[Vagus nerve stimulation and refractory partial epilepsies]

Since 1988, intermittent electric stimulation of the cervical portion of the left vagus nerve is proposed as additive treatment of epilepsy. The effects of vagus nerve stimulation (VNS) on the modulation of cerebral activity, shown in animals and confirmed by the data of functional imagery in human beings, can be apprehended by the anatomic and functional characteristics of this nerve, whereas the anti-epileptic mode of action remains unknown. Following five controlled multicentric studies, including 440 patients presenting refractory epilepsy, 20,000 patients worldwide have been treated by VNS for this indication. Proposed as additive symptomatic treatment of refractory epilepsies, VNS has proven effective and well tolerated by both children and adults with refractory partial epilepsy. After 2 years of treatment, patients achieve an overall average of 40 p. 100 reduction of seizure frequency. In 40 to 50 p. 100 of the patients, the frequency of seizure can even be decreased by 50 p. 100. Moreover, even in the absence of a significant reduction of seizure, patients subjected to this treatment have reported an improvement in their quality of life. The economic surveys also show a favorable impact of VNS on the management of refractory partial epilepsies.