Just as in children with epilepsy, ketogenic diet therapies can be safe and effective in adults with epilepsy but should only be undertaken with the support of medical professionals trained in their use, the group said.
Dr. Mackenzie Cervenka
“Motivation is the key to successful ketogenic diet therapy adherence,” first author Mackenzie Cervenka, MD, director of the Adult Epilepsy Diet Center and associate professor of neurology at Johns Hopkins University, Baltimore, said in an interview.
“Patients who are autonomous require self-motivation and having a strong support structure is important as well. For those patients who are dependents, their caregivers need to be motivated to manage their diet,” said Dr. Cervenka.
The guidelines were published online Oct. 30 in Neurology Clinical Practice.
Novel in adult neurology
Ketogenic diet therapies are high-fat, low-carbohydrate, and adequate-protein diets that induce fat metabolism and ketone production. Despite its use as an effective antiseizure therapy since the 1920s, ketogenic diet therapies remain novel in adult neurology.
Furthermore, while there are established guidelines for ketogenic diet therapies to reduce seizures in children, there were no formal recommendations for adults, until now.
Drawing on the experience of experts at 20 centers using ketogenic diet therapies in more than 2,100 adults with epilepsy in 10 countries, Dr. Cervenka and an international team developed recommendations on use of ketogenic diet therapies in adults.
The panel noted, “with a relatively mild side effect profile and the potential to reduce seizures in nearly 60% of adults with drug-resistant epilepsy, ketogenic diet therapies should be part of the repertoire of available options.”
Ketogenic diet therapies are appropriate to offer to adults with seizure types and epilepsy syndromes for which these treatments are known to be effective in children, they said. These include tuberous sclerosis complex, Rett syndrome, Lennox-Gastaut syndrome, glucose transporter type 1 deficiency syndrome, genetic generalized epilepsies, and focal epilepsies caused by underlying migrational disorders and resistant to antiseizure medication.
However, adults with drug-resistant focal epilepsy should be offered surgical evaluation first, given the higher anticipated rate of seizure freedom via this route, the panel said.
A focus on compliance
Experts at nearly all of the centers report using two or more ketogenic diet therapies. Ninety percent use the modified Atkins diet, 84% use the classic ketogenic diet, and 63% use the modified ketogenic diet and/or low glycemic index treatment. More than half of the centers (58%) use medium-chain triglyceride oil in combination with another ketogenic diet therapy to boost ketone body production.
The most important factors influencing the choice of ketogenic diet therapy are ease of diet application for the patient (100%) and patient and/or caregiver preference, home setting, and mode of feeding (90% each).
The panel recommended that ketogenic diet therapies be tailored to fit the needs of the individual, taking into account his or her physical and mental characteristics, underlying medical conditions, food preferences, type and amount of support from family and others, level of self-sufficiency, feeding habits, and ease of following the diet.
“Most of the differences between the child and adult recommendations have to do with compliance. Often, it’s more of a challenge for adults than for children,” said Dr. Cervenka.
The panel recommended providing adult patients with recipe ideas, individualized training on the ketogenic diet lifestyle from a dietitian or nutritionist, and guidance for meal planning and preparation before starting the diet. This will provide the greatest likelihood of success, as patients often report difficulties coping with carbohydrate restriction.
“In pediatric practice, positive responders typically remain on a ketogenic diet therapy for 2 years before considering weaning. Ketogenic diet therapy in adults is not time-limited. However, a minimum of 3 months of ketogenic diet therapy is recommended before any judgment of response is made,” the panel advised.
The panel pointed out the absolute metabolic contraindications and cautions related to feeding difficulties, gastrointestinal dysfunction, and digestion remain the same for both children and adults. However, they added that a range of common adult conditions such as hyperlipidemia, heart disease, diabetes, low bone density, and pregnancy “bring additional consideration, caution, and monitoring to ketogenic diet therapy use.”
