Inter-hemispheric functional coupling of eyes-closed resting EEG rhythms in adolescents with Down syndrome.
OBJECTIVE
We tested the hypothesis that inter-hemispheric directional functional coupling of eyes-closed resting EEG rhythms is abnormal in adolescents with Down syndrome (DS).


METHODS
Eyes-closed resting EEG data were recorded in 38 DS adolescents (18.7 years +/-0.67 SE, IQ=49+/-1.9 SE) and in 17 matched normal control subjects (NYoung=19.1 years +/-0.39 SE). The EEG data were recorded from 8 electrodes (Fp1, Fp2, C3, C4, T3, T4, O1, O2) referenced to vertex. 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). Power of EEG rhythms was evaluated by FFT for control purposes, whereas inter-hemispheric directional EEG functional coupling was computed by directed transfer function (DTF).


RESULTS
As expected, alpha, beta, and gamma power was widely higher in NYoung than DS subjects, whereas the opposite was true for delta power. As a novelty, DTF (directionality) values globally prevailed from right to left occipital areas in NYoung subjects and in the opposite direction in DS patients. A control experiment showed that this DTF difference could not be observed in the comparison between DS adults with mild cognitive impairment and normal age-matched adults.


CONCLUSIONS
These results indicate a peculiar abnormal directional inter-hemispheric interplay in visual occipital areas of DS adolescents.


CONCLUSIONS
Direction of inter-hemispheric EEG functional coupling unveils a new abnormal brain network feature in DS adolescents.
Babiloni
Claudio
C
Department of Biomedical Sciences, University of Foggia, Italy.
Albertini
Giorgio
G
Onorati
Paolo
P
Vecchio
Fabrizio
F
Buffo
Paola
P
Sarà
Marco
M
Condoluci
Claudia
C
Pistoia
Francesca
F
Carducci
Filippo
F
Rossini
Paolo M
PM
D000293:Adolescent; D000465:Algorithms; D003627:Data Interpretation, Statistical; D004314:Down Syndrome / Q000503:physiopathology*; D004569:Electroencephalography; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D009415:Nerve Net / Q000503:physiopathology; D009778:Occipital Lobe / Q000503:physiopathology; D010865:Pilot Projects; D014785:Vision, Ocular / Q000502:physiology; D014793:Visual Cortex / Q000503:physiopathology; D055815:Young Adult