Epileptic high-frequency network activity in a model of non-lesional temporal lobe epilepsy.

Research output: Contribution to journalArticle

Authors

Colleges, School and Institutes

Abstract

High-frequency cortical activity, particularly in the 250–600 Hz (fast ripple) band, has been implicated in playing a crucial role in epileptogenesis and seizure generation. Fast ripples are highly specific for the seizure initiation zone. However, evidence for the association of fast ripples with epileptic foci depends on animal models and human cases with substantial lesions in the form of hippocampal sclerosis, which suggests that neuronal loss may be required for fast ripples. In the present work, we tested whether cell loss is a necessary prerequisite for the generation of fast ripples, using a non-lesional model of temporal lobe epilepsy that lacks hippocampal sclerosis. The model is induced by unilateral intrahippocampal injection of tetanus toxin.Recordings from the hippocampi of freely-moving epileptic rats revealed high-frequency activity (4100 Hz), including fast ripples. High-frequency activity was present both during interictal discharges and seizure onset. Interictal fast ripples proved a significantly more reliable marker of the primary epileptogenic zone than the presence of either interictal discharges or ripples (100–250 Hz). These results suggest that fast ripple activity should be considered for its potential value in the pre-surgical workup of non-lesional temporal lobe epilepsy.

Details

Original languageEnglish
Pages (from-to)1380-90
Number of pages11
JournalBrain
Volume133
Issue numberPt 5
Publication statusPublished - 1 May 2010

Keywords

  • seizure onset, epilepsy, temporal lobe epilepsy, ripples, ictogenesis, fast ripples, non-lesional, high-frequency activity