The amyloid PET status in Primary Progressive Aphasia

Abstract Background Primary Progressive Aphasia (PPA) is a clinical and symptomatic concept due to neurodegenerative diseases which language symptom was dominant from early clinical stage. PPA is categorized into 3 subtypes such as Progressive non‐fluent aphasia (PNFA), Semantic dementia (SD), and logopenic progressive aphasia (LPA). In this study, we compared the differences of PPA subtypes depend on amyloid PET results. Method We recruited PPA patients who underwent standard aphasia test (SLTA) as Japanese aphasia test, cerebrospinal fluid AD biomarker, and amyloid PET. We divided into Amyloid PET positive (A(+) PPA) and negative (A(‐) PPA) group. then we compared the characterization of SLTA results and CSF biomarker between two groups. Result A total of 15 patients were included. There were 7 patients in A (+) PPA groups (2 males and 5 females, age: 65.3±8.3 years), and 8 patients in A (‐) PPA group (6 males and 2 females, age: 66.6±11.2 years). Regarding cerebrospinal fluid AD biomarkers, a significant decrease in Aβ42/40 (p < 0.01) and significant elevation in P‐tau (p<0.01) was observed in the A (+) PPA group compared to the A (‐) PPA group. In SLTA, the A (+) PPA had LPA: 57% and transcortical sensory aphasia: 29%. on the other hand, A (‐) PPA group had PNFA: 38% and SD: 50%. Conclusion This study showed there is the possibility of SLTA may be useful to predict AD pathology in patients with PPA.