title: Neuroanatomical correlates of emotional blunting in behavioral variant frontotemporal dementia and early-onset Alzheimer's disease.
abstract: BACKGROUND
  Emotional blunting is a characteristic feature of behavioral variant frontotemporal dementia (bvFTD) and can help discriminate between patients with bvFTD and other forms of younger-onset dementia.
  
  
  OBJECTIVE
  We compared the presence of emotional blunting symptoms in patients with bvFTD and early-onset Alzheimer's disease (AD), and investigated the neuroanatomical associations between emotional blunting and regional brain volume.
  
  
  METHODS
  Twenty-five individuals with bvFTD (n = 11) and early-onset AD (n = 14) underwent magnetic resonance imaging (MRI) and were rated on symptoms of emotional blunting using the Scale for Emotional Blunting (SEB). The two groups were compared on SEB ratings and MRI-derived brain volume using tensor-based morphometry. Voxel-wise linear regression was performed to determine neuroanatomical correlates of SEB scores.
  
  
  RESULTS
  The bvFTD group had significantly higher SEB scores compared to the AD group. On MRI, bvFTD patients had smaller bilateral frontal lobe volume compared to AD patients, while AD patients had smaller bilateral temporal and left parietal volume than bvFTD patients. In bvFTD, SEB ratings were strongly correlated with right anterior temporal volume, while the association between SEB and the right orbitofrontal cortex was non-significant.
  
  
  CONCLUSIONS
  Symptoms of emotional blunting were more prevalent in bvFTD than early-onset AD patients. These symptoms were particularly associated with right-sided atrophy, with significant involvement of the right anterior temporal region. Based on these findings, the SEB appears to measure symptoms of emotional blunting that are localized to the right anterior temporal lobe.
authors.affiliation: Department of Psychology, School of Behavioral Health, Loma Linda University, Loma Linda, CA, USA.
authors.forename: Grace J
authors.initials: GJ
authors.lastname: Lee
authors.affiliation: Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
authors.forename: Po H
authors.initials: PH
authors.lastname: Lu
authors.affiliation: Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA Greater Los Angeles VA Healthcare System, West Los Angeles, CA, USA.
authors.forename: Michelle J
authors.initials: MJ
authors.lastname: Mather
authors.affiliation: Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA Greater Los Angeles VA Healthcare System, West Los Angeles, CA, USA.
authors.forename: Jill
authors.initials: J
authors.lastname: Shapira
authors.affiliation: Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA Greater Los Angeles VA Healthcare System, West Los Angeles, CA, USA.
authors.forename: Elvira
authors.initials: E
authors.lastname: Jimenez
authors.affiliation: Departments of Psychiatry and Bioengineering, University of Illinois, Chicago, IL, USA.
authors.forename: Alex D
authors.initials: AD
authors.lastname: Leow
authors.affiliation: Laboratory of NeuroImaging, Institute for Neuroimaging and Informatics, Keck School of Medicine of USC, Los Angeles, CA, USA.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Thompson
authors.affiliation: Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA Greater Los Angeles VA Healthcare System, West Los Angeles, CA, USA.
authors.forename: Mario F
authors.initials: MF
authors.lastname: Mendez
mesh_terms: D000328:Adult; D000368:Aged; D000544:Alzheimer Disease / Q000150:complications* / Q000473:pathology*; D001526:Behavioral Symptoms / Q000209:etiology*; D005260:Female; D057180:Frontotemporal Dementia / Q000150:complications* / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019964:Mood Disorders / Q000209:etiology*; D011569:Psychiatric Status Rating Scales; D013223:Statistics as Topic
keywords: Alzheimer's disease; early onset; emotional blunting; frontotemporal dementia; magnetic resonance imaging