title: Are CSF Biomarkers Useful as Prognostic Indicators in Diagnostically Unresolved Cognitively Impaired Patients in a Normal Clinical Setting.
abstract: BACKGROUND
  Despite an extensive evaluation program, patients may remain diagnostically unresolved with regard to the etiology of their cognitive dysfunction. Cerebrospinal fluid neuroinflammation and Alzheimer disease (AD) biomarkers may act as indicators of neurodegenerative disorders in diagnostically unresolved patients.
  
  
  METHODS
  Data on 348 patients were retrospectively evaluated. All participants had a standardized diagnostic workup and follow-up in a memory clinic.
  
  
  RESULTS
  Aβ42levels and Aβ42/p-tau ratios were reduced and levels of t-tau and p-tau as well as the t-tau × p-tau/Aβ42ratio were elevated in diagnostically unresolved patients who clinically progressed, compared to a stable group. No differences in neuroinflammatory parameters were found.
  
  
  CONCLUSIONS
  AD biomarkers - in particular the Aβ42/p-tau ratio, but not neuroinflammatory parameters - predicted clinical progression, regardless of etiology.
authors.affiliation: Regional Dementia Research Centre, Department of Neurology, Zealand University Hospital, Roskilde, Denmark.
authors.forename: Malene
authors.initials: M
authors.lastname: Schjønning Nielsen
authors.affiliation: Danish Dementia Research Centre, Department of Neurology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Anja Hviid
authors.initials: AH
authors.lastname: Simonsen
authors.affiliation: The Research Unit for General Practice and Section of General Practice, Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Volkert
authors.initials: V
authors.lastname: Siersma
authors.affiliation: Danish Dementia Research Centre, Department of Neurology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Steen Gregers
authors.initials: SG
authors.lastname: Hasselbalch
authors.affiliation: Regional Dementia Research Centre, Department of Neurology, Zealand University Hospital, Roskilde, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Høgh
keywords: Alzheimer disease; Amyloid; Biomarker; Blood-brain barrier; Cerebrospinal fluid; Diagnosis; Inflammation; Mild cognitive impairment; Prognosis; Tau protein