Patterns of language decline in non-fluent primary progressive aphasia

Language samples collected yearly for up to 11 years post-onset of symptoms from four subjects presenting with non-fluent primary progressive aphasia (PPA) were analyzed and compared with samples collected from both non-brain-damaged subjects and those with agrammatic Broca's aphasia resulting from a single left-hemisphere stroke. Extensive analysis of lexical and morphosyntactic variables in these samples revealed two patterns of expressive language decline in the PPA subjects - one resembling that seen in our agrammatic aphasic subjects - i.e. impaired production of closed-class elements and loss of sentential structures governed by these elements-and the other characterized by advancing word-retrieval difficulties. These data are relevant for patient-management purposes and, in addition, they provide information relevant to language representation and organization