Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.783
Filtrar
1.
PLoS One ; 15(8): e0236986, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32866198

RESUMO

White matter hyperintensities (WMHs) are among the most commonly observed marker of cerebrovascular disease. Age is a key risk factor for WMH development. Cardiorespiratory fitness (CRF) is associated with increased vessel compliance, but it remains unknown if high CRF affects WMH volume. This study explored the effects of CRF on WMH volume in community-dwelling older adults. We further tested the possibility of an interaction between CRF and age on WMH volume. Participants were 76 adults between the ages of 59 and 77 (mean age = 65.36 years, SD = 3.92) who underwent a maximal graded exercise test and structural brain imaging. Results indicated that age was a predictor of WMH volume (beta = .32, p = .015). However, an age-by-CRF interaction was observed such that higher CRF was associated with lower WMH volume in older participants (beta = -.25, p = .040). Our findings suggest that higher levels of aerobic fitness may protect cerebrovascular health in older adults.


Assuntos
Envelhecimento/patologia , Envelhecimento/fisiologia , Aptidão Cardiorrespiratória/fisiologia , Substância Branca/diagnóstico por imagem , Idoso , Circulação Cerebrovascular/fisiologia , Transtornos Cerebrovasculares/diagnóstico por imagem , Transtornos Cerebrovasculares/patologia , Transtornos Cerebrovasculares/fisiopatologia , Teste de Esforço , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Neuroimagem , Fatores de Risco , Substância Branca/irrigação sanguínea , Substância Branca/patologia
2.
Neurol Neurochir Pol ; 54(4): 312-322, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32808273

RESUMO

AIM: To evaluate five illustrative cases and perform a literature review to identify and describe a working approach to adult-onset white matter diseases (WMD). STATE OF THE ART: Inherited WMD are a group of disorders often seen in childhood. In adulthood, progressive WMDs are rare, apart from the common nonspecific causes of hypertension and other cerebrovascular diseases. The pattern of WMDs on neuroimaging can be an important clue to the final diagnosis. Due to the adoption of a combined clinical-imaging-laboratory approach, WMD is becoming better recognised, in addition to the rapidly evolving field of genomics in this area. CLINICAL IMPLICATIONS: While paediatric WMDs have a well-defined and literature-based clinical-laboratory approach to diagnosis, adult-onset WMDs remain an important, pathologically diverse, radiographic phenotype, with different and distinct neuropathologies among the various subtypes of WMD. Adult-onset WMDs comprise a wide collection of both acquired and inherited aetiologies. While severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neurological complications are emerging, we are as yet unaware of it causing WMD outside of post-anoxic changes. It is important to recognise WMD as a potentially undefined acquired or genetic syndrome, even when extensive full genome testing reveals variants of unknown significance. FUTURE DIRECTIONS: We propose a combined clinical-imaging-laboratory approach to WMD and continued exploration of acquired and genetic factors. Adult-onset WMD, even given this approach, can be challenging because hypertension is often comorbid. Therefore, we propose that undiagnosed patients with WMD be entered into multicentre National Organisation for Rare Diseases registries to help researchers worldwide make new discoveries that will hopefully translate into future cures.


Assuntos
Leucoencefalopatias/diagnóstico , Leucoencefalopatias/etiologia , Adulto , Betacoronavirus , Infecções por Coronavirus , Humanos , Pandemias , Pneumonia Viral , Substância Branca/patologia
4.
J Thorac Cardiovasc Surg ; 160(2): e55-e66, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32689704

