A5041843137- Dementia and Cognitive Impairment Research
- Functional Brain Connectivity Studies
- Retinal Imaging and Analysis
- Advanced Neuroimaging Techniques and Applications
- Glaucoma and retinal disorders
- Alzheimer's disease research and treatments
- Advanced MRI Techniques and Applications
- Visual perception and processing mechanisms
- Neurological Disease Mechanisms and Treatments
- Genetic Neurodegenerative Diseases
- Parkinson's Disease Mechanisms and Treatments
- Olfactory and Sensory Function Studies
- Neurobiology of Language and Bilingualism
- Amyotrophic Lateral Sclerosis Research
- Health, Environment, Cognitive Aging
- Neuroinflammation and Neurodegeneration Mechanisms
- Retinal Diseases and Treatments
- Anesthesia and Pain Management
- EEG and Brain-Computer Interfaces
- Retinal and Optic Conditions
- Visual Attention and Saliency Detection
- Ophthalmology and Visual Impairment Studies
- Cerebrovascular and Carotid Artery Diseases
- Shoulder Injury and Treatment
- Cerebrovascular and genetic disorders
University College London
2012-2020
UK Dementia Research Institute
2011-2019
National Hospital for Neurology and Neurosurgery
2012-2019
Geelong Hospital
2018
University of Alberta
2013
University of Oxford
2013
University of Alberta Hospital
2012
A classification framework for posterior cortical atrophy (PCA) is proposed to improve the uniformity of definition syndrome in a variety research settings.
An expanded hexanucleotide repeat in the C9ORF72 gene has recently been identified as a major cause of familial frontotemporal lobar degeneration and motor neuron disease, including cases previously linked to chromosome 9. Here we present detailed retrospective clinical, neuroimaging histopathological analysis mutation case series relation other forms genetically determined ascertained at specialist centre. Eighteen probands (19 total) were identified, representing 35% with mutations, 36%...
Amyloid imaging studies of presymptomatic familial Alzheimer's disease have revealed the striatum and thalamus to be earliest sites amyloid deposition. This study aimed investigate whether there are associated volume diffusivity changes in these subcortical structures during symptomatic stages disease. As involved neural networks subserving complex cognitive behavioural functions, we also examined diffusion characteristics connecting white matter tracts. A cohort 20 presenilin 1 mutation...
Abstract Introduction The genetics underlying posterior cortical atrophy (PCA), typically a rare variant of Alzheimer's disease (AD), remain uncertain. Methods We genotyped 302 PCA patients from 11 centers, calculated risk at 24 loci for AD/DLB and performed an exploratory genome‐wide association study. Results confirm that variation in/near APOE/TOMM40 ( P = 6 × 10 −14 ) alters risk, but with smaller effect than typical AD (PCA: odds ratio [OR] 2.03, AD: OR 2.83, .0007). found evidence CR1...
The clinico-neuroradiological syndrome posterior cortical atrophy is the cardinal ‘visual dementia’ and most common atypical Alzheimer’s disease phenotype, offering insights into mechanisms underlying clinical heterogeneity, pathological propagation basic visual phenomena (e.g. crowding). Given extensive attention paid to patients’ (higher order) perceptual function, it surprising that there have been no systematic analyses of oculomotor function in this population. Here 20 patients with...
Posterior cortical atrophy (PCA) is a clinicoradiologic syndrome characterized by progressive decline in visual processing skills, relatively intact memory and language the early stages, of posterior brain regions. Misdiagnosis PCA common, owing not only to its relative rarity unusual variable presentation, but also because patients frequently first seek opinion an ophthalmologist, who may note normal eye examinations their usual tests appreciate dysfunction. Seeking raise awareness disease,...
Abstract Posterior cortical atrophy is a clinico-radiological syndrome characterized by progressive decline in visual processing and of posterior brain regions. With the majority cases attributable to Alzheimer’s disease recent evidence for genetic risk factors specifically related atrophy, can provide important insights into selective vulnerability phenotypic diversity. The present study describes first major longitudinal investigation progression. Three hundred sixty-one individuals (117...
Young onset Alzheimer's disease (YOAD) is defined as symptom before the age of 65, and particularly associated with phenotypic heterogeneity. Atypical presentations, such clinic-radiological visual syndrome Posterior Cortical Atrophy (PCA), often lead to delays in accurate diagnosis. Eyetracking has been used demonstrate basic oculomotor impairments individuals dementia. In present study, we aim explore relationship between eyetracking metrics standard tests cognition YOAD. Fifty-seven...
