[Surgical treatment for intractable epilepsy]

Epilepsy surgery can be divided into two categories, resective and disconnective procedures. The former includes lesionectomy, corticectomy, and lobectomy. The latter comprises MST (multiple subpial transection), corpus callosotomy, and hemispherotomy. In this presentation, the preoperative diagnosis and surgical outcomes of temporal lobectomy and MST will be illustrated. Temporal lobe epilepsy is one of the most common seizures in adult intractable epilepsy. Noninvasive preoperative evaluation, including analysis of seizure semiology, repetitive scalp EEG, and MR imaging, can definitely localize the seizure focus, without depending on invasive monitoring, in 70% of the cases. Seizure outcome after temporal lobectomy is generally satisfactory, with 70% seizure-free and > 90% significantly improved. However, verbal amnesia is an unavoidable sequela when the focus is on the speech-dominant side and preoperative MRI reveals little or no hippocampal atrophy. MST is an epoch-making surgical technique by which surgical treatment of eloquent cortex has become possible. In cases with neocortical epilepsy treated by MST alone or combined with corticectomy, 80% showed significant improvement, that is compatible with reported outcomes of corticectomy. MST can be also applied to treatments of extensive epileptic foci, Rasmussen's encephalitis, or Landau-Kleffner syndrome.