Toggle Main Menu Toggle Search

Open Access padlockePrints

Seizure localization using ictal phase-locked high gamma: A retrospective surgical outcome study

Lookup NU author(s): Professor Andrew Trevelyan


Full text for this publication is not currently held within this repository. Alternative links are provided below where available.


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.

Publication metadata

Author(s): Weiss SA, Lemesiou A, Connors R, Banks GP, McKhann GM, Goodman RR, Zhao BS, Filippi CG, Nowell M, Rodionov R, Diehl B, McEvoy AW, Walker MC, Trevelyan AJ, Bateman LM, Emerson RG, Schevon CA

Publication type: Article

Publication status: Published

Journal: Neurology

Year: 2015

Volume: 84

Issue: 23

Pages: 2320-2328

Print publication date: 09/06/2015

Online publication date: 13/05/2015

Acceptance date: 02/03/2015

ISSN (print): 0028-3878

ISSN (electronic): 1526-632X

Publisher: Lippincott Williams & Wilkins


DOI: 10.1212/WNL.0000000000001656


Altmetrics provided by Altmetric


Funder referenceFunder name
Department of Health's NIHR Biomedical Research Centres funding scheme
Epilepsy Foundation
Epilepsy Research UK
R25-10416928NIH/National Institute of Neurological Disorders and Stroke
R01-NS084142NIH/National Institute of Neurological Disorders and Stroke