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1.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 1701-1704, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018324

RESUMO

With an estimated five million new stroke survivors every year and a rapidly aging population suffering from hyperintensities and diseases of presumed vascular origin that affect white matter and contribute to cognitive decline, it is critical that we understand the impact of white matter damage on brain structure and behavior. Current techniques for assessing the impact of lesions consider only location, type, and extent, while ignoring how the affected region was connected to the rest of the brain. Regional brain function is a product of both local structure and its connectivity. Therefore, obtaining a map of white matter disconnection is a crucial step that could help us predict the behavioral deficits that patients exhibit. In the present work, we introduce a new practical method for computing lesion-based white matter disconnection maps that require only moderate computational resources. We achieve this by creating diffusion tractography models of the brains of healthy adults and assessing the connectivity between small regions. We then interrupt these connectivity models by projecting patients' lesions into them to compute predicted white matter disconnection. A quantified disconnection map can be computed for an individual patient in approximately 35 seconds using a single core CPU-based computation. In comparison, a similar quantification performed with other tools provided by MRtrix3 takes 5.47 minutes.


Assuntos
Substância Branca , Adulto , Idoso , Envelhecimento , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Imagem de Tensor de Difusão , Humanos , Substância Branca/diagnóstico por imagem
2.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 1746-1749, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018335

RESUMO

Glaucoma is a neurodegenerative disease of the visual system and is the leading cause of irreversible blindness worldwide. To date, its pathophysiological mechanisms remain unclear. This study evaluated the feasibility of advanced diffusion magnetic resonance imaging techniques for examining the microstructural environment of the visual pathway in glaucoma. While conventional diffusion tensor imaging (DTI) showed lower fractional anisotropy and higher directional diffusivities in the optic tracts of glaucoma patients than healthy controls, diffusion kurtosis imaging (DKI) and the extended white matter tract integrity (WMTI) model indicated lower radial kurtosis, higher axial and radial diffusivities in the extra-axonal space, lower axonal water fraction, and lower tortuosity in the same regions in glaucoma patients. These findings suggest glial involvements apart from compromised axonal integrity in glaucoma. In addition, DKI and WMTI but not DTI parameters significantly correlated with clinical ophthalmic measures via optical coherence tomography and visual field perimetry testing. Taken together, DKI and WMTI provided sensitive and comprehensive imaging biomarkers for quantifying glaucomatous damage in the white matter tract across clinical severity complementary to DTI.


Assuntos
Glaucoma , Doenças Neurodegenerativas , Trato Óptico , Substância Branca , Imagem de Tensor de Difusão , Glaucoma/diagnóstico por imagem , Humanos , Substância Branca/diagnóstico por imagem
3.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 1754-1757, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018337

RESUMO

White matter hyperintensities (WMH) are important biomarkers for cerebral small vessel disease and closely associated with other neurodegenerative process. In this paper, we proposed a fully automatic WMH segmentation method based on U-net architecture. CRF were combined with U-net to refine segmentation results. We used a new anatomical based spatial feature produced by brain tissue segmentation based on T1 image, along with intensities of T1 and T2-FLAIR images to train our neural network. We compared 8 forms of automated WMH segmentation methods, range from traditional statistical learnng methods to deep learning based methods, with different architecture and used different features. Results showed our proposed method achieved best performance in terms of most metrics, and the inclusion of anatomical based spatial features strongly increase the segmentation performance.


Assuntos
Leucoaraiose , Substância Branca , Algoritmos , Hormônio Liberador da Corticotropina , Humanos , Imagem por Ressonância Magnética , Substância Branca/diagnóstico por imagem
4.
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
5.
Neuroradiol J ; 33(5): 374-376, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32757827

RESUMO

We are reporting the imaging findings of the rare entity of critical illness-associated cerebral microbleeds in a COVID-19-positive 66-year-old woman with hypoxic respiratory failure, who was eventually intubated and ventilated. Multiple scattered cerebral microhaemorrhages diffusely distributed in the juxtacortical white matter and internal capsule region, sparing the deep and periventricular white matter, basal ganglia, thalami and cortex were seen, which is a unique imaging finding in critically ill patients with respiratory failure and hypoxemia requiring mechanical ventilation. The mechanism underlying these microhaemorrhages relates to the endpoint of critical illness, rather than a specific underlying disease.


