High-frequency oscillations: what is normal and what is not?
- PMID: 19055491
- DOI: 10.1111/j.1528-1167.2008.01917.x
High-frequency oscillations: what is normal and what is not?
Abstract
High-frequency oscillations (HFOs) in the 80-200 Hz range can be recorded from normal hippocampus and parahippocampal structures of humans and animals. They are believed to reflect inhibitory field potentials, which facilitate information transfer by synchronizing neuronal activity over long distances. HFOs in the range of 250-600 Hz (fast ripples, FRs) are pathologic and are readily recorded from hippocampus and parahippocampal structures of patients with mesial temporal lobe epilepsy, as well as rodent models of this disorder. These oscillations, and similar HFOs recorded from neocortex of patients, appear to identify brain tissue capable of spontaneous ictogenesis and are believed to reflect the neuronal substrates of epileptogenesis and epileptogenicity. The distinction between normal and pathologic HFOs (pHFOs), however, cannot be made on the basis of frequency alone, as oscillations in the FR frequency range can be recorded from some areas of normal neocortex, whereas oscillations in the ripple frequency range are present in epileptic dentate gyrus where normal ripples never occur and, therefore, appear to be pathologic. The suggestion that FRs may be harmonics of normal ripples is unlikely, because of their spatially distinct generators, and evidence that FRs reflect synchronized firing of abnormally bursting neurons rather than inhibitory field potentials. These synchronous population spikes, however, can fire at ripple frequencies, and their harmonics appear to give rise to FRs. Investigations into the fundamental neuronal processes responsible for pHFOs could provide insights into basic mechanisms of epilepsy. The potential for pHFOs to act as biomarkers for epileptogenesis and epileptogenicity is also discussed.
Similar articles
-
High-frequency oscillations recorded in human medial temporal lobe during sleep.Ann Neurol. 2004 Jul;56(1):108-15. doi: 10.1002/ana.20164. Ann Neurol. 2004. PMID: 15236407
-
Interictal high-frequency oscillations (100-500 Hz) in the intracerebral EEG of epileptic patients.Brain. 2007 Sep;130(Pt 9):2354-66. doi: 10.1093/brain/awm149. Epub 2007 Jul 11. Brain. 2007. PMID: 17626037
-
High-frequency oscillations after status epilepticus: epileptogenesis and seizure genesis.Epilepsia. 2004 Sep;45(9):1017-23. doi: 10.1111/j.0013-9580.2004.17004.x. Epilepsia. 2004. PMID: 15329064
-
Normal and Pathologic High-Frequency Oscillations.In: Noebels JL, Avoli M, Rogawski MA, Olsen RW, Delgado-Escueta AV, editors. Jasper's Basic Mechanisms of the Epilepsies [Internet]. 4th edition. Bethesda (MD): National Center for Biotechnology Information (US); 2012. In: Noebels JL, Avoli M, Rogawski MA, Olsen RW, Delgado-Escueta AV, editors. Jasper's Basic Mechanisms of the Epilepsies [Internet]. 4th edition. Bethesda (MD): National Center for Biotechnology Information (US); 2012. PMID: 22787623 Free Books & Documents. Review.
-
High-frequency oscillations and mesial temporal lobe epilepsy.Neurosci Lett. 2018 Feb 22;667:66-74. doi: 10.1016/j.neulet.2017.01.047. Epub 2017 Jan 20. Neurosci Lett. 2018. PMID: 28115239 Review.
Cited by
-
Discovering Neurophysiological Characteristics of Pathological High-Frequency Oscillations in Epilepsy with an Explainable Deep Generative Model.medRxiv [Preprint]. 2024 Jul 11:2024.07.10.24310189. doi: 10.1101/2024.07.10.24310189. medRxiv. 2024. PMID: 39040207 Free PMC article. Preprint.
-
Practical measurements distinguishing physiological and pathological stereoelectroencephalography channels based on high-frequency oscillations in the human brain.Epilepsia Open. 2024 Aug;9(4):1287-1299. doi: 10.1002/epi4.12950. Epub 2024 May 29. Epilepsia Open. 2024. PMID: 38808652 Free PMC article.
-
A machine learning toolbox for the analysis of sharp-wave ripples reveals common waveform features across species.Commun Biol. 2024 Mar 4;7(1):211. doi: 10.1038/s42003-024-05871-w. Commun Biol. 2024. PMID: 38438533 Free PMC article.
-
Examining the low-voltage fast seizure-onset and its response to optogenetic stimulation in a biophysical network model of the hippocampus.Cogn Neurodyn. 2024 Feb;18(1):265-282. doi: 10.1007/s11571-023-09935-1. Epub 2023 Feb 10. Cogn Neurodyn. 2024. PMID: 38406204
-
High frequency oscillation network dynamics predict outcome in non-palliative epilepsy surgery.Brain Commun. 2024 Feb 7;6(1):fcae032. doi: 10.1093/braincomms/fcae032. eCollection 2024. Brain Commun. 2024. PMID: 38384998 Free PMC article.
Publication types
MeSH terms
Grants and funding
LinkOut - more resources
Full Text Sources
Other Literature Sources
Medical