SUBTEMPORAL AMYGDALOHIPPOCAMPECTOMY FOR TREATING MEDICALLY INTRACTABLE TEMPORAL-LOBE EPILEPSY

A SUBTEMPORAL AMYGDALOHIPPOCAMPECTOMY technique has been developed for mesial temporal lobe epilepsy. The conventional subtemporal approach has been modified to diminish temporal lobe retraction and the risk of damage to the temporal lobe. In the new technique, the surgeons' posi tion has moved from above to below and the approach has been changed f rom anterolateral to posterolateral, thereby avoiding the voluminous and steeply inclined anterior temporal lobe. By this modified approach , it was unnecessary to remove the roof of the external auditory meatu s and it was estimated that both the retraction pressure and the exten t of temporal lobe retraction were reduced. To date, surgeons using th is approach have operated on four patients with temporal lobe epilepsy whose epileptic foci were in the mesial temporal structure; the infer ior temporal gyrus, the temporal tip, the vein of Labbe, and the ventr al bridging veins were preserved. After surgery, two patients became c ompletely free of seizures and the other two showed over 90% reduction in seizure frequency without neurological sequelae. Postoperative vis ual field examination revealed full visual fields without quadrantanop sia. This approach can preserve the temporal stem and lateral temporal lobe, it can be used to remove as much of the posterior hippocampus a s necessary, and it can be extended to conventional lobectomy if it is indicated.