RESUMO

OBJECTIVES: This study aims to evaluate the protective effects of progesterone on white matter injury and brain immaturity in neonatal rats with chronic hypoxia. METHODS: Three-day old Sprague-Dawley rats were randomly divided into 3 groups: (1) control (n = 48), rats were exposed to normoxia (fraction of inspired oxygen: 21% ± 0%); (2) chronic hypoxia (n = 48), rats were exposed to hypoxia (fraction of inspired oxygen: 10.5% ± 1.0%); and (3) progesterone (n = 48), rats were exposed to hypoxia and administrated with progesterone (8 mg/kg/d). Hematoxylin-eosin staining, immunohistochemistry, real-time quantitative polymerase chain reaction, and Western blot analyses were compared on postnatal day 14 in different groups. Motor skill and coordination abilities of rats were assessed via rotation experiments. RESULTS: Increased brain weights (P < .05), narrowed ventricular sizes (P < .01), and rotarod experiment scores (P < .01) were better in the progesterone group than in the chronic hypoxia group. The number of mature oligodendrocytes and myelin basic protein expression increased in the progesterone group compared with the chronic hypoxia group (P < .01). The polarization of M1 microglia cells in the corpus callosum of chronic hypoxia-induced hypomyelination rats was significantly increased, whereas there were fewer M2 microglia cells. Conversely, progesterone therapy had an opposite effect and caused an increase in M2 microglia polarization versus a reduction in M1 microglia cells. CONCLUSIONS: Progesterone could prevent white matter injury and improve brain maturation in a neonatal hypoxic rat model; this may be associated with inducing a switch from M1 to M2 in microglia.


Assuntos
Encéfalo/efeitos dos fármacos , Hipóxia/tratamento farmacológico , Leucoencefalopatias/prevenção & controle , Fármacos Neuroprotetores/farmacologia , Progesterona/farmacologia , Substância Branca/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Comportamento Animal/efeitos dos fármacos , Encéfalo/crescimento & desenvolvimento , Encéfalo/metabolismo , Plasticidade Celular/efeitos dos fármacos , Doença Crônica , Modelos Animais de Doenças , Feminino , Hipóxia/metabolismo , Hipóxia/patologia , Hipóxia/fisiopatologia , Leucoencefalopatias/metabolismo , Leucoencefalopatias/patologia , Leucoencefalopatias/fisiopatologia , Masculino , Microglia/efeitos dos fármacos , Microglia/metabolismo , Microglia/patologia , Atividade Motora/efeitos dos fármacos , Proteína Básica da Mielina/metabolismo , Oligodendroglia/efeitos dos fármacos , Oligodendroglia/metabolismo , Oligodendroglia/patologia , Ratos Sprague-Dawley , Substância Branca/metabolismo , Substância Branca/patologia , Substância Branca/fisiopatologia
5.
Neurology ; 95(5): e554-e562, 2020 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-32611644

RESUMO

OBJECTIVE: We postulated that cerebral amyloid angiopathy (CAA) is associated with white matter atrophy (WMA) and that WMA can be related to cognitive changes in CAA. METHODS: White matter volume expressed as percent of intracranial volume (pWMV) of prospectively enrolled patients without dementia diagnosed with probable CAA was compared to age-matched healthy controls (HC) and patients with Alzheimer disease (AD). Cognitive scores were also sought to understand the potential effects of WMA on cognitive function. RESULTS: Patients with CAA (n = 72) had significantly lower pWMV (27.97% ± 2.63) when compared to age-matched HC (n = 72; mean difference [MD], 2.38%; p < 0.0001) and patients with AD (n = 72; MD, 1.57%; p < 0.0001). Differences were most pronounced in the posterior occipital regions in both comparisons. When comparisons were restricted to groups of patients with CAA but no intracerebral hemorrhage (n = 32) or hypertension (n = 32), and age-matched HC and AD, the significant differences were unaltered. Within the CAA cohort, higher age, lobar microbleed counts, and presence of hypertension were associated with lower pWMV (p = 0.0007, p = 0.031, and p = 0.003, respectively). All associations remained independent in multivariable analyses. Within the CAA cohort, higher pWMV independently correlated with better scores of executive function. CONCLUSIONS: Patients with CAA show WMA when compared to age-matched HC and patients with AD. WMA independently correlates with the number of lobar microbleeds, a marker of CAA severity. Consistent spatial patterns of WMA especially in posterior regions might be related to CAA. The association between WMA and measures of executive function suggests that WMA might represent an important mediator of CAA-related neurologic dysfunction.


