Neuroscience

Epilepsy

Psychiatry

Surgery

Political science

Psychology

Medical physics

Surgical planning

Disconnection

Epilepsy surgery

Electroencephalography

Magnetoencephalography

Medicine

Nature Reviews Neurology

Candidates for epilepsy surgery must undergo presurgical evaluation to establish whether and how surgical treatment can stop seizures without causing neurological deficits. Various techniques, including MRI, PET, single-photon emission CT, video-EEG, magnetoencephalography and invasive EEG, aim to identify the diseased brain tissue and the involved network. Recent technical and methodological developments, encompassing both advances in&nbsp;existing techniques and new combinations of technologies, are enhancing the ability to define the optimal resection strategy. Multimodal interpretation and predictive computer models are expected to aid surgical planning and patient counselling, and multimodal intraoperative guidance is likely to increase surgical precision. In this Review, we discuss how&nbsp;the knowledge derived from these new approaches is challenging our way of thinking about surgery to stop focal seizures. In particular, we highlight the importance of looking beyond the EEG seizure onset zone and considering focal epilepsy as a brain network disease in which long-range connections need to be taken into account. We also explore how new diagnostic techniques are revealing essential information in the brain that was previously hidden from view. In patients with drug-resistant focal epilepsy, the success of surgery depends on predicting which resection or disconnection strategy will yield full seizure control. This Review highlights recent advances in presurgical assessment and discusses how concepts of focal epilepsy are changing.

Changing concepts in presurgical assessment for epilepsy surgery