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1.
J Magn Reson Imaging ; 58(4): 1011-1029, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37042392

RESUMO

Diffusion-weighted imaging has been applied to investigate alterations in multiple sclerosis (MS). In the last years, advanced diffusion models were used to identify subtle changes and early lesions in MS. Among these models, neurite orientation dispersion and density imaging (NODDI) is an emerging approach, quantifying specific neurite morphology in both grey (GM) and white matter (WM) tissue and increasing the specificity of diffusion imaging. In this systematic review, we summarized the NODDI findings in MS. A search was conducted on PubMed, Scopus, and Embase, which yielded a total number of 24 eligible studies. Compared to healthy tissue, these studies identified consistent alterations in NODDI metrics involving WM (neurite density index), and GM lesions (neurite density index), or normal-appearing WM tissue (isotropic volume fraction and neurite density index). Despite some limitations, we pointed out the potential of NODDI in MS to unravel microstructural alterations. These results might pave the way to a deeper understanding of the pathophysiological mechanism of MS. EVIDENCE LEVEL: 2. TECHNICAL EFFICACY: Stage 3.


Assuntos
Esclerose Múltipla , Substância Branca , Humanos , Neuritos , Imagem de Tensor de Difusão/métodos , Imagem de Difusão por Ressonância Magnética/métodos , Esclerose Múltipla/diagnóstico por imagem , Esclerose Múltipla/patologia , Substância Branca/diagnóstico por imagem , Substância Branca/patologia , Encéfalo/diagnóstico por imagem
2.
Cerebellum ; 21(4): 545-571, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35001330

RESUMO

Diffusion tensor imaging (DTI) is now having a strong momentum in research to evaluate the neural fibers of the CNS. This technique can study white matter (WM) microstructure in neurodegenerative disorders, including Parkinson's disease (PD). Previous neuroimaging studies have suggested cerebellar involvement in the pathogenesis of PD, and these cerebellum alterations can correlate with PD symptoms and stages. Using the PRISMA 2020 framework, PubMed and EMBASE were searched to retrieve relevant articles. Our search revealed 472 articles. After screening titles and abstracts, and full-text review, and implementing the inclusion criteria, 68 papers were selected for synthesis. Reviewing the selected studies revealed that the patterns of reduction in cerebellum WM integrity, assessed by fractional anisotropy, mean diffusivity, radial diffusivity, and axial diffusivity measures can differ symptoms and stages of PD. Cerebellar diffusion tensor imaging (DTI) changes in PD patients with "postural instability and gait difficulty" are significantly different from "tremor dominant" PD patients. Freezing of the gate is strongly related to cerebellar involvement depicted by DTI. The "reduced cognition," "visual disturbances," "sleep disorders," "depression," and "olfactory dysfunction" are not related to cerebellum microstructural changes on DTI, while "impulsive-compulsive behavior" can be linked to cerebellar WM alteration. Finally, higher PD stages and longer disease duration are associated with cerebellum white matter alteration depicted by DTI. Depiction of cerebellar white matter involvement in PD is feasible by DTI. There is an association with disease duration and severity and several clinical presentations with DTI findings. This clinical-imaging association may eventually improve disease management.


Assuntos
Doença de Parkinson , Substância Branca , Anisotropia , Imagem de Tensor de Difusão/métodos , Humanos , Neuroimagem , Doença de Parkinson/patologia , Substância Branca/diagnóstico por imagem , Substância Branca/patologia
3.
Int J Mol Sci ; 23(23)2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36499706

RESUMO

Treatment-resistant depression (TRD) is a severe disorder characterized by high relapse rates and decreased quality of life. An effective strategy in the management of TRD is deep brain stimulation (DBS), a technique consisting of the implantation of electrodes that receive a stimulation via a pacemaker-like stimulator into specific brain areas, detected through neuroimaging investigations, which include the subgenual cingulate cortex (sgCC), basal ganglia, and forebrain bundles. In this context, to improve our understanding of the mechanism underlying the antidepressant effects of DBS in TRD, we collected the results of diffusion tensor imaging (DTI) studies exploring how WM microstructure is associated with the therapeutic effects of DBS in TRD. A search on PubMed, Web of Science, and Scopus identified 11 investigations assessing WM microstructure in responders and non-responders to DBS. Altered WM microstructure, particularly in the sgCC, medial forebrain bundle, cingulum bundle, forceps minor, and uncinate fasciculus, was associated with the antidepressant effect of DBS in TRD. Overall, the results show that DBS targeting selective brain regions, including the sgCC, forebrain bundle, cingulum bundle, rectus gyrus, anterior limb of the internal capsule, forceps minor, and uncinate fasciculus, seem to be effective for the treatment of TRD.