Assuntos
Encéfalo/patologia , Angiopatia Amiloide Cerebral/patologia , Substância Branca/patologia , Idoso , Atrofia/patologia , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino
7.
Neurology ; 95(8): e943-e952, 2020 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-32646955

RESUMO

OBJECTIVE: To evaluate progressive white matter (WM) degeneration in amyotrophic lateral sclerosis (ALS). METHODS: Sixty-six patients with ALS and 43 healthy controls were enrolled in a prospective, longitudinal, multicenter study in the Canadian ALS Neuroimaging Consortium (CALSNIC). Participants underwent a harmonized neuroimaging protocol across 4 centers that included diffusion tensor imaging (DTI) for assessment of WM integrity. Three visits were accompanied by clinical assessments of disability (ALS Functional Rating Scale-Revised [ALSFRS-R]) and upper motor neuron (UMN) function. Voxel-wise whole-brain and quantitative tract-wise DTI assessments were done at baseline and longitudinally. Correction for site variance incorporated data from healthy controls and from healthy volunteers who underwent the DTI protocol at each center. RESULTS: Patients with ALS had a mean progressive decline in fractional anisotropy (FA) of the corticospinal tract (CST) and frontal lobes. Tract-wise analysis revealed reduced FA in the CST, corticopontine/corticorubral tract, and corticostriatal tract. CST FA correlated with UMN function, and frontal lobe FA correlated with the ALSFRS-R score. A progressive decline in CST FA correlated with a decline in the ALSFRS-R score and worsening UMN signs. Patients with fast vs slow progression had a greater reduction in FA of the CST and upper frontal lobe. CONCLUSIONS: Progressive WM degeneration in ALS is most prominent in the CST and frontal lobes and, to a lesser degree, in the corticopontine/corticorubral tracts and corticostriatal pathways. With the use of a harmonized imaging protocol and incorporation of analytic methods to address site-related variances, this study is an important milestone toward developing DTI biomarkers for cerebral degeneration in ALS. CLINICALTRIALSGOV IDENTIFIER: NCT02405182.


Assuntos
Esclerose Amiotrófica Lateral/diagnóstico por imagem , Córtex Cerebral/diagnóstico por imagem , Tratos Piramidais/diagnóstico por imagem , Substância Branca/diagnóstico por imagem , Adulto , Idoso , Esclerose Amiotrófica Lateral/patologia , Córtex Cerebral/patologia , Imagem de Tensor de Difusão , Progressão da Doença , Feminino , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Degeneração Neural/diagnóstico por imagem , Degeneração Neural/patologia , Neuroimagem/métodos , Estudos Prospectivos , Tratos Piramidais/patologia , Substância Branca/patologia
8.
Neurology ; 95(7): e781-e792, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32641518

RESUMO

OBJECTIVE: To study longitudinal recovery trajectories of white matter after sports-related concussion (SRC) by performing diffusion tensor imaging (DTI) on collegiate athletes who sustained SRC. METHODS: Collegiate athletes (n = 219, 82 concussed athletes, 68 contact-sport controls, and 69 non-contact-sport controls) were included from the Concussion Assessment, Research and Education Consortium. The participants completed clinical assessments and DTI at 4 time points: 24 to 48 hours after injury, asymptomatic state, 7 days after return-to-play, and 6 months after injury. Tract-based spatial statistics was used to investigate group differences in DTI metrics and to identify white-matter areas with persistent abnormalities. Generalized linear mixed models were used to study longitudinal changes and associations between outcome measures and DTI metrics. Cox proportional hazards model was used to study effects of white-matter abnormalities on recovery time. RESULTS: In the white matter of concussed athletes, DTI-derived mean diffusivity was significantly higher than in the controls at 24 to 48 hours after injury and beyond the point when the concussed athletes became asymptomatic. While the extent of affected white matter decreased over time, part of the corpus callosum had persistent group differences across all the time points. Furthermore, greater elevation of mean diffusivity at acute concussion was associated with worse clinical outcome measures (i.e., Brief Symptom Inventory scores and symptom severity scores) and prolonged recovery time. No significant differences in DTI metrics were observed between the contact-sport and non-contact-sport controls. CONCLUSIONS: Changes in white matter were evident after SRC at 6 months after injury but were not observed in contact-sport exposure. Furthermore, the persistent white-matter abnormalities were associated with clinical outcomes and delayed recovery time.


