title: Lateralization of mesial temporal lobe epilepsy with chronic ambulatory electrocorticography.
abstract: OBJECTIVE
  Patients with suspected mesial temporal lobe (MTL) epilepsy typically undergo inpatient video-electroencephalography (EEG) monitoring with scalp and/or intracranial electrodes for 1 to 2 weeks to localize and lateralize the seizure focus or foci. Chronic ambulatory electrocorticography (ECoG) in patients with MTL epilepsy may provide additional information about seizure lateralization. This analysis describes data obtained from chronic ambulatory ECoG in patients with suspected bilateral MTL epilepsy in order to assess the time required to determine the seizure lateralization and whether this information could influence treatment decisions.
  
  
  METHODS
  Ambulatory ECoG was reviewed in patients with suspected bilateral MTL epilepsy who were among a larger cohort with intractable epilepsy participating in a randomized controlled trial of responsive neurostimulation. Subjects were implanted with bilateral MTL leads and a cranially implanted neurostimulator programmed to detect abnormal interictal and ictal ECoG activity. ECoG data stored by the neurostimulator were reviewed to determine the lateralization of electrographic seizures and the interval of time until independent bilateral MTL electrographic seizures were recorded.
  
  
  RESULTS
  Eighty-two subjects were implanted with bilateral MTL leads and followed for 4.7 years on average (median 4.9 years). Independent bilateral MTL electrographic seizures were recorded in 84%. The average time to record bilateral electrographic seizures in the ambulatory setting was 41.6 days (median 13 days, range 0-376 days). Sixteen percent had only unilateral electrographic seizures after an average of 4.6 years of recording.
  
