Surgery for temporal lobe epilepsy

Abstract

Surgical treatment of refractory temporal lobe epilepsy is far superior to prolonged pharmaceutical treatment and freedom from seizures can be achieved in 60–80% of patients. Various surgical techniques have been developed through advances in diagnostic methods, above all magnetic resonance imaging (MRI). All of these techniques share the same principle of including the mesial temporal structures (e.g. amygdala, hippocampus, parahippocampus) in the resection. Anterior temporal lobe and anteromedial temporal lobe resections differ in the extent of the lateral temporal resection. In the case of a selective medial temporal lobe resection various surgical approaches have been described. The choice of the individual surgical approach is dependent on many surgeon and institution-specific factors with respect to freedom from seizures and minimization of neuropsychological morbidity. At the same time, they aim to reduce the morbidity, especially with respect to the neuropsychological outcome. Minimally invasive techniques, such as laser-induced thermal therapy (LITT) ablation technique continue the effort to maintain the good seizure outcome of open resection and to minimize the collateral damage associated with a resection. Furthermore, the minimally invasive nature of these techniques could reduce the inhibition threshold of patients for an intervention and, therefore, to reduce the number of candidates for epilepsy surgery who do not want to consent to an open surgical procedure. Experience with these methods is still comparatively low and it remains to be seen if they can achieve a similarly good long-term seizure outcome with the same low complication rate reported for surgical treatment of temporal lobe epilepsy.