Long-term outcomes of the ketogenic diet in the treatment of epilepsy have not previously been reported. A retrospective chart review of children treated with the ketogenic diet for more than 6 years at the Johns Hopkins Hospital was performed. The response was documented at clinic visits and by telephone contacts; laboratory studies were obtained approximately every 6 to 12 months. Satisfaction and tolerability were assessed by means of a brief parental telephone questionnaire. In all, 28 patients (15 males, 13 females), currently aged 7 to 23 years, were identified. The median baseline seizure frequency per week at diet onset was 630 (range 1-1400). Diet duration ranged from 6 to 12 years; 19 remain on the diet currently. After 6 years or more, 24 children experienced a more than 90% decrease in seizures, and 22 parents reported satisfaction with the diet's efficacy. Ten children were at less than the 10th centile for height at diet initiation; this number increased to 23 at the most recent follow-up (p=0.001). Kidney stones occurred in seven children and skeletal fractures in six. After 6 years or more the mean cholesterol level was 201mg/dl, high-density lipoprotein was 54mg/dl, low-density lipoprotein was 129mg/dl, and triglycerides were 97mg/dl. Efficacy and overall tolerability for children are maintained after prolonged use of the ketogenic diet. However, side effects, such as slowed growth, kidney stones, and fractures, should be monitored closely.

Long-term outcomes of the ketogenic diet in the treatment of epilepsy have not previously been reported. A retrospective chart review of children treated with the ketogenic diet for more than 6 years at the Johns Hopkins Hospital was performed. The response was documented at clinic visits and by telephone contacts; laboratory studies were obtained approximately every 6 to 12 months. Satisfaction and tolerability were assessed by means of a brief parental telephone questionnaire. In all, 28 patients (15 males, 13 females), currently aged 7 to 23 years, were identified. The median baseline seizure frequency per week at diet onset was 630 (range 1-1400). Diet duration ranged from 6 to 12 years; 19 remain on the diet currently. After 6 years or more, 24 children experienced a more than 90% decrease in seizures, and 22 parents reported satisfaction with the diet's efficacy. Ten children were at less than the 10th centile for height at diet initiation; this number increased to 23 at the most recent follow-up (p=0.001). Kidney stones occurred in seven children and skeletal fractures in six. After 6 years or more the mean cholesterol level was 201mg/dl, high-density lipoprotein was 54mg/dl, low-density lipoprotein was 129mg/dl, and triglycerides were 97mg/dl. Efficacy and overall tolerability for children are maintained after prolonged use of the ketogenic diet. However, side effects, such as slowed growth, kidney stones, and fractures, should be monitored closely.The ketogenic diet is a high-fat, low-carbohydrate, adequateprotein diet that was developed more than 80 years ago as a method of managing intractable epilepsy in children. 1 Previous studies have demonstrated that the efficacy of the diet in providing seizure control for children with difficult-to-manage seizures is at least equal to many of the newer anticonvulsant medications and often allows a decrease in medication. 2,3 Most epilepsy centers advocate use of the diet for 2 to 3 years if it controls seizures, followed by a gradual discontinuation in a manner similar to the withdrawal of anticonvulsants. Effects of the diet have been reported in patients who were on it for as long as 3 to 6 years' duration. 4 However, the ketogenic diet has been the only successful therapy for many children with epilepsy, and often these families continue the diet for longer periods.There are many questions regarding the long-term use of the ketogenic diet. Is it feasible for patients to remain on the diet for prolonged periods of time? Does the efficacy of the diet fluctuate over time? Does the diet become more tolerable over time, or do families eventually tire of the strict regimen of calculating ratios and weighing out foods? Established side effects of the ketogenic diet include kidney stones, dyslipidemia, changes in bone density, and slowed growth. [5][6][7][8][9][10][11][12][13] Most studies reporting on side effects have a follow-up period of less than 2 years, whereas a recent review examined diet complications after up to 4 years of treatment. 13 Are children on t...