Our review update included data from four new randomised studies of the ketogenic diet. Although none were blinded, some were of good quality. These studies suggest that in children, the ketogenic diet results in short to medium term benefits in seizure control, the effects of which are comparable to modern antiepileptic drugs. However, one study of long term outcome reports a high attrition rate for the diet. This would suggest that many children find the diet difficult to tolerate. The main reasons for drop-outs in the included studies included gastrointestinal side effects and dislike for the diet.
We found just three studies on the use of the diet in adults and none of these were randomised. There has been less research involving other diets. We found one randomised study of reasonable quality of the Atkins diet. This study showed similar benefits in seizure control with a less restrictive diet.
For those with medically intractable epilepsy or those in whom surgery is unsuitable, a ketogenic diet could improve seizure control, but tolerability is poor. One observational study suggested that the Atkins diet may have a similar effect on seizure control, but this requires more investigation.
Ketogenic diet in pediatric epilepsy patients with gastrostomy feeding.
Ketogenic diet is effective in the control of intractable seizures. Poor compliance is a major limiting factor. In one study, only 50% of children receiving the oral ketogenic diet remained on the diet after 1 year. Twelve children with static encephalopathy and intractable symptomatic epilepsy were given the ketogenic diet via gastrostomy tube. Mean age was 3 years (range, 7 months to 6.5 years). Mean seizure frequency at baseline was 199/month. Seizure frequency after 12 and 18 months of diet was compared with baseline. After 12 months on the diet, the number of antiepileptic drugs was compared with baseline. Median seizure reduction at 1 year and 18 months was 61% and 66%, respectively (P = 0.02). Individually, six patients had 90% seizure reduction, one had 75% reduction, three had 50% reduction, and two patients did not improve. Mean antiepileptic drugs at baseline was 2.8; at 12 months 1.6 (49% reduction). Three patients had weight loss. Two patients discontinued the diet at 13 months and 21 months, respectively, because of diarrhea and weight loss. Compliance with diet was 100% during treatment. This study suggests that the ketogenic diet via gastrostomy feeding tube is safe and effective in children with intractable seizures and ensures compliance.