Assuntos
Estimulação Encefálica Profunda , Transtorno Depressivo Resistente a Tratamento , Substância Branca , Humanos , Imagem de Tensor de Difusão/métodos , Substância Branca/diagnóstico por imagem , Estimulação Encefálica Profunda/métodos , Qualidade de Vida , Transtorno Depressivo Resistente a Tratamento/diagnóstico por imagem , Transtorno Depressivo Resistente a Tratamento/terapia , Antidepressivos/uso terapêutico
4.
Neurol Sci ; 42(4): 1411-1421, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32783160

RESUMO

OBJECTIVE: To investigate the pattern and severity of hippocampal subfield volume loss in patients with left and right mesial temporal lobe epilepsy (mTLE) using quantitative MRI volumetric analysis. METHODS: A total of 21 left and 14 right mTLE subjects, as well as 15 healthy controls, were enrolled in this cross-sectional study. A publically available magnetic resonance imaging (MRI) brain volumetry system (volBrain) was used for volumetric analysis of hippocampal subfields. The T1-weighted images were processed with a HIPS pipeline. RESULTS: A distinct pattern of hippocampal subfield atrophy was found between left and right mTLE patients when compared with controls. Patients with left mTLE exhibited ipsilateral hippocampal atrophy and segmental volume depletion of the Cornu Ammonis (CA) 2/CA3, CA4/dentate gyrus (DG), and strata radiatum-lacunosum-moleculare (SR-SL-SM). Those with right mTLE exhibited similar ipsilateral hippocampal atrophy but with additional segmental CA1 volume depletion. More extensive bilateral subfield volume loss was apparent with right mTLE patients. CONCLUSION: We demonstrate that left and right mTLE patients show a dissimilar pattern of hippocampal subfield atrophy, suggesting the pathophysiology of epileptogenesis in left and right mTLE to be different.


Assuntos
Epilepsia do Lobo Temporal , Estudos Transversais , Epilepsia do Lobo Temporal/diagnóstico por imagem , Hipocampo/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Lobo Temporal
5.
Front Neuroendocrinol ; 55: 100782, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31401292

RESUMO

Type 2 diabetes mellitus (T2DM) is associated with deficits in the structure and function of the brain. Diffusion tensor imaging (DTI) is a highly sensitive method for characterizing cerebral tissue microstructure. Using PRISMA guidelines, we identified 29 studies which have demonstrated widespread brain microstructural impairment and topological network disorganization in patients with T2DM. Most consistently reported structures with microstructural abnormalities were frontal, temporal, and parietal lobes in the lobar cluster; corpus callosum, cingulum, uncinate fasciculus, corona radiata, and internal and external capsules in the white matter cluster; thalamus in the subcortical cluster; and cerebellum. Microstructural abnormalities were correlated with pathological derangements in the endocrine profile as well as deficits in cognitive performance in the domains of memory, information-processing speed, executive function, and attention. Altogether, the findings suggest that the detrimental effects of T2DM on cognitive functions might be due to microstructural disruptions in the central neural structures.


Assuntos
Encéfalo/patologia , Disfunção Cognitiva/patologia , Complicações do Diabetes/patologia , Diabetes Mellitus Tipo 2/patologia , Imagem de Tensor de Difusão , Encéfalo/diagnóstico por imagem , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/etiologia , Complicações do Diabetes/diagnóstico por imagem , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/diagnóstico por imagem , Humanos
6.
J Neurosci Res ; 98(7): 1398-1416, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32333426

