Abstracts

This is a Late Breaking abstract

Rationale: Approximately 30% of epilepsy patients are resistant to antiseizure medicines. Non-drug treatments include resective surgery for appropriate cases, neurostimulation and dietary treatments. The evidence base for the use of ketogenic diets is well established for children and adolescents. However, the evidence base for adults with drug-resistant epilepsy (DRE) is less well established.

Methods: Patients with DRE in a tertiary epilepsy clinic were offered modified ketogenic diet (MKD) as a treatment option Patients provided informed consent to take part in an observational trial assessing tolerability and efficacy of MKD. Only MKD naïve subjects were recruited. Exclusion criteria were < 18 yrs, DRE not established, unable to adhere to MKD, transition patient from paediatrics  already established on MKD, surgical candidates and metabolic contraindications. No changes were made to baseline treatments unless there was significant deterioration of seizures. Seizure diaries were collected prospectively to determine reliably countable baseline seizure frequency. Patients were phased on to MKD  with dietetic support over 4 weeks as an outpatient treatment. Finger-prick serum betahydroxybutyrate and glucose levels were measured. Patients were followed up at 3, 6, 9, and 12 months.  Primary outcome was 12 month 50% responder rate.

Results: A total of 79 patients were consented. The age range was 18-73, 60% female and 30% had LD. The antiseizure exposure range prior to MKD was 3-14 drugs and duration of epilepsy was 4 to 67 years. Thirty-one patients did not either start (27) or complete (4) phase. A further 4 patients dropped out prior to completing 3 months. A further 11 were withdrawn at 3 months for lack of efficacy. Twenty-five patients achieved a 12 month 50% reduction in seizure frequency of which 6 were seizure free. This includes 2 subjects who were lost to follow up at 6 and 9 months respectively with the last observation being carried forward for those that completed at least 6 months data collection. Six patients did not achieve the 50% reduction in seizure frequency at 12 months and all were non-responders at 3 months but elected on stay on the diet for secondary benefits such as reduced seizure severity. One patient was lost to follow up after 3 months and 1 patient withdrew after 5 months. This patient was a responder at 3 months but subsequently relapsed despite good adherence. For subjects that completed  phase in, the 12 month 50% responder rate was 57% and the seizure freedom rate was 14%. Of the 79 patients consented, 39% did not complete the phase in. For those that completed phase, in 13% dropped out in the first 3 months. Subsequently, 7% were lost to follow up and 1 subject withdrew.

Conclusions: Although not an RCT, this 12 month prospective observational study demonstrates MKD should be considered in adults with DRE with a 50% responder rate and seizure freedom rate comparable or better than predicted with other treatment options aside from good surgical candidates. The MKD is well tolerated as an outpatient treatment.

Funding: None