Albert et al., 2011), underwent neuropsychological assessment, cerebrospinal fluid, genetic and MRI examinations. MRI surface‐based morphometry analyses was conducted with the FreeSurfer software to evaluate volumetric and thickness differences in the hippocampal subfields and its surrounding MTL areas.ResultCompared with MCI‐APOEε4 non‐carriers, the MCI‐APOEε4 carriers group showed a significant reduced volume in several areas of the left hemisphere. Specifically, in this hemisphere volumetric changes were found in the entorhinal cortex, the whole hippocampus and in its head, body and tail; the head of presubiculum, the head and body of subiculum, the CA1, CA3, CA4 subfields, the granulate cell of the molecular layer of dentate gyrus and the molecular layer of the hippocampus. This group also displayed a significant reduced volume in the right body of CA3 subfield.ConclusionThese results suggest that, in MCI adults, the presence of the APOEε4 genotype may have an additional neuropathological impact on the structure of brain regions of the MTL with a critical functional role in episodic memory, the most affected neurocognitive system in Alzheimer’s disease (AD). Particularly, the left MTL would show higher vulnerability to neurodegenerative changes in the prodromal stage of AD.

Behavioral and neural underpinnings of empathic characteristics in a Humanitude-care expert.

Humanitude approaches have shown positive effects in elderly care. However, the behavioral and neural underpinnings of empathic characteristics in Humanitude-care experts remain unknown. We investigated the empathic characteristics of a Humanitude-care expert (YG) and those of age-, sex-, and race-matched controls (n = 13). In a behavioral study, we measured subjective valence and arousal ratings and facial electromyography (EMG) of the corrugator supercilii and zygomatic major muscles while participants passively observed dynamic facial expressions associated with anger and happiness and their randomized mosaic patterns. In a functional magnetic resonance imaging (MRI) study, we measured brain activity while participants passively observed the same dynamic facial expressions and mosaics. In a structural MRI study, we acquired structural MRI data and analyzed gray matter volume. Our behavioral data showed that YG experienced higher subjective arousal and showed stronger facial EMG activity congruent with stimulus facial expressions compared with controls. The functional MRI data demonstrated that YG showed stronger activity in the ventral premotor cortex (PMv; covering the precentral gyrus and inferior frontal gyrus) and posterior middle temporal gyrus in the right hemisphere in response to dynamic facial expressions versus dynamic mosaics compared with controls. The structural MRI data revealed higher regional gray matter volume in the right PMv in YG than in controls. These results suggest that Humanitude-care experts have behavioral and neural characteristics associated with empathic social interactions.

Co-twin design in brain imaging-review on biomarkers of Alzheimer's disease.

Twin samples allow to conduct a quasi-experimental co-twin case-control approach that can control for genetic and environmental confounding in brain-cognition associations, being more informative on causality compared with studies in unrelated individuals. We conducted a review of studies that have utilized discordant co-twin design to investigate the associations of brain imaging markers of Alzheimer's disease and cognition. Inclusion criteria encompassed twin pairs discordant for cognition or Alzheimer's disease imaging markers and reporting of within-twin pair comparison on the association between cognition and brain measures. Our PubMed search (2022 April 23, updated 2023 March 9) resulted in 18 studies matching these criteria. Alzheimer's disease imaging markers have been addressed only by few studies, most with small sample size. Structural magnetic resonance imaging studies have indicated greater hippocampal volume and thicker cortex in co-twins with better cognitive performance compared with their co-twins with poorer cognitive performance. No studies have looked at cortical surface area. Positron emission tomography imaging studies have suggested that lower cortical glucose metabolism rate and higher cortical neuroinflammation, amyloid, and tau accumulations are related to poorer episodic memory in within-twin pair comparisons. Thus far, only cross-sectional within-twin pair associations of cortical amyloid and hippocampal volume with cognition have been replicated.

Unraveling the pathophysiology of schizophrenia: insights from structural magnetic resonance imaging studies.

