N Kuhnke1, C Klus1, M Dümpelmann1, A Schulze-Bonhage1, J Jacobs2. 1. Epilepsy Centre, Medical Center - University of Freiburg, Germany. 2. Epilepsy Centre, Medical Center - University of Freiburg, Germany. Electronic address: Julia.jacobs@uniklinik-freiburg.de.
Abstract
OBJECTIVE: High frequency oscillations (HFO) between 80-500 Hz are markers of epileptic areas in intracranial and maybe also scalp EEG. We investigate simultaneous recordings of scalp and intracranial EEG and hypothesize that scalp HFOs provide important additional clinical information in the presurgical setting. METHODS: Spikes and HFOs were visually identified in all intracranial scalp EEG channels. Analysis of correlation of event location between intracranial and scalp EEG as well as relationship between events and the SOZ and zone of surgical removal was performed. RESULTS: 24 patients could be included, 23 showed spikes and 19 HFOs on scalp recordings. In 15/19 patients highest scalp HFO rate was located over the implantation side, with 13 patients having the highest scalp and intracranial HFO rate over the same region. 17 patients underwent surgery, 7 became seizure free. Patients with poor post-operative outcome showed significantly more regions with HFO than those with seizure free outcome. CONCLUSIONS: Scalp HFOs are mostly located over the SOZ. Widespread scalp HFOs are indicative of a larger epileptic network and associated with poor postsurgical outcome. SIGNIFICANCE: Analysis of scalp HFO add clinically important information about the extent of epileptic areas during presurgical simultaneous scalp and intracranial EEG recordings.
OBJECTIVE: High frequency oscillations (HFO) between 80-500 Hz are markers of epileptic areas in intracranial and maybe also scalp EEG. We investigate simultaneous recordings of scalp and intracranial EEG and hypothesize that scalp HFOs provide important additional clinical information in the presurgical setting. METHODS: Spikes and HFOs were visually identified in all intracranial scalp EEG channels. Analysis of correlation of event location between intracranial and scalp EEG as well as relationship between events and the SOZ and zone of surgical removal was performed. RESULTS: 24 patients could be included, 23 showed spikes and 19 HFOs on scalp recordings. In 15/19 patients highest scalp HFO rate was located over the implantation side, with 13 patients having the highest scalp and intracranial HFO rate over the same region. 17 patients underwent surgery, 7 became seizure free. Patients with poor post-operative outcome showed significantly more regions with HFO than those with seizure free outcome. CONCLUSIONS:Scalp HFOs are mostly located over the SOZ. Widespread scalp HFOs are indicative of a larger epileptic network and associated with poor postsurgical outcome. SIGNIFICANCE: Analysis of scalp HFO add clinically important information about the extent of epileptic areas during presurgical simultaneous scalp and intracranial EEG recordings.
Authors: Jonas C Bruder; Christoph Schmelzeisen; Daniel Lachner-Piza; Peter Reinacher; Andreas Schulze-Bonhage; Julia Jacobs Journal: Front Neurol Date: 2021-02-10 Impact factor: 4.003
Authors: Dorottya Cserpan; Antonio Gennari; Luca Gaito; Santo Pietro Lo Biundo; Ruth Tuura; Johannes Sarnthein; Georgia Ramantani Journal: Epilepsia Open Date: 2022-05-06