Similar amyloid-β burden in posterior cortical atrophy and Alzheimer's disease

Alzheimer’s disease (AD) is the most common cause of dementia in the population. Late onset AD has a classic clinical picture with short-term memory deficit, apraxia and agnosia. Patients with early-onset AD may have an atypical clinical picture which complicates diagnosis. Atypical AD variants include the logopenic variant of primary progressive aphasia, posterior cortical atrophy, behavioral, biparietal, and cortico-basal variants. These variants have pathomorphological signs similar to classical AD, but at an early stage they are characterized by focal atrophy which explains their clinical polymorphism. This article provides a review of the current literature on atypical types of AD and presents a clinical case of a 62-year-old patient in whom the disease debuted with prosopagnosia due to focal atrophy of the temporo-occipital regions of the non-dominant hemisphere.

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Clinical Characteristic in Primary Progressive Aphasia in Relation to Alzheimer’s Disease Biomarkers

Journal of Alzheimer s Disease ◽

10.3233/jad-210392 ◽

2021 ◽

pp. 1-13

Author(s):

Sung Hoon Kang ◽

Hanna Cho ◽

Jiho Shin ◽

Hang-Rai Kim ◽

Young Noh ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Language Impairment ◽

Amyloid Β ◽

Primary Progressive Aphasia ◽

Cortical Atrophy ◽

Clinical Feature ◽

Progressive Aphasia ◽

Disease Biomarkers ◽

Primary Progressive

Background: Primary progressive aphasia (PPA) is associated with amyloid-β (Aβ) pathology. However, clinical feature of PPA based on Aβ positivity remains unclear. Objective: We aimed to assess the prevalence of Aβ positivity in patients with PPA and compare the clinical characteristics of patients with Aβ-positive (A+) and Aβ-negative (A–) PPA. Further, we applied Aβ and tau classification system (AT system) in patients with PPA for whom additional information of in vivo tau biomarker was available. Methods: We recruited 110 patients with PPA (41 semantic [svPPA], 27 non-fluent [nfvPPA], 32 logopenic [lvPPA], and 10 unclassified [ucPPA]) who underwent Aβ-PET imaging at multi centers. The extent of language impairment and cortical atrophy were compared between the A+ and A–PPA subgroups using general linear models. Results: The prevalence of Aβ positivity was highest in patients with lvPPA (81.3%), followed by ucPPA (60.0%), nfvPPA (18.5%), and svPPA (9.8%). The A+ PPA subgroup manifested cortical atrophy mainly in the left superior temporal/inferior parietal regions and had lower repetition scores compared to the A–PPA subgroup. Further, we observed that more than 90%(13/14) of the patients with A+ PPA had tau deposition. Conclusion: Our findings will help clinicians understand the patterns of language impairment and cortical atrophy in patients with PPA based on Aβ deposition. Considering that most of the A+ PPA patents are tau positive, understanding the influence of Alzheimer’s disease biomarkers on PPA might provide an opportunity for these patients to participate in clinical trials aimed for treating atypical Alzheimer’s disease.

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O4-03-06: Effects of cortical visual impairment on navigational ability in posterior cortical atrophy and typical Alzheimer's disease

Alzheimer s & Dementia ◽

10.1016/j.jalz.2015.07.485 ◽

2015 ◽

Vol 11 (7S_Part_6) ◽

pp. P274-P274 ◽

Cited By ~ 1

Author(s):

Keir X.X. Yong ◽

Catherine Holloway ◽

Amelia Carton ◽

Biao Yang ◽

Tatsuto Suzuki ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Visual Impairment ◽

Cortical Atrophy ◽

Posterior Cortical Atrophy ◽

Cortical Visual Impairment

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Posterior cortical atrophy: A rare variant of Alzheimer’s disease

Neurology International ◽

10.4081/ni.2018.7665 ◽

2018 ◽

Vol 10 (2) ◽

Cited By ~ 1

Author(s):

Michael A. Meyer ◽

Stephen A. Hudock

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Visual Cortex ◽

Primary Visual Cortex ◽

Photon Emission ◽

Occipital Cortex ◽

Cortical Atrophy ◽

Emission Computed Tomography ◽

Posterior Cortical Atrophy ◽

Homonymous Hemianopsia

Posterior cortical atrophy is a rare condition first described in 1988 involving progressive degeneration and atrophy of the occipital cortex, often recognized after an unexplained homonymous hemianopsia may be discovered. We report a case in association with Alzheimer’s disease in a 77-year-old female, who underwent brain single-photon emission computed tomography as well brain positron emission tomography using Florbetapir to further evaluate progressive cognitive decline. The patient had also been followed in Ophthalmology for glaucoma, where a progressive unexplained change in her visual field maps were noted over one year consistent with a progressive right homonymous hemianopsia. This rare combination of findings in association with her dementia led to a detailed review of all her imaging studies, concluding with the surprising recognition for a clear hemi-atrophy of the primary left occipital cortex was occurring, consistent with Alzheimer’s disease affecting the primary visual cortex. Further awareness of this disease pattern is needed, as Alzheimer’s disease typically does not affect the primary visual cortex; other conditions to consider in general include Lewy Body dementia, cortico-basal degeneration and prion disease.

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