title: Longitudinal change in everyday function and behavioral symptoms in frontotemporal dementia.
abstract: BACKGROUND
  The relationship between behavioral changes and functional decline in frontotemporal dementia (FTD) is not well understood.
  
  
  METHODS
  Thirty-nine patients (21 behavioral variant FTD [bvFTD], 18 semantic variant primary progressive aphasia [svPPA]) were followed up longitudinally (2-4 years follow-up). Functional (Disability Assessment for Dementia) and behavioral (Cambridge Behavioural Inventory Revised) assessments were included for between-group (pairwise comparisons, mixed model analysis) and within-group analyses (bivariate correlations).
  
  
  RESULTS
  Functionally, patients with bvFTD were more impaired than patients with svPPA at baseline and continued to be at follow-up, despite similar disease duration. By contrast, behavioral impairments differed between patient groups at baseline and at follow-up. At baseline, patients with bvFTD exhibited higher levels of apathy and changes in eating than patients with svPPA; disinhibited and stereotypical behaviors were similar. Over the years, patients with bvFTD showed reduction in disinhibition and stereotypical behavior while apathy and eating changes increased. By contrast, all measured behaviors increased in patients with svPPA over time. Finally, only apathy made longitudinal contributions to functional disability in patients with svPPA, whereas apathy and stereotypical behavior were associated with increased disability in patients with bvFTD.
  
  
  CONCLUSIONS
  Despite shared overlapping baseline behavioral symptoms, patients with bvFTD are more functionally impaired than patients with svPPA. Apathy has a strong role in disability for both bvFTD and svPPA, but stereotypical behaviors only contributed to functional deficits in patients with bvFTD. Our findings suggest that rigid/compulsive behaviors may in fact support activity engagement in patients with svPPA. Taken together, our results indicate that interventions to reduce disability in the FTD spectrum require an alternative rationale in comparison to Alzheimer disease dementia, and should carefully weigh the interaction of behavioral symptoms and functional status.
authors.affiliation: Ageing, Work & Health Research Unit (CMO, LC) and Speech Pathology (CEL), Faculty of Health Sciences, University of Sydney, Australia; Faculty of Medicine and Health Sciences (MH, EM), University of East Anglia, UK; Neuroscience Research Australia (CEL, JRH, OP); and ARC Centre of Excellence in Cognition and its Disorders (JRH, OP) and School of Medical Sciences (JRH, OP), University of New South Wales, Australia.
authors.forename: Claire M
authors.initials: CM
authors.lastname: O'Connor
authors.affiliation: Ageing, Work & Health Research Unit (CMO, LC) and Speech Pathology (CEL), Faculty of Health Sciences, University of Sydney, Australia; Faculty of Medicine and Health Sciences (MH, EM), University of East Anglia, UK; Neuroscience Research Australia (CEL, JRH, OP); and ARC Centre of Excellence in Cognition and its Disorders (JRH, OP) and School of Medical Sciences (JRH, OP), University of New South Wales, Australia.
authors.forename: Lindy
authors.initials: L
authors.lastname: Clemson
authors.affiliation: Ageing, Work & Health Research Unit (CMO, LC) and Speech Pathology (CEL), Faculty of Health Sciences, University of Sydney, Australia; Faculty of Medicine and Health Sciences (MH, EM), University of East Anglia, UK; Neuroscience Research Australia (CEL, JRH, OP); and ARC Centre of Excellence in Cognition and its Disorders (JRH, OP) and School of Medical Sciences (JRH, OP), University of New South Wales, Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Hornberger
authors.affiliation: Ageing, Work & Health Research Unit (CMO, LC) and Speech Pathology (CEL), Faculty of Health Sciences, University of Sydney, Australia; Faculty of Medicine and Health Sciences (MH, EM), University of East Anglia, UK; Neuroscience Research Australia (CEL, JRH, OP); and ARC Centre of Excellence in Cognition and its Disorders (JRH, OP) and School of Medical Sciences (JRH, OP), University of New South Wales, Australia.
authors.forename: Cristian E
authors.initials: CE
authors.lastname: Leyton
authors.affiliation: Ageing, Work & Health Research Unit (CMO, LC) and Speech Pathology (CEL), Faculty of Health Sciences, University of Sydney, Australia; Faculty of Medicine and Health Sciences (MH, EM), University of East Anglia, UK; Neuroscience Research Australia (CEL, JRH, OP); and ARC Centre of Excellence in Cognition and its Disorders (JRH, OP) and School of Medical Sciences (JRH, OP), University of New South Wales, Australia.
authors.forename: John R
authors.initials: JR
authors.lastname: Hodges
authors.affiliation: Ageing, Work & Health Research Unit (CMO, LC) and Speech Pathology (CEL), Faculty of Health Sciences, University of Sydney, Australia; Faculty of Medicine and Health Sciences (MH, EM), University of East Anglia, UK; Neuroscience Research Australia (CEL, JRH, OP); and ARC Centre of Excellence in Cognition and its Disorders (JRH, OP) and School of Medical Sciences (JRH, OP), University of New South Wales, Australia.
authors.forename: Olivier
authors.initials: O
authors.lastname: Piguet
authors.affiliation: Ageing, Work & Health Research Unit (CMO, LC) and Speech Pathology (CEL), Faculty of Health Sciences, University of Sydney, Australia; Faculty of Medicine and Health Sciences (MH, EM), University of East Anglia, UK; Neuroscience Research Australia (CEL, JRH, OP); and ARC Centre of Excellence in Cognition and its Disorders (JRH, OP) and School of Medical Sciences (JRH, OP), University of New South Wales, Australia.
authors.forename: Eneida
authors.initials: E
authors.lastname: Mioshi