Schizophrenia affects about 1% of the global population. In addition to the complex etiology, linking this illness to genetic, environmental, and neurobiological factors, the dynamic experiences associated with this disease, such as experiences of delusions, hallucinations, disorganized thinking, and abnormal behaviors, limit neurological consensuses regarding mechanisms underlying this disease. In this study, we recruited 72 patients with schizophrenia and 74 healthy individuals matched by age and sex to investigate the structural brain changes that may serve as prognostic biomarkers, indicating evidence of neural dysfunction underlying schizophrenia and subsequent cognitive and behavioral deficits. We used voxel-based morphometry (VBM) to determine these changes in the three tissue structures: the gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF). For both image processing and statistical analysis, we used statistical parametric mapping (SPM). Our results show that patients with schizophrenia exhibited a significant volume reduction in both GM and WM. In particular, GM volume reductions were more evident in the frontal, temporal, limbic, and parietal lobe, similarly the WM volume reductions were predominantly in the frontal, temporal, and limbic lobe. In addition, patients with schizophrenia demonstrated a significant increase in the CSF volume in the left third and lateral ventricle regions. This VBM study supports existing research showing that schizophrenia is associated with alterations in brain structure, including gray and white matter, and cerebrospinal fluid volume. These findings provide insights into the neurobiology of schizophrenia and may inform the development of more effective diagnostic and therapeutic approaches.

Abnormal Brain Structure Is Associated with Social and Communication Deficits in Children with Autism Spectrum Disorder: A Voxel-Based Morphometry Analysis.

Structural magnetic resonance imaging (sMRI) studies have shown abnormalities in the brain structure of ASD patients, but the relationship between structural changes and social communication problems is still unclear. This study aims to explore the structural mechanisms of clinical dysfunction in the brain of ASD children through voxel-based morphometry (VBM). After screening T1 structural images from the Autism Brain Imaging Data Exchange (ABIDE) database, 98 children aged 8-12 years old with ASD were matched with 105 children aged 8-12 years old with typical development (TD). Firstly, this study compared the differences in gray matter volume (GMV) between the two groups. Then, this study evaluated the relationship between GMV and the subtotal score of communications and social interaction on the Autism Diagnostic Observation Schedule (ADOS) in ASD children. Research has found that abnormal brain structures in ASD include the midbrain, pontine, bilateral hippocampus, left parahippocampal gyrus, left superior temporal gyrus, left temporal pole, left middle temporal gyrus and left superior occipital gyrus. In addition, in ASD children, the subtotal score of communications and social interaction on the ADOS were only significantly positively correlated with GMV in the left hippocampus, left superior temporal gyrus and left middle temporal gyrus. In summary, the gray matter structure of ASD children is abnormal, and different clinical dysfunction in ASD children is related to structural abnormalities in specific regions.

1218 GREY MATTER VOLUME AND NEUROTRANSMITTER RECEPTORS ABNORMALITIES IN PARKINSON’S DISEASE PSYCHOSIS: A META-ANALYSIS

Abstract Introduction Recent evidence suggests extensive grey matter abnormalities in Parkinson’s Disease Psychosis (PDP), as well as dysfunction of dopaminergic and serotonergic receptors. However, findings remain unclear. This meta-analysis aimed to identify neuroanatomical correlates of PDP and to examine the relationship between grey matter and key candidate receptors. Method Peak coordinates were extracted from structural magnetic resonance imaging (MRI) studies (identified through systematic searches on PubMed, Web of Science, and Embase) for PDP patients and Parkinson's Disease patients without psychosis (PDnP) and were analysed using Seed-based d mapping with permutation of subject images (SDM-PSI). Gene expression data for dopaminergic (D1/D2) and serotonergic (5-HT2a/5-HT1a) receptors were extracted from the Allen Human Brain Atlas, probe-to-gene re-annotation data were downloaded from Arnatkevic̆iūtė et al. (Neuroimage, 2019;189:353-67) and parcellated on 78 regions of the Desikan-Killiany brain atlas. Effect-size estimates, extracted from the SDM-PSI analysis for these 78 regions as a measure of grey matter in PDP patients, were entered in multiple regression models. Results 10 studies were included in the meta-analysis (PDP, n= 211; mean age = 69.01 years, 52.1% males; PDnP, n = 298, mean age = 67.34 years, 41.9 % males). Reduction in grey matter was observed in parieto-temporo-occipital regions in PDP patients (uncorrected, p < 0.05). When controlling for PD medications, expressed in Levodopa equivalent daily dose (LEDD), results remained significant (uncorrected, p < 0.05). 5-HT2a and 5-HT1a gene receptor expressions were associated with estimates of grey matter volume (5-HT2a, b=-0.20, p=0.01, adjusted for LEDD, b=-0.18, p=0.03; 5-HT1a, b=0.11, p=0.02, adjusted for LEDD, b=0.12, p=0.01). Conclusion We observed lower cortical volume in parieto-temporo-occipital areas, which are involved in information processing, integration, and attention in PDP compared to PDnP patients. We also reported an association between regional brain expression of serotonergic receptors and grey matter volume suggesting a role of serotonin in PDP.

