Megan Brooks

November 06, 2013

AUSTIN, Texas — Fine-tuning the ketogenic diet can have a modest effect on seizure control in children with refractory epilepsy, a retrospective study suggests.

The researchers found that adjusting diet and changing medications had similar benefits and were helpful in meeting seizure control expectations in about 1 in 5 children.

Jessica Selter, a medical student at Johns Hopkins University School of Medicine in Baltimore, Maryland, presented the findings here at the Child Neurology Society (CNS) 2013 Annual Meeting.

No Single "Stand Out" Dietary Change

The high-fat, low-carbohydrate ketogenic diet has "repeatedly" been shown to be effective in children with refractory epilepsy, "but some children don't have a complete response," Selter noted in an interview with Medscape Medical News.

"In this case, clinicians and dietitians will often try to make fine-tuning changes to the diet through dietary or medication adjustments to try to impact future control. But there really is a lack of evidence on the impact of those fine-tuning changes on future seizure control," Selter explained.

"We tried to characterize the fine-tuning changes that are made and determine their efficacy and in particular try to see if there was one that really stood out as most effective," she said.

The researchers reviewed the charts of 200 children who started the ketogenic diet at Johns Hopkins Hospital between October 2007 and June 2013. In most of these children (n = 156 [78%]), at least 1 change (intervention) was attempted. The chart review showed a total of 391 distinct and occasionally concurrent interventions, of which 256 were made specifically for seizure control.

"We found that there was an 18% chance that any change would lead to a greater than 50% seizure reduction but there was a 3% chance that a change would lead to resulting seizure freedom," Selter said. It's important to note that the likelihood of success did not decrease with each subsequent intervention, she noted.

No single dietary change stood out as the most effective, but calorie changes to the diet might be the least helpful, the researchers report. Increasing the fat to carbohydrate ratio and adding carnitine and medium-chain triglyceride (MCT) oil were similar and were more likely to help than was reducing calories, they say.

Predictors of a dietary change leading to seizure improvement were younger age (3.6 vs 5.1 years; P = .02), young age at seizure onset (1.2 vs 2 years; P = .049), and lower seizure frequency at baseline (230 vs 572 seizures per month; P = .003).

There was a trend for medication adjustment to be slightly more likely than dietary modification to lead to greater than 50% seizure reduction (24% vs 15%; P = .08). Medication adjustment is a "viable option and might make more of a difference as an add-on" to the ketogenic diet, the researchers conclude.

Overall, this study shows that fine-tuning the ketogenic diet can have a "modest impact on seizure control," Selter and colleagues conclude.

"While it makes sense to try to fine-tune the diet," Selter said, "it's important for clinicians and dietitians to talk with patients and parents and be realistic that there really isn't a very high likelihood that these fine-tuning changes can lead to seizure freedom. It's important to work with patients and their families to make these changes."

Benefits Beyond Seizure Control

Reached for comment, Elizabeth Donner, MD, pediatric neurologist at the Hospital for Sick Children, and associate professor, University of Toronto, Ontario, Canada, said, "It's important to note that this abstract reports the results of fine-tuning the diet on seizure outcome" only.

"In our experience, fine-tuning the diet allows for improvements not only in seizure control, but also in tolerability of the diet and palatability of the diet," she told Medscape Medical News. "More kids are able to take the diet if you are willing to make fine adjustments. Therefore, an important message is that adjustments can be made to the diet not just for seizure control but to assist children and families who are having difficulty sticking with the diet."

Dr. Donner also noted that the ketogenic diet is rigid and needs to be prescribed by an experienced medical team. "It is not something that can be implemented at home," she said, "but it actually can be flexible and there is some flexibility in how we use the diet. And that means we should consider using it in any kid who has drug-resistant seizures and are not surgical candidates. It needs to be on your list of options."

The ketogenic diet is also labor intensive and requires a lot of follow-up, she noted. "We see these kids before starting the diet to see if they are good candidates and once started on the diet, we see them back typically at 1 month, 2 months, and 3 months, then every 3 months and then eventually every 6 months," Dr. Donner said.

"If the family is coming from far away, then we have a conversation about whether it is feasible for them to come back for all those follow-up appointments. We try to do some of them by telemedicine. And between those follow-up appointments, families are typically in touch with our RN, our nurse practitioner, and our dietitian, making changes and talking about things between appointments," she said.

The authors and Dr. Donner have disclosed no relevant financial relationships.

Child Neurology Society (CNS) 2013 Annual Meeting. Abstract #170. Presented October 31, 2013.


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