Publications by authors named "Ann C Mckee"

Introduction: Alzheimer's disease (AD), primary age-related tauopathy (PART), and chronic traumatic encephalopathy (CTE) all feature hyperphosphorylated tau (p-tau)-immunoreactive neurofibrillary degeneration, but differ in neuroanatomical distribution and progression of neurofibrillary degeneration and amyloid beta (Aβ) deposition.

Methods: We used Nanostring GeoMx Digital Spatial Profiling to compare the expression of 70 proteins in neurofibrillary tangle (NFT)-bearing and non-NFT-bearing neurons in hippocampal CA1, CA2, and CA4 subregions and entorhinal cortex of cases with autopsy-confirmed AD (n = 8), PART (n = 7), and CTE (n = 5).

Results: There were numerous subregion-specific differences related to Aβ processing, autophagy/proteostasis, inflammation, gliosis, oxidative stress, neuronal/synaptic integrity, and p-tau epitopes among these different disorders.

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Neurodegeneration is a seminal feature of many neurological disorders. Chronic traumatic encephalopathy (CTE) is caused by repetitive head impacts (RHI) and is characterized by sulcal tau pathology. However, quantitative assessments of regional neurodegeneration in CTE have not been described.

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Importance: Chronic traumatic encephalopathy (CTE) is a neurodegenerative tauopathy associated with repetitive head impacts (RHIs). Prior research suggests a dose-response association between American football play duration and CTE risk and severity, but this association has not been studied for ice hockey.

Objective: To investigate associations of duration of ice hockey play with CTE diagnosis and severity, functional status, and dementia.

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Article Synopsis
  • Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease linked to frequent head injuries, often seen in athletes and military personnel, with a focus on its relationship with aggression and family mental health history.
  • The study analyzed data from deceased male brain donors with CTE, aiming to determine if the presence of CTE affects the relationship between first-degree family history of mental illness (1°FHMI) and aggression, using structured assessments and various demographic controls.
  • Results indicated that 1°FHMI was significantly correlated with aggression scores in individuals with CTE, suggesting that CTE pathology may influence aggression differently than previously understood, while no such association was found in those without CTE.
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Background And Objectives: CSF biomarkers of Aβ42 and phosphorylated tau (p-tau181) are used clinically for the detection of Alzheimer disease (AD) pathology during life. CSF biomarker validation studies have largely used clinical diagnoses and/or amyloid PET imaging as the reference standard. The few existing CSF-to-autopsy studies have been restricted to late-stage AD.

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Postmortem human brain tissue is a critical resource for studying neurodegenerative disease, providing critical insights into cellular morphology, pathology, and network connectivity. To improve standard microscopy and enable high-resolution, three-dimensional (3D) images of tissues at the subcellular level, tissue-clearing methods have been developed. These 3D images allow for the analysis of large regions of interest and can be used to study structural and spatial changes that occur during neurodegeneration.

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Background: Chronic traumatic encephalopathy (CTE) is a neurodegenerative tauopathy more frequently found in deceased former football players. CTE has heterogeneous clinical presentations with multifactorial causes. Previous literature has shown substance use (alcohol/drug) can contribute to Alzheimer's disease and related tauopathies pathologically and clinically.

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  • Parkinsonism is often linked to chronic traumatic encephalopathy (CTE) caused by repetitive head injuries, but the exact causes of parkinsonism in CTE patients are not fully understood.
  • This study examined brain donors diagnosed with CTE to determine how often parkinsonism occurs and its relationship with brain damage due to past sports-related injuries.
  • Results indicated that 24.7% of CTE participants experienced parkinsonism, which was associated with older age, higher dementia rates, and more severe stages of CTE, suggesting a significant connection between the severity of CTE and parkinsonism.
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Repetitive head impacts (RHI) sustained from contact sports are the largest risk factor for chronic traumatic encephalopathy (CTE). Currently, CTE can only be diagnosed after death and the multicellular cascade of events that trigger initial hyperphosphorylated tau (p-tau) deposition remain unclear. Further, the symptoms endorsed by young individuals with early disease are not fully explained by the extent of p-tau deposition, severely hampering development of therapeutic interventions.

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A major challenge in neuroscience is to visualize the structure of the human brain at different scales. Traditional histology reveals micro- and meso-scale brain features, but suffers from staining variability, tissue damage and distortion that impedes accurate 3D reconstructions. Here, we present a new 3D imaging framework that combines serial sectioning optical coherence tomography (S-OCT) with a deep-learning digital staining (DS) model.

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Repetitive head impacts (RHIs) from football are associated with the neurodegenerative tauopathy chronic traumatic encephalopathy (CTE). It is unclear whether a history of traumatic brain injury (TBI) is sufficient to precipitate CTE neuropathology. We examined the association between TBI and CTE neuropathology in 580 deceased individuals exposed to RHIs from football.

