Drug-resistant partial epilepsy has a heavy impact on quality of life and sometimes on life expectancy itself. Only a minority of patients may benefit from a curative epilepsy surgery. Neurostimulation, which can be an effective add-on treatment, is currently mainly represented by vagus nervus stimulation. Transcranial direct current stimulation, a non -invasive technique already used in other areas of neurology, may be efficient on some partial epilepsies, in particular through the individual configuration of stimulation, made possible by recent technological advances.

Main goal : To study the effect of transcranial electrical stimulation on the frequency of seizures in patients with drug-resistant partial epilepsy.

Hypothesis : Reduction of 50% or more in the frequency of occurrence of seizures within 24 hours following an individually configured TDCS session: responders in real TDCS vs placebo stimulation.

Inclusion Criteria:

• Age greater than or equal to 15 years;
• Patients with drug-partial resistant epilepsy with the following characteristics:
• Disabling epilepsy despite an optimized pharmacological treatment.
• An average of one seizure a day or more during the week preceding the inclusion
• Focal epilepsy in which epileptogenic zone is documented by paraclinical examinations consistent with clinical data
• Existence of measurable EEG markers of epilepsy
• Anti-epileptic drug treatment unmodified during the 2 weeks preceding the inclusion no change to treatment planned during the study.
• Signed informed consent.

Exclusion Criteria:

• Patients under 15 years;
• Patients in which a standard quality EEG recording is not possible
• Patients with ictal bradycardia or ictal syncope ;
• Patients with heart disease which may result in heart arrhythmia ;
• Incapacitated patients (curatorship, guardianship), patients deprived of liberty.
• Pregnant or lactating women
• Vagus nervus stimulation is not an exclusion criteria