Is electrocorticography-based language mapping ready to replace stimulation?

Worldwide experts consider presurgical electrocorticography (ECoG) or intracerebral electrode monitoring a necessary evaluation tool for a selected population of patients with focal epilepsy. The goal of chronic ECoG monitoring at bedside generally includes localizing the seizure onset zone presumably responsible for generation of habitual seizures and localizing the eloquent areas to be preserved for avoiding major functional deficits following cortical resection. Language function directly determines the quality of life in patients following epilepsy surgery; thus, each surgical team makes the best effort to localize the language areas before performing resective surgery.