Abstracts

Rationale: Vagal nerve stimulation (VNS) can help improve epileptic control in clients who have had insufficient epileptic control despite many different antiepileptic medications (AED's) or combinations of AED's. VNS is often used in conjunction with AED's in difficult to treat epilepsy. Topiramate is an AED with a common side effect of weight loss. Vagal nerve stimulation with parameters typically used for the treatment of epilepsy is not usually associated with clinically significant weight loss. A series of nine clients' case notes with four controls were reviewed to examine the effect of the combination of topiramate and VNS on epileptic control and weight. The goal of this case series was to assess the effect of topiramate in combination with VNS on weight and epileptic control. Methods: Case notes of nine clients with difficult to treat epilepsy were reviewed and divided into those who had a vagal nerve stimulator and were on topiramate and clients with a vagal nerve stimulator and pharmacotherapy other than topiramate. The first group contained five clients who were taking topiramate with inadequate effect, having previously been on other antiepileptic drugs (AED's) or combinations of AED's. Topiramate therapy continued after VNS was fitted. In the second group were four clients who had been treated with pharmacotherapy and did not gain satisfactory control of their epilepsy. They were fitted with a vagal nerve stimulator but were not on topiramate at the same time. They continued with pharmacotherapy other than topiramate in combination with their vagal nerve stimulators. Literature search was completed. Results: In the first group topiramate did not cause its well known side effect of weight loss when used alone and did not have an adequate effect on seizure reduction. However when clients on topiramate were fitted with a vagal nerve stimulator all of the clients gained better seizure control (100%) and four out of the five clients (80%) lost weight in conjunction with improved seizure control. Furthermore one client put weight back on when the battery of the VNS failed and suffered worsened seizure control at the same time. When the battery was replaced they began to lose weight again and regained better seizure control. The client who did not lose weight had co morbid hypothyroidism. In the second group, who were treated with vagal nerve stimulator and medication other than topiramate, all four had improved seizure control after VNS was inserted (100%), although weight loss was noticed in only one out of the four clients (25%). Conclusions: If topiramate has been unsuccessful it could be revisited with VNS in those with difficult to treat epilepsy, and could be a viable treatment option here. If topiramate has not been successful and not caused weight loss when used alone or as part of a medical regime, it may be worth revisiting after VNS insertion in people who are overweight with difficult to treat epilepsy.