Augmenting Dementia Cognitive Assessment With Instruction-Less Eye-Tracking Tests.

Eye-tracking technology is an innovative tool that holds promise for enhancing dementia screening. In this work, we introduce a novel way of extracting salient features directly from the raw eye-tracking data of a mixed sample of dementia patients during a novel instruction-less cognitive test. Our approach is based on self-supervised representation learning where, by training initially a deep neural network to solve a pretext task using well-defined available labels (e.g. recognising distinct cognitive activities in healthy individuals), the network encodes high-level semantic information which is useful for solving other problems of interest (e.g. dementia classification). Inspired by previous work in explainable AI, we use the Layer-wise Relevance Propagation (LRP) technique to describe our network's decisions in differentiating between the distinct cognitive activities. The extent to which eye-tracking features of dementia patients deviate from healthy behaviour is then explored, followed by a comparison between self-supervised and handcrafted representations on discriminating between participants with and without dementia. Our findings not only reveal novel self-supervised learning features that are more sensitive than handcrafted features in detecting performance differences between participants with and without dementia across a variety of tasks, but also validate that instruction-less eye-tracking tests can detect oculomotor biomarkers of dementia-related cognitive dysfunction. This work highlights the contribution of self-supervised representation learning techniques in biomedical applications where the small number of patients, the non-homogenous presentations of the disease and the complexity of the setting can be a challenge using state-of-the-art feature extraction methods.

Qualitative, exploratory pilot study to investigate how people living with posterior cortical atrophy, their carers and clinicians experience tests used to assess vision.

OBJECTIVES: To investigate the experiences and views of people living with posterior cortical atrophy (PCA), their family carers and healthcare professionals of vision assessment tests. DESIGN: A qualitative investigation using video recordings of vision assessments, semistructured interviews and audio recordings of a focus group. Interviews and focus group used broad, open questions around the topic to prompt and guide discussion. Video and audio recordings were transcribed, manually coded and analysed using framework analysis. SETTING: University College, London's Queen Square neurology centre provided the venues for all stages of the research. PARTICIPANTS: Participants living with PCA were one male and two females (age range 67-78 years). Health professional participants were a neurologist (male), two ophthalmologists (male) and an optometrist (female). PRIMARY AND SECONDARY OUTCOMES: (1) Experiences and attitudes of people living with PCA and health professionals to vision assessment tests, (2) views of health professionals and people living with PCA of whether some tests are more effective at discriminating between cortical vision problems and vision problems related to optical or ocular causes. RESULTS: Patients were able to engage with and complete a number of tests. Their partners played a vital role in the process. Participants reported that simple, short tests were more effective than more subjective tests. Examples of tests that appeared to be more problematic for the patient participants were the Amsler Grid and visual field analysis. CONCLUSIONS: Although limited in scope and execution, the project suggests that some vision assessment tests are likely to support health professionals to discriminate between cortical and optical/ocular causes of visual impairment. It supports existing evidence that there are vision assessments that people with dementia can engage with and complete. We identify areas of importance for future research and make tentative suggestions for clinical practice.

BRain health and healthy AgeINg in retired rugby union players, the BRAIN Study: study protocol for an observational study in the UK.

INTRODUCTION: Relatively little is known about the long-term health of former elite rugby players, or former sportspeople more generally. As well as the potential benefits of being former elite sportspersons, there may be potential health risks from exposures occurring during an individual's playing career, as well as following retirement. Each contact sport has vastly different playing dynamics, therefore exposing its players to different types of potential traumas. Current evidence suggests that these are not necessarily comparable in terms of pathophysiology, and their potential long-term adverse effects might also differ. There is currently limited but increasing evidence that poorer age-related and neurological health exists among former professional sportsmen exposed to repetitive concussions; however the evidence is limited on rugby union players, specifically. METHODS AND ANALYSIS: We present the protocol for a cross-sectional study to assess the association between self-reported history of concussion during a playing career, and subsequent measures of healthy ageing and neurological and cognitive impairment. We are recruiting a sample of approximately 200 retired rugby players (former Oxford and Cambridge University rugby players and members of the England Rugby International Club) aged 50 years or more, and collecting a number of general and neurological health-related outcome measures though validated assessments. Biomarkers of neurodegeneration (neurofilaments and tau) will be also be measured. Although the study is focusing on rugby union players specifically, the general study design and the methods for assessing neurological health are likely to be relevant to other studies of former elite sportspersons. ETHICS AND DISSEMINATION: The study has been approved by the Ethical Committee of London School of Hygiene and Tropical Medicine (reference: 11634-2). It is intended that results of this study will be published in peer-reviewed medical journals, communicated to participants, the general public and all relevant stakeholders.

The need for harmonisation 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.

The quantitative assessment of apraxic deficits in Alzheimer's disease.

The purpose of this study was to devise quantitative methods for the assessment of praxic skills of the upper limbs by developing a computerised task which permits each component of a sequence of actions to be timed precisely. Furthermore, two versions of such a quantitative measure were developed to investigate the relationship between meaningful and meaningless movements. The praxic skills of 35 patients with Alzheimer's disease (AD) and 75 healthy controls were assessed on two 3-item sequential movement tasks involving either meaningful or meaningless actions. A qualitative rating scale assessment of gesture imitation and pantomime was also administered. AD patients were significantly slower than controls on both the sequential movement tasks. Indeed, the correlation between AD patients' abilities on the novel and traditional tasks provided evidence that the sequential movement tasks constitute valid measures of praxis. Within the AD population, disease severity was also found to have a minimal and inconsistent influence upon praxis. The apraxia assessment results are considered in relation to the debate over whether apraxia constitutes an early or late feature of AD, and also to theoretical claims about the cognitive neuropsychological deficit underlying ideational apraxia.

A novel technique for the quantitative assessment of apraxic deficits: application to individuals with mild cognitive impairment.

The purpose of this study was to apply two novel quantitative assessments of apraxia to issues surrounding the cognitive profile of individuals with mild cognitive impairment (MCI) who are at increased risk of Alzheimer's disease (AD). In particular, it was wished to determine whether such quantitative assessment techniques can detect minor degrees of impairment at a stage in the putative disease process before apraxia has become clinically obvious. A total of 23 individuals with MCI and 75 healthy controls were assessed on two 3-item sequential movement tasks involving either meaningful or meaningless actions. A traditional rating scale assessment of gesture-to-command was also administered. MCI patients took significantly longer than control subjects to complete the sequential movement tasks despite unimpaired performance on the traditional gesture production tasks. Furthermore, retrospective analyses revealed that, at the group level, only MCI patients who subsequently proceeded to a clinical diagnosis of AD were significantly slower than controls at the initial assessment. These findings provide the first evidence that the neuropsychological deficits associated with MCI may extend to the domain of praxic functions. Consequently, this work contributes to the growing literature questioning the clinical usefulness of the concept of MCI and the appropriateness of current diagnostic criteria for distinguishing this condition from mild AD.