Abstracts

Rationale: The anticonvulsant mechanisms of the ketogenic diet are unclear but its efficacy has been demonstrated in pediatric patients. The classic ketogenic diet requires strict adherence to a 4:1 ratio of grams of fat to combined grams of carbohydrate and protein. Initiation requires a hospital admission. There are more accessible variants of the ketogenic diet that have been studied, most commonly the Modified Atkins Diet. These versions of the diet are less restrictive, improve adherence and can be started in the outpatient setting. There is limited data demonstrating the efficacy of the ketogenic diet for patients older than 13. We report data from our experience of treating 28 adolescent and adult patients with drug resistant epilepsy in the University of Virginia Diet Therapy Clinic from January 2008 until November 2017. Methods: We reviewed the electronic medical records for pre and post diet information about our patients: body mass index, lab values (comprehensive metabolic panel, complete blood count, fasting lipid profile), diagnostic studies (magnetic resonance imaging, routine EEG, continuous EEG from epilepsy monitoring unit admissions), reported seizure frequency, urinary ketone values, weights at follow up, food diary/records and discussion of reported side effects. Results: 21 patients (75%) were treated with the Modified Atkins Diet (MAD) and 7 patients (25%) followed the ketogenic diet (KD). The average age of our population was 23.8 years and the average duration on a diet was 10 months. At six-month follow up, 9 MAD treated patients (42%) experienced improvement in seizure frequency. Two MAD patients (9.5%) had more than 50% improvement and two MAD patients (9.5%) had over 90% seizure reduction. The ketogenic diet had a higher proportion of responders at the 3-month follow up visit. Four KD patients (57%) experienced an improvement in seizure frequency of at least 50%. Two of the KD (28.5%) patients experienced more than a 90% seizure reduction. The most significant period for loss to follow up was between the 3-month visit and the 6-month visit. The most common reasons for discontinuation were worsening seizures, difficulty with strict rules of the diet and high costs. The most common reported side effects were weight loss, constipation and worsening fatigue. Seizure frequency improved if patients remained adherent after 1 year.  Conclusions: Our data confirmed the efficacy of the Modified Atkins diet in the adolescent and adult age groups and identified a critical period in follow up (3 to 6 months). Patients should be offered the ketogenic diet and coached through this period to improve adherence and outcomes.  Funding: None