title: Coherence of brain electrical activity: a quality of life indicator in Alzheimer's disease?
abstract: OBJECTIVE
  To investigate the relationships between quality of life (QOL) and clinical and electroencephalogram (EEG) aspects in patients with Alzheimer's disease (AD).
  
  
  METHODS
  Twenty-eight patients with mild or moderate AD, 31 with Parkinson's disease (PD), and 27 normal controls (NC) were submitted to: CERAD neuropsychological battery, Hamilton Depression and Anxiety Rating Scales, Functional Activities Questionnaire, QOL scale for patients with AD, and quantitative EEG measures.
  
  
  RESULTS
  AD and PD patients had similar QOL (31.0 ± 5.8; 31.7 ± 4.8, respectively), worse than that of NC (37.5 ± 6.3). AD patients had lower global interhemispheric theta coherence (0.49 ± 0.04; 0.52 ± 0.05; 0.52 ± 0.05; respectively) than PD and NC. Multiple linear regression for QOL of AD patients revealed that global interhemispheric theta coherence, and Hamilton depression scores were significant factors (coefficients; 58.2 and -0.27, respectively; R2, 0.377).
  
  
  CONCLUSIONS
  Interhemispheric coherence correlates with QOL regardless of cognitive and functional variables and seems to be a neurophysiological indicator of QOL in AD patients.
authors.affiliation: Faculdade de Medicina, Pontifícia Universidade Católica de Campinas, Campinas, SP, Brazil.
authors.forename: Lineu Corrêa
authors.initials: LC
authors.lastname: Fonseca
authors.affiliation: Faculdade de Medicina, Pontifícia Universidade Católica de Campinas, Campinas, SP, Brazil.
authors.forename: Gloria M A S
authors.initials: GM
authors.lastname: Tedrus
authors.affiliation: Pontifícia Universidade Católica de Campinas, Campinas, SP, Brazil.
authors.forename: Ana Laura R A
authors.initials: AL
authors.lastname: Rezende
authors.affiliation: Pontifícia Universidade Católica de Campinas, Campinas, SP, Brazil.
authors.forename: Heitor F
authors.initials: HF
authors.lastname: Giordano
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000503:physiopathology*; D001921:Brain / Q000503:physiopathology*; D003863:Depression / Q000503:physiopathology; D004522:Educational Status; D004569:Electroencephalography; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D011788:Quality of Life; D012720:Severity of Illness Index