Assuntos
Edema Encefálico/diagnóstico por imagem , Hemorragia Cerebral/diagnóstico por imagem , Infecções por Coronavirus/diagnóstico por imagem , Pneumonia Viral/diagnóstico por imagem , Substância Branca/diagnóstico por imagem , Idoso , Betacoronavirus , Edema Encefálico/complicações , Hemorragia Cerebral/complicações , Infecções por Coronavirus/complicações , Infecções por Coronavirus/terapia , Estado Terminal , Feminino , Humanos , Hipóxia/etiologia , Hipóxia/terapia , Angiografia por Ressonância Magnética , Imagem por Ressonância Magnética , Pandemias , Pneumonia Viral/complicações , Pneumonia Viral/terapia , Respiração Artificial , Insuficiência Respiratória/etiologia , Insuficiência Respiratória/terapia , Tomografia Computadorizada por Raios X
6.
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
7.
Brain Behav Immun ; 89: 543-554, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32682993

RESUMO

OBJECTIVE: This systematic review aimed to synthesize early data on typology and topography of brain abnormalities in adults with COVID-19 in acute/subacute phase. METHODS: We performed systematic literature search via PubMed, Google Scholar and ScienceDirect on articles published between January 1 and July 05, 2020, using the following strategy and key words: ((covid[Title/Abstract]) OR (sars-cov-2[Title/Abstract]) OR (coronavirus[Title/Abstract])) AND (brain[Title/Abstract]). A total of 286 non-duplicate matches were screened for original contributions reporting brain imaging data related to SARS-Cov-2 presentation in adults. RESULTS: The selection criteria were met by 26 articles (including 21 case reports, and 5 cohort studies). The data analysis in a total of 361 patients revealed that brain abnormalities were noted in 124/361 (34%) reviewed cases. Neurologic symptoms were the primary reason for referral for neuroimaging across the studies. Modalities included CT (-angiogram, -perfusion, -venogram), EEG, MRI (-angiogram, functional), and PET. The most frequently reported brain abnormalities were brain white matter (WM) hyperintensities on MRI 66/124 (53% affected cases) and hypodensities on CT (additional 23% affected cases), followed by microhemorrhages, hemorrhages and infarcts, while other types were found in <5% affected cases. WM abnormalities were most frequently noted in bilateral anterior and posterior cerebral WM (50% affected cases). CONCLUSION: About a third of acute/subacute COVID-19 patients referred for neuroimaging show brain abnormalities suggestive of COVID-19-related etiology. The predominant neuroimaging features were diffuse cerebral WM hypodensities / hyperintensities attributable to leukoencephalopathy, leukoaraiosis or rarefield WM.


Assuntos
Encéfalo/diagnóstico por imagem , Hemorragia Cerebral/diagnóstico por imagem , Infarto Cerebral/diagnóstico por imagem , Infecções por Coronavirus/diagnóstico por imagem , Leucoaraiose/diagnóstico por imagem , Leucoencefalopatias/diagnóstico por imagem , Pneumonia Viral/diagnóstico por imagem , Doença Aguda , Betacoronavirus , Angiografia Cerebral , Hemorragia Cerebral/etiologia , Infarto Cerebral/etiologia , Angiografia por Tomografia Computadorizada , Infecções por Coronavirus/complicações , Eletroencefalografia , Humanos , Leucoaraiose/etiologia , Leucoencefalopatias/etiologia , Imagem por Ressonância Magnética , Pandemias , Pneumonia Viral/complicações , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Substância Branca/diagnóstico por imagem
8.
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
9.
PLoS Genet ; 16(6): e1008841, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32544203

