A longitudinal analysis of the frontotemporal dementia rating scale as a sensitive measure of disease trajectory
Eve Ferry‐Bolder, Arabella Bouzigues, Phoebe H Foster, Georgia Peakman, Caroline V Greaves, Rhian S Convery, John C. van Swieten, Lize C. Jiskoot, Harro Seelaar, Fermin Moreno, Raquel Sanchez‐Valle, Robert Laforce, Caroline Graff, Mario Masellis, Carmela Tartaglia, James B. Rowe, Barbara Borroni, Elizabeth Finger, Matthis Synofzik, Daniela Galimberti, Rik Vandenberghe, Alexandre de Mendonça, Christopher Butler, Alexander Gerhard, Simon Ducharme, Isabelle Le Ber, Pietro Tiraboschi, Isabel Santana, Florence Pasquier, Johannes Levin, Markus Otto, Sandro Sorbi, Jonathan D. Rohrer, Lucy L. Russell,- Psychiatry and Mental health
- Cellular and Molecular Neuroscience
- Geriatrics and Gerontology
- Neurology (clinical)
- Developmental Neuroscience
- Health Policy
- Epidemiology
Abstract
Background
Previous research in genetic frontotemporal dementia (FTD) has suggested that the FTD Rating Scale (FRS) may be a more sensitive measure of disease severity than the Clinical Dementia Rating scale plus National Alzheimer’s Coordinating Centre Frontotemporal Lobar Degeneration score (CDR+NACC FTLD). This study aims to assess the potential of longitudinal measurement of the FRS to track disease trajectory, using data from the Genetic FTD Initiative (GENFI).
Method
119 mutation negative controls and 270 mutation carriers (52 MAPT, 107 GRN, 111 C9orf72) from the GENFI cohort completed the FRS at their baseline and follow‐up visits. Participants were grouped by disease severity according to their CDR+NACC FTLD global score at the baseline visit, which generated five mutation groups: asymptomatic (0), prodromal (0.5), mild (1), moderate (2), and severe (3), plus the control group. Annualised FRS change scores were generated for each participant (mean interval between visits = 1.3 years, standard deviation = 0.6). For each of the genetic groups, correlations with annualised change score for the MMSE and the CDR+NACC FTLD SOB were performed.
Result
As disease becomes more severe, the annualised change in FRS was larger, peaking at the moderate stage: asymptomatic 0.6 (8.0), prodromal ‐5.1, (23.2), mild ‐7.2 (24.8), moderate ‐7.8 (11.6), severe ‐1.8 (8.2). The moderate group was significantly different from controls (p = 0.018) and the asymptomatic group (p = 0.030). The annualised change in FRS negatively correlated with the annualised change in CDR+NACC FTLD Sum of Boxes (Rho = ‐0.4, p<0.001) and positively correlated with the annualised change in MMSE (Rho = 0.3, p = 0.001) in GRN MCs but not in MAPT or C9orf72.
Conclusion
The FRS shows promise as a sensitive clinical outcome measure, but only at certain stages of the disease. More sophisticated modelling utilising the wider GENFI cohort will help to establish the real potential for use in clinical settings.