Assuntos
Traumatismos em Atletas/reabilitação , Concussão Encefálica/patologia , Imagem de Tensor de Difusão , Substância Branca/patologia , Adolescente , Adulto , Atletas , Traumatismos em Atletas/diagnóstico por imagem , Concussão Encefálica/diagnóstico , Concussão Encefálica/fisiopatologia , Corpo Caloso/patologia , Corpo Caloso/fisiopatologia , Imagem de Difusão por Ressonância Magnética/métodos , Imagem de Tensor de Difusão/métodos , Feminino , Futebol Americano/lesões , Humanos , Masculino , Substância Branca/fisiopatologia , Adulto Jovem
9.
PLoS One ; 15(7): e0236473, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32716979

RESUMO

Cerebral white-matter hyperintensities (WMHs) on MRI is associated with reduced compliance of the cerebral arterioles. We hypothesized that an echocardiography index for left ventricular (LV) diastolic function, E/e', might reflect the cerebral arteriolar compliance and evaluated the association between E/e' and long-term progression rate of the cerebral WMH volume. This retrospective study included individuals who were ≥ 50 years of age, with a preserved LV ejection fraction (≥ 50%) and neurological function status (modified Rankin scale score ≤1), and underwent initial and follow-up MRI evaluations within intervals of 34-45 months. Baseline clinical, laboratory, and echocardiography markers such as ejection fraction, LV mass index, and E/e' were obtained. WMH volume progression rate between the baseline and follow-up MRIs was designated as the outcome factor. 392 individuals (57.1% men; mean age: 66.7±8.4 years) were followed-up for 38.2±3.4 months. The mean WMH volume progression rate was 1.35±2.65 mL/year. The log-transformed value of WMH volume progression rate was linearly associated with the log-transformed E/e' (B coefficient = 0.365; 95% confidence interval [CI] 0.180-0.551; P = 0.001), along with the log-transformed values of baseline WMH volume (B = 0.142; 95% CI 0.106-0.179; P<0.001) and glomerular filtration rate (B = -0.182; 95% CI -0.321-0.044; P = 0.010). Additionally, a subgroup with an E/e' ≥15 exhibited a significantly higher WMH progression rate compared to the subgroups with lower E/e' values (P<0.001), especially in the lower quartiles (quartiles 1 and 2) of the baseline WMH volume. We concluded that echocardiographic marker E/e' is associated with the long-term progression rate of cerebral WMHs in population with preserved LV systolic function.


Assuntos
Progressão da Doença , Ecocardiografia , Substância Branca/diagnóstico por imagem , Substância Branca/patologia , Idoso , Idoso de 80 Anos ou mais , Humanos , Pessoa de Meia-Idade , Tamanho do Órgão
10.
BMC Neurol ; 20(1): 258, 2020 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-32600288

RESUMO

BACKGROUND: Leukodystrophies are familial heterogeneous disorders primarily affecting the white matter, which are defined as hypomyelinating or demyelinating based on disease severity as assessed at MRI. Recently, a group of clinically overlapping hypomyelinating leukodystrophies (HL) has been associated with mutations in RNA polymerase III enzymes (Pol III) subunits. CASE PRESENTATION: In this manuscript, we describe two Italian siblings carrying a novel POLR3A genotype. MRI imaging, genetic analysis, and clinical data led to diagnosing HL type 7. The female sibling, at the age of 34, is tetra-paretic and suffers from severe cognitive regression. She had a disease onset at the age of 19, characterized by slow and progressive cognitive impairment associated with gait disturbances and amenorrhea. The male sibling was diagnosed during an MRI carried out for cephalalgia at the age of 41. After 5 years, he developed mild cognitive impairment, dystonia with 4-limb hypotonia, and moderate dysmetria with balance and gait impairment. CONCLUSIONS: The present study provides the first evidence of unusually late age of onset in HL, describing two siblings with a novel POLR3A genotype which showed the first symptoms at the age of 41 and 19, respectively. This provides a powerful insight into clinical heterogeneity and genotype-phenotype correlation in POLR3A related HL.


