title: Clinical impact of a high-frequency seizure onset zone in a case of bitemporal epilepsy.
abstract: High-frequency activity has been described as having a role in the initiation of epileptic seizures. The case of a patient with refractory bitemporal epilepsy is presented. Extraoperative monitoring with depth and subdural electrodes revealed an ictal pattern with a build-up of high-frequency (> 80 Hz) activity originating in the cortex, with spread to both hippocampi. This observation was only revealed with the use of high-pass filtering, and represented crucial information that significantly influenced the decision about the side, localization and extent of resection. Removal of the cortex generating high-frequency activity, led to cessation of seizures in this patient. Current knowledge about the role of high-frequency activity and the case presented here support the importance of recording with equipment capable of detecting fast activity during the presurgical invasive monitoring. An active search for a high-frequency seizure onset zone in patients with structurally-unaffected hippocampi may improve the outcome beyond that possible with conventional bandwidth, invasive EEG recordings.
authors.affiliation: Department of Neurophysiology, Division of Neuroscience, School of Medicine, The University of Birmingham, Birmingham, United Kingdom. p.jiruska@bham.ac.uk
authors.forename: Premysl
authors.initials: P
authors.lastname: Jiruska
authors.forename: Martin
authors.initials: M
authors.lastname: Tomasek
authors.forename: David
authors.initials: D
authors.lastname: Netuka
authors.forename: Jakub
authors.initials: J
authors.lastname: Otahal
authors.forename: John G R
authors.initials: JG
authors.lastname: Jefferys
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Li
authors.forename: Petr
authors.initials: P
authors.lastname: Marusic
mesh_terms: D002540:Cerebral Cortex / Q000473:pathology / Q000503:physiopathology; D004567:Electrodes, Implanted; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D005260:Female; D006624:Hippocampus / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D019635:Neurosurgical Procedures; D049268:Positron-Emission Tomography; D013702:Temporal Lobe / Q000473:pathology / Q000503:physiopathology / Q000601:surgery