Direct electrical stimulations of the temporal pole in human

We report the results of 105 intracortical electrical stimulations of the temporo-polar cortex performed in 30 patients during stereo-electroencephalography (SEEG) investigation of drug-resistant temporal lobe epilepsy. Clinical responses were elicited in 50% of the patients during 26 of the 105 stimulations. Responses are coherent with data found in the literature with mostly psychic, viscero-sensitive, autonomic and viscero-motor phenomena being elicited. Nearly all responses were evoked by stimulation of the antero-medial part of the temporo-polar cortex whereas only once was a clinical response elicited during stimulation of the lateral part of the temporo-polar cortex. Induced auras were more frequently reported when there was an afterdischarge associated to the clinical response (60 and 75% of the stimulation followed by a localized or a diffusing after-discharge, respectively) then when there wasn't any after-discharge following stimulation. The clinical responses evoked during stimulation of the temporo-polar cortex only have a limited topographic specificity since they closely resemble symptoms elicited by stimulation of other limbic or paralimbic areas. Nonetheless these results do suggest that the antero-medial part of the temporo-polar cortex is included in the symptomatogenic zone in so-called "temporo-limbic" epilepsies.