Distinguishing Subtypes in Primary Progressive Aphasia: Application of the Sydney Language Battery

Background/Aims: Primary progressive aphasia (PPA) comprises three main subtypes, varying in clinical features, patterns of brain atrophy, and underlying pathology. Differentiation of these variants is important for treatment and planning; however, simple, effective cognitive tests to aid diagnosis are lacking. This study introduces a new language battery - the SYDBAT (Sydney Language Battery) - to assist clinicians. Methods: Fifty-seven PPA patients and 54 age- and education-matched healthy controls were compared on naming, repetition, word comprehension, and semantic association subtests. Results: Significant group differences were found for all tasks, reflecting different language profiles for each group. Using discriminative function analysis, 80% of PPA cases were correctly classified from three SYDBAT scores, from which a simple diagnostic algorithm was defined. Conclusion: The SYDBAT is a fast and simple tool which provides a valuable adjunct to clinicians diagnosing PPA.