title: Seizures induced by direct electrical cortical stimulation--Mechanisms and clinical considerations.
abstract: Direct electrical cortical stimulation (CS) is widely used to map eloquent cortex. It can be applied extraoperatively in patients undergoing intracranial EEG recordings using chronically implanted electrodes (subdural, depth or a combination), or it can be used intraoperatively. Seizures can be induced by CS but there is controversy regarding the utility of CS induced seizures in defining the epileptogenic zone and hence practice varies considerably between centres. Some centres use seizures induced by direct CS routinely to aid in defining the epileptogenic zone. In contrast, others do not rely on such information and explicitly avoid stimulating seizures during cortical mapping. Intra- and extraoperative techniques have been used to stimulate seizures with varying results, which may in part reflect these methodological differences. We here aim to review current views, definitions and studies on seizures induced by direct electrical CS. In addition we discuss mechanisms and methodological considerations of this procedure.
authors.affiliation: Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK; Department of Neurology, University of Muenster, Muenster, Germany; Department of Clinical Neurophysiology, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK.
authors.forename: Stjepana
authors.initials: S
authors.lastname: Kovac
authors.affiliation: Inserm U836, Grenoble, France; University Grenoble Alpes, GIN, Grenoble, France; Neurology Department, CHU de Grenoble, Hospital Michallon, Grenoble, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Kahane
authors.affiliation: Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK; Department of Clinical Neurophysiology, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK. Electronic address: b.diehl@ucl.ac.uk.
authors.forename: Beate
authors.initials: B
authors.lastname: Diehl
mesh_terms: D058256:Brain Waves; D006801:Humans; D012640:Seizures / Q000209:etiology / Q000503:physiopathology*; D065908:Transcranial Direct Current Stimulation / Q000009:adverse effects / Q000379:methods*
keywords: Cortical mapping; Direct CS; Epilepsy; Epilepsy surgery