FIELD: medicine.SUBSTANCE: invention refers to medicine, namely to neurosurgery, and can be used in surgical treatment of pharmacoresic-mediated primary and secondary generalized epilepsy. Access point is determined on the coronal suture, perpendicular to the skull surface, by 5.9–6.1 cm lateral to the sagittal suture. Entry point and the trajectory are determined individually, based on the preoperative thin-slit MRT and the neuronavigation station. First and second stages of the surgical intervention are performed in the third ventricle, access to which is performed through a Monroe opening. Flexible video endoscope is inserted through the envelope of the rigid rigidoscope endoscope, which is inserted into the third ventricle through a Monroe opening. That is followed by inspection of the third ventricle and determining anatomical landmarks: mamillary bodies, hypophysis funnel, chiasmus, terminal plate, anterior solder. That is followed by total dissection of the anterior adhesion. That is followed by an endoscopic trans-ventrication transforaminal disassembly of the posterior commissure by means of a flexible endoscope which is bent backward through 180° and adhesions of the leads, wherein the first anatomical landmark, which is visualized when the endoscope moves towards the posterior commissure, is an intertalimal adhesion for imaging the posterior wall of the third ventricle, and bypassing the intertalimal adhesion. Then posterior commissure is incised. Thereafter, the corpus callosum is incised at the junction between the lateral ventricle wall and the transparent septum. Reference point for selecting the incision site is pulsation of pericallous arteries, which is determined through a thinned corpus callosum, the totality of dissection of which is determined by identification of an interhemispheric space, pericallous tank and arteries. After all endoscopic steps, the rigid endoscope is removed from the surgical site. Defect in a dura mater is closed and seale