RESUMO

Hypomyelination, a neurological condition characterized by decreased production of myelin sheets by glial cells, often has no known etiology. Elucidating the genetic causes of hypomyelination provides a better understanding of myelination, as well as means to diagnose, council, and treat patients. Here, we present evidence that YIPPEE LIKE 3 (YPEL3), a gene whose developmental role was previously unknown, is required for central and peripheral glial cell development. We identified a child with a constellation of clinical features including cerebral hypomyelination, abnormal peripheral nerve conduction, hypotonia, areflexia, and hypertrophic peripheral nerves. Exome and genome sequencing revealed a de novo mutation that creates a frameshift in the open reading frame of YPEL3, leading to an early stop codon. We used zebrafish as a model system to validate that YPEL3 mutations are causative of neuropathy. We found that ypel3 is expressed in the zebrafish central and peripheral nervous system. Using CRISPR/Cas9 technology, we created zebrafish mutants carrying a genomic lesion similar to that of the patient. Our analysis revealed that Ypel3 is required for development of oligodendrocyte precursor cells, timely exit of the perineurial glial precursors from the central nervous system (CNS), formation of the perineurium, and Schwann cell maturation. Consistent with these observations, zebrafish ypel3 mutants have metabolomic signatures characteristic of oligodendrocyte and Schwann cell differentiation defects, show decreased levels of Myelin basic protein in the central and peripheral nervous system, and develop defasciculated peripheral nerves. Locomotion defects were observed in adult zebrafish ypel3 mutants. These studies demonstrate that Ypel3 is a novel gene required for perineurial cell development and glial myelination.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/genética , Bainha de Mielina/patologia , Neurogênese/genética , Proteínas Supressoras de Tumor/genética , Animais , Plexo Braquial/diagnóstico por imagem , Criança , Análise Mutacional de DNA , Modelos Animais de Doenças , Embrião não Mamífero , Feminino , Mutação da Fase de Leitura , Substância Cinzenta/diagnóstico por imagem , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/diagnóstico por imagem , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/patologia , Humanos , Imagem por Ressonância Magnética , Neuroglia/patologia , Oligodendroglia , Nervo Isquiático/diagnóstico por imagem , Substância Branca/diagnóstico por imagem , Sequenciamento Completo do Exoma , Peixe-Zebra , Proteínas de Peixe-Zebra/genética
10.
Nat Commun ; 11(1): 3030, 2020 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-32541779

RESUMO

Selectively attributing beliefs to specific agents is core to reasoning about other people and imagining oneself in different states. Evidence suggests humans might achieve this by simulating each other's computations in agent-specific neural circuits, but it is not known how circuits become agent-specific. Here we investigate whether agent-specificity adapts to social context. We train subjects on social learning tasks, manipulating the frequency with which self and other see the same information. Training alters the agent-specificity of prediction error (PE) circuits for at least 24 h, modulating the extent to which another agent's PE is experienced as one's own and influencing perspective-taking in an independent task. Ventromedial prefrontal myelin density, indexed by magnetisation transfer, correlates with the strength of this adaptation. We describe a frontotemporal learning network, which exploits relationships between different agents' computations. Our findings suggest that Self-Other boundaries are learnable variables, shaped by the statistical structure of social experience.


Assuntos
Córtex Pré-Frontal/fisiologia , Aprendizado Social , Adulto , Feminino , Humanos , Imaginação , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Bainha de Mielina/metabolismo , Valor Preditivo dos Testes , Córtex Pré-Frontal/diagnóstico por imagem , Comportamento Social , Substância Branca/diagnóstico por imagem , Substância Branca/fisiologia , Adulto Jovem
11.
PLoS One ; 15(6): e0233915, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32484819

