Mesial temporal epilepsy: comparison of morphological changes after different neurosurgery approaches with clinical seizure outcome

Background: Mesial temporal lobe epilepsy (MTLE) is the most surgically amenable epilepsy diagnosis and the results of epilepsy surgery are clearly superior to prolonged medical therapy. Stereotactic radiofrequency amygdalohippocampectomy (SAHE) is an alternative therapy of MTLE to the open neurosurgery approaches. In our hospital SAHE has been used since 2004. We produced lesions from the occipital access with a single trajectory in the long axis of amygdalohippocampal complex (AHK) using the probe with a flexible active tip. The aim of this study was to correlate the morphological changes after different neurosurgical approaches including volume reduction of the target structures / the hippocampus, the amygdala, entorhinal (EC) and perirhinal (PRC) cortices/ with the clinical seizure outcome. Methods: We included 26 consecutive patients, who underwent SAHE using Leksell stereotactic system and 10 patients treated by microsurgical amygdalohippocampectomy (AHE). MR volumetry of hippocampus, amygdale, EC and PRC was performed 1 year after the procedure. The clinical outcome was assessed 2 years after the procedure according to Engel's Classification. Results: No serious adverse events occurred after both procedures. One year after SAHE, the hippocampal volume decreased by 55.5 18.0% (p