On the origin of epileptic High Frequency Oscillations observed on clinical electrodes

M. Shamas 1 P. Benquet 1 I. Merlet 1 M. Khalil 2 W. El Falou 2 A. Nica 1 F. Wendling 1
1 LTSI - Laboratoire Traitement du Signal et de l'Image
2 Lebanese University [Beirut]
Abstract : Objective: In this study we aim to identify the key (patho)physiological mechanisms and biophysical factors which impact the observability and spectral features of High Frequency Oscillations (HFOs).Methods: In order to accurately replicate HFOs we developed virtual-brain/virtual-electrode simulation environment combining novel neurophysiological models of neuronal populations with biophysical models for the source/sensor relationship. Both (patho)physiological mechanisms (synaptic transmission, depolarizing GABAA effect, hyperexcitability) and physical factors (geometry of extended cortical sources, size and position of electrodes) were taken into account. Simulated HFOs were compared to real HFOs extracted from intracerebral recordings of 2 patients.Results: Our results revealed that HFO pathological activity is being generated by feed-forward activation of cortical interneurons that produce fast depolarizing GABAergic post-synaptic potentials (PSPs) onto pyramidal cells. Out of phase patterns of depolarizing GABAergic PSPs explained the shape, entropy and spatiotemporal features of real human HFOs.Conclusions: The terminology “high-frequency oscillation” (HFO) might be misleading as the fast ripple component (200–600 Hz) is more likely a “high-frequency activity” (HFA), the origin of which is independent from any oscillatory process.Significance: New insights regarding the origins and observability of HFOs along depth-EEG electrodes were gained in terms of spatial extent and 3D geometry of neuronal sources.
Keywords : Neuronal population model Depolarizing GABA Depth-EEG Generation mechanisms High frequency oscillations
Document type :
Journal articles
Complete list of metadatas

Cited literature [57 references]  Display  Hide  Download
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01740202
Contributor : Laurent Jonchère <>
Submitted on : Friday, July 6, 2018 - 9:20:53 AM
Last modification on : Friday, November 30, 2018 - 1:38:59 PM
Long-term archiving on : Tuesday, October 2, 2018 - 4:21:47 AM

File

Shamas et al_On the origin of ...
Files produced by the author(s)

Identifiers

Collections

UNIV-RENNES1 | LTSI | UNIV-RENNES

Citation

M. Shamas, P. Benquet, I. Merlet, M. Khalil, W. El Falou, et al.. On the origin of epileptic High Frequency Oscillations observed on clinical electrodes. Clinical Neurophysiology, Elsevier, 2018, 129 (4), pp.829-841. ⟨10.1016/j.clinph.2018.01.062⟩. ⟨hal-01740202⟩

Export

BibTeX TEI DC DCterms EndNote

Share

Metrics

Record views

318

Files downloads

115