Previous imaging studies of congenital blindness have studied individuals with heterogeneous causes blindness, which may influence the nature and extent cross-modal plasticity. Here, we scanned a homogeneous group blind people bilateral anophthalmia, condition in both eyes fail to develop, and, as result, visual pathway is not stimulated by either light or retinal waves. This model presents an opportunity investigate effects very early deafferentation on functional organization brain. In...
Retinal thickness can be measured non-invasively with optical coherence tomography (OCT) and may offer compelling potential as a biomarker for Alzheimer's disease (AD). thinning is hypothesized to result of retrograde atrophy and/or parallel neurodegenerative processes. Changes in the visual pathway are particular interest posterior cortical (PCA), most common atypical AD phenotype predominantly affecting parietal-occipital cortices. We therefore evaluated retinal non-invasive...
Crowding is a breakdown in the ability to identify objects clutter, and major constraint on object recognition. particularly impairs perception peripheral, amblyopic possibly developing vision. Here we argue that crowding also critical factor limiting central vision of individuals with neurodegeneration occipital cortices. In current study, posterior cortical atrophy (n = 26), typical Alzheimer's disease 17) healthy control subjects 14) completed centrally-presented tests letter...
<h3>Objective:</h3> We report (1) the quantitative investigation of text reading in posterior cortical atrophy (PCA), and (2) effects 2 novel software-based aids that result dramatic improvements ability patients with PCA. <h3>Methods:</h3> Reading performance, eye movements, fixations were assessed PCA typical Alzheimer disease healthy controls (experiment 1). Two (single- double-word) evaluated based on notion reducing spatial oculomotor demands might support 2). <h3>Results:</h3> Mean...
Posterior cortical atrophy (PCA) is a neurodegenerative syndrome characterized by progressive visual dysfunction and parietal, occipital, occipitotemporal atrophy. The aim of this study was to compare the impact PCA typical Alzheimer's disease (tAD) on everyday functional abilities neuropsychiatric status. Cambridge Behavioural Inventory-Revised given carers 32 71 tAD patients. patients showed significantly greater impairment in skills self-care while group aspects memory orientation,...
Posterior cortical atrophy (PCA) is a neurodegenerative syndrome characterized by impaired higher visual processing skills; however, motor features more commonly associated with corticobasal may also occur. We investigated the frequency and clinical characteristics of in 44 PCA patients and, 30 controls, conducted voxel-based morphometry, thickness, subcortical volumetric analyses their magnetic resonance imaging. Prominent limb rigidity was used to define PCA-motor subgroup. A total 30%...
Emotional behavioral disturbances are hallmarks of many dementias but their pathophysiology is poorly understood. Here we addressed this issue using the paradigm emotionally salient sounds.
Abnormal responsiveness to salient sensory signals is often a prominent feature of dementia diseases, particularly the frontotemporal lobar degenerations, but has been little studied. Here we assessed processing one important class signals, looming sounds, in canonical syndromes. We manipulated tones using intensity cues create percepts approaching ("looming") or less withdrawing sounds. Pupil dilatation responses and behavioral rating these stimuli were compared patients fulfilling...
Reading deficits are a common early feature of the degenerative syndrome posterior cortical atrophy (PCA) but poorly understood even at single word level. The current study evaluated reading accuracy and speed 26 PCA patients, 17 typical Alzheimer's disease (tAD) patients 14 healthy controls on corpus 192 words in which following perceptual properties were manipulated systematically: inter-letter spacing, font size, length, type, case confusability. was significantly less accurate slower...
Partial or complete Balint's syndrome is a core feature of the clinico-radiological posterior cortical atrophy (PCA), in which individuals experience progressive deterioration vision. Although multi-object arrays are frequently used to detect simultanagnosia clinical assessment and diagnosis PCA, date there have been no group studies scene perception patients with syndrome. The current study involved three linked experiments conducted PCA healthy controls. Experiment 1 evaluated accuracy...
Age at onset (AAO) has been shown to influence the phenotype of Alzheimer's disease (AD), but how it affects atypical presentations AD remains unknown. Posterior cortical atrophy (PCA) is most common form AD. In this study, we aimed investigate effect AAO on thickness and cognitive function in 98 PCA patients. We used Freesurfer (v5.3.0) compare with both as a continuous variable, by dichotomizing groups based median age (58 years). dichotomized analyses, found pattern suggestive thinner...
Regular, routine, multimodal analgesia provides better pain relief following Caesarean section than reliance on "as required" opiate dosing. This quality improvement report describes the effective use of an education programme coupled with a highlighted, preprinted medication chart, employing "Nudge Theory" principles to achieve significant improvements in administration analgesic medications patients after operations.An acute service audit identified serious deficiency delivery regular...