Abstracts

RATIONALE: Vagus Nerve Stimulstion[tm] (VNS) is approved as adjunctive therapy for various partial epilepsies. The NeuroCybernetic Prosthesis[reg] NCP device has various settings that provide chronic stimlation to control seizures. These settings include: output current, signal on and off time, signal frequency, and pulse width. A magnet may be used on demand by patients or care givers to abort seizures. The neurogenerator has independent settings for use of the magnet:magnet output current, magnet on time, and magnet pulse width. Very little is described in the literature regarding actual magnet settings used to abort seizures. Our objective is to study the most clinically effective VNS magnet current settings to abort intractable partial onset seizures. At the end of this activity, participants should be able to discuss the variety of settings that can be sucessful in aborting intractable partial seizures.
METHODS: Prospective analysis of VNS magnet settings parameters necessary to abort various partial seizures was done. While the emphasis of this presentation is on demand magnet use, chronic parameters will be reviewed. Nine patients were followed. There were seven females and 2 males. The age ranged from 26 years to 55 years of age. Duration of VNS therapy was one month to 3 years.
RESULTS: Magnet settings of 2.75 mA - 3.0 mA were found to abort 100% of simple seizures.Approximately 98% of secondarily generalized clonic tonic seizures were aborted. Complex partial seizures without secondarily generalized seizures were aborted with output current ranges of 1.5 mA to 2.25 mA with variable results.
CONCLUSIONS: We conclude highter magnet current should be strongly considered in patients with poorly controlled secodarily generalized clonic tonic seizures. Further studies should be done to confirm these results.