[Presurgical diagnosis of epilepsy and surgical epilepsy treatment]

Abstract

20% of patients with focal epilepsy suffer from medically refractory seizures. Many of these patients can be cured by a surgical intervention removing the brain area where the seizures are originating (epileptogenic zone). 6000 patients in Austria would benefit from epilepsy surgery with an additional 150-200 new patients appearing each year. Potential candidates have to undergo an extensive presurgical work-up. During the non-invasive Phase I each patient is evaluated with an intensive video-EEG monitoring with scalp-EEG, a high resolution MRI, a SPECT and/or PET, a neuropsychological evaluation and a Wada-test. If the epileptogenic zone cannot be localized adequately with these methods, invasive electrophysiological techniques (epidural Peg-electrodes, Foramen-ovale electrodes, depth electrodes, subdural strip and grid electrodes) have to be applied. Operative strategies for temporal lobe epilepsies include antero-mesial temporal lobe resections and selective amygdala-hippocampectomies. Extratemporal epilepsies are treated by cortical resections guided by structural and electrophysiological parameters. The new technique of multiple subpial transections facilitates treatment of seizures originating in essential brain regions. Catastrophic epilepsies of early childhood often are caused by extensive pathologies affecting one hemisphere and can be treated successfully by large multilobar resections or hemispherectomies. Epilepsy surgery renders 70-80% of patients seizure free and thus can be regarded as an effective and safe treatment option for patients with medically refractory focal epilepsies.