Abstracts

Rationale: Ketogenic dietary treatments for epilepsy have been used since 1921 in children and adults with intractable epilepsy. The classic ketogenic diet and the modified Atkins diet (MAD) are both nonpharmacologic therapies shown to be effective. Approximately 55% of adults started on the MAD at the Johns Hopkins Adult Epilepsy Diet Center (AEDC) are women of childbearing age. The goal of these dietary treatments is to reduce seizures through carbohydrate reduction and the breakdown of fat into ketone bodies, resulting in ketosis. However, it is known that other conditions that induce ketosis (e.g. starvation), may lead to menstrual dysfunction. In addition, 30-50% of women with epilepsy have a pattern of seizures that correlates with their menstrual cycle, termed catamenial epilepsy. Women with catamenial epilepsy typically have an increase in seizure frequency around either ovulation or menstruation. There have been anecdotal reports from women in the AEDC that have noticed an overall reduction in seizures while on MAD, yet develop a new pattern of residual seizures occurring in a catamenial pattern. Methods: There were 46 pre-menopausal women in the AEDC from 2010-2013 who started the MAD and stayed on it for 3 or more months. Patient charts were reviewed for calendars submitted by the women (which charted dates of seizures and menses) and self-report of a catamenial pattern during a clinic visit. The calendars were analyzed for seizure occurance and frequency in relation to the phases of the menstrual cycle to determine if they fulfilled criteria for a catamenial pattern each month. Results: Of the 46 women analyzed, 11 self-reported that seizures seemed related to their menses since starting MAD. Comprehensive calendars were available for 5, and of these, 4 had a clear catamenial pattern. None had evidence of a catamenial pattern immediately after starting the diet, but typically the number of months with this pattern increased over time compared to pre-MAD. One patient reported "carbohydrate cravings" during her menses and difficulty adhering to the diet at that time. Conclusions: Women may develop a catamenial epilepsy pattern on MAD. Possible explanations include difficulty maintaining ketosis around ovulation or menses secondary to a hormone mediated mechanism or simply poor adherence to the diet during that time. A more in depth investigation into the relationship between the menstrual cycle, seizures, and ketosis is needed as ketogenic diets become more widely used in adult women with epilepsy.