RESUMO

Cognitive control and incentive sensitivity are related to overeating and obesity. Optimal white matter integrity is relevant for an efficient interaction among reward-related brain regions. However, its relationship with sensitivity to incentives remains controversial. The aim of this study was to assess the incentive sensitivity and its relationship to white matter integrity in normal-weight and overweight groups. Seventy-six young adults participated in this study: 31 were normal-weight (body mass index [BMI] 18.5 to < 25.0 kg/m2, 14 females) and 45 were overweight (BMI ≥ 25.0 kg/m2, 22 females). Incentive sensitivity was assessed using an antisaccade task that evaluates the effect of incentives (neutral, reward, and loss avoidance) on cognitive control performance. Diffusion tensor imaging studies were performed to assess white matter integrity. The relationship between white matter microstructure and incentive sensitivity was investigated through tract-based spatial statistics. Behavioral antisaccade results showed that normal-weight participants presented higher accuracy (78.0 vs. 66.7%, p = 0.01) for loss avoidance incentive compared to overweight participants. Diffusion tensor imaging analysis revealed a positive relationship between fractional anisotropy and loss avoidance accuracy in the normal-weight group (p < 0.05). No relationship reached significance in the overweight group. These results support the hypothesis that white matter integrity is relevant for performance in an incentivized antisaccade task.


Assuntos
Encéfalo/diagnóstico por imagem , Sistema Nervoso Central/fisiopatologia , Cognição/fisiologia , Obesidade/fisiopatologia , Adulto , Anisotropia , Índice de Massa Corporal , Encéfalo/fisiologia , Mapeamento Encefálico , Sistema Nervoso Central/diagnóstico por imagem , Chile/epidemiologia , Imagem de Tensor de Difusão , Movimentos Oculares/fisiologia , Feminino , Humanos , Masculino , Obesidade/diagnóstico por imagem , Obesidade/epidemiologia , Perda de Peso/fisiologia , Substância Branca/diagnóstico por imagem , Substância Branca/fisiologia , Adulto Jovem
12.
Am J Psychiatry ; 177(6): 491-496, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32475142

RESUMO

Six articles in the June 2020 issue of the American Journal of Psychiatry address the overall construct of cognition. These articles have a broad connection to cognition, which is itself a broad concept. From the experimental psychology perspective, cognition is the set of processes associated with attending, learning, knowing, and remembering. From the clinical perspective, a number of neuropsychiatric conditions are defined by the presence of cognitive impairment, with onset ranging from childhood, such as attention deficit hyperactivity disorder and intellectual disability, to later life, such as dementia. Other conditions have notable cognitive impairments even if specific cognitive impairments are not an explicit part of their formal diagnostic criteria, including autism spectrum disorder and schizophrenia. Thus, the array of articles in this issue are related to each other and also may make important points about the role of cognition in everyday functioning and the connections between cognitive impairments in neuropsychiatric conditions and in the human population in general. Further, these articles address the neurobiological substrates that have an impact on cognition, with important implications in other domains, such as genomics. Finally, through sophisticated research methods, they clarify the results of previous studies that were affected by a variety of methodological challenges.


Assuntos
Antidepressivos/uso terapêutico , Transtorno do Deficit de Atenção com Hiperatividade/genética , Transtorno Autístico/epidemiologia , Benzodiazepinas/uso terapêutico , Cognição , Demência/epidemiologia , Sono , Feminino , Humanos , Gravidez , Efeitos Tardios da Exposição Pré-Natal/epidemiologia , Fatores de Proteção , Fatores de Risco , Esquizofrenia/diagnóstico por imagem , Substância Branca/diagnóstico por imagem
13.
Neurology ; 95(6): e718-e732, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32518148

