Pattern of behavioral disturbances in corticobasal degeneration syndrome and progressive supranuclear palsy

Background: A careful characterization of behavioral abnormalities in corticobasal degeneration syndrome (CBDS) and progressive supranuclear palsy (PSP) by reliable tools is still lacking. Literature data provided evidence of the usefulness of the Frontal Behavioral Inventory (FBI) to operationalize such disturbances, particularly in the frontotemporal lobar degeneration spectrum. The study aimed to evaluate the frequency and pattern of presentation of behavioral disturbances in a large sample of CBDS and PSP patients by FBI. Methods: Sixty-eight CBDS and 57 PSP patients entered the study and underwent a standardized clinical and neuropsychological battery, and a structural brain imaging study. Behavioral disturbances were carefully analyzed by FBI. Results: FBI scores were relatively low in both groups, being 6.7 ± 8.2 and 5.6 ± 6.1 in CBDS and PSP, respectively. Comparison of the behavioral profile between CBDS and PSP patients showed significant differences in apathy were more frequent in the latter (57.9% vs. 33.8%, P = 0.007), and the presence of alien hand/apraxia more frequent in the former group 39.7% vs. 10.5%, P = 0.001). Apathy correlated neither with age nor with motor disturbances as measured by UPDRS-III. Overall, the most frequent behavioral abnormalities present in both groups (>25%) were aspontaneity and logopenia. Aphasia (27.9%) and irritability (35.3%) were more frequent in CBDS compared to PSP, even if not statistically different. Discussion: The present study has provided measures of behavioral disturbances in a population of PSP and CBDS patients, and further confirms the usefulness of the FBI scale.