An outline of experimental and clinical data concerning the radiosurgical treatment of epilepsies is given. The article deals with 13 patients who were treated at our institution for intractable mesial temporal lobe epilepsy with mesial temporal sclerosis between November 1995 and May 1999. In these patients the duration of epilepsy was long and encephalopathic neurological and neuropsychological signs were present in virtually all. Epileptological results which are worse than those in the only one comparable published study are discussed. Complex partial seizures frequency tended to rise between 4th and –10thmonths after irradiation and then fell to approximately one fourth of the original frequency two years after irradiation. We found partial upper lateral quadrant anopia as a permanent side effect in 2 patients. The poor effect of irradiation led us to epilepsy surgery in 2 patients. MRI changes after radiosurgery and choice of optimal radiosurgical plans are given. Collateral oedema was seen in 8 patients, started earlier and was found more often in those irradiated with higher doses. In 3 of them it had an expansive character and in 2 clinical signs of intracranial hypertension were present.

        Key words: epilepsy, mesiotemporal epilepsy, radiosurgery, gamma knife