RESUMO

Compensation is described as normal or near to normal performance in Parkinson's disease (PD), despite the ongoing neural loss. Functional compensation typically proceeds in an inverse U-shaped manner: compensation initiates in the prodromal phase, followed by an increasing episode until plateauing and diminishes in the advanced stages of the disease. The first evidence of the structural compensation was reported by functional magnetic resonance imaging studies. Recent studies, which have used diffusion tensor imaging (DTI) as the basis for their investigation, have shown improved white matter diffusional properties both in motor- and non-motor-related structures in association with improved clinical scores in patients with PD. The majority of DTI studies have demonstrated microstructural compensation in the prodromal/early stages of PD at the regional scale. However, there have been reports of compensation in later stages of the disease and the whole-brain/network scale that are probably due to the heterogeneous nature of PD. Although serving as a promising beginning to characterize compensation, lots remain to be clarified in understanding the underlying mechanisms of compensation and its structural pattern in PD. The existing knowledge gap necessitates studies that their main research questions are focused on structural compensation. This requirement becomes more apparent because structural compensation evidence has mostly emerged from the post hoc analysis of data and incidental findings of studies. Thus, future studies are required to investigate compensatory microstructural changes in PD to clarify the exact underlying mechanisms. These studies would also provide a basis to develop clinical improvements in the early diagnosis and management of PD.


Assuntos
Encéfalo/diagnóstico por imagem , Doença de Parkinson/diagnóstico por imagem , Substância Branca/diagnóstico por imagem , Imagem de Tensor de Difusão , Humanos , Processamento de Imagem Assistida por Computador
7.
Hum Brain Mapp ; 40(3): 1017-1036, 2019 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-30289588

RESUMO

Diffusion tensor imaging (DTI) has revolutionized our understanding of the neural underpinnings of alcohol teratogenesis. This technique can detect alterations in white matter in neurodevelopmental disorders, such as fetal alcohol spectrum disorder (FASD). Using Prisma guidelines, we identified 23 DTI studies conducted on individuals with prenatal alcohol exposure (PAE). These studies confirm the widespread nature of brain damage in PAE by reporting diffusivity alterations in commissural, association, and projection fibers; and in relation to increasing cognitive impairment. Reduced integrity in terms of lower fractional anisotropy (FA) and higher mean diffusivity (MD) and radial diffusivity (RD) is reported more consistently in the corpus callosum, cerebellar peduncles, cingulum, and longitudinal fasciculi connecting frontal and temporoparietal regions. Although these interesting results provide insight into FASD neuropathology, it is important to investigate the clinical diversity of this disorder for better treatment options and prediction of progression. The aim of this review is to provide a summary of different patterns of neural structure between PAE and typically developed individuals. We further discuss the association of alterations in diffusivity with demographic features and symptomatology of PAE. With the accumulated knowledge of the neural correlates of FASD presenting symptoms, a comprehensive understanding of the heterogeneity in FASD will potentially improve the disease management and will highlight the diagnostic challenges and potential areas of future research avenues, where neural markers may be beneficial.


Assuntos
Imagem de Tensor de Difusão/métodos , Transtornos do Espectro Alcoólico Fetal/diagnóstico por imagem , Transtornos do Espectro Alcoólico Fetal/patologia , Substância Branca/diagnóstico por imagem , Substância Branca/patologia , Humanos , Neuroimagem/métodos
8.
Neurol Sci ; 40(2): 283-291, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30386933

RESUMO

OBJECTIVE: Although olfaction dysfunction is now considered as an established clinical marker of prodromal Parkinson disease (PD), little is known about the neural underpinnings of olfaction dysfunction in the prodromal phase of PD. The aim of this study was to examine the microstructural association of olfaction in prodromal PD compared to early stage drug-naïve PD patients. METHODS: Diffusion MRI connectometry was conducted on 18 early PD and 17 prodromal PD patients to investigate the differences in group in terms of altered connectivity, i.e., integrity of white matter tracts, and subsequently to study the correlation of University of Pennsylvania Smell Identification Test (UPSIT) score to white matter integrity in each group using a multiple regression model considering age, sex, RBD, and MoCA, as covariates. RESULTS: Individuals with prodromal PD had significantly higher quantitative anisotropy (QA) comparing with PD patients in bilateral middle cerebellar peduncles and right arcuate fasciculus. Multiple regression analysis in prodromal PD demonstrated positive association between UPSIT score and connectivity in left and right subgenual cingulum, right inferior fronto-occipital fasciculus, left corticospinal tract, left parietopontine, left corticothalamic tract, and the body and the splenium of corpus callosum. CONCLUSION: These results indicate that PD and prodromal PD patients, which were matched for sex, UPSIT, and MoCA scores, have different white matter fiber architecture. Thus, it is postulated that olfaction dysfunction in prodromal and early clinical phases of PD may involve distinct pathogenesis. Increased network connectivity in prodromal and early PD may suggest the neural compensation.


