Publications by authors named "R Fleysher"

Background: The cortical gray matter-white matter interface (GWI) is a natural transition zone where the composition of brain tissue abruptly changes and is a location for pathologic change in brain disorders. While diffusion magnetic resonance imaging (dMRI) is a reliable and well-established technique to characterize brain microstructure, the GWI is difficult to assess with dMRI due to partial volume effects and is normally excluded from such studies.

Methods: In this study, we introduce an approach to characterize the dMRI microstructural profile across the GWI and to assess the sharpness of the microstructural transition from cortical gray matter (GM) to white matter (WM).

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Rationale And Objectives: This study examined the brain effects of mild severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection which are incompletely understood. Our objective was to ascertain within-person changes associated with mild coronavirus disease 2019 (COVID-19) in otherwise healthy adults.

Materials And Methods: We leveraged existing pre-pandemic baseline neuroimaging and neurocognitive data, and collected follow-up data from uninfected controls and individuals with prior mild COVID-19, during December 2020 and January 2021, when vaccines were not yet available.

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Article Synopsis
  • The hypothalamus plays a crucial role in maintaining homeostasis and is linked to aging, with changes observed in mouse models leading to cognitive decline.
  • A study involving older adults used advanced imaging to explore the relationship between hypothalamic microstructure and neurocognitive factors, revealing that changes in mean diffusivity were age-related and correlated with decreased cortical thickness.
  • The research found that lower levels of fractional anisotropy in the hypothalamus may predict cognitive decline over time, marking the first evidence of a direct link between hypothalamic structure and cognitive aging in humans.
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Heterozygous deletions in the ANKS1B gene cause ANKS1B neurodevelopmental syndrome (ANDS), a rare genetic disease characterized by autism spectrum disorder (ASD), attention deficit/hyperactivity disorder, and speech and motor deficits. The ANKS1B gene encodes for AIDA-1, a protein that is enriched at neuronal synapses and regulates synaptic plasticity. Here we report an unexpected role for oligodendroglial deficits in ANDS pathophysiology.

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Objective: To investigate the clinical outcomes of patients with rheumatoid arthritis (RA) with COVID-19.

Methods: This retrospective study consisted of 361 patients with RA+ and 45,954 patients with RA- (March 2020 to August 2022) who tested positive for SARS-CoV-2 by polymerase-chain-reaction in the Montefiore Health System, which serves a large low-income, minority-predominant population in the Bronx and was an epicenter of the initial pandemic and subsequent surges. Primary outcomes were hospitalization, critical illness, and all-cause mortality associated with SARS-CoV-2 infection.

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