THE ONTOGENY OF SEIZURES IN A RAT MODEL OF LIMBIC EPILEPSY - EVIDENCEFOR A KINDLING PROCESS IN THE DEVELOPMENT OF CHRONIC SPONTANEOUS SEIZURES

Kindling is an experimental model for epilepsy in which repeated stimu li induce longer electrographic seizures and eventually cause behavior al convulsions. Although kindling has some features that are similar t o chronic human epilepsy, it is not known whether this process plays a role in the development of chronic seizure disorders. We have recentl y described a rat model of chronic spontaneous limbic seizures that ha s a number of similarities to human limbic epilepsy. To determine whet her a kindling process is involved in the ontogeny of the seizures in this animal model, we continuously monitored 16 rats with EEG and clos ed circuit television until they had experienced a minimum of 5 and as many as 10 seizures following the first motor seizure. All animals ha d at least one non-motor seizure before the first motor event (mean 5. 1 +/- 0.9 S.E.M. initial non-motor seizures, range 1-12). In addition the seizures significantly lengthened in duration with succeeding even ts (mean 90 s for the first motor seizure to mean 110 s for the tenth subsequent seizure). These data demonstrate that there is a kindling p rocess involved in the early development of chronic limbic seizures.