Much to their surprise, researchers at Johns Hopkins Children’s Center recently found that cognitive improvement is one of the most common goals of parents with children with intractable epilepsy prior to starting the ketogenic diet.

“What we did expect when we asked parents to write down their top treatment goals of the ketogenic diet was for them to list a decrease in seizures and decrease in seizure medications as their top goals. Although this was true, however, we were surprised that improved cognition and alertness was actually one of the top three goals listed by parents, and the most significant determinants of longer diet duration”, said Sharifeh Farasat, a junior medical student at Johns Hopkins and lead author of the study, which was run by the John M. Freeman Pediatric Epilepsy Center at Johns Hopkins Hospital.

Study Design

Since 1998, all parents of the 226 children started on the ketogenic diet at Johns Hopkins Hospital have been asked to handwrite their personal goals and criteria for success on the diet. This letter was written during the first 2-3 days of the diet admission period and inserted into the child’s ketogenic diet chart. From September 1998 to November 2004, researchers identified 100 children for whom there was at least one parent letter and 6 months of follow-up information. The letters were examined for a maximum of three written goals in the order of presentation, level of desired seizure reduction, and amount of AED reduction. Children were evaluated at 6 months for seizure frequency, number of AEDs, and subjective psychomotor improvement as reported by parents and neurologists, and then outcomes were correlated with the parents’ pre-diet goals and expectations.

What is the ketogenic diet?

The ketogenic diet is a special high-fat, low-carbohydrate diet prescribed by doctors to treat children whose seizures have not responded to several different seizure medicines. It is particularly recommended for children with the Lennox-Gastaut syndrome, but also has benefits for children with infantile spasms, Dravet syndrome, tuberous sclerosis, Doose syndrome, and children with gastrostomy tubes (easy to provide).

The typical ketogenic diet, called the "long-chain triglyceride diet," provides 3 to 4 grams of fat for every 1 gram of carbohydrate and protein. The dietician recommends a daily diet that contains 75 to 100 calories for every kilogram (2.2 pounds) of body weight and 1-2 grams of protein for every kilogram of body weight. The kinds of foods that provide fat for the ketogenic diet are butter, cream, mayonnaise, and heavy whipping cream. The diet can be made creatively, and many families use foods such as shrimp, cheese, hot dogs, nuts, and sugar-free jello to make it more appetizing for their children. Because the amount of carbohydrate and protein in the diet have to be restricted, it is very important that the meals be prepared carefully. No other sources of carbohydrates can be eaten, and for this reason, the ketogenic diet is supervised by a dietician.

Typically the diet is started in the hospital. The child usually begins by fasting (except for water) under close medical supervision for 48 hours. For instance, the child might go into the hospital on Monday, start fasting at 6 p.m. and continue to have only water until 6 a.m. on Wednesday. Then the child's urine is tested to see if it shows ketones. If ketones are found, the diet is then begun. The child stays in the hospital for another 2 to 3 days for close monitoring. During this time, the parents are taught more about the diet. Some hospitals and ketogenic diet centers do not start with a fast, or shorten it. There is good evidence for both approaches.

Alternatives to the ketogenic diet currently under investigation include a modified Atkins diet and a low glycemic index diet (at Johns Hopkins Hospital and Massachusetts General Hospital, respectively). Both allow for more carbohydrates and protein and avoid the need for hospitalizations, weighing foods, and fasting. However, both have possible side effects and should not be done without a physician or dietitian involved.

Implications of Study

“This study is the first to examine parental expectations prior to initiating the ketogenic diet. Traditionally, at our center we do not present cognitive improvement as a potential outcome of the ketogenic diet.” said Farasat. “However, this study suggests we should definitely discuss it more frequently with parents as it is a common concern and treatment goal.”

The question then arises, “Why is cognitive improvement such a surprising treatment goal amongst clinicians?” According to Farasat, cognition is not something that can be measured or monitored by clinicians as scientifically or concretely as seizures and certainly takes more time in the clinic to assess. Most neurologists keep track of seizures, and if cognitive improvement occurs it is a “fringe benefit”, but perhaps that is not what is truly most important for parents. Alane and James Lynch, parents of a child participating in the study, agree. “Neurologists tend to focus on the control seizures because there is no way to know if the seizures are causing pathology of the brain or visa versa. But our doctors expressed to us that only good things could happen after the seizures were controlled. So we started the diet hoping that seizure control would result in cognitive development.” Alane said. “Sure we wanted seizure control, but above all, we wanted our daughter to be an active part of our family,” said James.

Since starting their daughter on the ketogenic diet the Lynch’s have seen what they describe as a miraculous change in their daughter’s cognitive abilities. “Before starting on the diet our daughter was on several different medications which were not only, not controlling her seizures, but were also making her regress developmentally,” said Alane Lynch. “She was not talking or playing or interacting with us at all and would sleep after each seizure. Now, she’s fully-functioning, singing songs, playing games and has an incredible sense of humor,” said James. Both parents note that while their daughter is still speech delayed and not cognitively where she should be at five years old, she is on the right path now and progressing each day.

For more information regarding the ketogenic diet you may go to:

• www.epilepsy.com/epilepsy/treatment_ketogenic_diet.html
• www.epilepsy.com/epilepsy/ketogenic_link

References

1. Farasat S, Kossoff EH, Pillas DJ, Rubenstein JE, Vining EP, Freeman JM. The importance of cognition in parental expectations prior to starting the ketogenic diet.Epilepsy Behav 2006; 8 (2) pp. 406-410.