Epileptic Network Surgery: From Network Basis to Clinical Practice

Abstract

Epilepsy is a common chronic neurologic disorder, with about 30%-40% of patients suffering from recurrent seizures despite receiving enough antiseizure medication. Growing evidence of extensive structural and functional research has revealed that epilepsy is a network disorder, and the network investigation is crucial in the presurgical evaluation. This narrative review is aimed at providing an overview of the conceptual development of epileptic surgery, the epileptic network formation, and the network-oriented strategy in clinical practice. We searched the PubMed database before October 2022 with no language or regional restrictions for studies of network exploration in epilepsy patients. The study eligibility criteria were original connectivity or network research studies using neuroimaging or neurophysiological approaches, focusing on seizure localization, neuropsychological evaluation, neuromodulation, or surgical prognosis. The initial search revealed 2046 studies. The selection process presented 746 papers that meet the inclusion criteria. The results indicated that epilepsy was characterized by the alternation of brain networks, which account for the clinical, electrographic, and neurocognitive phenomena related to human seizures and changes across different disease stages. Hubs have garnered significant attention due to their extensive connections, which make them prone to facilitating the spread of seizures to various brain regions. Unlike the seizure onset zone, the removal of the majority of these ictogenic nodes demonstrated a significant correlation with positive outcomes. Therefore, performing a network analysis during the epilepsy presurgical evaluation seems essential and will influence surgical decisions. It is hoped that studying the network of epilepsy will enhance our ability to determine the most appropriate surgical strategy for patients with epilepsy, thus contributing to success in terms of effective seizure control with maximal sparing or even improvement of brain functioning.