Assuntos
Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/genética , RNA Polimerase III/genética , Adulto , Idade de Início , Encéfalo/patologia , Feminino , Genótipo , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/patologia , Humanos , Imagem por Ressonância Magnética , Masculino , Mutação , Irmãos , Substância Branca/patologia
12.
Neurology ; 95(1): e79-e88, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32493718

RESUMO

OBJECTIVE: To examine etiologic stroke subtypes and vascular risk factor profiles and their association with white matter hyperintensity (WMH) burden in patients hospitalized for acute ischemic stroke (AIS). METHODS: For the MRI Genetics Interface Exploration (MRI-GENIE) study, we systematically assembled brain imaging and phenotypic data for 3,301 patients with AIS. All cases underwent standardized web tool-based stroke subtyping with the Causative Classification of Ischemic Stroke (CCS). WMH volume (WMHv) was measured on T2 brain MRI scans of 2,529 patients with a fully automated deep-learning trained algorithm. Univariable and multivariable linear mixed-effects modeling was carried out to investigate the relationship of vascular risk factors with WMHv and CCS subtypes. RESULTS: Patients with AIS with large artery atherosclerosis, major cardioembolic stroke, small artery occlusion (SAO), other, and undetermined causes of AIS differed significantly in their vascular risk factor profile (all p < 0.001). Median WMHv in all patients with AIS was 5.86 cm3 (interquartile range 2.18-14.61 cm3) and differed significantly across CCS subtypes (p < 0.0001). In multivariable analysis, age, hypertension, prior stroke, smoking (all p < 0.001), and diabetes mellitus (p = 0.041) were independent predictors of WMHv. When adjusted for confounders, patients with SAO had significantly higher WMHv compared to those with all other stroke subtypes (p < 0.001). CONCLUSION: In this international multicenter, hospital-based cohort of patients with AIS, we demonstrate that vascular risk factor profiles and extent of WMH burden differ by CCS subtype, with the highest lesion burden detected in patients with SAO. These findings further support the small vessel hypothesis of WMH lesions detected on brain MRI of patients with ischemic stroke.


Assuntos
Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/patologia , Substância Branca/patologia , Idoso , Idoso de 80 Anos ou mais , Arteriopatias Oclusivas/complicações , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/etiologia , Isquemia Encefálica/patologia , Aprendizado Profundo , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Acidente Vascular Cerebral/diagnóstico por imagem , Substância Branca/diagnóstico por imagem
13.
BMC Neurol ; 20(1): 236, 2020 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-32517723

RESUMO

BACKGROUND: Diffusion tensor imaging (DTI) is an effective method to identify subtle changes to normal-appearing white matter (WM). Here we analyzed the DTI data with other examinations, including motor evoked potentials (MEPs), histopathological images, and behavioral results, to reflect the lesion development in different degrees of spinal cord injury (SCI) in acute and subacute stages. METHOD: Except for 2 Sprague -Dawley rats which died from the anesthesia accident, the rest 42 female rats were randomized into 3 groups: control group (n = 6), moderate group (n = 18), and severe group (n = 18). Moderate (a 50-g aneurysm clip with 0.4-mm thickness spacer) or severe (a 50-g aneurysm clip with no spacer) contusion SCI at T8 vertebrae was induced. Then the electrophysiological assessments via MEPs, behavioral deterioration via the Basso, Beattie, and Bresnaha (BBB) scores, DTI data, and histopathology examination were analyzed. RESULTS: In this study, we found that the damage of WM myelin, MEPs amplitude, BBB scores and the decreases in the values of fractional anisotropy (FA) and axial diffusivity (AD) were more obvious in the severe injury group than those of the moderate group. Additionally, the FA and AD values could identify the extent of SCI in subacute and early acute SCI respectively, which was reflected in a robust correlations with MEPs and BBB scores. While the values of radial diffusivity (RD) showed no significant changes. CONCLUSIONS: Our data confirmed that DTI was a valuable in ex vivo imaging tool to identify damaged white matter tracts after graded SCI in rat, which may provide useful information for the early identification of the severity of SCI.


