title: Seizure localization using ictal phase-locked high gamma: A retrospective surgical outcome study.
abstract: OBJECTIVE
  To determine whether resection of areas with evidence of intense, synchronized neural firing during seizures is an accurate indicator of postoperative outcome.
  
  
  METHODS
  Channels meeting phase-locked high gamma (PLHG) criteria were identified retrospectively from intracranial EEG recordings (102 seizures, 46 implantations, 45 patients). Extent of removal of both the seizure onset zone (SOZ) and PLHG was correlated with seizure outcome, classified as good (Engel class I or II, n = 32) or poor (Engel class III or IV, n = 13).
  
  
  RESULTS
  Patients with good outcomes had significantly greater proportions of both SOZ and the first 4 (early) PLHG sites resected. Improved outcome classification was noted with early PLHG, as measured by the area under the receiver operating characteristic curves (PLHG 0.79, SOZ 0.68) and by odds ratios for resections including at least 75% of sites identified by each measure (PLHG 9.7 [95% CI: 2.3-41.5], SOZ 5.3 [95% CI: 1.2-23.3]). Among patients with resection of at least 75% of the SOZ, 78% (n = 30) had good outcomes, increasing to 91% when the resection also included at least 75% of early PLHG sites (n = 22).
  
  
  CONCLUSIONS
  This study demonstrates the localizing value of early PLHG, which is comparable to that provided by the SOZ. Incorporation of PLHG into the clinical evaluation may improve surgical efficacy and help to focus resections on the most critical areas.
authors.affiliation: From the Departments of Neurology (R.C., L.M.B., R.G.E., C.A.S.), Neurological Surgery (G.P.B., G.M.M., R.R.G.), and Radiology (B.Z., C.G.F.), Columbia University, New York; Hospital for Special Surgery (R.G.E.), Cornell University, New York, NY; Department of Clinical and Experimental Epilepsy (A.L., M.N., R.R., B.D., A.W.M., M.C.W.), Institute of Neurology, University College London; Institute for Neuroscience (A.J.T.), Newcastle University, UK; and Department of Neurology (S.A.W.), UCLA David Geffen School of Medicine, Los Angeles, CA.
authors.forename: Shennan A
authors.initials: SA
authors.lastname: Weiss
authors.affiliation: From the Departments of Neurology (R.C., L.M.B., R.G.E., C.A.S.), Neurological Surgery (G.P.B., G.M.M., R.R.G.), and Radiology (B.Z., C.G.F.), Columbia University, New York; Hospital for Special Surgery (R.G.E.), Cornell University, New York, NY; Department of Clinical and Experimental Epilepsy (A.L., M.N., R.R., B.D., A.W.M., M.C.W.), Institute of Neurology, University College London; Institute for Neuroscience (A.J.T.), Newcastle University, UK; and Department of Neurology (S.A.W.), UCLA David Geffen School of Medicine, Los Angeles, CA.
authors.forename: Athena
authors.initials: A
authors.lastname: Lemesiou
authors.affiliation: From the Departments of Neurology (R.C., L.M.B., R.G.E., C.A.S.), Neurological Surgery (G.P.B., G.M.M., R.R.G.), and Radiology (B.Z., C.G.F.), Columbia University, New York; Hospital for Special Surgery (R.G.E.), Cornell University, New York, NY; Department of Clinical and Experimental Epilepsy (A.L., M.N., R.R., B.D., A.W.M., M.C.W.), Institute of Neurology, University College London; Institute for Neuroscience (A.J.T.), Newcastle University, UK; and Department of Neurology (S.A.W.), UCLA David Geffen School of Medicine, Los Angeles, CA.
authors.forename: Robert
authors.initials: R
authors.lastname: Connors
authors.affiliation: From the Departments of Neurology (R.C., L.M.B., R.G.E., C.A.S.), Neurological Surgery (G.P.B., G.M.M., R.R.G.), and Radiology (B.Z., C.G.F.), Columbia University, New York; Hospital for Special Surgery (R.G.E.), Cornell University, New York, NY; Department of Clinical and Experimental Epilepsy (A.L., M.N., R.R., B.D., A.W.M., M.C.W.), Institute of Neurology, University College London; Institute for Neuroscience (A.J.T.), Newcastle University, UK; and Department of Neurology (S.A.W.), UCLA David Geffen School of Medicine, Los Angeles, CA.