  
  CONCLUSIONS
  About one third of the subjects implanted with bilateral MTL electrodes required >1 month of chronic ambulatory ECoG before the first contralateral MTL electrographic seizure was recorded. Some patients with suspected bilateral MTL seizures had only unilateral electrographic seizures. Chronic ambulatory ECoG in patients with suspected bilateral MTL seizures provides data in a naturalistic setting, may complement data from inpatient video-EEG monitoring, and can contribute to treatment decisions.
authors.affiliation: Pacific Epilepsy Program, Pacific Medical Center, San Francisco, California, 94115, U.S.A.
authors.forename: David
authors.initials: D
authors.lastname: King-Stephens
authors.affiliation: NeuroPace, Inc., Mountain View, California, 94043, U.S.A.
authors.forename: Emily
authors.initials: E
authors.lastname: Mirro
authors.affiliation: Pacific Epilepsy Program, Pacific Medical Center, San Francisco, California, 94115, U.S.A.
authors.forename: Peter B
authors.initials: PB
authors.lastname: Weber
authors.affiliation: Pacific Epilepsy Program, Pacific Medical Center, San Francisco, California, 94115, U.S.A.
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Laxer
authors.affiliation: Department of Neurology, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, U.S.A.
authors.forename: Paul C
authors.initials: PC
authors.lastname: Van Ness
authors.affiliation: Department of Neurology, Indiana University, Indianapolis, Indiana, 46202, U.S.A.
authors.forename: Vicenta
authors.initials: V
authors.lastname: Salanova
authors.affiliation: Oregon Health and Science University, Portland, Oregon, 97239, U.S.A.
authors.forename: David C
authors.initials: DC
authors.lastname: Spencer
authors.affiliation: USC Comprehensive Epilepsy Program, Los Angeles, California, 90089, U.S.A.
authors.forename: Christianne N
authors.initials: CN
authors.lastname: Heck
authors.affiliation: Baylor College of Medicine, Houston, Texas, 77030, U.S.A.
authors.forename: Alica
authors.initials: A
authors.lastname: Goldman
authors.affiliation: Dartmouth-Hitchcock Epilepsy Center, Lebanon, New Hampshire, 03756, U.S.A.
authors.forename: Barbara
authors.initials: B
authors.lastname: Jobst
authors.affiliation: George Washington University, Washington, District of Columbia, 20052, U.S.A.
authors.forename: Donald C
authors.initials: DC
authors.lastname: Shields
authors.affiliation: Johns Hopkins Epilepsy Center, Baltimore, Maryland, 21287, U.S.A.
authors.forename: Gregory K
authors.initials: GK
authors.lastname: Bergey
authors.affiliation: Department of Neurology, University of Florida, Gainesville, Florida, 32611, U.S.A.
authors.forename: Stephan
authors.initials: S
authors.lastname: Eisenschenk
authors.affiliation: Department of Neurology, Mayo Clinic, Rochester, Minnesota, 55905, U.S.A.
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Worrell
authors.affiliation: Rush Epilepsy Center, Chicago, Illinois, 60612, U.S.A.
authors.forename: Marvin A
authors.initials: MA
authors.lastname: Rossi
authors.affiliation: Department of Neurosurgery, Emory University School of Medicine, Atlanta, Georgia, U.S.A.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Gross
authors.affiliation: MGH Epilepsy Service, Massachusetts General Hospital, Boston, Massachusetts, 02114, U.S.A.
authors.forename: Andrew J
authors.identifier: http://orcid.org/0000-0002-0828-826X
authors.initials: AJ
authors.lastname: Cole
authors.affiliation: Jefferson Comprehensive Epilepsy Center, Thomas Jefferson University, Philadelphia, Pennsylvania, 19107, U.S.A.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Sperling
authors.affiliation: Cleveland Clinic Neurological Institute, Cleveland, Ohio, 44195, U.S.A.
authors.forename: Dileep R
authors.initials: DR
authors.lastname: Nair
authors.affiliation: Swedish Neuroscience Institute, Seattle, Washington, 98052, U.S.A.
authors.forename: Ryder P
authors.initials: RP
authors.lastname: Gwinn
authors.affiliation: Georgia Regents University, Augusta, Georgia, 30912, U.S.A.
authors.forename: Yong D
authors.initials: YD
authors.lastname: Park
authors.affiliation: University of Wisconsin, Madison, Wisconsin, 53792, U.S.A.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Rutecki
authors.affiliation: Comprehensive Epilepsy Center, University of Virginia, Charlottesville, Virginia, 22908, U.S.A.
authors.forename: Nathan B
authors.initials: NB
authors.lastname: Fountain
authors.affiliation: Mayo Clinic Jacksonville, Jacksonville, Florida, 32224, U.S.A.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Wharen
authors.affiliation: Yale University School of Medicine, New Haven, Connecticut, 06510, U.S.A.
authors.forename: Lawrence J
authors.initials: LJ
authors.lastname: Hirsch
authors.affiliation: Comprehensive Epilepsy Center, Miami Children's Hospital, Miami, Florida, 33155, U.S.A.
authors.forename: Ian O
authors.initials: IO
authors.lastname: Miller
authors.affiliation: Henry Ford Hospital, Detroit, Michigan, 48202, U.S.A.
authors.forename: Gregory L
authors.initials: GL
authors.lastname: Barkley
authors.affiliation: The Medical University of South Carolina, Charleston, South Carolina, 29425, U.S.A.
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Edwards
authors.affiliation: Institute of Neurology and Neurosurgery at Saint Barnabas, Livingston, New Jersey, 07039, U.S.A.
authors.forename: Eric B
authors.initials: EB
authors.lastname: Geller
authors.affiliation: University of Rochester Medical Center, Rochester, New York, 14642, U.S.A.
authors.forename: Michel J
authors.initials: MJ
authors.lastname: Berg
authors.affiliation: Via Christi Comprehensive Epilepsy Center, Wichita, Kansas, 67214, U.S.A.
authors.forename: Toni L
authors.initials: TL
authors.lastname: Sadler
authors.affiliation: NeuroPace, Inc., Mountain View, California, 94043, U.S.A.
authors.forename: Felice T
authors.initials: FT
authors.lastname: Sun
authors.affiliation: NeuroPace, Inc., Mountain View, California, 94043, U.S.A.|Stanford Comprehensive Epilepsy Center, Stanford, California, 94305, U.S.A.
authors.forename: Martha J
authors.initials: MJ
authors.lastname: Morrell
mesh_terms: D000293:Adolescent; D000328:Adult; D058256:Brain Waves / Q000502:physiology*; D015716:Electrocardiography, Ambulatory; D004567:Electrodes, Implanted; D004833:Epilepsy, Temporal Lobe / Q000473:pathology* / Q000503:physiopathology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006624:Hippocampus / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D055815:Young Adult
keywords: Ambulatory EEG; EEG monitoring; Electrocorticography; Intracranial EEG; Localization; Responsive stimulation