title: High frequency oscillations can pinpoint seizures progressing to status epilepticus.
abstract: Status epilepticus (SE) is defined as a seizure lasting more than 5min or a period of recurrent seizures without recovery between them. SE is a serious emergency condition that requires immediate intervention; therefore, identifying SE electrophysiological markers may translate in prompt care to stop it. Here, we analyzed the EEG signals recorded from the CA3 region of the hippocampus and the entorhinal cortex in rats that responded to systemic administration of 4-aminopyridine (4AP) by generating either isolated seizures or seizures progressing to SE. We found that high frequency oscillations (HFOs) - which can be categorized as ripples (80-200Hz) and fast ripples (250-500Hz) - had different patterns of occurrence in the two groups (n=5 for each group). Specifically, fast ripples in CA3 and entorhinal cortex of the SE group occurred at higher rates than ripples, both during the ictal and post-ictal periods when compared to the HFOs recorded from the isolated seizure group. Our data reveal that different patterns of HFO occurrence can pinpoint seizures progressing to SE, thus suggesting the involvement of different neuronal networks at the termination of seizure discharges.
authors.affiliation: Montreal Neurological Institute, McGill University, Montréal H3A 2B4 QC, Canada; Department of Neurology & Neurosurgery, McGill University, Montréal H3A 2B4 QC, Canada; Department of Physiology, McGill University, Montréal H3A 2B4 QC, Canada.
authors.forename: Pariya
authors.initials: P
authors.lastname: Salami
authors.affiliation: Montreal Neurological Institute, McGill University, Montréal H3A 2B4 QC, Canada; Department of Neurology & Neurosurgery, McGill University, Montréal H3A 2B4 QC, Canada; Department of Physiology, McGill University, Montréal H3A 2B4 QC, Canada.
authors.forename: Maxime
authors.initials: M
authors.lastname: Lévesque
authors.affiliation: Montreal Neurological Institute, McGill University, Montréal H3A 2B4 QC, Canada; Department of Neurology & Neurosurgery, McGill University, Montréal H3A 2B4 QC, Canada; Department of Physiology, McGill University, Montréal H3A 2B4 QC, Canada. Electronic address: massimo.avoli@mcgill.ca.
authors.forename: Massimo
authors.initials: M
authors.lastname: Avoli
mesh_terms: D015761:4-Aminopyridine / Q000633:toxicity; D000818:Animals; D058256:Brain Waves / Q000187:drug effects / Q000502:physiology*; D004195:Disease Models, Animal; D018450:Disease Progression; D004569:Electroencephalography; D006624:Hippocampus / Q000187:drug effects / Q000503:physiopathology; D008297:Male; D010507:Periodicity; D026902:Potassium Channel Blockers / Q000633:toxicity; D051381:Rats; D017207:Rats, Sprague-Dawley; D012640:Seizures / Q000209:etiology*; D013226:Status Epilepticus / Q000139:chemically induced / Q000150:complications* / Q000473:pathology*
chemical_list: D026902:Potassium Channel Blockers; D015761:4-Aminopyridine
keywords: 4-Aminopyridine; Entorhinal cortex; High frequency oscillations; Hippocampus; Status epilepticus