Ketogenic dietary therapies for adults with epilepsy: feasibility and classification of response

Ketogenic dietary therapies are an effective treatment for children with drug-resistant epilepsy. There is currently no high-quality evidence regarding ketogenic dietary therapies in adults, and further research has been recommended. This audit aimed to provide further evidence for the feasibility of dietary treatment for adults and to consider factors that may aid response classification in this population. We evaluated the effectiveness and tolerability of ketogenic dietary therapies in 23 adults with epilepsy attending specialist clinics. Medical notes were used to obtain seizure frequency information and other effects associated with dietary treatment. Individuals who achieved ≥50% seizure reduction at all follow-up points were classified as responders. Response rates, in terms of seizure frequency, were similar to those commonly reported in pediatric cohorts: 9/23 (39%) adults were classified as responders. These responders remained on the diet for at least one year (follow-up: 1-10 years). Other benefits reported by patients, but not quantified, included a reduction in seizure severity and increased alertness and concentration. Such factors often favor continuation of ketogenic dietary therapies despite a <50% seizure reduction. One individual experienced psychosis while following dietary treatment; most commonly reported adverse events were gastrointestinal. Adverse events did not lead to discontinuation of treatment in any cases. Our findings suggest that adults with epilepsy are able to follow ketogenic dietary therapies long-term, and such treatment can lead to seizure reduction. Other aspects besides seizure frequency may be relevant when classifying response in adults, and appropriate ways to quantify these factors should be considered for use in future studies.