Intracerebral Electrical Stimulation and the Optimisation of Presurgical Planning in Drug-refractory Partial Epilepsy
Intracerebral Electrical Stimulation and the Optimisation of Presurgical Planning in Drug-refractory Partial Epilepsy
Patients with drug-refractory epilepsy sometimes need to be implanted with intracerebral
 electrodes in order to identify their seizure onset zone. During this procedure, direct
 electrical brain stimulations represent a standard clinical practice to assess seizure
 sensitivity and for functional mapping. This study aims at assessing if extending the range
 of stimulation frequencies of the usual clinical frequencies is of benefit for the definition
 of the seizure onset zone and hence for the presurgical planning.
Patients with drug-refractory epilepsy sometimes need to be implanted with intracerebral
 electrodes in order to identify their seizure onset zone. During this procedure, direct brain
 electrical stimulations is a standard clinical practice to assess seizure sensitivity and for
 functional mapping. However the efficiency of these stimulations can be questioned and could
 potentially be improved. Indeed, only two typical frequencies are commonly used in our
 epilepsy centre, 1Hz and 50Hz, without clear clinical or scientific justification for these
 specific frequencies.

 This study aims at assessing if extending the range of stimulation frequencies of the usual
 clinical frequencies could improve the definition of the seizure onset zone and hence the
 presurgical planning. We will maintain the usual stimulation frequencies (standard clinical
 stimulations condition) and add new frequencies to the protocol (research stimulations
 condition). The choice of these new frequencies will be based either on the spontaneous
 frequency of the onset of the patients' typical seizures or on physiological frequencies
 depending on the brain structures stimulated (i.e., theta in the medial temporal lobe).

 The protocol will be proposed to all patients undergoing a stereo-electro-encephalography
 (SEEG) in our epilepsy center and the efficiency of the two conditions (standard clinical
 stimulations condition vs research stimulations condition) will be compared. The efficiency
 will be assessed as any epileptic event, recorded in the intracerebral EEG or symptom induced
 by the stimulations. This project will last 36 months. 20 patients will be included.
Inclusion Criteria:

 -  all patients undergoing a stereo-electro-encephalography (SEEG), age 12 to 65 years
 old.

 Exclusion Criteria:

 -  usual excluding criteria for a SEEG.