Abstracts

Rationale: The seizure reducing effect of dietary treatment is well documented in children. This study aimed at examining the effect of modified Atkins diet in adults with drug resistant focal epilepsy. Methods: Adults (> 16 years) with drug resistant focal epilepsy were recruited from a tertiary referral epilepsy center and randomized to either 12 weeks on modified Atkins diet (maximal daily carbohydrate allowance of 16 grams) (n = 37) or habitual diet (n = 38). The patients were enrolled from March 2011 to March 2017.Participant flow is shown in figure 1. Data from 25 participants in the diet group and 33 in the control group were available for final analysis. The effect of the diet was evaluated by calculating the per cent change in the mean weekly seizure frequency from baseline to weeks 5-12 of the diet period.To assess compliance, evening blood ketosis (finger-prick) was measured in hospital stays and daily evening urine ketosis was recorded at home during 12 weeks on the diet. Dietary ketogenic ratio was calculated from 3 days’ weighed food records in week 10. Serum concentrations of antiepileptic drugs (AED) were measured in venous blood after an overnight fast.Fisher’s exact test was used to analyze the diet’s effect on seizure frequency. Per cent change in serum concentration of AEDs was tested with Student’s t-test. Results: The two groups were similar with respect to baseline characteristics; the mean age and female gender in the diet and the control group was 35.2 and 37.6 years and 15 (60%) and 16 (49%), respectively. Mean number of previously tried AEDs was 7.8 and 9.3, respectively.Of the 25 who completed the diet intervention, three (12%) achieved >50% seizure reduction while four (16%) experienced >50% seizure increase. In the control group (n=33) three (9%) reported > 50% seizure reduction and two (6%) experienced seizure increase, p=0.52. The diet was well tolerated, with no serious adverse events reported.We observed a decrease in mean per cent serum concentration of all available AEDs (p < 0.001). The mean decrease was -17% (95% Confidence Interval (CI), -10 to -23) in the diet group, while a small mean increase was found in the control group, 2% (95% CI, -3 to 7).In the diet group, the mean ketogenic ratio was 1.7 (95% CI, 1.5 to 2.1) (n=23). Mean evening blood ketosis measured during hospital stay was 1.0 mmol/L (range: 0.1 to 4.3, median: 0.6) and the at-home 12 weeks average daily evening urinary ketosis was 5.6 mmol/L (95% CI, 4.0 to 7.2) (n=23), indicating good compliance. Conclusions: In this study of adults with severe drug resistant focal epilepsy, a modified Atkins diet did not reduce seizure frequency after 12 weeks on a group level. There were, however, large inter-individual variations. A diet-induced seizure reducing effect may have been counteracted by a fall in the serum concentrations of AEDs. Funding: This project has been made possible by the Norwegian ExtraFoundation for Health and Rehabilitation.