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Article Synopsis
  • Chronic traumatic encephalopathy (CTE) is a neurodegenerative condition linked to repeated head trauma and characterized by tau protein aggregates in the brain, which typically progress from the neocortex to other brain areas as the disease advances.
  • A subset of CTE cases known as cortical-sparing CTE (CSCTE) involves less tau buildup in the neocortex but more in the medial temporal lobe and brainstem, affecting around 11% of brain donors diagnosed with CTE.
  • Clinically, individuals with CSCTE showed fewer dementia symptoms and less cognitive decline compared to typical high-stage CTE patients, but exhibited earlier onset of behavioral and motor symptoms.
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Background: Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease characterized by hyperphosphorylated tau (p-tau) accumulation. The clinical features associated with CTE pathology are unclear. In brain donors with autopsy-confirmed CTE, we investigated the association of CTE p-tau pathology density and location with cognitive, functional, and neuropsychiatric symptoms.

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Plasma-to-autopsy studies are essential for validation of blood biomarkers and understanding their relation to Alzheimer's disease (AD) pathology. Few such studies have been done on phosphorylated tau (p-tau) and those that exist have made limited or no comparison of the different p-tau variants. This study is the first to use immunoprecipitation mass spectrometry (IP-MS) to compare the accuracy of eight different plasma tau species in predicting autopsy-confirmed AD.

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Article Synopsis
  • - The study investigates tau pathology in chronic traumatic encephalopathy (CTE) using tau PET imaging from 218 participants, including former professional and college football players, and a control group of individuals without head impact exposure.
  • - Elevated tau levels were found in former football players compared to controls, especially in older players over 60 with cumulative head impact exposure, but PET imaging didn't effectively distinguish between individuals with and without traumatic encephalopathy syndrome.
  • - The authors emphasize the need for further research to better understand the link between tau pathology and chronic traumatic brain injuries, as current findings only partially clarify these relationships.
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  • This study investigates the impact of repetitive head impacts (RHI) on cognitive decline and dementia by examining the brains of 571 donors exposed to RHI, focusing on 13 different neuropathologies.
  • It was found that a significant majority (77.2%) of these donors exhibited moderate to severe neurodegenerative or cerebrovascular issues, with chronic traumatic encephalopathy (CTE) being the most common pathology.
  • The research highlights that several pathologies, including Alzheimer’s disease and Lewy body disease, are interrelated and contribute significantly to cognitive impairment in individuals with a history of RHI.
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  • This study investigated the effectiveness of plasma glial fibrillary acidic protein (GFAP) as a biomarker for cognitive impairment in Alzheimer's disease (AD) compared to other biomarkers like neurofilament light chain (NfL) and phosphorylated tau (p-tau).
  • The research analyzed plasma samples from 567 participants and correlated GFAP levels with cognitive functions and dementia severity, finding that GFAP was significantly more effective in differentiating between normal cognition and AD dementia or mild cognitive impairment.
  • While higher GFAP levels were linked to worse cognitive performance and dementia symptoms, it specifically predicted memory decline over time but did not indicate progression to mild cognitive impairment or dementia.
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The study of aging and neurodegenerative processes in the human brain requires a comprehensive understanding of cytoarchitectonic, myeloarchitectonic, and vascular structures. Recent computational advances have enabled volumetric reconstruction of the human brain using thousands of stained slices, however, tissue distortions and loss resulting from standard histological processing have hindered deformation-free reconstruction. Here, the authors describe an integrated serial sectioning polarization-sensitive optical coherence tomography (PSOCT) and two photon microscopy (2PM) system to provide label-free multi-contrast imaging of intact brain structures, including scattering, birefringence, and autofluorescence of human brain tissue.

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Article Synopsis
  • Understanding age acceleration in the brain helps differentiate biological age from chronological age, offering insights into normal brain function and age-related diseases like Alzheimer's.
  • Researchers developed a deep learning model using digitized post-mortem hippocampal tissue images to estimate brain age, achieving an average error of about 5.45 years.
  • The study found that histopathological brain age acceleration correlates strongly with clinical outcomes, suggesting it could be a valuable tool for assessing brain aging factors beyond traditional epigenetic measures.
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Background: Exposure to repetitive head impacts (RHI) in American football players can lead to cognitive impairment and dementia due to neurodegenerative disease, particularly chronic traumatic encephalopathy (CTE). The pathognomonic lesion of CTE consists of perivascular aggregates of hyper-phosphorylated tau in neurons at the depths of cortical sulci. However, it is unclear whether exposure to RHI accelerates amyloid-β (Aβ) plaque formation and increases the risk for Alzheimer's disease (AD).

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Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease associated with repetitive head trauma. Brain pathology in CTE is characterized by neuronal loss, gliosis, and a distinctive pattern of neuronal accumulation of hyper-phosphorylated tau (p-tau) and phospho-TDP43 (p-TDP43). Visual anomalies have been reported by patients with CTE, but the ocular pathology underlying these symptoms is unknown.

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Article Synopsis
  • * The study analyzed data from 152 brain donors under 30 years old, revealing that 41.4% were diagnosed with CTE, primarily in its mild stages.
  • * CTE cases were more prevalent among older athletes, particularly males in amateur sports like football, with those diagnosed having significantly longer playing careers.
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