Abstracts

Rationale: Ketogenic diet (KD) is commonly used as an adjunctive treatment in refractory epilepsies. Clinical and animal studies already showed its efficiency in reducing seizures. The aim of this study is to evaluate the potential neuroprotective effect of KD after lithium-pilocarpine induced status epilepticus (SE) in adult rats. Usually, in this model of temporal lobe epilepsy, all adult animals subjected to SE exhibit neuronal loss in hippocampus and parahippocampal cortices, leading to refractory spontaneous recurrent epileptic seizures after a latent period of epileptogenesis. Methods: Forty 50-day-old rats were divided in four weight-matched groups and fed controlled diets: Normocaloric Carbohydrate (NC), Hypocaloric Carbohydrate (HC), Normocaloric Ketogenic (NK) and Hypocaloric Ketogenic (HK). After 21 days of the selected diet, lithium-pilocarpine SE was induced. The diets were continued for one week after SE. We studied the acute electroclinical features of SE as well as its long-term consequences on epileptogenesis and neuronal loss. Results: Electroclinical features of SE were similar in the four groups of rats. Whatever the diet, all rats became epileptic without significant difference in the duration of epileptogenesis. As well, parahippocampal cortices were severely damaged in all four groups. Compared to the NC diet, the HC, NK and HK diets displayed a neuroprotective effect in hippocampal hilus, CA1 and CA3 layers. There was no potentiation between the ketogenic diet and calorie restriction. Conclusions: The ketogenic diet as well as the calorie restricted diet exhibit a neuroprotective effect in hippocampal layers after lithium-pilocarpine SE, without cooperative effect. As it is already known in this model, the lack of concurrent neuroprotection of hippocampus and parahippocampal cortices leads to the absence of effect of these diets on the duration of epileptogenesis.