Decline in Visual and Posterior Cortical Functions in Logopenic Progressive Aphasia (P5-6.001)

Abstract

<h3>Objective:</h3> To determine how frequently features of posterior cortical atrophy (PCA) occur in patients with logopenic progressive aphasia (LPA) and determine the neuroimaging correlates of these features. <h3>Background:</h3> LPA and PCA are two atypical clinical variants of Alzheimer’s disease. Overlap can be observed clinically between phenotypes, although it is unclear how frequently patients meeting criteria for LPA develop clinical PCA features, and whether these features are associated with neuroanatomical overlap with PCA. <h3>Design/Methods:</h3> Thirty-six LPA patients recruited by the Neurodegenerative Research Group underwent extensive neuropsychological testing, MRI and [¹⁸F] flortaucipir PET. All patients were evaluated for PCA features including simultanagnosia, Gerstmann syndromes, ideomotor apraxia, and visuospatial and visuoperceptual function, with cut-points used to define abnormality. Patients were classified as Pure-LPA (having no PCA feature), LPA+ (impairment on one test) or LPA-PCA (impairment on 2+ tests). Neuroimaging profiles in each of the three LPA groups were compared to 14 matched healthy controls and 14 matched typical PCA patients using multiple regression analysis in SPM12. <h3>Results:</h3> Eleven patients (31%) were classified as pure-LPA, 16 (44%) as LPA+ and 9 (25%) as LPA-PCA. There were no differences in disease duration, naming, or sentence repetition across groups. The LPA+ group showed worse simultanagnosia (29%), ideomotor apraxia and Gerstmann syndrome (34%) compared to Pure-LPA group. The LPA-PCA group showed further worsening in simultanagnosia (89%), and visuospatial and visuoperceptual impairment compared to LPA+ group. All three LPA groups showed greater left temporoparietal volume loss and flortaucipir uptake compared to controls and PCA, with greater flortaucipir uptake occurring in the occipital and frontal lobes in LPA+ and LPA-PCA compared to Pure-LPA. <h3>Conclusions:</h3> Our results demonstrate that LPA patients can develop features of PCA related to spread of tau into occipito-frontal regions, highlighting syndromic and anatomical overlap between atypical variants of AD. <b>Disclosure:</b> Dr. Singh has nothing to disclose. Dr. Graff-Radford has received personal compensation for serving as an employee of Mayo Clinic. Dr. Graff-Radford has received personal compensation in the range of $0-$499 for serving on a Scientific Advisory or Data Safety Monitoring board for NINDS/NIH. Dr. Graff-Radford has received personal compensation in the range of $5,000-$9,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for American Academy of Neurology. The institution of Dr. Graff-Radford has received research support from NIH. Arenn Faye Carlos, MD has nothing to disclose. The institution of Dr. Machulda has received research support from NIH. Christopher Schwarz has received personal compensation for serving as an employee of Mayo Clinic. The institution of Christopher Schwarz has received research support from NIH. Matthew Senjem has received stock or an ownership interest from Align Technology, Inc.. Matthew Senjem has received stock or an ownership interest from Inovio Biomedical Corp.. Matthew Senjem has received stock or an ownership interest from Johnson &amp; Johnson. Matthew Senjem has received stock or an ownership interest from Mesa Laboratories, Inc.. Matthew Senjem has received stock or an ownership interest from Nvidia Inc.. Matthew Senjem has received stock or an ownership interest from LHC Group, Inc.. Matthew Senjem has received stock or an ownership interest from Natus Medical Incorporated. Matthew Senjem has received stock or an ownership interest from Varex Imaging Corporation. Matthew Senjem has received personal compensation in the range of $100,000-$499,999 for serving as a IT Technical Specialist II with Mayo Clinic. The institution of Dr. Jack has received research support from NIH. The institution of Dr. Jack has received research support from Alexander Family Alzheimer’s Disease Research Professorship of the Mayo Clinic. Dr. Lowe has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for AVID Radiopharmaceutical. Dr. Lowe has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Eisai Inc. The institution of Dr. Lowe has received research support from AVID Radiopharmaceuticals. Dr. Josephs has nothing to disclose. Dr. Whitwell has nothing to disclose.