Content Validity of the Modified Functional Scale for the Assessment and Rating of Ataxia (f-SARA) Instrument in Spinocerebellar Ataxia.

The functional Scale for the Assessment and Rating of Ataxia (f-SARA) assesses Gait, Stance, Sitting, and Speech. It was developed as a potentially clinically meaningful measure of spinocerebellar ataxia (SCA) progression for clinical trial use. Here, we evaluated content validity of the f-SARA.

Life course, genetic, and neuropathological associations with brain age in the 1946 British Birth Cohort: a population-based study.

Background: A neuroimaging-based biomarker termed the brain age is thought to reflect variability in the brain's ageing process and predict longevity. Using Insight 46, a unique narrow-age birth cohort, we aimed to examine potential drivers and correlates of brain age.

Methods: Participants, born in a single week in 1946 in mainland Britain, have had 24 prospective waves of data collection to date, including MRI and amyloid PET imaging at approximately 70 years old.

Dissociable effects of -ε4 and β-amyloid pathology on visual working memory.

Although -ε4 carriers are at significantly higher risk of developing Alzheimer's disease than non-carriers, controversial evidence suggests that -ε4 might confer some advantages, explaining the survival of this gene (antagonistic pleiotropy). In a population-based cohort born in one week in 1946 (assessed aged 69-71), we assessed differential effects of -ε4 and β-amyloid pathology (quantified using F-Florbetapir-PET) on visual working memory (object-location binding). In 398 cognitively normal participants, -ε4 and β-amyloid had opposing effects on object identification, predicting better and poorer recall respectively.

Visual short-term memory impairments in presymptomatic familial Alzheimer's disease: A longitudinal observational study.

Visual short-term memory (VSTM) deficits including VSTM binding have been associated with Alzheimer's disease (AD) from preclinical to dementia stages, cross-sectionally. Yet, longitudinal investigations are lacking. The objective of this study was to evaluate VSTM function longitudinally and in relation to expected symptom onset in a cohort of familial Alzheimer's disease.

Subjective cognitive complaints at age 70: associations with amyloid and mental health.

Objective: To investigate subjective cognitive decline (SCD) in relation to β-amyloid pathology and to test for associations with anxiety, depression, objective cognition and family history of dementia in the Insight 46 study.

Methods: Cognitively unimpaired ~70-year-old participants, all born in the same week in 1946 (n=460, 49% female, 18% amyloid-positive), underwent assessments including the SCD-Questionnaire (MyCog). MyCog scores were evaluated with respect to F-Florbetapir-PET amyloid status (positive/negative).

Eye-tracking indices of impaired encoding of visual short-term memory in familial Alzheimer's disease.

The basis of visual short-term memory (VSTM) impairments in preclinical Alzheimer's disease (AD) remains unclear. Research suggests that eye movements may serve as indirect surrogates to investigate VSTM. Yet, investigations in preclinical populations are lacking.

Disease duration in autosomal dominant familial Alzheimer disease: A survival analysis.

Objective: To use survival modeling to estimate disease duration in autosomal dominant familial Alzheimer disease (ADAD) and ascertain whether factors influencing age at onset also affect survival.

Methods: Symptomatic mutation carriers (201 presenilin 1 [] and 55 amyloid precursor protein []) from ADAD families referred to the Dementia Research Centre, between 1987 and 2019, were included. Survival was assessed with respect to age at onset, year of birth, ε4 status, cognitive presentation, and sex using multilevel mixed-effects Weibull survival models.

Quantitative detection and staging of presymptomatic cognitive decline in familial Alzheimer's disease: a retrospective cohort analysis.

Background: Understanding the earliest manifestations of Alzheimer's disease (AD) is key to realising disease-modifying treatments. Advances in neuroimaging and fluid biomarkers have improved our ability to identify AD pathology in vivo. The critical next step is improved detection and staging of early cognitive change.

Impaired mechanism of visual focal attention in posterior cortical atrophy.

Simultanagnosia, a deficit in holistic visual perception, is among the most prominent features of posterior cortical atrophy (PCA). Deficits in visuoperceptual and attentional mechanisms could contribute to simultanagnosia. In the present study, we explored the impaired visual perception of global configuration with two main hypotheses: (a) It is due to a deficit in processing low-spatial frequency stimuli, and (b) it arises from deficits in adjusting attentional focus.

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.

Plasma phospho-tau181 in presymptomatic and symptomatic familial Alzheimer's disease: a longitudinal cohort study.

Blood biomarkers have great potential to advance clinical care and accelerate trials in Alzheimer's disease (AD). Plasma phospho-tau181 (p-tau181) is a promising blood biomarker however, it is unknown if levels increase in presymptomatic AD. Therefore, we investigated the timing of p-tau181 changes using 153 blood samples from 70 individuals in a longitudinal study of familial AD (FAD).

Unusual Pattern of Reading Errors in a Patient with Posterior Cortical Atrophy.

Posterior cortical atrophy (PCA) is a degenerative condition characterized by a progressive deterioration of visual processing. Dyslexia constitutes an early and frequent visual symptom of the disease and previous comprehensive investigations in series of individuals have extensively documented a characteristic abundance of visual errors as the most prevalent error category in this population. Here we describe the profile of a patient with PCA, C.

ReadClear: An Assistive Reading Tool for People Living with Posterior Cortical Atrophy.

Background: Progressive reading impairment is an early and debilitating symptom of posterior cortical atrophy (PCA) arising from the progressive deterioration of visual processing skills.

Objective: The goal of this study was to test the effectiveness of a purpose-built reading app (ReadClear) co-produced with people living with PCA and designed to reduce the reading difficulties experienced by this population (e.g.

Longitudinal neuroanatomical and cognitive progression of posterior cortical atrophy.

Posterior cortical atrophy is a clinico-radiological syndrome characterized by progressive decline in visual processing and atrophy of posterior brain regions. With the majority of cases attributable to Alzheimer's disease and recent evidence for genetic risk factors specifically related to posterior cortical atrophy, the syndrome can provide important insights into selective vulnerability and phenotypic diversity. The present study describes the first major longitudinal investigation of posterior cortical atrophy disease progression.

Assessing cognitive dysfunction in Parkinson's disease: An online tool to detect visuo-perceptual deficits.

Background: People with Parkinson's disease (PD) who develop visuo-perceptual deficits are at higher risk of dementia, but we lack tests that detect subtle visuo-perceptual deficits and can be performed by untrained personnel. Hallucinations are associated with cognitive impairment and typically involve perception of complex objects. Changes in object perception may therefore be a sensitive marker of visuo-perceptual deficits in PD.

Eyetracking Metrics in Young Onset Alzheimer's Disease: A Window into Cognitive Visual Functions.

Young onset Alzheimer's disease (YOAD) is defined as symptom onset before the age of 65 years and is particularly associated with phenotypic heterogeneity. Atypical presentations, such as the clinic-radiological visual syndrome posterior cortical atrophy (PCA), often lead to delays in accurate diagnosis. Eyetracking has been used to demonstrate basic oculomotor impairments in individuals with dementia.