Recording of fast activity at the onset of partial seizures: Depth EEG vs. scalp EEG. - Inserm - Institut national de la santé et de la recherche médicale Access content directly
Journal Articles NeuroImage Year : 2012

Recording of fast activity at the onset of partial seizures: Depth EEG vs. scalp EEG.

Abstract

Rapid discharges (25-80Hz), a characteristic EEG pattern often recorded at seizure onset in partial epilepsies, are often considered as electrophysiological signatures of the epileptogenic zone. While the recording of rapid discharges from intracranial electrodes has long been established, their observation from the scalp is challenging. The prevailing view is that rapid discharges cannot be seen clearly (or at all) in scalp EEG because they have low signal-to-noise ratio. To date, however, no studies have investigated the 'observability' of rapid discharges, i.e. under what conditions and to what extent they can be visible in recorded EEG signals. Here, we used a model-based approach to examine the impact of several factors (distance to sources, skull conductivity, source area, source synchrony, and background activity) on the observability of rapid discharges in simultaneously simulated depth EEG and scalp EEG signals. In our simulations, the rapid discharge was clearly present in depth EEG signals but mostly almost not visible in scalp EEG signals. We identified some of the factors that may limit the observability of the rapid discharge on the scalp. Notably, surrounding background activity was found to be the most critical factor. The findings are discussed in relation to the presurgical evaluation of epilepsy.
Fichier principal
Vignette du fichier
Microsoft_Word_-_manuscript_revised_r2.doc.pdf (3.94 Mo) Télécharger le fichier
Origin : Files produced by the author(s)
Loading...

Dates and versions

inserm-00664028 , version 1 (24-02-2012)

Identifiers

Cite

Délphine Cosandier-Rimélé, Fabrice Bartolomei, Isabelle Merlet, Patrick Chauvel, Fabrice Wendling. Recording of fast activity at the onset of partial seizures: Depth EEG vs. scalp EEG.. NeuroImage, 2012, 59 (4), pp.3474-87. ⟨10.1016/j.neuroimage.2011.11.045⟩. ⟨inserm-00664028⟩
174 View
362 Download

Altmetric

Share

Gmail Facebook X LinkedIn More