STUDY ON FREQQQUENCY –AMPLITUDE GRADIENT
IN PEDIATRIC SLEEP EEGs
GUO ZC, CAI FC
Children’s Hospital, Chongqing University of
Medical Sciences, Chongqing, China
Objective: To explore the really
clinical significance of the Frequency-Amplitude Gradient (FAG) in
pediatric sleep EEGs.
Method: The patients and normal
children were divided into corresponding five groups in accordance with age
(~ 1yr, ~ 3yr,~ 5yr, ~10yr, ~ 14yr as group Ⅰ,Ⅱ,Ⅲ ,Ⅳ,Ⅴ).Simultaneous
EEGs and Brain Electric Activity Mapping were performed during awake and
sleep .The energy ratio of slow waves between parietal-occipital and
frontal prefrontal area namely FAG , was calculated. The time-amplitude of
EEG was converted into frequency-energy relation.
Results: 31 normal children and 43
patients with encephalopathy illness fell into the study. The mean values
of FAG in normal children of groups Ⅰ,Ⅱ,Ⅲ were higher than 1.0 and were interpreted as
normal FAG. The mean values of FAG in patients of groups Ⅰ,Ⅱ,Ⅲ were lover than 1.0 and were interpreted as absence
of FAG. Significant differences were found between the normal children
groups and the patient Groups(Ps<0.05~0.01).The mean value of Fag in
group Ⅳ normal children group and
the patients in group(Ps>0.05).The mean value of FAG in group Ⅴ normal children was lower
than 1.o no significant difference between the corresponding normal
children group and the patients group(Ps>0.05).
Conclusions: The EEG pattern of FAG was well-developed
in normal children at 4mos of age, progressively decrement till 10 years
old and absence of FAG when approaching 14 years. Neurological illness may
be associated with loss of FAG. The Fag examination is a valuable parameter
in distinguishing normal sleep EEG and encephalopathy illness.