Abstracts

The ketogenic diet (KD) is effective in many cases of medically refractory epilepsy in children, but the KD is difficult to administer and maintain. Studies of the KD mechanism have focused on the role of ketosis, with relatively little attention to the possible role of the type and quantity of fat. To determine whether fat type affects seizure frequency and long-term effects of seizures on learning and memory, we studied the effects of 3 different diets in juvenile rats with kainic acid (KA)-induced epilepsy. We tested the hypothesis that a diet enriched in polyunsaturated fatty acids (PUFAs) is associated with an antiepileptic effect, since PUFAs are necessary for optimal brain development and exert a stabilizing effect of excitatory membranes (Prostagland Leukotr Essen Fatty Acids 67:131, 2002). We compared a control diet with a diet enriched in PUFA, a classic KD, and a KD diet with PUFA as the main fat component. On P29-35, male rats were subjected to status epilepticus induced by KA 10 mg/kg i.p. After recovery, rats were assigned to a control diet (n=6) or one of 3 experimental diets: PUFA (n=8), KD (n=7), or KD-PUFA (n=7). Diets were administered isocalorically with calories restricted to 80-90% of the recommended daily requirement for rats. For the next 3 months, rats were monitored visually for approximately 100 hours in total, by trained observers. The number, characteristics, and severity of spontaneous recurrent seizures (SRS) were recorded and compared among dietary treatments. Spontaneous seizures were observed in 67% of animals on the control diet, 50% of the PUFA group, 29% of the KD, and 43% of the KD-PUFA group. Seizure frequency was significantly lower in the KD group (p=0.038) compared to the other dietary groups. There were no significant differences between dietary groups in the percent of rats experiencing one class III-V spontaneous seizure (p=0.503) or in seizure severity (p=0.432). The classic KD afforded protection against spontaneous seizures in the KA model in juvenile rats. The PUFA diet alone or PUFAs added to the standard KD did not result in significant protection against seizures in this model. (Supported by The Charlie Foundation.)