Variable electrobehavioral patterns during focal nonconvulsive status epilepticus induced by unilateral intrahippocampal injection of kainic acid.
OBJECTIVE
Nonconvulsive status epilepticus (ncSE) is a severe condition that may result in neurologic sequelae and epilepsy resistant to pharmacologic treatment. We analyze here seizure and electroencephalography (EEG) patterns and their correlation to the development of a chronic epileptic condition in a guinea pig model of focal ncSE induced by intrahippocampal injection of kainic acid (KA).


METHODS
Electrobehavioral patterns during ncSE induced by unilateral injection of 1 μg of KA in the CA1 region of the hippocampus were characterized by continuous video-EEG monitoring in 13 guinea pigs bilaterally implanted with recording electrodes in the hippocampus and neocortex.


RESULTS
Video-EEG analysis demonstrates a high variability of seizure type and duration during KA-induced ncSE. Seizures showed focal signs correlated with diverse epileptiform EEG discharge distributions, either diffuse or localized. Nonfocal (bilateral motor) signs during seizures most likely correlated with a diffuse EEG pattern. The evolution into a chronic epileptic condition correlated neither with the severity of seizure pattern nor with the diffusion of the EEG discharges observed during the ncSE.


CONCLUSIONS
Video-EEG monitoring in a guinea pig model of ncSE induced by unilateral hippocampal injection of KA demonstrates a high variability of electrobehavioral patterns. We demonstrate that the seizure severity score during focal ncSE is not a predictor of the evolution into a chronic epileptic condition of mesial temporal lobe epilepsy.
Unit of Epileptology and Experimental Neurophysiology, Fondazione Neurological Institute Carlo Besta, Milan, Italy; Unit of Clinical Neurophysiology, Scientific Institute IRCCS E. Medea, Bosisio Parini (LC), Italy.
Salvatore
S
Arcieri
Rosa
R
Velotti
Francesco
F
Noè
Giovanni
G
Carriero
Alessandro
A
Cattalini
Barbara
B
Galbardi
Vadym
V
Gnatkovsky
Marco
M
de Curtis
D000818:Animals; D004195:Disease Models, Animal; D004569:Electroencephalography; D018690:Excitatory Amino Acid Agonists / Q000633:toxicity*; D007839:Functional Laterality / Q000187:drug effects*; D006168:Guinea Pigs; D006624:Hippocampus / Q000187:drug effects* / Q000502:physiology; D007608:Kainic Acid / Q000633:toxicity*; D008297:Male; D013226:Status Epilepticus / Q000150:complications* / Q000209:etiology*; D013997:Time Factors; D014741:Video Recording
D018690:Excitatory Amino Acid Agonists; D007608:Kainic Acid
Guinea pig; Intrahippocampal kainic acid; Seizures; Temporal lobe epilepsy model