Decision-making in temporal lobe epilepsy surgery

Epilepsy surgery is a successful treatment option for patients with drug resistant temporal lobe epilepsy. To decide whether patients are surgery candidates, a complex presurgical work-up is performed, starting with basic diagnostic tests (patient history, MRI, video EEG monitoring), followed by tests with increasing invasiveness (PET, intracranial EEG monitoring). In this thesis, we assessed the added value of a selection of tests used in the presurgical work-up: patient history, MRI, video EEG monitoring, FDG-PET, and the bilateral intracranial amobarbital procedure (IAP or Wada test). Furthermore, we assessed whether postoperative seizure freedom can accurately be predicted and we assessed whether epilepsy surgery is utilized to its full extent in the Netherlands. We conclude that the presurgical work-up for temporal lobe epilepsy surgery could be more efficient: the combination of MRI, interictal EEG and ictal EEG can select a subgroup of patients who are eligible for surgery, without the need for further testing; FDG-PET can be performed in more patients, especially when MRI and video EEG monitoring are inconclusive; and IAP can be performed unilaterally in stead of bilaterally in most patients. Furthermore, the model we derived to predict postoperative seizure freedom one year after surgery had a moderate ability to predict seizure freedom. Finally, we conclude that epilepsy surgery should be considered in more patients currently treated in secondary and tertiary care in the Netherlands.