The behavioural variant frontotemporal dementia phenocopy syndrome is a distinct entity - evidence from a longitudinal study

Devenney, E., Swinn, T., Mioshi, E., Hornberger, M. ORCID: https://orcid.org/0000-0002-2214-3788, Dawson, K. E., Mead, S., Rowe, J. B. and Hodges, J. R. (2018) The behavioural variant frontotemporal dementia phenocopy syndrome is a distinct entity - evidence from a longitudinal study. BMC Neurology, 18. ISSN 1471-2377

[thumbnail of Published manuscript]
Preview
PDF (Published manuscript) - Published Version
Available under License Creative Commons Attribution.

Download (520kB) | Preview

Abstract

Background: This study aimed to i) examine the frequency of C9orf72 expansions in a cohort of patients with the behavioural variant frontotemporal dementia (bvFTD) phenocopy syndrome, ii) observe outcomes in a group of phenocopy syndrome with very long term follow-up and iii) compare progression in a cohort of patients with the phenocopy syndrome to a cohort of patients with probable bvFTD. Methods: Blood was obtained from 16 phenocopy cases. All met criteria for possible bvFTD and were labeled as phenocopy cases if they showed no functional decline, normal cognitive performance on the Addenbrooke’s Cognitive Examination-Revised (ACE-R) and a lack of atrophy on brain imaging, over at least 3 years of follow-up. In addition, we obtained very long term follow-up data in 6 cases. A mixed model analysis approach determined the pattern of change in cognition and behaviour over time in phenocopy cases compared to 27 probable bvFTD cases. Results: All 16 patients were screened for the C9orf72 expansion that was present in only one (6.25%). Of the 6 cases available for very long-term follow-up (13 - 21 years) none showed progression to frank dementia. Moreover, there was a decrease in the caregiver ratings of behavioural symptoms over time. Phenocopy cases showed significantly slower rates of progression compared to probable bvFTD patients (p < 0.006). Conclusion: The vast majority of patients with the bvFTD phenocopy syndrome remain stable over many years. An occasional patient can harbor the C9orf72 expansion. The aetiology of the remaining cases remains unknown but it appears very unlikely to reflect a neurodegenerative syndrome due to lack of clinical progression or atrophy on imaging.

Item Type: Article
Uncontrolled Keywords: frontotemporal dementia,phenocopy syndrome,prognosis,genetics,cognition,behaviour
Faculty \ School: Faculty of Medicine and Health Sciences > School of Health Sciences
Faculty of Medicine and Health Sciences > Norwich Medical School
UEA Research Groups: Faculty of Medicine and Health Sciences > Research Groups > Dementia & Complexity in Later Life
Faculty of Medicine and Health Sciences > Research Groups > Mental Health
Faculty of Medicine and Health Sciences > Research Centres > Lifespan Health
Related URLs:
Depositing User: Pure Connector
Date Deposited: 11 May 2018 11:30
Last Modified: 19 Oct 2023 02:12
URI: https://ueaeprints.uea.ac.uk/id/eprint/67034
DOI: 10.1186/s12883-018-1060-1

Downloads

Downloads per month over past year

Actions (login required)

View Item View Item