Abstracts

Rationale: The vagus nerve stimulator (VNS) is approved for the treatment of medically intractable complex partial seizures (CPS), for which it is an effective treatment. A substantial number of patients with CPS also have psychogenic non-epileptic seizures (PNES). We questioned whether VNS is effective in patients who have CPS and PNES. Methods: We surveyed our adult clinic population for patients who had both CPS and PNES documented by video-EEG (VEEG) for whom treatment included VNS. We evaluated the effectiveness of VNS in all patients who met these criteria. Results: Eight adults (5 women, 3 men; mean age 39 years) met the above criteria. Mean age at the onset of epilepsy was 13 years. Mean duration of VNS therapy was 40 months (range 5-74 months). A total of 54 events were recorded by VEEG, including 17 CPS and 37 PNES. The VNS effected complete control of generalized tonic-clonic seizures and produced > 90% reduction in CPS for the three men. None of five women reported benefit to seizure control, although one enjoyed a more euphoric mood. Two women indicated that their seizures were more frequent after VNS, leading to removal of the device in one case and deactivation in the other. Conclusions: VNS should be considered with caution in patients who have a combination of CPS and PNES, particularly women.