The identification of the epileptogenic lesion to be surgically removed is at present mainly based on EEG and stereo-EEG study. Barbiturates employed have been pentobarbital sodium and methohexitalum. 15 epileptic patients were investigated and subsequently operated upon (cortectomy or lobectomy). In 9 patients with temporal foci the interictal paroxysmal activity increased in 7 (no correlation being noted between this action and stage of barbiturate sleep). Only seldomly have focal paroxysmal abnormalities been observed to disappear and only in the fast activity stage. Fast-activity failed to appear in the temporal cortex and/or the rhinencephalic structures ipsilateral to the primary focus in 8 cases. In 4 cases, slow focal abnormalities appeared or were increased. Secondary paroxysmal activity ('mirror focus'-like) in the contralateral temporal lobe, present in 5 cases, always disappeared during barbiturate infusion. Of 6 patients with extra-temporal foci only 3 showed increased paroxysmal lesional abnormality. In 2 cases slow focal abnormalities were noted to increase. No secure decrement or inhibition of distant abnormalities was noted. So, the study of modification induced by barbiturates in depth-recordings gives useful data in order to correctly identify the primary focus in the epilepsies with bitemporal abnormalities. In extra-temporal foci, barbiturates produced less striking results but, all the same, some useful information could be gained.
|Journal||Electroencephalography and Clinical Neurophysiology|
|Publication status||Published - 1977|
ASJC Scopus subject areas
- Clinical Neurology