Assuntos
Imagem de Tensor de Difusão/métodos , Potencial Evocado Motor/fisiologia , Traumatismos da Medula Espinal/patologia , Traumatismos da Medula Espinal/fisiopatologia , Animais , Anisotropia , Feminino , Ratos , Ratos Sprague-Dawley , Substância Branca/patologia , Substância Branca/fisiopatologia
14.
Mayo Clin Proc ; 95(6): 1195-1205, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32498775

RESUMO

OBJECTIVE: To report population age-specific prevalence of core cerebrovascular disease lesions (infarctions, cerebral microbleeds, and white-matter hyperintensities detected with magnetic resonance imaging); estimate cut points for white-matter hyperintensity positivity; investigate sex differences in prevalence; and estimate prevalence of any core cerebrovascular disease features. PATIENTS AND METHODS: Participants in the population-based Mayo Clinic Study of Aging aged 50 to 89 years underwent fluid-attenuated inversion recovery and T2* gradient-recalled echo magnetic resonance imaging to assess cerebrovascular disease between October 10, 2011, and September 29, 2017. We characterized each participant as having infarct, normal versus abnormal white-matter hyperintensity, cerebral microbleed, or a combination of lesions. Prevalence of cerebrovascular disease biomarkers was derived through adjustment for nonparticipation and standardization to the population of Olmsted County, Minnesota. RESULTS: Among 1462 participants without dementia (median [range] age, 68 [50 to 89] y; men, 52.7%), core cerebrovascular disease features increased with age. Prevalence (95% CI) of cerebral microbleeds was 13.6% (11.6%-15.6%); infarcts, 11.7% (9.7%-13.8%); and abnormal white-matter hyperintensity, 10.7% (8.7%-12.6%). Infarcts and cerebral microbleeds were more common among men. In contrast, abnormal white-matter hyperintensity was more common among women ages 60 to 79 y and men, ages 80 y and older. Prevalence of any core cerebrovascular disease feature determined by presence of at least one cerebrovascular disease feature increased from 9.5% (ages 50 to 59 y) to 73.8% (ages 80 to 89 y). CONCLUSION: Whereas this study focused on participants without dementia, the high prevalence of cerebrovascular disease imaging lesions in elderly persons makes assignment of clinical relevance to cognition and other downstream manifestations more probabilistic than deterministic.


Assuntos
Envelhecimento/fisiologia , Transtornos Cerebrovasculares/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Transtornos Cerebrovasculares/epidemiologia , Transtornos Cerebrovasculares/patologia , Estudos de Coortes , Feminino , Humanos , Imagem por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Prevalência , Distribuição por Sexo , Substância Branca/diagnóstico por imagem , Substância Branca/patologia
15.
Zhongguo Ying Yong Sheng Li Xue Za Zhi ; 36(1): 77-81, 2020 Jan 28.
Artigo em Chinês | MEDLINE | ID: mdl-32476377

RESUMO

OBJECTIVE: To evaluate the effects of prenatal radiation of 850~1 900 MHz mobile phone on white matter in cerebellum of adult rat offspring. METHODS: Pregnant rats were randomly divided into short term maternal radiation group, long term maternal radiation group and control group. Rats in short term and long term maternal radiation group were exposed to 6 h/d and 24 h/d mobile phone radiation during 1-17 days of pregnancy, respectively. The cerebellums of offspring rats at the age of 3 month(n=8)were taken. Cell morphology in cerebellum was studied by hematoxylin-eosin (HE) staining. The expressions of myelin basic protein (MBP), neurofilament-L (NF-L) and glial fibrillary acidic protein (GFAP) in cerebellum of rat offspring were detected by immunohistochemistry and Western blot. RESULTS: Compared to control group, the morphological changes of purkinje cells in cerebellum were obvious in rat offspring of short term and long term maternal radiation group. Compared to control group, decreased MBP and NF-L expressions and increased GFAP expression were observed in long term maternal radiation group(all P<0.05). Compared to short term radiation group, the expressions of MBP and NF-L were down-regulated (all P<0.05) and the expression of GFAP was up- regulated(P<0.05) in long term radiation group. CONCLUSION: Prenatal mobile phone radiation might lead to the damage of myelin and axon with activity of astrocytes in cerebellum of male rat offspring, which is related to the extent of radiation.