RESUMO

OBJECTIVE: To characterize the extent of CNS involvement in children with Pompe disease using brain MRI and developmental assessments. METHODS: The study included 14 children (ages 6-18 years) with infantile Pompe disease (IPD) (n = 12) or late-onset Pompe disease (LOPD) (n = 2) receiving enzyme replacement therapy. White matter (WM) hyperintense foci seen in the brain MRIs were systematically quantified using the Fazekas scale (FS) grading system with a novel approach: the individual FS scores from 10 anatomical areas were summed to yield a total FS score (range absent [0] to severe [30]) for each child. The FS scores were compared to developmental assessments of cognition and language obtained during the same time period. RESULTS: Mild to severe WM hyperintense foci were seen in 10/12 children with IPD (median age 10.6 years) with total FS scores ranging from 2 to 23. Periventricular, subcortical, and deep WM were involved. WM hyperintense foci were seen throughout the path of the corticospinal tracts in the brain in children with IPD. Two children with IPD had no WM hyperintense foci. Children with IPD had relative weaknesses in processing speed, fluid reasoning, visual perception, and receptive vocabulary. The 2 children with LOPD had no WM hyperintense foci, and high scores on most developmental assessments. CONCLUSION: This study systematically characterized WM hyperintense foci in children with IPD, which could serve as a benchmark for longitudinal follow-up of WM abnormalities in patients with Pompe disease and other known neurodegenerative disorders or leukodystrophies in children.


Assuntos
Encefalopatias Metabólicas Congênitas/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Deficiências do Desenvolvimento/diagnóstico por imagem , Doença de Depósito de Glicogênio Tipo II/diagnóstico por imagem , Imagem por Ressonância Magnética , Neuroimagem , Adolescente , Idade de Início , Encéfalo/patologia , Encefalopatias Metabólicas Congênitas/etiologia , Criança , Transtornos Cognitivos/diagnóstico por imagem , Transtornos Cognitivos/etiologia , Estudos Transversais , Deficiências do Desenvolvimento/etiologia , Terapia de Reposição de Enzimas , Glucana 1,4-alfa-Glucosidase/uso terapêutico , Doença de Depósito de Glicogênio Tipo II/complicações , Doença de Depósito de Glicogênio Tipo II/tratamento farmacológico , Doença de Depósito de Glicogênio Tipo II/psicologia , Humanos , Transtornos da Linguagem/diagnóstico por imagem , Transtornos da Linguagem/etiologia , Imagem por Ressonância Magnética/métodos , Neuroimagem/métodos , Substância Branca/diagnóstico por imagem
14.
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
15.
Neurology ; 95(3): e291-e298, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32576636

RESUMO

OBJECTIVE: To determine whether deep white matter and periventricular hyperintensities affect the motor symptoms of Parkinson disease (PD) differently, we analyzed MRI and dopamine transporter imaging. METHODS: We analyzed the medical records of patients with de novo PD who underwent dopamine transporter PET scanning and MRI at their first visit. Deep white matter and periventricular hyperintensities were scored with a visual rating scale, and motor symptoms were assessed by Unified Parkinson's Disease Rating Scale motor score and tremor, rigidity, bradykinesia, and axial symptom subscores. The influence of white matter hyperintensity on motor symptoms was explored using multivariable linear regression models. RESULTS: A total of 93 patients (mean age, 67.2 ± 9.9 years; 44 male) were included and the mean motor score was 25.0 ± 10.8. Subscores for bradykinesia and axial symptoms were correlated with both deep white matter and periventricular hyperintensities scores. Multivariable linear regression models revealed that deep white matter hyperintensities score was significantly associated with subscore for bradykinesia and periventricular hyperintensities score was associated with subscores for bradykinesia and axial symptoms after adjusting for putaminal dopamine transporter availability and clinical factors. CONCLUSIONS: These results demonstrate that deep white matter hyperintensities are associated with bradykinesia and periventricular hyperintensities are associated with bradykinesia and axial symptoms in patients with PD independently of the severity of dopaminergic depletion.


