Rationale: About one third of patients with epilepsy have pharmacologically refractory epilepsy. This subset of patients pose a significant challenge to the epilepsy community, with negative impact on development, co-morbidities, and economic burden. Both the ketogenic diet (KD) and Vagus Nerve Stimulator (VNS) have been well studied and established effective treatments for patients with refractory epilepsy. This study assesses the efficacy of the combined treatment using VNS and KD.

 Methods: Retrospective chart review assessing seizure control in patients who are treated with both VNS and KD. Particular attention was given to the seizure control achieved with both treatments to assess if combined therapy provided improved efficacy. Seizure outcome was defined as a 50% or more improvement in seizures from baseline.

Results: A total of 473 patients have VNS implanted and 150 patients are treated with KGD. 13 patients had both VNS and KD treatment. Of these patients, 10 (Group A) had KD started after VNS had been implanted for at least 18 months. And 3 patients (Group B) had VNS implanted after being treated with KGD for at least 6 months. Response from a seizure control perspective was assessed 6 months after the introduction of the second therapy.

No change

< 50%

50%-70%

>75%

Group A

2 (20%)

1(10%)

4(40%)

3 (30%)

Group B

0

1 (33%)

2 (67%)

 Conclusion:  The simultaneous treatment with both VNS, and KD potentially provides synergistic anti-epileptic effect that is cumulative and seems sustainable over a 12 months period after the introduction of both therapies