Assuntos
Telefone Celular , Cerebelo/efeitos da radiação , Radiação Eletromagnética , Efeitos Tardios da Exposição Pré-Natal , Substância Branca/efeitos da radiação , Animais , Cerebelo/patologia , Feminino , Proteína Glial Fibrilar Ácida/metabolismo , Masculino , Proteína Básica da Mielina/metabolismo , Proteínas de Neurofilamentos/metabolismo , Gravidez , Distribuição Aleatória , Ratos , Substância Branca/patologia
17.
PLoS One ; 15(5): e0232826, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32379845

RESUMO

This study aimed to investigate abnormalities in the gray matter and white matter (GM and WM, respectively) that are shared between schizophrenia (SZ) and bipolar disorder (BD). We used 3T-magnetic resonance imaging to examine patients with SZ, BD, or healthy control (HC) subjects (aged 20-50 years, N = 65 in each group). We generated modulated GM maps through voxel-based morphometry (VBM) for T1-weighted images and skeletonized fractional anisotropy, mean diffusion, and radial diffusivity maps through tract-based special statistics (TBSS) methods for diffusion tensor imaging (DTI) data. These data were analyzed using a generalized linear model with pairwise comparisons between groups with a family-wise error corrected P < 0.017. The VBM analysis revealed widespread decreases in GM volume in SZ compared to HC, but patients with BD showed GM volume deficits limited to the right thalamus and left insular lobe. The TBSS analysis showed alterations of DTI parameters in widespread WM tracts both in SZ and BD patients compared to HC. The two disorders had WM alterations in the corpus callosum, superior longitudinal fasciculus, internal capsule, external capsule, posterior thalamic radiation, and fornix. However, we observed no differences in GM volume or WM integrity between SZ and BD. The study results suggest that GM volume deficits in the thalamus and insular lobe along with widespread disruptions of WM integrity might be the common neural mechanisms underlying the pathologies of SZ and BD.


Assuntos
Transtorno Bipolar/patologia , Substância Cinzenta/patologia , Esquizofrenia/patologia , Substância Branca/patologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
18.
PLoS One ; 15(5): e0232975, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32392241

RESUMO

Finite element models combined with animal experimental models of spinal cord injury provides the opportunity for investigating the effects of the injury mechanism on the neural tissue deformation and the resulting tissue damage. Thus, we developed a finite element model of the mouse cervical spinal cord in order to investigate the effect of morphological, experimental and mechanical factors on the spinal cord mechanical behavior subjected to transverse contusion. The overall mechanical behavior of the model was validated with experimental data of unilateral cervical contusion in mice. The effects of the spinal cord material properties, diameter and curvature, and of the impactor position and inclination on the strain distribution were investigated in 8 spinal cord anatomical regions of interest for 98 configurations of the model. Pareto analysis revealed that the material properties had a significant effect (p<0.01) for all regions of interest of the spinal cord and was the most influential factor for 7 out of 8 regions. This highlighted the need for comprehensive mechanical characterization of the gray and white matter in order to develop effective models capable of predicting tissue deformation during spinal cord injuries.


Assuntos
Modelos Neurológicos , Traumatismos da Medula Espinal/patologia , Traumatismos da Medula Espinal/fisiopatologia , Animais , Fenômenos Biomecânicos , Simulação por Computador , Modelos Animais de Doenças , Análise de Elementos Finitos , Substância Cinzenta/patologia , Substância Cinzenta/fisiopatologia , Humanos , Imageamento Tridimensional , Camundongos , Traumatismos da Medula Espinal/etiologia , Substância Branca/patologia , Substância Branca/fisiopatologia
19.
Neurology ; 94(23): e2424-e2435, 2020 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-32358221