Nilotinib: from animal-based studies to clinical investigation in Alzheimer's disease patients.

Nilotinib: from animal-based studies to clinical investigation in Alzheimer's disease patients.

Associations of phosphorylated tau pathology with whole-hemisphere ex vivo morphometry in 7 tesla MRI.

Neurodegenerative disorders are associated with different pathologies that often co-occur but cannot be measured specifically with in vivo methods. Thirty-three brain hemispheres from donors with an Alzheimer's disease (AD) spectrum diagnosis underwent T2-weighted magnetic resonance imaging (MRI). Gray matter thickness was paired with histopathology from the closest anatomic region in the contralateral hemisphere. Partial Spearman correlation of phosphorylated tau and cortical thickness with TAR DNA-binding protein 43 (TDP-43) and α-synuclein scores, age, sex, and postmortem interval as covariates showed significant relationships in entorhinal and primary visual cortices, temporal pole, and insular and posterior cingulate gyri. Linear models including Braak stages, TDP-43 and α-synuclein scores, age, sex, and postmortem interval showed significant correlation between Braak stage and thickness in the parahippocampal gyrus, entorhinal cortex, and Broadman area 35. We demonstrated an association of measures of AD pathology with tissue loss in several AD regions despite a limited range of pathology in these cases. Neurodegenerative disorders are associated with co-occurring pathologies that cannot be measured specifically with in vivo methods. Identification of the topographic patterns of these pathologies in structural magnetic resonance imaging (MRI) may provide probabilistic biomarkers. We demonstrated the correlation of the specific patterns of tissue loss from ex vivo brain MRI with underlying pathologies detected in postmortem brain hemispheres in patients with Alzheimer's disease (AD) spectrum disorders. The results provide insight into the interpretation of in vivo structural MRI studies in patients with AD spectrum disorders.

Altered functional connectivity of the right caudate nucleus in chronic migraine: a resting-state fMRI study

BackgroundThe definitive pathogenic mechanisms underlying chronic migraine (CM) remain unclear. Mounting evidence from functional and structural magnetic resonance imaging (MRI) studies suggests that the caudate nucleus (CN) plays a role in the cognitive, sensory, and emotional integration of pain information in patients with migraine. However, evidence concerning the role played by CN in CM patients is limited. Here, we used the CN as the seed to explore patterns of functional connectivity (FC) among healthy controls (HCs), patients with episodic migraine (EM), and patients with CM.MethodsWe included 25 HCs, 23 EM patients, and 46 CM patients in this study. All participants underwent resting-state functional MRI scans on a GE 3.0T MRI system. We performed seed-based FC analyses among the three groups using the bilateral CNs as seeds. We also compared the subgroups of CM (with and without medication overuse headache, males and females) and performed Pearson’s correlation analyses between FC values and the clinical features of CM patients.ResultsFC values between the right CN and five clusters (mainly involved in emotion, cognition, and sensory-related brain regions) were higher in CM patients than in HCs. Compared to EM patients, enhanced FC values between the bilateral precuneus, left anterior cingulate gyrus, right middle cingulate cortex, right lingual gyrus, and right CN were shown in the CM patients. There were no significant differences between CM patients with and without MOH, males and females. FC values between the bilateral calcarine cortex, lingual gyrus, and right CN were positively correlated with body mass index. Moreover, right CN-related FC values in the left calcarine cortex and right lingual gyrus were inversely correlated with visual analogue scale scores for headaches.ConclusionOur results revealed abnormal right CN-based FC values in CM patients, suggesting dysfunction of brain networks associated with pain perception and multi-regulation (emotion, cognition, and sensory). Aberrant FC of the CN can provide potential neuroimaging markers for the diagnosis and treatment of CM.

Changes in gray matter volume following electroconvulsive therapy in adolescent depression with suicidal ideation: A longitudinal structural magnetic resonance imaging study.

