EEG abnormalities are associated with different cognitive profiles in Alzheimer's disease.
OBJECTIVE
Our purpose was to investigate associations between different cognitive profiles and their underlying functional brain changes as measured by electroencephalogram (EEG) in Alzheimer's disease (AD).


METHODS
EEG was obtained and neuropsychological performance assessed in 254 patients with AD. The EEGs were visually assessed for the presence of focal and/or diffuse abnormalities. Multivariate analysis of variance for repeated measures was performed with presence of focal and/or diffuse abnormalities as between-subjects factor and neuropsychological tests as within-subject factor. Age, sex and education were entered as covariates.


RESULTS
Twenty-eight percent of the patients had a normal EEG, 32% had focal abnormalities, 14% diffuse abnormalities and 26% had both focal and diffuse abnormalities. Patients with a normal EEG presented with a cognitive profile in which memory was mostly impaired. Patients with focal and diffuse EEG abnormalities presented with a nonmemory profile.


CONCLUSIONS
These results illustrate that specific types of EEG abnormalities are associated with different cognitive profiles in AD, providing biological support in terms of brain functioning for variability in cognitive impairment.
Alzheimer Center, Department of Neurology, VU University Medical Center, Amsterdam, The Netherlands. l.smits@vumc.nl
Lieke L
LL
Smits
Maarten
M
Liedorp
Teddy
T
Koene
Ilona E W
IE
Roos-Reuling
Afina W
AW
Lemstra
Philip
P
Scheltens
Cornelis J
CJ
Stam
Wiesje M
WM
van der Flier
D000368:Aged; D000375:Aging / Q000523:psychology; D000544:Alzheimer Disease / Q000503:physiopathology* / Q000523:psychology*; D003071:Cognition / Q000502:physiology*; D015331:Cohort Studies; D003627:Data Interpretation, Statistical; D004522:Educational Status; D004569:Electroencephalography / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D012727:Sex Characteristics