Assuntos
Encéfalo/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética , Transtornos do Olfato/diagnóstico por imagem , Transtornos do Olfato/etiologia , Doença de Parkinson/complicações , Doença de Parkinson/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Vias Neurais/diagnóstico por imagem , Transtornos do Olfato/fisiopatologia , Doença de Parkinson/fisiopatologia , Sintomas Prodrômicos , Estudos Prospectivos , Substância Branca/diagnóstico por imagem
9.
Neurol Sci ; 40(6): 1209-1216, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30868482

RESUMO

BACKGROUND: Medial temporal lobe epilepsy (mTLE) has been associated with widespread white mater (WM) alternations in addition to mesial temporal sclerosis (MTS). Herein, we aimed to investigate the correlation between disease duration and WM structural abnormalities in mTLE using diffusion MRI (DMRI) connectometry approach. METHOD: DMRI connectometry was conducted on 24 patients with mTLE. A multiple regression model was used to investigate white matter tracts with microstructural correlates to disease duration, controlling for age and sex. DMRI data were processed in the MNI space using q-space diffeomorphic reconstruction to obtain the spin distribution function (SDF). The SDF values were converted to quantitative anisotropy (QA) and used in further analyses. RESULTS: Connectometry analysis identified impaired white matter QA of the following fibers to be correlated with disease duration: bilateral retrosplenial cingulum, bilateral fornix, right inferior longitudinal fasciculus (ILF), and genu of corpus callosum (CC) (FDR = 0.009). CONCLUSION: Our results were obtained from DMRI connectometry, which indicates the connectivity and the level of diffusion in nerve fibers rather just the direction of diffusion. Compared to previous studies investigating the correlation between duration of epilepsy and white matter integrity in mTLE patients, we detected broader and somewhat different associations in midline structures and component of limbic system. However, further studies with larger sample sizes are required to elucidate previous and current results.


Assuntos
Encéfalo/patologia , Epilepsia do Lobo Temporal/patologia , Substância Branca/patologia , Adulto , Encéfalo/diagnóstico por imagem , Conectoma , Imagem de Difusão por Ressonância Magnética , Progressão da Doença , Epilepsia do Lobo Temporal/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Vias Neurais/diagnóstico por imagem , Vias Neurais/patologia , Substância Branca/diagnóstico por imagem
10.
Int Psychogeriatr ; 31(1): 5-12, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29560834

RESUMO

ABSTRACTObjective:Research on psychobiological markers of Parkinson's disease (PD) remains a hot topic. Non-motor symptoms such as depression and REM sleep behavior disorder (RBD) each attribute to a particular neurodegenerative cluster in PD, and might enlighten the way for early prediction/detection of PD. The neuropathology of mood disturbances remains unclear. In fact, a few studies have investigated depression using diffusion magnetic resonance imaging (diffusion MRI). METHOD: Diffusion MRI of PD patients without comorbid RBD was used to assess whether microstructural abnormalities are detectable in the brain of 40 PD patients with depression compared to 19 patients without depression. Diffusion MRI connectometry was used to carry out group analysis between age- and gender-matched PD patients with and without depressive symptoms. Diffusion MRI connectometry is based on spin distribution function, which quantifies the density of diffusing water and is a sensitive and specific analytical method to psychological differences between groups. RESULTS: A significant difference (FDR = 0.016129) was observed in the left and right uncinate fasciculi, left and right inferior longitudinal fasciculi, left and right fornices, left inferior fronto-occipital fasciculus, right corticospinal tract, genu of corpus callosum, and middle cerebellar peduncle. CONCLUSION: These results suggest the prominent circuits involved in emotion recognition, particularly negative emotions, might be impaired in comorbid depressive symptoms in PD.


Assuntos
Depressão/fisiopatologia , Diagnóstico Precoce , Doença de Parkinson/fisiopatologia , Transtorno do Comportamento do Sono REM/fisiopatologia , Substância Branca/patologia , Idoso , Depressão/diagnóstico , Imagem de Difusão por Ressonância Magnética , Progressão da Doença , Feminino , Humanos , Cooperação Internacional , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/complicações , Doença de Parkinson/diagnóstico , Transtorno do Comportamento do Sono REM/diagnóstico , Substância Branca/fisiopatologia
12.
Exp Brain Res ; 235(10): 2935-2945, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28702836

