Heterogeneous Language Profiles in Patients with Primary Progressive Aphasia due to Alzheimer’s Disease

Article type: Research Article

Authors: Louwersheimer, Eva^{a; *} | Keulen, M. Antoinette^a | Steenwijk, Martijn D.^b | Wattjes, Mike P.^b | Jiskoot, Lize C.^c | Vrenken, Hugo^b | Teunissen, Charlotte E.^d | van Berckel, Bart N.M.^b | van der Flier, Wiesje M.^{a; e} | Scheltens, Philip^a | van Swieten, John C.^{c; f} | Pijnenburg, Yolande A.L.^a

Affiliations: [a] Alzheimer Center and Department of Neurology, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands | [b] MS Center Amsterdam and Department of Radiology and Nuclear Medicine, Neuroscience campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands | [c] Department of Neurology, Erasmus University Medical Center, Rotterdam, The Netherlands | [d] Neurochemistry Laboratory and Biobank, Department of Clinical Chemistry, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands | [e] Department of Epidemiology & Biostatistics, VU University Medical Center, Amsterdam, The Netherlands | [f] Department of Clinical Genetics, VU University Medical Center, Amsterdam, The Netherlands

Correspondence: [*] Correspondence to: Eva Louwersheimer, Alzheimer Center & Department of Neurology, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands. Tel.: +31204440823; Fax: +31204448529; E-mail: e.louwersheimer@vumc.nl.

Abstract: Background:The logopenic variant of Primary Progressive Aphasia (lvPPA) is associated with underlying Alzheimer’s disease (AD) pathology and characterized by impaired single word retrieval and repetition of phrases and sentences. Objective:We set out to study whether logopenic aphasia is indeed the prototypic language profile in PPA patients with biomarker evidence of underlying AD pathology and to correlate language profiles with cortical atrophy patterns on MRI. Methods:Inclusion criteria: (I) clinical diagnosis of PPA; (II) CSF profile and/or PiB-PET scan indicative for amyloid pathology; (III) availability of expert language evaluation. Based on language evaluation, patients were classified as lvPPA (fulfilling lvPPA core criteria), lvPPA extended (fulfilling core criteria plus other language disturbances), or PPA unclassifiable (not fulfilling lvPPA core criteria). Cortical atrophy patterns on MRI were visually rated and quantitative measurements of cortical thickness were performed using FreeSurfer. Results:We included 22 patients (age 67±7 years, 50% female, MMSE 21±6). 41% were classified as lvPPA, 36% as lvPPA extended with additional deficits in language comprehension and/or confrontation naming, and 23% as PPA unclassifiable. By both qualitative and quantitative measurements, patients with lvPPA showed mild global cortical atrophy on MRI, whereas patients with lvPPA extended showed more focal cortical atrophy, predominantly at the left tempo-parietal side. For PPA unclassifiable, qualitative measurements revealed a heterogeneous atrophy pattern. Conclusion:Although most patients fulfilled the lvPPA criteria, we found that their language profiles were heterogeneous. The clinical and radiological spectrum of PPA due to underlying AD pathology is broader than pure lvPPA.

Keywords: Atypical Alzheimer’s disease, cerebral atrophy, language disorders, logopenic aphasia, neurodegenerative disorder, primary progressive aphasia

DOI: 10.3233/JAD-150812

Journal: Journal of Alzheimer's Disease, vol. 51, no. 2, pp. 581-590, 2016