Disease progression in frontotemporal dementia and Alzheimer disease: the contribution of staging scales

Introduction: There is a shortage of validated instruments to estimate disease progression in frontotemporal dementia (FTD).
Objectives: To evaluate the ability of the FTD Rating Scale (FTD-FRS) to detect functional and behavioral changes in patients diagnosed with the behavioral variant of FTD (bvFTD), primary progressive aphasia (PPA) and Alzheimer disease (AD) after 12 months of the initial evaluation, compared to the Clinical Dementia Rating scale - frontotemporal lobar degeneration (CDR-FTLD) and the original Clinical Dementia Rating scale (CDR).
Methods: The sample consisted of 70 individuals, aged 40+ years, with at least two years of schooling, 31 with the diagnosis of bvFTD, 12 with PPA (8 with semantic variant and 4 with non-fluent variant) and 27 with AD. The FTD-FRS, the CDR and the two additional CDR-FTLD items were completed by a clinician, based on the information provided by the caregiver with frequent contact with the patient. The Addenbrooke’s Cognitive Examination-Revised (ACE-R) was completed by patients. After 12 months, the same protocol was applied.
Results: The FTD-FRS, CDR-FTLD and CDR detected significant decline after 12 months in the three clinical groups (exception: FTD-FRS for PPA). The CDR was less sensitive to severe disease stages.
Conclusions: The FTD-FRS and the CDR-FTLD are especially useful tools for dementia staging in AD and in the FTD spectrum.