Early detection of cryptic memory and glucose uptake deficits in pre-pathological APP mice

Earlier diagnosis and treatment of Alzheimer's disease would greatly benefit from the identification of biomarkers at the prodromal stage. Using a prominent animal model of aspects of the disease, we here show using clinically relevant methodologies that very young, pre-pathological PDAPP mice, which overexpress mutant human amyloid precursor protein in the brain, exhibit two cryptic deficits that are normally undetected using standard methods of assessment. Despite learning a spatial memory task normally and displaying normal brain glucose uptake, they display faster forgetting after a long delay following performance to a criterion, together with a strong impairment of brain glucose uptake at the time of attempted memory retrieval. Preliminary observations suggest that these deficits, likely caused by an impairment in systems consolidation, could be rescued by immunotherapy with an anti-β-amyloid antibody. Our data suggest a biomarker strategy for the early detection of β-amyloid-related abnormalities

The need for harmonization and innovation of neuropsychological assessment in neurodegenerative dementias in Europe: consensus document of the Joint Program for Neurodegenerative Diseases Working Group

Cognitive, behavioural, and functional assessment is crucial in longitudinal studies of neurodegenerative dementias (NDD). Central issues, such as the definition of the study population (asymptomatic, at risk, or individuals with dementia), the detection of change/decline, and the assessment of relevant outcomes depend on quantitative measures of cognitive, behavioural, and functional status. Currently, we are far from having available reliable protocols and tools for the assessment of dementias in Europe. The main problems are the heterogeneity of the tools used across different European countries, the lack of standardisation of administration and scoring methods across centres, and the limited information available about the psychometric properties of many tests currently in widespread use. This situation makes it hard to compare results across studies carried out in different centres, thus hampering research progress, in particular towards the contribution to a “big data” common data set. We present here the results of a project funded by the Joint Program for Neurodegenerative Diseases (JPND) and by the Italian Ministry of Health. The project aimed at providing a consensus framework for the harmonisation of assessment tools to be applied to research in neurodegenerative disorders affecting cognition across Europe. A panel of European experts reviewed the current methods of neuropsychological assessment, identified pending issues, and made recommendations for the harmonisation of neuropsychological assessment of neurodegenerative dementias in Europe. A consensus was achieved on the general recommendations to be followed in developing procedures and tools for neuropsychological assessment, with the aim of harmonising tools and procedures to achieve more reliable data on the cognitive-behavioural examination. The results of this study should be considered as a first step to enhancing a common view and practise on NDD assessment across European countries

Current State of Self-Administered Brief Computerized Cognitive Assessments for Detection of Cognitive Disorders in Older Adults: A Systematic Review.

Early diagnosis of cognitive disorders in older adults is a major healthcare priority with benefits to patients, families, and health systems. Rapid advances in digital technology offer potential for developing innovative diagnostic pathways to support early diagnosis. Brief self-administered computerized cognitive tools in particular hold promise for clinical implementation by minimizing demands on staff time. In this study, we conducted a systematic review of self-administered computerized cognitive assessment measures designed for the detection of cognitive impairment in older adults. Studies were identified via a systematic search of published peer-reviewed literature across major scientific databases. All studies reporting on psychometric validation of brief (≤30 minutes) self-administered computerized measures for detection of MCI and all-cause dementia in older adults were included. Seventeen studies reporting on 10 cognitive tools met inclusion criteria and were subjected to systematic review. There was substantial variability in characteristics of validation samples and reliability and validity estimates. Only 2 measures evaluated feasibility and usability in the intended clinical settings. Similar to past reviews, we found variability across measures with regard to psychometric rigor and potential for widescale applicability in clinical settings. Despite the promise that self-administered cognitive tests hold for clinical implementation, important gaps in scientific rigor in development, validation, and feasibility studies of these measures remain. Developments in technology and biomarker studies provide potential avenues for future directions on the use of digital technology in clinical care

Self-Administered Cognitive Testing by Older Adults At-Risk for Cognitive Decline

