WASHINGTON – Advances in dietary therapy for nonlesional epilepsy have made it a more feasible approach for many patients because of options that now include a "smarter and gentler" ketogenic diet and a modified Atkins diet, Dr. Eric Kossoff said at the annual meeting of the American Epilepsy Society.
"We’ve come a long way ... in making diets easier, safer [and] more palatable, and that’s really opened up many different options for patients who didn’t have diet as an option before," said Dr. Kossoff, a pediatric neurologist at Johns Hopkins Children’s Center, Baltimore. For patients with nonlesional epilepsy, diets can be helpful – sometimes even resulting in seizure freedom – and should be considered earlier in the course of treatment, he added.
Most of his discussion focused on pediatric patients, but he said that some children continue the diet into adulthood, and there is increasing interest in the potential of dietary approaches, particularly a modified Atkins diet, for adults with nonlesional epilepsy. Adult epilepsy diet centers also are starting to appear in large U.S. cities and internationally.
Dr. Eric Kossoff
The currently recommended ketogenic diet (high fat, moderate protein, and low carbohydrate) is far less rigid and restrictive than the traditional ketogenic diet used for more than 80 years, which entailed starting the diet in the hospital with intensive dietician involvement, precisely weighing food with a gram scale, and following the diet for 6 months to 2 years, he pointed out. Dieticians have more leeway in making the diet more palatable, with resources like the online KetoCalculator program that helps families plan and create meals.
There is now more information that health care practitioners can use to predict the type of patient more likely to respond to diet. Fasting and hospital admission are no longer needed, and adverse events are anticipated and prevented, not treated, said Dr. Kossoff, who is also medical director of the Ketogenic Diet Center at the John M. Freeman Pediatric Epilepsy Center at Johns Hopkins. In a 2007 study of diet in 45 children with lesional epilepsy, there was some response to diet, but none of the children were seizure free (Seizure 2007;16:615-9). At Johns Hopkins and other epilepsy centers in the United States and elsewhere, the ketogenic diet is mostly recommended as a treatment for nonlesional epilepsy, based on this study and anecdotal experience, with the exception of tuberous sclerosis, he added.
In addition, clinical data from multiple prospective and retrospective studies have provided solid evidence that the diet can be effective, he said. These include "dramatic" results of a randomized controlled study, which found that 38% of the children on the ketogenic diet had more than a 50% reduction in baseline seizures after 3 months, compared with 6% of controls (Lancet Neurol. 2008;7:500-6). "This really did change a lot of mind-sets that diet had not been proven," he said. Based on the results of the available studies combined, there is about a 50%-55% likelihood of a response with diet and about a 15% likelihood of being seizure free, he noted.
The need to fast is now being reconsidered by most centers, Dr. Kossoff said. A 2005 randomized controlled study that compared the effects of starting the diet with fasting to gradually introducing the diet without a fasting period found that while fasting resulted in a more rapid rise in serum ketones, seizure-free and seizure-reduction rates at 3 months were similar in both groups. Fasting can be viewed as "an IV load of a ketogenic diet," he added. "It gets the seizure improvement to occur quicker, but long term, it doesn’t seem to make much of a difference."
Improvements in addressing weight loss, vomiting, constipation, and other potential side effects of the ketogenic diet include the use of supplements such as multivitamins, vitamin D, and selenium, as well as laxatives. At Johns Hopkins, Dr. Kossoff and his associates have found that the use of oral citrates reduces the risk of kidney stones associated with the diet to less than 1% (from about 5%-6%).
Traditionally, the ketogenic diet has been recommended for up to 2 years, but most studies indicate that patients who will benefit will start to respond within 2-4 weeks, and it is not necessary to wait for 6 months to see if they respond. He and his associates recommend waiting for at least 3 months to see if a patient responds.
Traditionally, 2 years on the diet has been recommended, but there are studies indicating a shorter period of time may be adequate. Some patients, however, have a recurrence when they stop the diet and need to continue the diet into adulthood for as long as 20-30 years, if necessary.