[In vivo and in vitro neurophysiological features of epilepsy].
BACKGROUND
Some electrophysiological aspects of the interictal activity in temporal lobe epilepsy (TLE) are under debate. However, surgery is often guided by both, pre and intra operative recordings of interictal activity. Some of these studies include intraoperative electrocorticography (ECoG) that guide tailored resection.


OBJECTIVE
To analyze several aspects of interictal activity recorded by ECoG and to explore its electrophysiological basis in vitro.


METHODS
ECoGs from thirteen patients suffering drug resistant TLE were analyzed. Both linear and non linear methods were introduced to explore the ECoG signals. In two cases, neocortical tissue was also electrophysiologically studied in vitro.


RESULTS
Interictal ECoG activity showed a mesial origin, a cortical origin or a mixed mesial/temporal origin. Both in cortical and mesial/cortical origin, cortical interictal ECoG signals are characterized by spatiotemporal clusters of activity. In vitro study of cortical tissue from these clusters showed alterations in the synaptic control of excitability.


CONCLUSIONS
Our results suggest an electrophysiological basis of interictal activity. Combination of linear and non linear methods is a very useful tool to explore on line the interictal ECoG activity during surgery.
Menéndez De La Prida
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Unidad de Cartografía Cerebral, Instituto Pluridisciplinar, Universidad Complutense de Madrid, Madrid, 28040, España. liset@eucmax.sim.ucm.es
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Pozo
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D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000293:Adolescent; D000328:Adult; D001640:Bicuculline / Q000494:pharmacology; D002648:Child; D003292:Convulsants / Q000494:pharmacology; D004569:Electroencephalography; D004594:Electrophysiology / Q000379:methods*; D004827:Epilepsy / Q000503:physiopathology* / Q000601:surgery; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*
D003292:Convulsants; D018691:Excitatory Amino Acid Antagonists; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D001640:Bicuculline