RESUMO

OBJECTIVE: To determine the predictive power of white matter neuronal networks (i.e., structural connectomes [SCs]) in discriminating memory-impaired patients with temporal lobe epilepsy (TLE) from those with normal memory. METHODS: T1- and diffusion MRI (dMRI), clinical variables, and neuropsychological measures of verbal memory were available for 81 patients with TLE. Prediction of memory impairment was performed with a tree-based classifier (XGBoost) for 4 models: (1) a clinical model including demographic and clinical features, (2) a hippocampal volume (HCV) model, (3) a tract model including 5 temporal lobe white matter association tracts derived from a dMRI atlas, and (4) an SC model based on dMRI. SCs were derived by extracting cortical-cortical connections from a temporal lobe subnetwork with probabilistic tractography. Principal component (PC) analysis was then applied to reduce the dimensionality of the SC, yielding 10 PCs. Multimodal models were also tested combining SCs and tracts with HCV. Each model was trained on 48 patients from 1 epilepsy center and tested on 33 patients from a different center. RESULTS: Multimodal models that included the SC + HCV model yielded the highest classification accuracy (81%; 0.90 sensitivity; 0.67 specificity), outperforming the clinical model (61%; p < 0.001) and HCV model (66%; p < 0.001). In addition, the unimodal SC model (76% accuracy) and tract model (73% accuracy) outperformed the clinical model (p < 0.001) and HCV model (p < 0.001) for classifying patients with TLE with and without memory impairment. Furthermore, the SC identified that short-range temporal-temporal connections were important contributors to memory performance. CONCLUSION: SCs and tract-based models are stronger predictors of memory impairment in TLE than HCVs and clinical variables. However, SCs may provide additional information about local cortical-cortical connectivity contributing to memory that is not captured in large association tracts.


Assuntos
Conectoma , Epilepsia do Lobo Temporal/psicologia , Transtornos da Memória/etiologia , Adulto , Anisotropia , Área Sob a Curva , Imagem de Tensor de Difusão , Escolaridade , Epilepsia do Lobo Temporal/diagnóstico por imagem , Epilepsia do Lobo Temporal/patologia , Feminino , Hipocampo/diagnóstico por imagem , Hipocampo/patologia , Humanos , Masculino , Transtornos da Memória/diagnóstico por imagem , Transtornos da Memória/patologia , Pessoa de Meia-Idade , Modelos Neurológicos , Testes Neuropsicológicos , Tamanho do Órgão , Análise de Componente Principal , Curva ROC , Sensibilidade e Especificidade , Aprendizagem Verbal/fisiologia , Substância Branca/diagnóstico por imagem , Substância Branca/patologia , Adulto Jovem
20.
BMC Neurol ; 20(1): 185, 2020 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-32404188

RESUMO

BACKGROUND: To explore the feasibility of the metrics of diffusion kurtosis imaging (DKI) for investigations of the microstructural changes of spinal cord injury in patients with degenerative cervical myelopathy (DCM) and the correlation between Japan Orthopaedic Association (JOA) scores and DKI metrics. METHODS: Fifty-seven patients with DCM and 38 healthy volunteers underwent 3.0 T magnetic resonance (MR) imaging with routine MRI sequences and DKI from echo-planar imaging sequence. Based on the JOA score, DCM patients were divided into four subgroups. DKI metrics of the DCM group and control group were obtained and compared, separately for the white matter (WM) and the gray matter (GM). RESULTS: The FA values in WM were significantly lower (P = 0.020) in the DCM group than in the control group. The MK values in GM were lower (P = 0.011) in the DCM group than in the control group. The MD values in WM were significantly higher (P = 0.010) in the DCM group than in the control group. In GM, the JOA score was positively correlated with the MK values (r = 0.768, P < 0.05). In the WM, the JOA score was positively correlated with the FA values (r = 0.612, P < 0.05). CONCLUSION: DKI provides quantitive evaluation to the characters of microstructure of the spinal cord damage in patients with DCM compared to conventional MR. MK values can reflect microstructural abnormalities of gray matter of the cervical spinal cord and provide more information beyond that obtained with routine diffusion metrics. In addition, MK values of GM and FA values of WM may as a be highly sensitive biomarker for the degree of cervical spinal cord damage.


Assuntos
Medula Cervical/diagnóstico por imagem , Imagem Ecoplanar/métodos , Neuroimagem/métodos , Doenças da Medula Espinal/diagnóstico por imagem , Adulto , Medula Cervical/patologia , Feminino , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/patologia , Humanos , Japão , Imagem por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Doenças da Medula Espinal/patologia , Substância Branca/diagnóstico por imagem , Substância Branca/patologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA