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Background: Flortaucipir (tau) positron emission tomography (PET) binding distinguishes individuals with clinically well-established posterior cortical atrophy (PCA) due to Alzheimer disease (AD) from cognitively normal (CN) contr...
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Background: Flortaucipir (tau) positron emission tomography (PET) binding distinguishes individuals with clinically well-established posterior cortical atrophy (PCA) due to Alzheimer disease (AD) from cognitively normal (CN) controls. However, it is not known whether tau-PET binding patterns differentiate individuals with PCA from those with amnestic AD, particularly early in the symptomatic stages of disease.
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Background: Progressive reading impairment is an early and debilitating symptom of posterior cortical atrophy (PCA) arising from the progressive deterioration of visual processing skills.
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Abstract Background Posterior cortical atrophy (PCA) is one of the atypical Alzheimer's disease variants, characterized by predominant visuospatial and visuoperceptual deficits, with established dorsal and ventral subtypes. A thir...
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Abstract Background Posterior cortical atrophy (PCA) is one of the atypical Alzheimer's disease variants, characterized by predominant visuospatial and visuoperceptual deficits, with established dorsal and ventral subtypes. A third primary occipital (caudal) variant has been suggested. We aimed to determine its demographics, clinical manifestations, and biomarker findings. Methods Fifty‐two PCA patients were investigated. Patients underwent neuropsychological assessment, magnetic resonance imaging, and fluorodeoxyglucose (FDG)‐, amyloid‐, and tau‐positron emission tomography (tau‐PET) scans. Normalized regional FDG‐PET values were represented as z‐scores relative to a control population. Patients were divided into “primary occipital” and “other PCA” subgroups according to FDG‐PET‐defined criteria, with primary occipital defined as patients in which the z‐scores for occipital subregions were at least one standard deviation lower (SD) (i.e., more abnormal) than the z‐scores in all other brain regions. Global amyloid‐PET, temporo‐parietal FDG‐PET, and temporal tau‐PET regions‐of‐interest (ROIs) were calculated. Results Nine patients were classified as primary occipital; they were older (p?=?0.034) and had more years of education (p?=?0.007) than other PCA patients. The primary occipital group performed worse on the Ishihara test for color perception (p?收起
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Background: Posterior cortical atrophy (PCA) is a neurocognitive disorder characterized by difficulty localizing in space. Recognizing PCA is important because it is usually missed early in its course and may result from a number ...
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Background: Posterior cortical atrophy (PCA) is a neurocognitive disorder characterized by difficulty localizing in space. Recognizing PCA is important because it is usually missed early in its course and may result from a number of neurological disorders other than Alzheimer's disease (AD). Objective: This study aimed to clarify whether impaired visual search tasks of spatial localization distinguished patients with PCA from those with other more typical dementias as well as from healthy control (HC) subjects. Methods: Twelve patients meeting neuroimaging-supported Consensus Criteria for PCA, 12 comparably advanced patients with amnestic-predominant typical AD (tAD), and 24 HC participants were compared on tests of untimed and timed visual search, spatial neglect, mental rotation, environmental orientation, visuospatial construction, and face recognition. Results: Only abnormalities in untimed and timed visual search and environmental orientation distinguished the PCA patients from both the tAD group and the HC group without also distinguishing the tAD patients from HC's. The PCA patients also had a tendency to greater difficulty scanning left hemispace compared to HC's. Visuospatial constructions, although worse in PCA, and face recognition were impaired in both dementia groups. Conclusions: These findings support the concept of PCA as a disorder of spatial processing and localization, indicating that visual search tasks are particularly sensitive and specific for detecting PCA and distinguishing it from more typical dementia syndromes.
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Posterior cortical atrophy is a rare neurodegenerative disease that presents with progressive higher-order visual impairment. We describe a case of posterior cortical atrophy in a 62-year-old, right-handed man, who initially prese...
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Posterior cortical atrophy is a rare neurodegenerative disease that presents with progressive higher-order visual impairment. We describe a case of posterior cortical atrophy in a 62-year-old, right-handed man, who initially presented with difficulty in viewing the television screen, followed by reading difficulty a few months later, and then developed features of Balint’s syndrome over the course of 3 years. We report an illusion, which we noticed at the time of the initial presentation, where the characters in the television appeared to be popping out of the screen. We describe this as the “pop-out illusion”. ? 2021 Informa UK Limited, trading as Taylor & Francis Group.
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Alzheimer's dementia (AD) is the commonest type of dementia presenting with initial episodic memory decline followed by involvement of other cognitive domains. Posterior cortical atrophy (PCA) is one of the variants of Alzheimer's...
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Alzheimer's dementia (AD) is the commonest type of dementia presenting with initial episodic memory decline followed by involvement of other cognitive domains. Posterior cortical atrophy (PCA) is one of the variants of Alzheimer's dementia (AD) characterized by the atypical presentation of relatively persevered memory in the initial stage. PCA is an uncommon early onset dementia affecting adults between 50 and 65 years. It presents predominantly with visuo-spatial and visuo-perceptual deficits. PCA is a phenotype with varied etiology most common being Alzheimer's disease. The complex and atypical presentation with preserved memory and insight in patients with PCA poses challenge to clinicians in diagnosing at initial stages. There is also paucity of research on prevalence, course, prognosis and management of PCA. In this article we describe a middle aged gentlemen presenting with clinical features suggestive of PCA. We also discussed relevant literature.
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Alzheimer's disease (AD) is now conceptualized as a biological entity defined by amyloid and tau deposition and neurodegeneration, with heterogeneous clinical presentations. With the aid of in vivo biomarkers, clinicians are bette...
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Alzheimer's disease (AD) is now conceptualized as a biological entity defined by amyloid and tau deposition and neurodegeneration, with heterogeneous clinical presentations. With the aid of in vivo biomarkers, clinicians are better poised to examine clinical syndromic variability arising from a common pathology. Word retrieval deficits, measured using verbal fluency and confrontation naming tests, are hallmark features of the early clinical stages of the amnestic presentations of AD, specifically in category fluency and naming with relatively spared letter fluency. As yet, there is no consensus regarding performance on these tests in atypical clinical phenotypes of AD, including posterior cortical atrophy (PCA) and logopenic primary progressive aphasia (lvPPA), in individuals who are amyloid-positive (A beta+) but present with different clinical profiles and patterns of neurodegeneration compared to amnestic AD. The goal of the current study is to determine how A beta+ individuals across the syndromic spectrum of AD perform on three different word retrieval tasks. A secondary goal is to determine the neuroanatomical substrates underlying word retrieval performance in these A beta+ individuals. Thirty-two A beta+ participants with the amnestic presentation, 16 with A beta+ PCA, 22 with A beta+ lvPPA, and 99 amyloid-negative (A beta-) control participants were evaluated with verbal fluency and visual confrontation naming tests as well as high-resolution MRI. The A beta+ patient groups were rated at very mild or mild levels of severity (CDR 0.5 or 1) and had comparable levels of global cognitive impairment (average MMSE = 23.7 + 3.9). Behaviorally, we found that the word retrieval profile of PCA patients is comparable to that of amnestic patients, characterized by intact letter fluency but impaired category fluency and visual confrontation naming, while lvPPA patients demonstrated impairment across all tests of word retrieval. Across all AD variants, we observed that letter fluency was associated with cortical thickness in prefrontal, central precuneus, lateral parietal and temporal cortex, while category fluency and naming were associated with cortical thickness in left middle frontal gyrus, posterior middle temporal gyrus, and lateral parietal cortex. Visual confrontation naming was uniquely associated with atrophy in inferior temporal and visual association cortex. We conclude that a better understanding of the word retrieval profiles and underlying neurodegeneration across the AD syndromic spectrum will help improve interpretation of neuropsychological profiles with regard to the localization of neurodegeneration, particularly in the atypical AD variants.
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Posterior cortical atrophy (PCA) is a neurodegenerative syndrome characterized by impaired higher visual processing skills; however, motor features more commonly associated with corticobasal syndrome may also occur. We investigate...
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Posterior cortical atrophy (PCA) is a neurodegenerative syndrome characterized by impaired higher visual processing skills; however, motor features more commonly associated with corticobasal syndrome may also occur. We investigated the frequency and clinical characteristics of motor features in 44 PCA patients and, with 30 controls, conducted voxel-based morphometry, cortical thickness, and subcortical volumetric analyses of their magnetic resonance imaging. Prominent limb rigidity was used to define a PCA-motor subgroup. A total of 30% (13) had PCA-motor; all demonstrating asymmetrical left upper limb rigidity. Limb apraxia was more frequent and asymmetrical in PCA-motor, as was myoclonus. Tremor and alien limb phenomena only occurred in this subgroup. The subgroups did not differ in neuropsychological test performance or apolipoprotein E4 allele frequency. Greater asymmetry of atrophy occurred in PCA-motor, particularly involving right frontoparietal and peri-rolandic cortices, putamen, and thalamus. The 9 patients (including 4 PCA-motor) with pathology or cerebrospinal fluid all showed evidence of Alzheimer's disease. Our data suggest that PCA patients with motor features have greater atrophy of contralateral sensorimotor areas but are still likely to have underlying Alzheimer's disease. (C) 2014 The Authors. Published by Elsevier Inc. All rights reserved.
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Objective: A case of Posterior Cortical Atrophy syndrome of a suspected non-Alzheimer disease pathology type is presented to illustrate prospective diagnosis and course. Method: A 54-year-old woman with vague memory complaints und...
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Objective: A case of Posterior Cortical Atrophy syndrome of a suspected non-Alzheimer disease pathology type is presented to illustrate prospective diagnosis and course. Method: A 54-year-old woman with vague memory complaints underwent serial neuropsychological assessment, MRI, PET, and CSF screening; data are reviewed. Results: While early diagnosis was confounded by multiple factors, classic visuospatial symptoms were later demonstrated using routine neuropsychological methods. Serial MRI, PET, and CSF screening argued strongly for an alternative underlying pathology to AD. At age 59, her condition had progressed to dementia. Conclusions: Findings underscore the need for further research on suspected non-amyloid-based pathologies.
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