[Epileptic discharges at the temporal area in patients with medial temporal sclerosis--usefulness of the 10% electrode system].
OBJECTIVE
We evaluated the usefulness of the 10% electrode system for detection of epileptic discharges (EDs) in temporal lobe epilepsy (TLE).


METHODS
The subjects were fifteen TLE patients with childhood onset. EEG was examined using the 10/20 system with additional electrodes (bilateral anterior temporal electrodes by Gibbs's method and 10% electrodes at the temporal area by the 10% electrodes system). We extracted 300 EDs (20 samples from each patient), measured the amplitude of each ED and searched for a preceding discharge. We classified the subjects in two groups based on MRI findings: one with medial temporal sclerosis (MTS group), and the other without (Non MTS group).


RESULTS
It was noted that 53.3% of EDs detected at the temporal area demonstrated the maximal amplitude at 10% electrodes. We identified a preceding discharge on 10% electrodes in 40.0% of EDs. In the MTS group, 85.7% of EDs demonstrated the maximal amplitude on 10% electrodes. In the Non MTS group, there was no difference in the amplitude of ED between 10/20 electrodes and 10% electrodes. We recognized preceding discharges in 68.6% of EDs on 10% electrodes (F9(10), FT9(10)) or left or right anterior temporal electrode in the MTS group. However, we could not identify preceding discharges in 55.0% of EDs in the Non MTS group.


CONCLUSIONS
The maximal amplitude of ED in patients with TLE was recognized on 10% electrodes. EDs in the MTS group frequently appeared on 10% electrodes (FT7(8) and T9(10)). We suggest that the 10% electrode system offers some advantages over the 10/20 system for detecting EDs in TLE patients with MTS.
Yoshiko
Ken-ichi
K
Department of Clinical Laboratory, Nagoya University Hospital, Nagoya.
Negoro
Tamiko
T
Ando
Hiroshi
H
D000293:Adolescent; D000328:Adult; D004566:Electrodes; D004569:Electroencephalography / Q000379:methods*; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D013702:Temporal Lobe / Q000503:physiopathology*