Quantitative Assessment of the Effect of Chronic Kidney Disease on Plasma P-Tau217 Concentrations.

Background And Objectives: Chronic kidney disease (CKD) is known to be associated with increased plasma phosphorylated tau217 (p-tau217) concentrations, potentially confounding the utility of plasma p-tau217 measurements as a marker of amyloid pathology in individuals with suspected Alzheimer disease (AD). In this study, we quantitatively investigate the relationship of plasma p-tau217 concentrations vs estimated glomerular filtration rate (eGFR) in individuals with CKD with and without amyloid pathology.

Methods: This was a retrospective examination of data from 2 observational cohorts from either the Mayo Clinic Study of Aging or the Alzheimer's Disease Research Center cohorts.

Real-Time 2D Phase-Contrast MRI to Assess Cardiac- and Respiratory-Driven CSF Movement in Normal Pressure Hydrocephalus.

Background And Purpose: In idiopathic normal pressure hydrocephalus (iNPH) patients, cerebrospinal fluid (CSF) flow is typically evaluated with a cardiac-gated two-dimensional (2D) phase-contrast (PC) MRI through the cerebral aqueduct. This approach is limited by the evaluation of a single location and does not account for respiration effects on flow. In this study, we quantified the cardiac and respiratory contributions to CSF movement at multiple intracranial locations using a real-time 2D PC-MRI and evaluated the diagnostic value of CSF dynamics biomarkers in classifying iNPH patients.

Quantifying CSF Dynamics disruption in idiopathic normal pressure hydrocephalus using phase lag between transmantle pressure and volumetric flow rate.

Background And Purpose: Idiopathic normal pressure hydrocephalus (iNPH) is a cerebrospinal fluid (CSF) dynamics disorder as evidenced by the delayed ascent of radiotracers over the cerebral convexity on radionuclide cisternography. However, the exact mechanism causing this disruption remains unclear. Elucidating the pathophysiology of iNPH is crucial, as it is a treatable cause of dementia.

Clinical and radiologic distinctions between familial cavernous malformation syndrome and cerebral amyloid angiopathy.

Purpose: Familial cerebral cavernous malformation syndrome (FCCM) is characterized by multiple hemorrhagic lesions and is sometimes mistaken for cerebral amyloid angiopathy (CAA).

Methods: We compared clinical and radiologic characteristics in patients with definite (N = 32) and presumed FCCM (n = 76) to patients with definite (N = 29) and probable CAA (N = 21).

Results: Patients with CAA were older (78.

Alzheimer's Disease Clinical Trials: What Have We Learned From Magnetic Resonance Imaging.

Alzheimer's disease (AD) is the leading cause of cognitive impairment and dementia worldwide with rising prevalence, incidence and mortality. Despite many decades of research, there remains an unmet need for disease-modifying treatment that can significantly alter the progression of disease. Recently, with United States Food and Drug Administration (FDA) drug approvals, there have been tremendous advances in this area, with agents demonstrating effects on cognition and biomarkers.

Alzheimer Disease Cerebrospinal Fluid Biomarkers in a Tertiary Neurology Practice.

Objective: To evaluate the performance of Alzheimer disease (AD) cerebrospinal fluid (CSF) biomarkers in a tertiary neurology clinic setting with high frequency of non-AD cases, including normal pressure hydrocephalus (NPH).

Methods: There were 534 patients who underwent AD CSF biomarkers (Roche Elecsys Aβ42, p-Tau181, total-Tau) from April 1, 2020, through April 23, 2021. A behavioral neurologist blinded to CSF results assigned a clinical diagnosis retrospectively on the basis of consensus criteria, and a neuroradiologist blinded to the diagnosis and CSF studies graded brain magnetic resonance images for indicators of CSF dynamics disorders.

Can white matter hyperintensities based Fazekas visual assessment scales inform about Alzheimer's disease pathology in the population?

Background: White matter hyperintensities (WMH) are considered hallmark features of cerebral small vessel disease and have recently been linked to Alzheimer's disease pathology. Their distinct spatial distributions, namely periventricular versus deep WMH, may differ by underlying age-related and pathobiological processes contributing to cognitive decline. We aimed to identify the spatial patterns of WMH using the 4-scale Fazekas visual assessment and explore their differential association with age, vascular health, Alzheimer's imaging markers, namely amyloid and tau burden, and cognition.

Evaluation of MR Elastography as a Noninvasive Diagnostic Test for Spontaneous Intracranial Hypotension.

