Executive Dysfunction and Behavioral Symptoms Are Associated with Deficits in Instrumental Activities of Daily Living in Frontotemporal Dementia

Abstract

Background: Deficits in instrumental activities of daily living (ADLs) may be more prominent in behavioral variant frontotemporal dementia (bvFTD) than in nonfluent/agrammatic variant primary progressive aphasia (nfvPPA) or semantic variant primary progressive aphasia (svPPA). It is uncertain whether frontotemporal dementia (FTD) subgroups exhibit different patterns and/or predictors of functional impairment.

Methods: We examined data from participants diagnosed with bvFTD (n = 607), svPPA (n = 132), and nfvPPA (n = 155) who were included in the National Alzheimer's Coordinating Center (NACC) Uniform Data Set (UDS) and assessed with the Functional Activities Questionnaire (FAQ). Stepwise multiple linear regression analyses were performed to identify associations between FAQ scores and cognitive/behavioral deficits using the NACC UDS neuropsychological testing battery and the Neuropsychiatric Inventory Questionnaire.

Results: FAQ scores were higher in bvFTD than svPPA or nfvPPA. Functional deficits across FTD subtypes differed in severity, but not pattern, and were driven by executive dysfunction and behavioral symptoms.

Conclusion: Executive dysfunction and behavioral symptoms underlie instrumental ADL deficits in FTD, which are most prominent in bvFTD.

Figure 1

Total FAQ scores A) across all participants in the bvFTD, svPPA, and nfvPPA groups and B) stratified by disease duration. Error bars represent standard error of the mean. Parentheses denote number of participants in each analysis. Bonferroni corrected post hoc analyses: *p<0.017 versus bvFTD in unadjusted analyses.

Figure 2

A) Unadjusted and B) adjusted individual FAQ item scores for participants in the bvFTD, svPPA, and nfvPPA groups. Error bars represent standard error of the mean. Bonferroni corrected post hoc analyses: *p<0.017 versus bvFTD and †p<0.017 versus svPPA.