authors.forename: Garrett P
authors.initials: GP
authors.lastname: Banks
authors.affiliation: From the Departments of Neurology (R.C., L.M.B., R.G.E., C.A.S.), Neurological Surgery (G.P.B., G.M.M., R.R.G.), and Radiology (B.Z., C.G.F.), Columbia University, New York; Hospital for Special Surgery (R.G.E.), Cornell University, New York, NY; Department of Clinical and Experimental Epilepsy (A.L., M.N., R.R., B.D., A.W.M., M.C.W.), Institute of Neurology, University College London; Institute for Neuroscience (A.J.T.), Newcastle University, UK; and Department of Neurology (S.A.W.), UCLA David Geffen School of Medicine, Los Angeles, CA.
authors.forename: Guy M
authors.initials: GM
authors.lastname: McKhann
authors.affiliation: From the Departments of Neurology (R.C., L.M.B., R.G.E., C.A.S.), Neurological Surgery (G.P.B., G.M.M., R.R.G.), and Radiology (B.Z., C.G.F.), Columbia University, New York; Hospital for Special Surgery (R.G.E.), Cornell University, New York, NY; Department of Clinical and Experimental Epilepsy (A.L., M.N., R.R., B.D., A.W.M., M.C.W.), Institute of Neurology, University College London; Institute for Neuroscience (A.J.T.), Newcastle University, UK; and Department of Neurology (S.A.W.), UCLA David Geffen School of Medicine, Los Angeles, CA.
authors.forename: Robert R
authors.initials: RR
authors.lastname: Goodman
authors.affiliation: From the Departments of Neurology (R.C., L.M.B., R.G.E., C.A.S.), Neurological Surgery (G.P.B., G.M.M., R.R.G.), and Radiology (B.Z., C.G.F.), Columbia University, New York; Hospital for Special Surgery (R.G.E.), Cornell University, New York, NY; Department of Clinical and Experimental Epilepsy (A.L., M.N., R.R., B.D., A.W.M., M.C.W.), Institute of Neurology, University College London; Institute for Neuroscience (A.J.T.), Newcastle University, UK; and Department of Neurology (S.A.W.), UCLA David Geffen School of Medicine, Los Angeles, CA.
authors.forename: Binsheng
authors.initials: B
authors.lastname: Zhao
authors.affiliation: From the Departments of Neurology (R.C., L.M.B., R.G.E., C.A.S.), Neurological Surgery (G.P.B., G.M.M., R.R.G.), and Radiology (B.Z., C.G.F.), Columbia University, New York; Hospital for Special Surgery (R.G.E.), Cornell University, New York, NY; Department of Clinical and Experimental Epilepsy (A.L., M.N., R.R., B.D., A.W.M., M.C.W.), Institute of Neurology, University College London; Institute for Neuroscience (A.J.T.), Newcastle University, UK; and Department of Neurology (S.A.W.), UCLA David Geffen School of Medicine, Los Angeles, CA.
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Filippi
authors.affiliation: From the Departments of Neurology (R.C., L.M.B., R.G.E., C.A.S.), Neurological Surgery (G.P.B., G.M.M., R.R.G.), and Radiology (B.Z., C.G.F.), Columbia University, New York; Hospital for Special Surgery (R.G.E.), Cornell University, New York, NY; Department of Clinical and Experimental Epilepsy (A.L., M.N., R.R., B.D., A.W.M., M.C.W.), Institute of Neurology, University College London; Institute for Neuroscience (A.J.T.), Newcastle University, UK; and Department of Neurology (S.A.W.), UCLA David Geffen School of Medicine, Los Angeles, CA.
authors.forename: Mark
authors.initials: M
authors.lastname: Nowell
authors.affiliation: From the Departments of Neurology (R.C., L.M.B., R.G.E., C.A.S.), Neurological Surgery (G.P.B., G.M.M., R.R.G.), and Radiology (B.Z., C.G.F.), Columbia University, New York; Hospital for Special Surgery (R.G.E.), Cornell University, New York, NY; Department of Clinical and Experimental Epilepsy (A.L., M.N., R.R., B.D., A.W.M., M.C.W.), Institute of Neurology, University College London; Institute for Neuroscience (A.J.T.), Newcastle University, UK; and Department of Neurology (S.A.W.), UCLA David Geffen School of Medicine, Los Angeles, CA.
authors.forename: Roman
authors.initials: R
authors.lastname: Rodionov
authors.affiliation: From the Departments of Neurology (R.C., L.M.B., R.G.E., C.A.S.), Neurological Surgery (G.P.B., G.M.M., R.R.G.), and Radiology (B.Z., C.G.F.), Columbia University, New York; Hospital for Special Surgery (R.G.E.), Cornell University, New York, NY; Department of Clinical and Experimental Epilepsy (A.L., M.N., R.R., B.D., A.W.M., M.C.W.), Institute of Neurology, University College London; Institute for Neuroscience (A.J.T.), Newcastle University, UK; and Department of Neurology (S.A.W.), UCLA David Geffen School of Medicine, Los Angeles, CA.
