Behavioral features in semantic dementia vs other forms of progressive aphasias

Objective: To compare the behavioral profiles in different variants of primary progressive aphasia (PPA). Methods: We classified 67 patients with PPA into three clinical variants: semantic dementia (SEMD), progressive nonfluent aphasia (PNFA), and logopenic progressive aphasia (LPA), and we compared the severity of behavioral dysfunction, as measured by the Neuropsychiatric Inventory, in these groups and patients with frontotemporal dementia (FTD) and Alzheimer disease (AD). Results: SEMD was associated with significantly more socioemotional behavioral dysfunction than the other two variants of PPA and than AD, specifically more disinhibition, aberrant motor behavior, and eating disorders-behaviors that are typical of FTD. In contrast, PNFA and LPA did not differ from each other or from AD in the type or severity of behavioral dysfunction. Behavioral abnormalities increased in severity with disease duration in SEMD, but this association was not detected in PNFA or LPA. Conclusions: Semantic dementia is associated with significantly more behavioral dysfunction than other variants of primary progressive aphasia, specifically behavioral features typical of frontotemporal dementia.