title: Sources of cortical rhythms change as a function of cognitive impairment in pathological aging: a multicenter study.
abstract: OBJECTIVE
  The present study tested the hypothesis that cortical electroencephalographic (EEG) rhythms. change across normal elderly (Nold), mild cognitive impairment (MCI), and Alzheimer's disease (AD) subjects as a function of the global cognitive level.
  
  
  METHODS
  Resting eyes-closed EEG data were recorded in 155 MCI, 193 mild AD, and 126 age-matched Nold subjects. EEG rhythms of interest were delta (2-4 Hz), theta (4-8 Hz), alpha 1 (8-10.5 Hz), alpha 2 (10.5-13 Hz), beta 1 (13-20 Hz), and beta 2 (20-30 Hz). EEG cortical sources were estimated by LORETA.
  
  
  RESULTS
  Occipital delta and alpha 1 sources in parietal, occipital, temporal, and 'limbic' areas had an intermediate magnitude in MCI subjects compared to mild AD and Nold subjects. These five EEG sources presented both linear and nonlinear (linear, exponential, logarithmic, and power) correlations with the global cognitive level (as revealed by mini mental state examination score) across all subjects.
  
  
  CONCLUSIONS
  Cortical EEG rhythms change in pathological aging as a function of the global cognitive level.
  
  
  CONCLUSIONS
  The present functional data on large populations support the 'transitional hypothesis' of a shadow zone across normality, pre-clinical stage of dementia (MCI), and AD.
authors.affiliation: Dip. Fisiologia Umana e Farmacologia, Univ. La Sapienza Rome, Italy. claudio.babiloni@uniroma1.it
authors.forename: Claudio
authors.initials: C
authors.lastname: Babiloni
authors.forename: Giuliano
authors.initials: G
authors.lastname: Binetti
authors.forename: Emanuele
authors.initials: E
authors.lastname: Cassetta
authors.forename: Gloria
authors.initials: G
authors.lastname: Dal Forno
authors.forename: Claudio
authors.initials: C
authors.lastname: Del Percio
authors.forename: Florinda
authors.initials: F
authors.lastname: Ferreri
authors.forename: Raffaele
authors.initials: R
authors.lastname: Ferri
authors.forename: Giovanni
authors.initials: G
authors.lastname: Frisoni
authors.forename: Koichi
authors.initials: K
authors.lastname: Hirata
authors.forename: Bartolo
authors.initials: B
authors.lastname: Lanuzza
authors.forename: Carlo
authors.initials: C
authors.lastname: Miniussi
authors.forename: Davide V
authors.initials: DV
authors.lastname: Moretti
authors.forename: Flavio
authors.initials: F
authors.lastname: Nobili
authors.forename: Guido
authors.initials: G
authors.lastname: Rodriguez
authors.forename: Gian Luca
authors.initials: GL
authors.lastname: Romani
authors.forename: Serenella
authors.initials: S
authors.lastname: Salinari
authors.forename: Paolo M
authors.initials: PM
authors.lastname: Rossini
mesh_terms: D000368:Aged; D000375:Aging / Q000473:pathology*; D000544:Alzheimer Disease / Q000503:physiopathology; D001931:Brain Mapping; D016022:Case-Control Studies; D002540:Cerebral Cortex / Q000503:physiopathology*; D003072:Cognition Disorders / Q000503:physiopathology*; D004569:Electroencephalography / Q000145:classification / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008609:Mental Status Schedule / Q000706:statistics & numerical data; D008875:Middle Aged; D012189:Retrospective Studies; D012815:Signal Processing, Computer-Assisted; D013057:Spectrum Analysis; D013223:Statistics as Topic