Applicability and Correlates of a Symptom-Led Staging System for Primary Progressive Aphasia

Background: This study aimed at assessing the applicability of a symptom-led staging system for primary progressive aphasia (PPA) based on retrospective medical records, as well as at exploring their demographic and clinical correlates. Methods: 75 PPA patients (10 semantic, 28 non-fluent, 22 logopenic, and 16 mixed variants) were retrospectively staged according to the PPA Progression Planning Aid (PPA-Squared) system, which stages the disease by accounting for clinical features along three axes: (1) Communication; (2) Non-Verbal Thinking and Personality; (3) Personal Care and Well-Being. The percentage of successfully staged patients was computed. The association between PPA-Squared scores and demographic and clinical data was tested via non-parametric tests. The predictive capability of PPA-Squared scores towards survival was explored via a Mantel-Cox test. Results: 89.3% of patients were successfully staged based on retrospective medical records. The PPA-Squared was associated with the MMSE (p < 0.001), ADL (p = 0.021), and IADL scores (p < 0.001) and a set of second-level cognitive measures tapping on attention, executive functions, language, long-term memory, and visuo-spatial abilities (p ≤ 0.049). No association was found between the PPA-Squared and demographic features, symptom duration, PPA phenotype, the presence of motor involvement, and survival. Discussion: The PPA-Squared is a feasible and clinically valid tool for staging PPA patients based on their cognitive and functional status.