Background And Purpose: Spontaneous intracranial hypotension is a condition resulting from a leak of CSF from the spinal canal arising independent of a medical procedure. Spontaneous intracranial hypotension can present with normal brain MR imaging findings and nonspecific symptoms, leading to the underdiagnosis in some patients and unnecessary invasive myelography in others who are found not to have the condition. Given the likelihood that spontaneous intracranial hypotension alters intracranial biomechanics, the goal of this study was to evaluate MR elastography as a potential noninvasive test to diagnose the condition.

Prediction of Surgical Outcomes in Normal Pressure Hydrocephalus by MR Elastography.

Background And Purpose: Normal pressure hydrocephalus is a treatable cause of dementia associated with distinct mechanical property signatures in the brain as measured by MR elastography. In this study, we tested the hypothesis that specific anatomic features of normal pressure hydrocephalus are associated with unique mechanical property alterations. Then, we tested the hypothesis that summary measures of these mechanical signatures can be used to predict clinical outcomes.

Patients with normal pressure hydrocephalus have fewer enlarged perivascular spaces in the centrum semiovale compared to cognitively unimpaired individuals.

Introduction: Enlarged perivascular spaces (ePVS) may be an indicator of glymphatic dysfunction. Limited studies have evaluated the role of ePVS in idiopathic normal pressure hydrocephalus (iNPH). We aimed to characterize the distribution and number of ePVS in iNPH compared to controls.

Prevalence of Developmental Venous Anomalies in Association with Sporadic Cavernous Malformations on 7T MRI.

Background And Purpose: The etiology of sporadic cavernous malformations is not well-understood. However, recent evidence suggests that they may arise from a developmental venous anomaly. The goal of this study was to evaluate the prevalence of developmental venous anomalies associated with sporadic cavernous malformations using 7T MR imaging.

Normal pressure hydrocephalus, or Hakim syndrome: review and update.

This review makes the case that idiopathic normal pressure hydrocephalus (iNPH) is an outdated term because new information indicates that the syndrome is less idiopathic and that the cerebrospinal fluid (CSF) pressure of normal individuals is affected by several factors such as body mass index, age, and sex. Our review updates the epidemiology of iNPH and provides a clinical approach to the management of these patients. All the clinical features of iNPH are common in older individuals, and each has many causes, so the diagnosis is difficult.

Modeling the temporal evolution of plasma p-tau in relation to amyloid beta and tau PET.

Introduction: The timing of plasma biomarker changes is not well understood. The goal of this study was to evaluate the temporal co-evolution of plasma and positron emission tomography (PET) Alzheimer's disease (AD) biomarkers.

Methods: We included 1408 Mayo Clinic Study of Aging and Alzheimer's Disease Research Center participants.

The diamagnetic component map from quantitative susceptibility mapping (QSM) source separation reveals pathological alteration in Alzheimer's disease-driven neurodegeneration.

A sensitive and accurate imaging technique capable of tracking the disease progression of Alzheimer's Disease (AD) driven amnestic dementia would be beneficial. A currently available method for pathology detection in AD with high accuracy is Positron Emission Tomography (PET) imaging, despite certain limitations such as low spatial resolution, off-targeting error, and radiation exposure. Non-invasive MRI scanning with quantitative magnetic susceptibility measurements can be used as a complementary tool.

Evaluation of a compact 3 T MRI scanner for patients with implanted devices.

Access to high-quality MR exams is severely limited for patients with some implanted devices due to labeled MR safety conditions, but small-bore systems can overcome this limitation. For example, a compact 3 T MR scanner (C3T) with high-performance gradients can acquire exams of the head, extremities, and infants. Because of its reduced bore size and the patient being advanced only partially into the bore, the associated electromagnetic (EM) fields drop off rapidly caudal to the head, compared to whole-body systems.

Evidence against a temporal association between cerebrovascular disease and Alzheimer's disease imaging biomarkers.

Whether a relationship exists between cerebrovascular disease and Alzheimer's disease has been a source of controversy. Evaluation of the temporal progression of imaging biomarkers of these disease processes may inform mechanistic associations. We investigate the relationship of disease trajectories of cerebrovascular disease (white matter hyperintensity, WMH, and fractional anisotropy, FA) and Alzheimer's disease (amyloid and tau PET) biomarkers in 2406 Mayo Clinic Study of Aging and Mayo Alzheimer's Disease Research Center participants using accelerated failure time models.