Self-administered computerized cognitive testing could effectively monitor older individuals at-risk for cognitive decline at home. In this study, we tested the feasibility and reliability of 3 tablet-based executive functioning measures and an executive composite score in a sample of 30 older adults (age 80±6) with high multimorbidity. The tests were examiner-administered at baseline and then self-administered by the participants at home across 2 subsequent days. Eight of the participants reported no prior experience with touchscreen technology. Twenty-seven participants completed both self-administered assessments, and 28 completed at least one. Cronbach's alpha (individual tests: .87-.89, composite: .93) and correlations between examiner-administered and self-administered performances (individual tests: .72-.91, composite: .93) were high. The participants who had never used a smartphone or a tablet computer showed comparable consistency. Remote self-administered tablet-based testing in older adults at-risk for cognitive decline is feasible and reliable, even among participants without prior technology experience

Quantitative 7T phase imaging in premanifest Huntington disease.

Background and purposeIn vivo MR imaging and postmortem neuropathologic studies have demonstrated elevated iron concentration and atrophy within the striatum of patients with Huntington disease, implicating neuronal loss and iron accumulation in the pathogenesis of this neurodegenerative disorder. We used 7T MR imaging to determine whether quantitative phase, a measurement that reflects both iron content and tissue microstructure, is altered in subjects with premanifest Huntington disease.Materials and methodsLocal field shift, calculated from 7T MR phase images, was quantified in 13 subjects with premanifest Huntington disease and 13 age- and sex-matched controls. All participants underwent 3T and 7T MR imaging, including volumetric T1 and 7T gradient recalled-echo sequences. Local field shift maps were created from 7T phase data and registered to caudate ROIs automatically parcellated from the 3T T1 images. Huntington disease-specific disease burden and neurocognitive and motor evaluations were also performed and compared with local field shift.ResultsSubjects with premanifest Huntington disease had smaller caudate volume and higher local field shift than controls. A significant correlation between these measurements was not detected, and prediction accuracy for disease state improved with inclusion of both variables. A positive correlation between local field shift and genetic disease burden was also found, and there was a trend toward significant correlations between local field shift and neurocognitive tests of working memory and executive function.ConclusionsSubjects with premanifest Huntington disease exhibit differences in 7T MR imaging phase within the caudate nuclei that correlate with genetic disease burden and trend with neurocognitive assessments. Ultra-high-field MR imaging of quantitative phase may be a useful approach for monitoring neurodegeneration in premanifest Huntington disease

Quantitative 7T phase imaging in premanifest Huntington disease.

Background and purposeIn vivo MR imaging and postmortem neuropathologic studies have demonstrated elevated iron concentration and atrophy within the striatum of patients with Huntington disease, implicating neuronal loss and iron accumulation in the pathogenesis of this neurodegenerative disorder. We used 7T MR imaging to determine whether quantitative phase, a measurement that reflects both iron content and tissue microstructure, is altered in subjects with premanifest Huntington disease.Materials and methodsLocal field shift, calculated from 7T MR phase images, was quantified in 13 subjects with premanifest Huntington disease and 13 age- and sex-matched controls. All participants underwent 3T and 7T MR imaging, including volumetric T1 and 7T gradient recalled-echo sequences. Local field shift maps were created from 7T phase data and registered to caudate ROIs automatically parcellated from the 3T T1 images. Huntington disease-specific disease burden and neurocognitive and motor evaluations were also performed and compared with local field shift.ResultsSubjects with premanifest Huntington disease had smaller caudate volume and higher local field shift than controls. A significant correlation between these measurements was not detected, and prediction accuracy for disease state improved with inclusion of both variables. A positive correlation between local field shift and genetic disease burden was also found, and there was a trend toward significant correlations between local field shift and neurocognitive tests of working memory and executive function.ConclusionsSubjects with premanifest Huntington disease exhibit differences in 7T MR imaging phase within the caudate nuclei that correlate with genetic disease burden and trend with neurocognitive assessments. Ultra-high-field MR imaging of quantitative phase may be a useful approach for monitoring neurodegeneration in premanifest Huntington disease