title: Late-onset behavioral variant of frontotemporal lobar degeneration versus Alzheimer's disease: Interest of cerebrospinal fluid biomarker ratios.
abstract: BACKGROUND
  Cerebrospinal fluid (CSF) biomarker ratios were never evaluated in late-onset (>65 years) behavioral variant of frontotemporal lobar degeneration (bvFTLD) versus Alzheimer's disease (AD).
  
  
  METHODS
  A retrospective monocentric study on 44 clinically suspected amnestic AD or bvFTLD patients with onset after 65 years and available CSF and clinical data.
  
  
  RESULTS
  The final clinical diagnosis was AD (n = 28; 64%), late-onset bvFTLD (n = 14; 32%), and others (n = 2; 4%). Applying the CSF cutoff total-tau/Aβ1-42 of 1.06, all the bvFTLD were in the FTLD range (<1.06, bvFTLD/FTLD), whereas the AD patients were either in the AD (>1.06, AD/AD) or in the FTLD range (<1.06, AD/FTLD); CSF biomarkers were significantly different in these three groups, but not neuroradiological features or presence of episodic memory deficit.
  
  
  CONCLUSIONS
  Late-onset bvFTLD is underdiagnosed. The available CSF biomarker ratio cutoff need further improvement and overestimated late-onset bvFTLD but could potentially differentiate it from AD, notably in case of conflicting results.
authors.affiliation: Department of Neurology and Memory Research and Resources Center, Gui de Chauliac University Hospital, Montpellier, France.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Marelli
authors.affiliation: Department of Neurology and Memory Research and Resources Center, Gui de Chauliac University Hospital, Montpellier, France; INSERM U 1061-Neuropsychiatry: Epidemiological and Clinical Research, Montpellier, France.
authors.forename: Laure-Anne
authors.initials: LA
authors.lastname: Gutierrez
authors.affiliation: Institut d'Imagerie Fonctionnelle Humaine, I2FH, Gui de Chauliac University Hospital, Montpellier, France; Department of Neuroradiology, Gui de Chauliac University Hospital, Montpellier, France; Team "Plasticity of Central Nervous System, Stem Cells and Glial Tumors," Institut National de la Santé et de la Recherche Médicale Unité 583, Institut of Neurosciences of Montpellier, Saint Eloi Hospital, Montpellier, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Menjot de Champfleur
authors.affiliation: INSERM U 1061-Neuropsychiatry: Epidemiological and Clinical Research, Montpellier, France; Institut d'Imagerie Fonctionnelle Humaine, I2FH, Gui de Chauliac University Hospital, Montpellier, France; Department of Neuroradiology, Gui de Chauliac University Hospital, Montpellier, France; INSERM U 1198 - Molecular Mechanisms in Neurodegenerative Diseases, Montpellier, France.
authors.forename: Celine
authors.initials: C
authors.lastname: Charroud
authors.affiliation: Department of Nuclear Medicine, Gui de Chauliac University Hospital, Montpellier, France.
authors.forename: Delphine
authors.initials: D
authors.lastname: De Verbizier
authors.affiliation: Department of Neurology and Memory Research and Resources Center, Gui de Chauliac University Hospital, Montpellier, France.
authors.forename: Jacques
authors.initials: J
authors.lastname: Touchon
authors.affiliation: Department of Neurology and Memory Research and Resources Center, Gui de Chauliac University Hospital, Montpellier, France.
authors.forename: Patrice
authors.initials: P
authors.lastname: Douillet
authors.affiliation: Department of Neurology and Memory Research and Resources Center, Gui de Chauliac University Hospital, Montpellier, France; INSERM U 1061-Neuropsychiatry: Epidemiological and Clinical Research, Montpellier, France.
authors.forename: Claudine
authors.initials: C
authors.lastname: Berr
authors.affiliation: CHRU de Montpellier, Université de Montpellier, Institute of Regenerative Medicine and Bio-therapy (IRMB), INSERM U1183, CCBHM, Laboratoire de Biochimie Protéomique Clinique, Montpellier, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Lehmann
authors.affiliation: Department of Neurology and Memory Research and Resources Center, Gui de Chauliac University Hospital, Montpellier, France; CHRU de Montpellier, Université de Montpellier, Institute of Regenerative Medicine and Bio-therapy (IRMB), INSERM U1183, CCBHM, Laboratoire de Biochimie Protéomique Clinique, Montpellier, France.
authors.forename: Audrey
authors.initials: A
authors.lastname: Gabelle
keywords: Alzheimer's disease; Biomarkers; Cerebrospinal fluid; Differential diagnosis; Frontotemporal lobar degeneration; Late-onset frontotemporal lobar degeneration