RESUMO

Study of bilingual brain has provided evidence for probable advantageous outcomes of early second language learning and brain structural correlates to these outcomes. DMRI connectometry is a novel approach that tracts fibers based on correlation of the adjacent voxels with a variable of interest or group differences. Using the data deposited by Pliatsikas et al., we investigated through diffusion MRI connectometry and correlation analysis, the structural differences in white matter tracts of 20 healthy sequential bilingual adults who used English as a second language on a daily basis, compared to 25 age matched in fiber differentiation analyses. Connectometry results revealed increased connectivity in corpus callosum (CC), bilateral cingulum, arcuate fasciculus (AF), and left IFOF of sequential bilingual adults. All the above fibers except cingulum had positive association with language immersion period. We introduce cingulum as a tract with increased connectivity in late bilingual adults. We also found an increase in white matter connectivity conventional language-related fibers such as AF, and areas that had been shown in previous studies addressing WM differences between early or late bilinguals and monolinguals, inferior frontooccipital fasciculus, and CC. Pliatsikas reported a confounding effect for the immersion period, as a regressor in TBSS model. Through DMRI connectometry and correlation analysis, we showed that quantitative anisotropy of all of the significant fibers from connectometry analysis, except cingulum, had direct correlation with the duration of immersion period of the bilingual group into the second language.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Aprendizagem , Multilinguismo , Rede Nervosa/diagnóstico por imagem , Substância Branca/diagnóstico por imagem , Adulto , Feminino , Humanos , Masculino , Fatores de Tempo , Adulto Jovem
13.
Sleep Breath ; 21(1): 155-161, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27853964

RESUMO

PURPOSE: REM (rapid eye movement) sleep behavior disorder (RBD) is characterized by increased muscle tone and violent limb movements and is a usual symptom of the early stages of Parkinson's disease (PD). PD patients with RBD represent faster motor and cognitive dysfunction progression. However, there are limited studies on possible structural brain changes underpinning this disorder. METHODS: Diffusion magnetic resonance imaging (DMRI) was used to assess whether microstructural abnormalities in the brain of 23 RBD positive PD are detectable compared to 31 RBD negative PD. DMRI scans were analyzed without a prior hypothesis. Diffusion MRI connectometry was used to carry out group analysis between age and gender matched PD patients with and without RBD. Diffusion MRI connectometry is based on spin distribution function (SDF) which quantifies the density of diffusing water and is more sensitive to psychological differences between groups. RESULTS: Patients with RBD positive showed microstructural white matter changes in the left and right cingulum, inferior front occipital fasciculus (IFOF), bilateral corticospinal tracts (CST), and middle cerebellar peduncles (MCPs), compared to patients without RBD. CONCLUSIONS: White matter alterations in the cingulum, IFOF regions, and corpus callosum might explain faster cognitive deterioration in PD patients with RBD, in terms of visual recognition and visuospatial dysfunction and executive function. Disturbed brain structural tissue markers in CST in PD + RBD patients, could be justified in the light of faster motor progression in these patients.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Imagem de Difusão por Ressonância Magnética , Vias Neurais/diagnóstico por imagem , Vias Neurais/fisiopatologia , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/fisiopatologia , Transtorno do Comportamento do Sono REM/diagnóstico por imagem , Transtorno do Comportamento do Sono REM/fisiopatologia , Idoso , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/fisiopatologia , Conectoma , Progressão da Doença , Diagnóstico Precoce , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência
15.
Schizophr Bull ; 2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-39212653

RESUMO

BACKGROUND AND HYPOTHESIS: Altered functional connectivity (FC) has been frequently reported in psychosis. Studying FC and its time-varying patterns in early-stage psychosis allows the investigation of the neural mechanisms of this disorder without the confounding effects of drug treatment or illness-related factors. STUDY DESIGN: We employed resting-state functional magnetic resonance imaging (rs-fMRI) to explore FC in individuals with early psychosis (EP), who also underwent clinical and neuropsychological assessments. 96 EP and 56 demographically matched healthy controls (HC) from the Human Connectome Project for Early Psychosis database were included. Multivariate analyses using spatial group independent component analysis were used to compute static FC and dynamic functional network connectivity (dFNC). Partial correlations between FC measures and clinical and cognitive variables were performed to test brain-behavior associations. STUDY RESULTS: Compared to HC, EP showed higher static FC in the striatum and temporal, frontal, and parietal cortex, as well as lower FC in the frontal, parietal, and occipital gyrus. We found a negative correlation in EP between cognitive function and FC in the right striatum FC (pFWE = 0.009). All dFNC parameters, including dynamism and fluidity measures, were altered in EP, and positive symptoms were negatively correlated with the meta-state changes and the total distance (pFWE = 0.040 and pFWE = 0.049). CONCLUSIONS: Our findings support the view that psychosis is characterized from the early stages by complex alterations in intrinsic static and dynamic FC, that may ultimately result in positive symptoms and cognitive deficits.