Assuntos
Transtornos das Habilidades Motoras/diagnóstico por imagem , Transtornos das Habilidades Motoras/metabolismo , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/metabolismo , Substância Branca/diagnóstico por imagem , Substância Branca/metabolismo , Idoso , Feminino , Humanos , Imagem por Ressonância Magnética/tendências , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons/tendências
16.
Maturitas ; 137: 24-29, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32498933

RESUMO

BACKGROUND: Higher levels of physical activity (PA) are known to be associated with better white matter integrity measured by diffusion tensor imaging (DTI) in older adults in cross-sectional studies. However, no studies have investigated the association between PA levels and the evolution of DTI parameters (fractional anisotropy and mean diffusivity). OBJECTIVES: To examine the cross-sectional associations between PA levels and DTI parameters, then to investigate the association between baseline PA levels and the evolution of DTI parameters in older adults. METHODS: Data on magnetic resonance imaging with DTI method from the Multidomain Alzheimer's Preventive Trial (MAPT) study were used; 228 participants had data on DTI measured at three time-points over five years. Fractional anisotropy and mean diffusivity were acquired for six different brain regions. RESULTS: No significant associations were found in the cross-sectional analyses. Only one association was found: compared with active individuals, a faster worsening in the mean diffusivity of the uncinate fasciculus region was found in inactive individuals (-5.0 × 10-6 (-9.5 × 10-5, 4.9 × 10-6)). CONCLUSIONS: In this study, we found that the condition of the uncinate fasciculus region may be susceptible to changes in PA levels in older adults. Longitudinal studies that assess fitness and PA using objective measurements (e.g. cardiorespiratory fitness and accelerometry) could shed some new light on this topic.


Assuntos
Exercício Físico , Substância Branca/diagnóstico por imagem , Idoso , Anisotropia , Estudos Transversais , Imagem de Tensor de Difusão , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Estudos Prospectivos , Comportamento Sedentário
17.
Neurology ; 95(14): e2016-e2027, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-32546654

RESUMO

OBJECTIVES: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is considered to have potential neuroinvasiveness that might lead to acute brain disorders or contribute to respiratory distress in patients with coronavirus disease 2019 (COVID-19). This study investigates the occurrence of structural brain abnormalities in non-survivors of COVID-19 in a virtopsy framework. METHODS: In this prospective, monocentric, case series study, consecutive patients who fulfilled the following inclusion criteria benefited from an early postmortem structural brain MRI: death <24 hours, SARS-CoV-2 detection on nasopharyngeal swab specimen, chest CT scan suggestive of COVID-19, absence of known focal brain lesion, and MRI compatibility. RESULTS: Among the 62 patients who died of COVID-19 from March 31, 2020, to April 24, 2020, at our institution, 19 decedents fulfilled the inclusion criteria. Parenchymal brain abnormalities were observed in 4 decedents: subcortical microbleeds and macrobleeds (2 decedents), cortico-subcortical edematous changes evocative of posterior reversible encephalopathy syndrome (PRES; 1 decedent), and nonspecific deep white matter changes (1 decedent). Asymmetric olfactory bulbs were found in 4 other decedents without downstream olfactory tract abnormalities. No brainstem MRI signal abnormality was observed. CONCLUSIONS: Postmortem brain MRI demonstrates hemorrhagic and PRES-related brain lesions in non-survivors of COVID-19. SARS-CoV-2-related olfactory impairment seems to be limited to olfactory bulbs. Brainstem MRI findings do not support a brain-related contribution to respiratory distress in COVID-19.


Assuntos
Edema Encefálico/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Hemorragia Cerebral/diagnóstico por imagem , Infecções por Coronavirus/diagnóstico por imagem , Pneumonia Viral/diagnóstico por imagem , Síndrome da Leucoencefalopatia Posterior/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Betacoronavirus , Imagem de Difusão por Ressonância Magnética , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Bulbo Olfatório/diagnóstico por imagem , Pandemias , Mudanças Depois da Morte , Estudos Prospectivos , Substância Branca/diagnóstico por imagem
18.
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
19.
PLoS One ; 15(5): e0233684, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32470000

