Abstracts

Rationale: Although there has been a resurgence of interest in dietary treatments for epilepsy, little evidence exists in adults for evaluating who may best respond to the diet. The aim of this retrospective study was to evaluate the efficacy of the Modified Atkins Diet (MAD) and Low Glycemic Index Diet (LGID) among patients with refractory epilepsy who had not undergone epilepsy surgery, specifically evaluating efficacy by subgroups based on imaging abnormalities, epilepsy type, and diet type. Methods: Medical records of patients with medically intractable epilepsy treated with MAD or LGID were retrospectively reviewed. All patients were seen at the Dietary Treatments of Epilepsy Clinic at the Rush Epilepsy Center by an epileptologist and a registered dietitian (RD). All patients attended an educational session, followed by individual meetings with both the RD and epileptologist. Either the MAD or LGID was then initiated based on clinician recommendation and patient preference. Exclusion criteria included patients that 1) were not intractable, 2) had undergone epilepsy surgery prior to initiation of the diet, 3) failed to follow-up at 3 months, 4) were deemed non-compliant, or 5) were < 17 years of age. Outcomes included the following self-reported factors following 3 months of diet therapy: 1) improvement in seizure frequency, defined as >50% improvement in seizure frequency, 2) milder seizures, defined as a self-reported decrease in duration or severity of seizures, and 3) improvement in quality of life, reported as subjective improvement in mood and/or alertness. Sub-group analyses were performed based on 1) abnormal imaging, defined as any finding other than chronic microvascular changes or diffuse atrophy as noted on MRI/CT, 2) type of epilepsy, defined as primary generalized or focal/multifocal, with type being determined clinically, based on seizure semiology, supported by EEG evidence where available, and 3) type of diet at follow up, defined as MAD or LGID. Results: A total of 40 patients were reviewed; patients were primarily female (70%, 28/40), white (75%, 30/40), and had a mean age of 40 years (range 17-70 years). Subgroup analyses (Table 1) revealed that 67% of patients (10/15) with abnormal imaging, and 56% of patients (14/25) with normal imaging reported >50% improvement in seizure frequency. A total of 83% (5/6) of those with generalized epilepsy, and 56% (19/34) of those with focal/multifocal epilepsy reported >50% improvement in seizure frequency. Lastly, 71% of patients (17/24) on MAD, and 44% of patients (7/16) on the LGID reported >50% improvement in seizure frequency. Conclusions: This retrospective study adds to the evidence that both the MAD and LGID are effective in improving seizure control and quality of life in adults with refractory epilepsy, regardless of the presence or absence of abnormal imaging. It suggests that patients with generalized epilepsy may have a better response to modified ketogenic diets than those with focal/multifocal epilepsy. Additionally, patients on more restrictive forms of the diet (MAD) have a better response rate than those on less restrictive forms of the diet (LGID). Future larger cohort studies are needed to further assess these subgroup findings. Funding: None.