EEG correlates in the spectrum of cognitive decline.
OBJECTIVE
To investigate relations between EEG measures and performance on tests of global cognition, memory, language and executive functioning.


METHODS
Twenty-two controls, 18 patients with mild cognitive impairment (MCI) and 16 with probable Alzheimer's disease (AD) underwent neuropsychological and EEG investigations. We used the following EEG measures: theta relative power during eyes closed, alpha reactivity during memory activation (i.e. the percentual decrease in alpha power as compared to eyes closed) and alpha coherence during eyes closed and memory activation.


RESULTS
Theta relative power was increased in AD patients as compared with controls (p<0.001) and MCI patients (p<0.01) and related to decreased performance in all cognitive domains. Alpha reactivity was decreased in AD patients as compared with controls (p<0.005) and related to decreased performance on tests of global cognition, memory and executive functioning. Alpha coherence did not differ between groups and was unrelated to cognition.


CONCLUSIONS
EEG power measures were associated with decreased performance on tests of global cognition, memory, language and executive functioning, while coherence measures were not.


CONCLUSIONS
The EEG yielded several power measures related to cognitive functions. These EEG power measures might prove useful in prospective studies aimed at predicting longitudinal cognitive decline and dementia.
van der Hiele
K
K
Department of Neurology, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands. K.van_der_hiele@lumc.nl
Vein
A A
AA
Reijntjes
R H A M
RH
Westendorp
R G J
RG
Bollen
E L E M
EL
van Buchem
M A
MA
van Dijk
J G
JG
Middelkoop
H A M
HA
D000368:Aged; D000369:Aged, 80 and over; D000513:Alpha Rhythm; D000544:Alzheimer Disease; D003071:Cognition; D003072:Cognition Disorders / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology*; D018450:Disease Progression; D004569:Electroencephalography; D005260:Female; D006801:Humans; D007802:Language; D008297:Male; D008568:Memory; D009483:Neuropsychological Tests; D012720:Severity of Illness Index; D013826:Theta Rhythm