RESUMO

White matter abnormalities are well-established in adult patients with psychosis. Less is known about abnormalities in the rarely occurring adolescent early onset psychosis (EOP). In particular, whether antipsychotic medication might impact white matter microstructure is not known. Using 3T diffusion weighted imaging, we investigated differences in white matter microstructure and the impact of antipsychotic medication status in medicated (n = 11) and unmedicated (n = 11) EOP patients relative to healthy controls (n = 33), aged between 12-18 years. Using Tract-based Spatial Statistics, we calculate case-control differences in scalar diffusion measures, i.e. fractional anisotropy (FA), axial diffusion (AD) and radial diffusion (RD), and investigated their association with antipsychotic medication in patients. We found significantly lower FA in the left genu of the corpus callosum, the left anterior corona radiata (ACR) and the right superior longitudinal fasciculus in EOP patients relative to healthy controls. AD values were also lower in the left ACR, largely overlapping with the FA findings. Mean FA in the left ACR was significantly associated with antipsychotic medication status (Cohen's d = 1.37, 95% CI [0.01, 2.68], p = 0.008), showing higher FA values in medicated compared to unmedicated EOP patients. The present study is the first to link antipsychotic medication status to altered regional FA in the left ACR, a region hypothesized to contribute to the etiology of psychosis. Replications are warranted to draw firm conclusions about putatively enhancing effects of antipsychotic medication on white matter microstructure in adolescent-onset psychosis.


Assuntos
Antipsicóticos/administração & dosagem , Imagem de Tensor de Difusão , Transtornos Psicóticos/diagnóstico por imagem , Transtornos Psicóticos/tratamento farmacológico , Substância Branca/diagnóstico por imagem , Adolescente , Anisotropia , Criança , Feminino , Humanos , Masculino
20.
PLoS One ; 15(5): e0228119, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32407389

RESUMO

Simulating transcranial electric stimulation is actively researched as knowledge about the distribution of the electrical field is decisive for understanding the variability in the elicited stimulation effect. Several software pipelines comprehensively solve this task in an automated manner for standard use-cases. However, simulations for non-standard applications such as uncommon electrode shapes or the creation of head models from non-optimized T1-weighted imaging data and the inclusion of irregular structures are more difficult to accomplish. We address these limitations and suggest a comprehensive workflow to simulate transcranial electric stimulation based on open-source tools. The workflow covers the head model creation from MRI data, the electrode modeling, the modeling of anisotropic conductivity behavior of the white matter, the numerical simulation and visualization. Skin, skull, air cavities, cerebrospinal fluid, white matter, and gray matter are segmented semi-automatically from T1-weighted MR images. Electrodes of arbitrary number and shape can be modeled. The meshing of the head model is implemented in a way to preserve the feature edges of the electrodes and is free of topological restrictions of the considered structures of the head model. White matter anisotropy can be computed from diffusion-tensor imaging data. Our solver application was verified analytically and by contrasting the tDCS simulation results with that of other simulation pipelines (SimNIBS 3.0, ROAST 3.0). An agreement in both cases underlines the validity of our workflow. Our suggested solutions facilitate investigations of irregular structures in patients (e.g. lesions, implants) or new electrode types. For a coupled use of the described workflow, we provide documentation and disclose the full source code of the developed tools.


Assuntos
Encéfalo/fisiologia , Sistema Nervoso Central/fisiologia , Cabeça/fisiologia , Estimulação Transcraniana por Corrente Contínua , Algoritmos , Anisotropia , Encéfalo/diagnóstico por imagem , Encéfalo/efeitos da radiação , Sistema Nervoso Central/diagnóstico por imagem , Sistema Nervoso Central/efeitos da radiação , Imagem de Tensor de Difusão , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/efeitos da radiação , Cabeça/diagnóstico por imagem , Cabeça/efeitos da radiação , Humanos , Processamento de Imagem Assistida por Computador , Imagem por Ressonância Magnética , Modelos Teóricos , Substância Branca/diagnóstico por imagem , Substância Branca/efeitos da radiação , Fluxo de Trabalho
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