P2–079: CSF and PPA

Le résumé fourni par la source

Primary progressive aphasia (PPA) is a heterogeneous clinical entity that could be subdivided in distinct neuropsychological variants. These distinct clinical profiles, which reflect the distinct topography and underlying pathological processes, may also differ in terms of their cerebrospinal fluid (CSF) markers. Thus, the aim of this study was to detect cases of PPA with putative AD pathology and to test hypothesis that patients with logopenic variant in contrast to others subtypes, have predominantly CSF Alzheimer disease profile. We compared in retrospective observational study the levels of CSF biomarkers in patients suffering from PPA. Forty patients who underwent CSF biomarker analysis of amyloid β Aβ 42, total tau (t-tau) and phosphorylated tau on amino acid 181 (p-tau) were clinically classified in three variants according to new international recommendations, 21 logopenic (LPA), 9 semantic dementia (SD), 5 non fluent (PNFA); and 5 aphasic patients with troubles hard to classify (A). Individually, each clinical classification of PPA was correlated to the CSF profile of the patients to evaluate the a posteriori predictability of clinical presentation and the language evaluation for diagnosis of underlying AD pathology. Our results showed that independently of age, disease duration, education level and clinical severity indices, LPA patients have significantly lower level of Aβ42, higher levels of total Tau, and P-Tau and lower IATI index in the CSF than three other variants of PPA. LPA patients have most of times typical biological AD profile. These findings are in favour of the hypothesis that the logopenic variant of PPA represents an atypical presentation of Alzheimer's disease. This could have implications for therapy. In addition, they highlight the heterogeneity of pathological processes in AD, validating the existence of atypical forms of the disease.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.