Lesion guided stereotactic radiofrequency thermocoagulation for palliative, in selected cases curative epilepsy surgery.

INTRODUCTION: Resective epilepsy surgery is an established treatment option in patients with pharmacoresistant, lesion related epilepsy. Yet, if the presurgical work-up proves multi-focal organization of the epileptogenic zone, or the area of intended resection is close to eloquent brain areas, patients may decide against resections because of an unfavorable risk-benefit-ratio. We assess if lesion guided cortical stereotactic radiofrequency thermocoagulation (L-RFTC) is a potential surgical alternative in these patients. METHODS: We performed seven procedures of L-RFTC. Three patients had monofocal epilepsy arising close to eloquent structures; in four, invasive pre-surgical workup documented monofocal seizure onset but strong interictal epileptic activity also independent and distant from the seizure onset zone. L-RFTC was restricted to the lesional area (=seizure onset site). RESULTS: 12 to 37 months after RFTC worthwhile seizure improvement was achieved in 6 patients. One patient became seizure free following complete coagulation of a focal cortical dysplasia, two had had 1-2 auras under tapered but not under continued medication. In one patient only subclinical seizures persisted. In one patient hypermotor seizures were transformed into milder short tonic seizures and another one had a seizure reduction by 50%. Only one patient did not profit at all. One patient developed a persisting neurological deficit. SIGNIFICANCE: In patients with complex epileptogenic zones L-RFTC can lead to worthwhile seizure reduction. This qualifies this procedure as a palliative surgical technique with potential good risk-benefit ratio. In patients with small focal cortical dysplasias L-RFTC may even allow minimal-invasive surgery with curative intention.