RADIOSURGERY OF EPILEPSY

Since 1982 a series of 11 epileptic patients have been treated with st ereotactic radiosurgery. Patients were intracranially recorded with co rtical and deep electrodes until the location of the epileptogenic foc us was determined. A deep electrode was stereotactically placed at thi s point to confirm the accuracy of the location. All patients received radiosurgery with a gamma source and a dose of 10 to 20 Gy, except tw o of them in which a betatron was used. The results were: Total disapp earance of the crises and withdrawal of medication: 4 cases (36%). Mor e than 80% reduction of crises: 3 cases (27%). More than 50% reduction of crises: 2 cases (18%). Less than 50% reduction of crises: 2 caws ( 18%). No complications were observed, even in those cases in which the focus was located near critical areas of the brain. The efficacy of t he low doses used accounts for non-destructive mechanisms, probably me diated by a neuronal plasticity phenomenon, as experimental studies su ggest. The lack of complications can make this therapeutic approach an alternative to be considered when critical areas are involved.