Therapeutic thermocoagulation will be carried out in patients with drug-resistant focal epilepsy in cases where an epileptogenic zone is found and proven according to stereo-electroencephalography (SEEG) data.

Open-label, pilot, non-comparative, interventional cohort study. Each patient will be examined at least 8 times (8 visits will pass): Visit 0 - screening (within 14 days before Visit 1), Visit 1 (visit includes the procedure for the destruction of the epileptogenic focus), Visits 2 and 3 (after 1 and 2 days after Visit 1) - a repeated procedure for the destruction of the epileptogenic focus with an incomplete effect of the first procedure (not mandatory, carried out by the decision of the principal investigator), Visits 4-7 (7, 14, 30, 180 days after the procedure for the destruction of the epileptogenic focus).

Patients will be divided into 4 cohorts of 4 patients. Enrollment in the study of the next cohort of patients will be based on the safety analysis of the previous cohort 1 day after the manipulation.

After assessing the position of the electrodes based on the conjugation of brain MRI data before and after SEEG implantation and seizure recording, the ictal zone is determined. Thus, the localization of pathological activity is determined on the basis of neuroimaging data, as well as in accordance with the activity under certain contacts of the SEEG electrodes.

After explaining the treatment options to the patient and relatives, informed voluntary consent is taken for the implementation of this procedure.

Using a radio frequency generator Cosman RFG-G4, destruction is carried out at the necessary electrode contacts with a power of 3W, exposure time of 180 sec. In case of pain occurrence, the procedure is immediately terminated. After the procedure, the patient continues SEEG monitoring for 3 days.

If additional epileptogenic zones are identified, if necessary, a repeated thermocoagulation is performed (on the 2nd and 3rd days of the study). If there is no need for a second thermocoagulation, then Visits 2 and 3 are not performed. Next, the patient undergoes removal of the electrodes, a control MRI study is performed. Follow-up includes follow-up for 6 months. Visits 4-6 involve phone interviews with patients. During the conversation, the researcher should clarify complaints, general well-being, the presence and frequency of epileptic seizures over the period of time that has passed since the previous visit.

Inclusion Criteria:

1. Diagnosis of symptomatic drug-resistant epilepsy according to anamnesis, results of video EEG monitoring with registration of epileptic seizures.
2. The epileptogenic zone verified using invasive electrodes.
3. The patient has read the information sheet and signed the informed consent form.

Non-inclusion Criteria:

1. Persons with mental disorders.
2. Women during pregnancy, childbirth.
3. Women during breastfeeding.
4. Reception of anticoagulants.
5. Location of the epileptogenic focus within functionally significant areas, large vessels of the brain.
6. Primary generalized forms of epilepsy.

Exclusion Criteria:

1. Absence of a registered seizure on stereo-EEG.
2. Absence of a focal pattern during invasive stereo-EEG monitoring.

Dropout Criteria:

1. Refusal of the patient from observation
2. The occurrence of contraindications that may prevent participation in diagnostic and treatment activities.
3. Unwillingness or inability of the patient to comply with the requirements of the protocol, including the presence of any condition (physical, mental or social) that may affect his ability to comply with the requirements of the study
4. Identification of conditions during the study that meet the exclusion criteria for non-inclusion of patients.
5. Lack of effect from thermocoagulation within a month after manipulation or worsening of the condition associated with an increase in the number/severity of epileptic seizures.

2 months after completion of the study

upon the request