Apolipoprotein E and alpha brain rhythms in mild cognitive impairment: a multicentric electroencephalogram study.
OBJECTIVE
Relationships between the apolipoprotein E epsilon4 allele and electroencephalographic (EEG) rhythmicity have been demonstrated in Alzheimer's disease (AD) patients but not in the preclinical stage prodromic to it, namely, mild cognitive impairment (MCI). The present multicentric EEG study tested the hypothesis that presence of epsilon4 affects sources of resting EEG rhythms in both MCI and AD subjects.


METHODS
We enrolled 89 MCI subjects (34.8% with epsilon4) and 103 AD patients (50.4% with epsilon4). Resting eyes-closed EEG data were recorded for all subjects. EEG rhythms of interest were delta (2-4 Hz), theta (4-8 Hz), alpha 1 (8-10.5 Hz), alpha 2 (10.5-13Hz), beta 1 (13-20 Hz), and beta 2 (20-30 Hz). EEG cortical sources were estimated by low-resolution brain electromagnetic tomography.


RESULTS
Results showed that amplitude of alpha 1 and 2 sources in occipital, temporal, and limbic areas was lower in subjects carrying the epsilon4 allele than in those not carrying the epsilon4 allele (p < 0.01). This was true for both MCI and AD. For the first time to our knowledge, a relationship was shown between ApoE genotype and global neurophysiological phenotype (ie, cortical alpha rhythmicity) in a preclinical AD condition, MCI, in addition to clinically manifest AD.


CONCLUSIONS
Such a demonstration motivates future genotype-EEG phenotype studies for the early prediction of AD conversion in individual MCI subjects.
Babiloni
Claudio
C
Dipartimento di Fisiologia Umana e Farmacologia, Universitá La Sapienza, Rome, Italy. claudio.babiloni@uniroma1.it
Benussi
Luisa
L
Binetti
Giuliano
G
Cassetta
Emanuele
E
Dal Forno
Gloria
G
Del Percio
Claudio
C
Ferreri
Florinda
F
Ferri
Raffaele
R
Frisoni
Giovanni
G
Ghidoni
Roberta
R
Miniussi
Carlo
C
Rodriguez
Guido
G
Romani
Gian Luca
GL
Squitti
Rosanna
R
Ventriglia
Maria Carla
MC
Rossini
Paolo M
PM
D000368:Aged; D000483:Alleles; D000513:Alpha Rhythm; D000544:Alzheimer Disease / Q000235:genetics / Q000503:physiopathology; D000704:Analysis of Variance; D001057:Apolipoproteins E / Q000235:genetics*; D001921:Brain / Q000473:pathology / Q000503:physiopathology*; D001931:Brain Mapping; D003072:Cognition Disorders / Q000235:genetics* / Q000503:physiopathology*; D004569:Electroencephalography / Q000379:methods; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008609:Mental Status Schedule / Q000706:statistics & numerical data; D008875:Middle Aged; D012815:Signal Processing, Computer-Assisted
D001057:Apolipoproteins E