A ketogenic diet has different effects upon seizures induced by maximal electroshock and by pentylenetetrazole infusion

The purpose of these experiments was to determine whether a ketogenic diet previously shown to elevate seizure threshold also reduced seizure severity . Seizure threshold was tested by intravenous infusion of pentylenetetrazol e (PTZ) whereas seizure severity was determined from measuring the hindlimb extension to flexion (E/F) ratio after seizures were evoked by maximal ele ctroshock stimulation (MES). Surprisingly, seizures evoked by MES were more severe in animals fed a calorie-restricted ketogenic diet. Controls fed an isocaloric, calorie-restricted normal diet also exhibited more severe seiz ures than did animals fed the same diet ad libitum. When seizure threshold was evaluated in the same animals, those animals fed a calorie-restricted k etogenic diet exhibited a significant increase in seizure resistance compar ed to animals fed a ketogenic diet ad libitum, a calorie-restricted normal diet or a normal diet ad libitum. These findings suggest that both the amou nt and type of food affect seizures in rats and show that diet-related seiz ure protection depends upon the method by which seizures are provoked. (C) 2000 Elsevier Science B.V. All rights reserved.