title: Focal Seizures Induced by Intracranial Electroencephalogram Grids.
abstract: Here we present a unique, but important seizure variant directly related to placement of subdural grids. Two distinct epileptogenic zones were identified, one which correlated with the patient's baseline seizures and a separate zone associated with atypical semiology and localization. Inspection of this zone at surgery revealed cortical deformation from the grid itself. The patient underwent successful surgical resection of the primary epileptogenic zone, but not that of the atypical zone. She remains seizure free at two years following surgery. Recognition of grid-induced seizures is important as they may confound the interpretation of intracranial electroencephalograms (iEEG) and mislead resective surgery.
authors.affiliation: Department of Neurosurgery, The Hospital of the University of Pennsylvania.
authors.forename: Eric
authors.initials: E
authors.lastname: Hudgins
authors.affiliation: Department of Neurology, University of Colorado Hospital.
authors.forename: Mesha-Gay
authors.initials: MG
authors.lastname: Brown
authors.affiliation: Department of Neurology, The Hospital of the University of Pennsylvania.
authors.forename: Brian
authors.initials: B
authors.lastname: Litt
authors.affiliation: Department of Neurology, The Hospital of the University of Pennsylvania.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Davis
authors.affiliation: Department of Neurosurgery, The Hospital of the University of Pennsylvania.
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Richardson
authors.affiliation: Department of Neurosurgery, The Hospital of the University of Pennsylvania.
authors.forename: Timothy
authors.initials: T
authors.lastname: Lucas
keywords: eeg analysis; epilepsy surgery; refractory epilepsy; seizures