title: Longitudinal Executive Function and Episodic Memory Profiles in Behavioral-Variant Frontotemporal Dementia and Alzheimer's Disease.
abstract: With comparable baseline performance on executive functions (EF) and memory between Alzheimer's disease (AD) and behavioral-variant frontotemporal dementia (bvFTD), it is currently unclear if both diseases can be distinguished longitudinally on these measures reliably.
  
  
  
  A total of 111 participants (33 AD, 31 bvFTD, and 47 controls) were followed-up annually over a 4-year period and tested on measures of EF, memory, and orientation. Linear mixed-effect models were constructed using disease severity as a nuisance variable to examine profiles of neuropsychological performance decline.
  
  
  
  At baseline, overlap in terms of cognitive impairment between bvFTD and AD on multiple EF, memory, and orientation measures was present. Longitudinally, only disinhibition (Hayling total errors) appeared sensitive to discriminating AD from bvFTD; however, only after the first annual follow-up. Subgroup analyses on smaller samples revealed comparable profiles on EF tasks at baseline and over time between bvFTD and AD who presented with impaired EF at presentation, and on memory and orientation tasks between AD and bvFTD who presented with severe amnesia.
  
  
  
  Our results replicate previous findings showing only moderate discriminability between AD and bvFTD at clinical presentation on EF and memory measures. More importantly, we also show that longitudinal trajectories strongly overlap for both dementias on these measures. Disinhibition emerged as the sole measure that in the long run was significantly more impaired in bvFTD. Future studies should use tests designed to target cortical regions that are specifically impaired in bvFTD, such as the ventromedial prefrontal cortex, to improve the accurate discrimination of these diseases. (JINS, 2017, 23, 34-43).
authors.affiliation: 1Department of Neurology,Manipal Hospital,Bangalore,India.
authors.forename: Siddharth
authors.identifier: 0000-0002-8591-042X
authors.initials: S
authors.lastname: Ramanan
authors.affiliation: 2Norwich Medical School,University of East Anglia,Norwich,United Kingdom.
authors.forename: Maxime
authors.initials: M
authors.lastname: Bertoux
authors.affiliation: 2Norwich Medical School,University of East Anglia,Norwich,United Kingdom.
authors.forename: Emma
authors.initials: E
authors.lastname: Flanagan
authors.affiliation: 3School of Psychology,The University of New South Wales,Sydney,NSW,Australia.
authors.forename: Muireann
authors.initials: M
authors.lastname: Irish
authors.affiliation: 4Neuroscience Research Australia,Randwick,Sydney,NSW,Australia.
authors.forename: Olivier
authors.initials: O
authors.lastname: Piguet
authors.affiliation: 4Neuroscience Research Australia,Randwick,Sydney,NSW,Australia.
authors.forename: John R
authors.initials: JR
authors.lastname: Hodges
authors.affiliation: 2Norwich Medical School,University of East Anglia,Norwich,United Kingdom.
authors.forename: Michael
authors.initials: M
authors.lastname: Hornberger
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications*; D003072:Cognition Disorders / Q000209:etiology*; D056344:Executive Function / Q000502:physiology*; D005260:Female; D057180:Frontotemporal Dementia / Q000150:complications*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008569:Memory Disorders / Q000209:etiology*; D061212:Memory, Episodic; D008875:Middle Aged; D009483:Neuropsychological Tests; D013223:Statistics as Topic; D018709:Statistics, Nonparametric
keywords: Alzheimer’s disease; Behavioral-variant frontotemporal dementia; Episodic memory; Longitudinal; Orientation; executive functions