16.
Heliyon ; 10(8): e29420, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38638964

RESUMO

Frontal variant Alzheimer's disease (AD) manifests with either behavioral or dysexecutive syndromes. Recent efforts to gain a deeper understanding of this phenotype have led to a re-conceptualization of frontal AD. Behavioral (bAD) and dysexecutive (dAD) phenotypes could be considered subtypes, as suggested by both clinical and neuroimaging studies. In this review, we focused on imaging studies to highlight specific brain patterns in these two uncommon clinical AD phenotypes. Although studies did not compare directly these two variants, a common epicenter located in the frontal cortex could be inferred. On the contrary, 18F-FDG-PET findings suggested differing metabolic patterns, with bAD showing specific involvement of frontal regions and dAD exhibiting widespread alterations. Structural MRI findings confirmed this pattern, suggesting that degeneration might involve neural circuits associated with behavioral control in bAD and attentional networks in dAD. Furthermore, molecular imaging has identified different neocortical tau distribution in bAD and dAD patients compared to typical AD patients, although the distribution is remarkably heterogeneous. In contrast, Aß deposition patterns are less differentiated between these atypical variants and typical AD. Although preliminary, these findings underscore the complexity of AD frontal phenotypes and suggest that they represent distinct entities. Further research is essential to refine our understanding of the pathophysiological mechanisms in frontal AD.

17.
Brain Imaging Behav ; 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38777951

RESUMO

Spaceflight-induced brain changes have been commonly reported in astronauts. The role of microgravity in the alteration of the brain structure, microstructure, and function can be tested with magnetic resonance imaging (MRI) techniques. Here, we aim to provide a comprehensive overview of Spaceflight studies exploring the potential role of brain alterations identified by MRI in astronauts. We conducted a search on PubMed, Web of Science, and Scopus to find neuroimaging correlates of spaceflight experience using MRI. A total of 20 studies (structural MRI n = 8, diffusion-based MRI n = 2, functional MRI n = 1, structural MRI and diffusion-weighted MRI n = 6, structural MRI and functional MRI n = 3) met our inclusion criteria. Overall, the studies showed that regardless of the MRI techniques, mission duration significantly impacts the human brain, prompting the inclusion of various brain regions as features in the analyses. After spaceflight, notable alterations were also observed in the superior occipital gyrus and the precentral gyrus which show alterations in connectivity and activation during spaceflight. The results provided highlight the alterations in brain structure after spaceflight, the unique patterns of brain remodeling, the challenges in drawing unified conclusions, and the impact of microgravity on intracranial cerebrospinal fluid volume.

18.
J Affect Disord ; 351: 615-623, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38290585

RESUMO

BACKGROUND: The early years after the onset of psychotic disorders, known as "early psychosis" (EP) are critical to determining the path of psychosis trajectory. We used a Diffusion Magnetic Resonance Imaging (DMRI) connectometry approach to assess the microstructural changes of white matter (WM) associated with EP. METHODS: We used the Human Connectome Project in Early Psychosis (HCP-EP) dataset to collect DMRI data from patients with EP. The imaging data were processed in the Montreal Neuroimaging Initiative space and transformed into quantitative anisotropy (QA). The QA value was translated into the WM connectivity of each tract and used in the subsequent analysis. RESULTS: 121 patients with EP (94 non-affective/27 affective) and 56 healthy controls were recruited. EP was associated with increased QA in the body and tapetum of corpus callosum (CC) and decreased QA in the bilateral cerebellum, and middle cerebellar peduncle. Compared to non-affective psychosis, affective psychosis showed increased QA in the bilateral cerebellum and vermis and decreased QA in the forceps minor, body of CC, right cingulum, and bilateral inferior fronto-occipital fasciculus. Furthermore, QA changes in several WM tracts were correlated with positive and negative symptom scale scores. LIMITATIONS: DMRI intrinsic limitations, limited sample size, and neurobiological effects of psychotropic treatment. CONCLUSIONS: EP is associated with alterations in WM connectivity primarily in the CC and cerebellar regions. Also, affective and non-affective psychosis have distinct alterations in WM connectivity. These results can be used for the early diagnosis and differentiation of psychotic disorders.