ObjectiveWe aimed to investigate changes in whole-brain gray matter volumes (GMVs) before and after electroconvulsive therapy (ECT) in adolescents with major depressive disorder (MDD) and suicidal ideation (SI).MethodsThirty adolescents with MDD and SI were observed, and structural magnetic resonance imaging (sMRI) was performed at baseline and after ECT for each patient. But Twenty-five healthy controls (HCs) were scanned only at baseline. The voxel-based morphometry (VBM) techniques were used to examine GMVs.ResultsCompared with HCs, MDDs at baseline showed decreased GMVs in the left middle temporal gyrus, right superior temporal gyrus, right middle temporal gyrus, left precuneus, right precuneus, and left superior frontal gyrus. After ECT, MDDs showed increased GMVs in the right superior frontal gyrus and right superior temporal gyrus. Pearson’s correlation found that Beck Scale for Suicide Ideation (BSSI) scores at baseline were negatively correlated with GMVs in the left superior frontal gyrus and HAMD and BSSI scores after ECT were negatively correlated with GMVs in the right superior temporal gyrus.ConclusionFrontal–temporal–precuneus structure changes may be a potential cause of depressive and suicidal symptoms in adolescents. ECT may improve depressive and suicidal symptoms in adolescents by regulating brain structures to compensate original defects.

Machine learning for autism spectrum disorder diagnosis using structural magnetic resonance imaging: Promising but challenging.

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder that affects approximately 1% of the population and causes significant burdens. ASD’s pathogenesis remains elusive; hence, diagnosis is based on a constellation of behaviors. Structural magnetic resonance imaging (sMRI) studies have shown several abnormalities in volumetric and geometric features of the autistic brain. However, inconsistent findings prevented most contributions from being translated into clinical practice. Establishing reliable biomarkers for ASD using sMRI is crucial for the correct diagnosis and treatment. In recent years, machine learning (ML) and specifically deep learning (DL) have quickly extended to almost every sector, notably in disease diagnosis. Thus, this has led to a shift and improvement in ASD diagnostic methods, fulfilling most clinical diagnostic requirements. However, ASD discovery remains difficult. This review examines the ML-based ASD diagnosis literature over the past 5 years. A literature-based taxonomy of the research landscape has been mapped, and the major aspects of this topic have been covered. First, we provide an overview of ML’s general classification pipeline and the features of sMRI. Next, representative studies are highlighted and discussed in detail with respect to methods, and biomarkers. Finally, we highlight many common challenges and make recommendations for future directions. In short, the limited sample size was the main obstacle; Thus, comprehensive data sets and rigorous methods are necessary to check the generalizability of the results. ML technologies are expected to advance significantly in the coming years, contributing to the diagnosis of ASD and helping clinicians soon.

Unsupervised high-frequency smartphone-based cognitive assessments are reliable, valid, and feasible in older adults at risk for Alzheimer's disease.

Smartphones have the potential for capturing subtle changes in cognition that characterize preclinical Alzheimer's disease (AD) in older adults. The Ambulatory Research in Cognition (ARC) smartphone application is based on principles from ecological momentary assessment (EMA) and administers brief tests of associative memory, processing speed, and working memory up to 4 times per day over 7 consecutive days. ARC was designed to be administered unsupervised using participants' personal devices in their everyday environments. We evaluated the reliability and validity of ARC in a sample of 268 cognitively normal older adults (ages 65-97 years) and 22 individuals with very mild dementia (ages 61-88 years). Participants completed at least one 7-day cycle of ARC testing and conventional cognitive assessments; most also completed cerebrospinal fluid, amyloid and tau positron emission tomography, and structural magnetic resonance imaging studies. First, ARC tasks were reliable as between-person reliability across the 7-day cycle and test-retest reliabilities at 6-month and 1-year follow-ups all exceeded 0.85. Second, ARC demonstrated construct validity as evidenced by correlations with conventional cognitive measures (r = 0.53 between composite scores). Third, ARC measures correlated with AD biomarker burden at baseline to a similar degree as conventional cognitive measures. Finally, the intensive 7-day cycle indicated that ARC was feasible (86.50% approached chose to enroll), well tolerated (80.42% adherence, 4.83% dropout), and was rated favorably by older adult participants. Overall, the results suggest that ARC is reliable and valid and represents a feasible tool for assessing cognitive changes associated with the earliest stages of AD.