Brain electrical activity mapping in childhood absence epilepsy.
BACKGROUND
Brain electrical activity mapping (BEAM) studies related to children with epileptic seizures have been rarely reported. The authors wished to search for BEAM values in children with epilepsy, to better understand the changes in the cerebral field distribution of epileptiform events.


METHODS
Electroencephalographies (EEGs) of 19 Chinese children with childhood absence epilepsy (CAE), but with normal intelligence, were studied prospectively and consecutively. Among them, 11 were boys aged from 6-12 years; 8 girls aged from 6-13 years. EEGs were simultaneously recorded on the Concerto (32 channels), and on the EEG machine, according to standardized recommendations. Frequency or spectral analysis was measured in terms of Band power (uv2), RMS (uv) and InstVolt (uv). Maps were also displayed simultaneously as color in their topographic distriution, with four-picture maximum.


RESULTS
In comparing the four bands of background activities in subjects with eyes closed and open, in the different subgroups, there were no significant differences between boys and girls, nor between the group with epileptiform discharge events (EDE) and the group without EDE, except for the beta band in subjects with eyes closed of the EDE group. There was a significant increase of band power in the group treated with valproic acid, and an increase over the F3 in beta band, Fp1, F4 in theta band, F3, F4, P4, 02 in delta band, but no significant increase was found in alpha band. EDE was also measured and mapped and showed bilateral symmetry with a mid-frontal maximum. Root mean square (RMS) measurements of epochs, from the beginning of EDE to the end of EDE, showed significant increases in voltage over the F8 area.


CONCLUSIONS
BEAM can clearly show cerebral field distribution, but also can employ statistical tests to give significance to the analyzed data. Furthermore, BEAM may be helpful for localization of the epileptiform discharges in EEG.
Chi
C S
CS
Department of Pediatrics, Taichung Veterans General Hospital, Taiwan, R.O.C.
Mak
S C
SC
Chen
C H
CH
Shian
W J
WJ
D000293:Adolescent; D001931:Brain Mapping; D002648:Child; D004569:Electroencephalography; D004832:Epilepsy, Absence / Q000188:drug therapy / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D014635:Valproic Acid / Q000627:therapeutic use
D014635:Valproic Acid