DOI: 10.1101/478594Nov 30, 2018Paper

Excitatory GABAergic signalling is associated with acquired benzodiazepine resistance in status epilepticus

BioRxiv : the Preprint Server for Biology
Richard J BurmanJoseph V. Raimondo

Abstract

Status epilepticus (SE) is defined as a state of unrelenting seizure activity. Generalised convulsive SE is associated with a rapidly rising mortality rate, and thus constitutes a medical emergency. Benzodiazepines, which act as positive modulators of chloride (Cl-) permeable GABAA receptors, are indicated as first-line treatment, but this is ineffective in many cases. We found that 48% of children presenting with SE were unresponsive to benzodiazepine treatment, and critically, that the duration of SE at the time of treatment is an important predictor of non-responsiveness. We therefore investigated the cellular mechanisms that underlie acquired benzodiazepine resistance, using rodent organotypic and acute brain slices. Removing Mg2+ ions leads to an evolving pattern of epileptiform activity, and eventually to a persistent state of repetitive discharges that strongly resembles clinical EEG recordings of SE. We found that diazepam loses its antiseizure efficacy and conversely exacerbates epileptiform activity during this stage of SE-like activity. Interestingly, a low concentration of the barbiturate phenobarbital had a similar exacerbating effect on SE-like activity, whilst a high concentration of phenobarbital was effective a...Continue Reading

Related Concepts

Brain
Diagnostic Imaging
Diazepam
Electroencephalography
Gramicidin A
Ions
Phenobarbital
Rodent
Status Epilepticus
Clinic

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