title: Quantitative EEG markers relate to Alzheimer's disease severity in the Prospective Dementia Registry Austria (PRODEM).
abstract: OBJECTIVE
  To investigate which single quantitative electro-encephalographic (QEEG) marker or which combination of markers correlates best with Alzheimer's disease (AD) severity as measured by the Mini-Mental State Examination (MMSE).
  
  
  METHODS
  We compared quantitative EEG markers for slowing (relative band powers), synchrony (coherence, canonical correlation, Granger causality) and complexity (auto-mutual information, Shannon/Tsallis entropy) in 118 AD patients from the multi-centric study PRODEM Austria. Signal spectra were determined using an indirect spectral estimator. Analyses were adjusted for age, sex, duration of dementia, and level of education.
  
  
  RESULTS
  For the whole group (39 possible, 79 probable AD cases) MMSE scores explained 33% of the variations in relative theta power during face encoding, and 31% of auto-mutual information in resting state with eyes closed. MMSE scores explained also 25% of the overall QEEG factor. This factor was thus subordinate to individual markers. In probable AD, QEEG coefficients of determination were always higher than in the whole group, where MMSE scores explained 51% of the variations in relative theta power.
  
  
  CONCLUSIONS
  Selected QEEG markers show strong associations with AD severity. Both cognitive and resting state should be used for QEEG assessments.
  
  
  CONCLUSIONS
  Our data indicate theta power measured during face-name encoding to be most closely related to AD severity.
authors.affiliation: AIT Austrian Institute of Technology GmbH, Vienna, Austria. Electronic address: Heinrich.garn@ait.ac.at.
authors.forename: Heinrich
authors.initials: H
authors.lastname: Garn
authors.affiliation: AIT Austrian Institute of Technology GmbH, Vienna, Austria.
authors.forename: Markus
authors.initials: M
authors.lastname: Waser
authors.affiliation: Vienna University of Technology, Vienna, Austria.
authors.forename: Manfred
authors.initials: M
authors.lastname: Deistler
authors.affiliation: Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Benke
authors.affiliation: Department of Neurology, Vienna Medical University, Vienna, Austria.
authors.forename: Peter
authors.initials: P
authors.lastname: Dal-Bianco
authors.affiliation: Department of Neurology, Linz General Hospital, Linz, Austria.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Ransmayr
authors.affiliation: Department of Neurology, Graz Medical University, Graz, Austria.
authors.forename: Helena
authors.initials: H
authors.lastname: Schmidt
authors.affiliation: Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Guenter
authors.initials: G
authors.lastname: Sanin
authors.affiliation: Department of Neurology, Vienna Medical University, Vienna, Austria.
authors.forename: Peter
authors.initials: P
authors.lastname: Santer
authors.affiliation: Department of Neurology, Linz General Hospital, Linz, Austria.
authors.forename: Georg
authors.initials: G
authors.lastname: Caravias
authors.affiliation: Department of Neurology, Graz Medical University, Graz, Austria.
authors.forename: Stephan
authors.initials: S
authors.lastname: Seiler
authors.affiliation: Dr. Grossegger & Drbal GmbH, Vienna, Austria.
authors.forename: Dieter
authors.initials: D
authors.lastname: Grossegger
authors.affiliation: Dr. Grossegger & Drbal GmbH, Vienna, Austria.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Fruehwirt
authors.affiliation: Department of Neurology, Graz Medical University, Graz, Austria.
authors.forename: Reinhold
authors.initials: R
authors.lastname: Schmidt
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000503:physiopathology; D001317:Austria; D015415:Biomarkers; D001921:Brain / Q000503:physiopathology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011446:Prospective Studies; D012042:Registries; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers
keywords: Alzheimer’s disease; PRODEM; Quantitative electroencephalogram