Objective: To evaluate the construct validity of the Frontal Behavioral Inventory (FBI) and to describe the evolution of the behavioral abnormalities of the behavioral and aphasic presentations of frontotemporal dementia (FTD) by means of a 3-year longitudinal study.
Background: The FBI is a standardized behavioral questionnaire useful in the diagnosis and quantification of the personality and behavior disorder FTD.
Method: Patients who had three consecutive yearly assessments with the FBI were selected, 12 with the behavioral variant of FTD (FTD-bv) and 14 with Primary Progressive Aphasia (PPA).
Results: FBI scores rose as the disease progressed in both the FTD-bv and PPA groups over the 3 years of testing. Initial mean FBI scores of the FTD-bv group were above the cutoff for FTD as established for this diagnosis with previous standardization. By the third year, the mean FBI score of PPA patients was also above the established cutoff for FTD.
Conclusions: The outcome of the study demonstrates that the FBI is sensitive to changes in behavior and personality in both variants of FTD. The FBI can be used to describe the evolution of symptoms and the course of the illness of Pick complex patients who present initially with FTD-bv or who present with PPA and subsequently develop the behavioral disorder.