Microsurgical and stereotactic radiofrequency amygdalohippocampectomy for the treatment of mesial temporal lobe epilepsy: different volume reduction, similar clinical seizure control.

We compared stereotactic radiofrequency amygdalohippocampectomy (SAHE) with microsurgical amygdalohippocampectomy (AHE) in a group of 33 patients with mesial temporal lobe epilepsy in terms of hippocampal and amygdalar volume reductions and clinical outcome. In 23 subjects treated by SAHE, the hippocampal volume decreased by 58.0% (20.0; median, quartile range), with p = 10(-4), and the amygdalar volume decreased by 55.2% (23.8), with p = 10(-4). Two years after SAHE, 74% of patients were classified as class I, 22% as class II and 4% as class III. In 10 subjects treated by AHE, 83.5% (11.2) of the hippocampal and 53.1% (53.9) of the amygdalar volumes were removed (p = 0.05 and p = 0.005, respectively). Two years after the operation, 50% of the subjects were classified as class I, 30% as class II and 10% as class III and IV. To conclude, SAHE leads to a similar reduction of the amygdalar volume but to a significantly lower reduction of the hippocampal volume than AHE. The clinical outcome of SAHE is comparable with that of AHE.