authors.forename: Beate
authors.initials: B
authors.lastname: Diehl
authors.affiliation: From the Departments of Neurology (R.C., L.M.B., R.G.E., C.A.S.), Neurological Surgery (G.P.B., G.M.M., R.R.G.), and Radiology (B.Z., C.G.F.), Columbia University, New York; Hospital for Special Surgery (R.G.E.), Cornell University, New York, NY; Department of Clinical and Experimental Epilepsy (A.L., M.N., R.R., B.D., A.W.M., M.C.W.), Institute of Neurology, University College London; Institute for Neuroscience (A.J.T.), Newcastle University, UK; and Department of Neurology (S.A.W.), UCLA David Geffen School of Medicine, Los Angeles, CA.
authors.forename: Andrew W
authors.initials: AW
authors.lastname: McEvoy
authors.affiliation: From the Departments of Neurology (R.C., L.M.B., R.G.E., C.A.S.), Neurological Surgery (G.P.B., G.M.M., R.R.G.), and Radiology (B.Z., C.G.F.), Columbia University, New York; Hospital for Special Surgery (R.G.E.), Cornell University, New York, NY; Department of Clinical and Experimental Epilepsy (A.L., M.N., R.R., B.D., A.W.M., M.C.W.), Institute of Neurology, University College London; Institute for Neuroscience (A.J.T.), Newcastle University, UK; and Department of Neurology (S.A.W.), UCLA David Geffen School of Medicine, Los Angeles, CA.
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Walker
authors.affiliation: From the Departments of Neurology (R.C., L.M.B., R.G.E., C.A.S.), Neurological Surgery (G.P.B., G.M.M., R.R.G.), and Radiology (B.Z., C.G.F.), Columbia University, New York; Hospital for Special Surgery (R.G.E.), Cornell University, New York, NY; Department of Clinical and Experimental Epilepsy (A.L., M.N., R.R., B.D., A.W.M., M.C.W.), Institute of Neurology, University College London; Institute for Neuroscience (A.J.T.), Newcastle University, UK; and Department of Neurology (S.A.W.), UCLA David Geffen School of Medicine, Los Angeles, CA.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Trevelyan
authors.affiliation: From the Departments of Neurology (R.C., L.M.B., R.G.E., C.A.S.), Neurological Surgery (G.P.B., G.M.M., R.R.G.), and Radiology (B.Z., C.G.F.), Columbia University, New York; Hospital for Special Surgery (R.G.E.), Cornell University, New York, NY; Department of Clinical and Experimental Epilepsy (A.L., M.N., R.R., B.D., A.W.M., M.C.W.), Institute of Neurology, University College London; Institute for Neuroscience (A.J.T.), Newcastle University, UK; and Department of Neurology (S.A.W.), UCLA David Geffen School of Medicine, Los Angeles, CA.
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Bateman
authors.affiliation: From the Departments of Neurology (R.C., L.M.B., R.G.E., C.A.S.), Neurological Surgery (G.P.B., G.M.M., R.R.G.), and Radiology (B.Z., C.G.F.), Columbia University, New York; Hospital for Special Surgery (R.G.E.), Cornell University, New York, NY; Department of Clinical and Experimental Epilepsy (A.L., M.N., R.R., B.D., A.W.M., M.C.W.), Institute of Neurology, University College London; Institute for Neuroscience (A.J.T.), Newcastle University, UK; and Department of Neurology (S.A.W.), UCLA David Geffen School of Medicine, Los Angeles, CA.
authors.forename: Ronald G
authors.initials: RG
authors.lastname: Emerson
authors.affiliation: From the Departments of Neurology (R.C., L.M.B., R.G.E., C.A.S.), Neurological Surgery (G.P.B., G.M.M., R.R.G.), and Radiology (B.Z., C.G.F.), Columbia University, New York; Hospital for Special Surgery (R.G.E.), Cornell University, New York, NY; Department of Clinical and Experimental Epilepsy (A.L., M.N., R.R., B.D., A.W.M., M.C.W.), Institute of Neurology, University College London; Institute for Neuroscience (A.J.T.), Newcastle University, UK; and Department of Neurology (S.A.W.), UCLA David Geffen School of Medicine, Los Angeles, CA. cas2044@columbia.edu.
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Schevon
mesh_terms: D004567:Electrodes, Implanted; D004569:Electroencephalography / Q000379:methods*; D065818:Gamma Rhythm / Q000502:physiology*; D006801:Humans; D017063:Outcome Assessment, Health Care; D012189:Retrospective Studies; D012640:Seizures / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology / Q000601:surgery