Abstract
BACKGROUND: Behavioral variant frontotemporal dementia (bvFTD) is pathologically heterogeneous. With emerging therapeutics, determining underlying pathology during life is increasingly important. Neuropsychiatric symptoms are prevalent and diagnostic in bvFTD. METHODS: We assessed the neuropsychiatric profile of patients with clinically diagnosed bvFTD as a function of pathology at autopsy. Patients with a clinical diagnosis of bvFTD at the initial visit were selected from the National Alzheimer's Coordinating Center (NACC) database. Neuropsychiatric symptoms endorsed on the Neuropsychiatric Inventory Questionnaire (NPI-Q) were analyzed. RESULTS: Of 149 patients with clinically diagnosed bvFTD, pathology was primarily Alzheimer's disease (AD) in 20.5%. These patients differed from those with underlying frontotemporal lobar degeneration: patients with AD pathology (plaques and tangles) were more likely to have hallucinations, delusions, or agitation. Patients were further differentiated into tau-positive (30% of cases, including Pick's disease, FTD and parkinsonism with tau-positive or argyrophilic inclusions, and other tauopathies) or tau-negative cases (70% of cases, including bvFTD tau-negative ubiquitin-positive inclusions). These patients also differed in some of the neuropsychiatric symptoms seen. Tau-negative cases were more likely to demonstrate depression, delusions, and changes in appetite and eating. CONCLUSIONS: These preliminary findings contribute to our increasing ability to predict, using simple clinical tools, the neuropathological underpinnings of bvFTD during life.