title: Quantitative Electroencephalography as a Diagnostic Tool for Alzheimer's Dementia in Adults with Down Syndrome.
abstract: BACKGROUND
  Assessment of dementia in individuals with intellectual disability is complex due to great inter-individual variability in cognitive function prior to dementia and a lack of standardized instruments. Studies have indicated that quantitative electroencephalography (qEEG) results may be used as a diagnostic marker for dementia. The aim of this study was to examine the value of qEEG in the diagnostic evaluation of dementia in patients with Down syndrome (DS).
  
  
  METHODS
  The study included 21 patients with DS and mild-to-moderate dementia due to Alzheimer's disease (DS-AD) and 16 age-matched adults with DS without cognitive deterioration assessed by the informant-based Dementia Screening Questionnaire in Intellectual Disability (DSQIID). Conventional EEG was performed and analysed quantitatively using fast Fourier transformation. Outcomes were centroid frequency, peak frequency, absolute power, and relative power.
  
  
  RESULTS
  In several regions of the brain, a significant decrease in the theta-1 band (4-7 Hz) was identified for the centroid frequency. A significant negative correlation was demonstrated between the mean of the centroid frequency of the theta-1 band and the total DSQIID score.
  
  
  CONCLUSIONS
  We found that qEEG can detect a significant decrease in centroid frequency in a sample of patients with DS-AD as compared to a sample of adults with DS and no cognitive deterioration.
authors.affiliation: Danish Dementia Research Centre, Copenhagen University Hospital, Rigshospitalet, Denmark.
authors.forename: Lise Cronberg
authors.initials: LC
authors.lastname: Salem
authors.affiliation: Epilepsy Clinic, Department of Neurology, Copenhagen University Hospital, Rigshospitalet, Denmark.
authors.forename: Anne
authors.initials: A
authors.lastname: Sabers
authors.affiliation: Neurophysiology Center, Roskilde University Hospital, Roskilde, Denmark.
authors.forename: Troels W
authors.initials: TW
authors.lastname: Kjaer
authors.affiliation: Danish Dementia Research Centre, Copenhagen University Hospital, Rigshospitalet, Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: Musaeus
authors.affiliation: Department of Clinical Neurophysiology, Copenhagen University Hospital, Rigshospitalet, Denmark.
authors.forename: Martin N
authors.initials: MN
authors.lastname: Nielsen
authors.affiliation: Centre for Seniors with Disabilities, Copenhagen, Denmark.
authors.forename: Anne-Grete
authors.initials: AG
authors.lastname: Nielsen
authors.affiliation: Danish Dementia Research Centre, Copenhagen University Hospital, Rigshospitalet, Denmark.
authors.forename: Gunhild
authors.initials: G
authors.lastname: Waldemar
keywords: Alzheimer's dementia; Diagnostic assessment; Down syndrome; Quantitative electroencephalography