Assuntos
Conectoma , Transtornos Psicóticos , Substância Branca , Humanos , Substância Branca/diagnóstico por imagem , Substância Branca/patologia , Imagem de Difusão por Ressonância Magnética/métodos , Transtornos Psicóticos/diagnóstico , Neuroimagem , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Anisotropia
19.
Brain Imaging Behav ; 2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-39103671

RESUMO

BACKGROUND: Recent studies have suggested that the hippocampus (HC) is involved in cognitive and behavioral functions beyond memory. We aimed to investigate how the volume of each subfield of the HC is associated with distinct patterns of coping strategies, emotion regulation, and impulsivity in a healthy population. METHODS: We studied a total of 218 healthy subjects using the Leipzig mind-brain-body dataset. Participants were assessed for coping strategies, emotion regulation, and impulsivity using the Cognitive Emotion Regulation Questionnaire (CERQ), Coping Orientations to Problems Experienced (COPE), Impulsive Behavior Scale (UPPS), and Behavioral Activation and Inhibition System (BAS/BIS). The associations between HC subfield volumes including CA1, CA2/3, CA4/DG, SR-SL-SM, and subiculum, and behavioral scores were examined using multiple linear regression models adjusted for possible confounders, including age, sex, years of education, handedness, total intracranial volume (ICV), and HC volume. RESULTS: The use of emotional support, venting, and positive reframing coping strategies were significantly and positively correlated with total, total right, and total left HC volumes. Venting was significantly associated with CA1 after adjusting for age, sex, handedness, and education (P=0.001, B = 0.265, P-FDR = 0.005). No significant association was observed between CERQ subscales and HC subfield volumes after controlling for confounders and multiple analyses. However, sensation-seeking subscale of the UPPS-P was positively correlated with total and right CA2-CA3 volumes after adjustments for age, sex, handedness, ICV, and HC volumes (P=0.002, B = 0.266, P-FDR = 0.035). BAS and BIS subscales did not show significant relationship with HC subfield volumes. CONCLUSION: Patterns of HC subfields volumes are associated with coping strategies, impulsivity, and emotion regulation. In particular, using emotional support, positive reframing, venting, and sensation seeking are significantly associated with certain HC subfield volumes. These findings suggest that the hippocampus may play a crucial role in modulating emotional responses and behavioral adaptations, offering potential targets for therapeutic interventions.

20.
Behav Brain Res ; 476: 115222, 2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-39216828

RESUMO

BACKGROUND: Our comprehension of the interplay of cognition and the brain remains constrained. While functional imaging studies have identified cognitive brain regions, structural correlates of cognitive functions remain underexplored. Advanced methods like Diffusion Magnetic Resonance Imaging (DMRI) facilitate the exploration of brain connectivity and White Matter (WM) tract microstructure. Therefore, we conducted connectometry method on DMRI data, to reveal WM tracts associated with cognition. METHODS: 125 healthy participants from the National Institute of Mental Health Intramural Healthy Volunteer Dataset were recruited. Multiple regression analyses were conducted between DMRI-derived Quantitative Anisotropy (QA) values within WM tracts and scores of participants in Flanker Inhibitory Control and Attention Test (attention), Dimensional Change Card Sort (executive function), Picture Sequence Memory Test (episodic memory), and List Sorting Working Memory Test (working memory) tasks from National Institute of Health toolbox. The significance level was set at False Discovery Rate (FDR)<0.05. RESULTS: We identified significant positive correlations between the QA of WM tracts within the left cerebellum and bilateral fornix with attention, executive functioning, and episodic memory (FDR=0.018, 0.0002, and 0.0002, respectively), and a negative correlation between QA of WM tracts within bilateral cerebellum with attention (FDR=0.028). Working memory demonstrated positive correlations with QA of left inferior longitudinal and left inferior fronto-occipital fasciculi (FDR=0.0009), while it showed a negative correlation with QA of right cerebellar tracts (FDR=0.0005). CONCLUSION: Our results underscore the intricate link between cognitive performance and WM integrity in frontal, temporal, and cerebellar regions, offering insights into early detection and targeted interventions for cognitive disorders.

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