Is vagus nerve stimulation a treatment option for patients with drug-resistant idiopathic generalized epilepsy?

BACKGROUND: The value of vagus nerve stimulation (VNS) for treating patients with drug-resistant idiopathic generalized epilepsy (IGE) is not well documented. PATIENTS AND METHODS: Twelve patients (2 males, 10 females) with a mean age of 31 years (11-48 years) and with drug-resistant IGE had VNS implanted in the period 1995-2006. All had generalized seizures documented by video-electroencephalogram. Mean follow-up period was 23 months (9-54 months). RESULTS: There was a total seizure reduction of 61% (P = 0.0002). There was 62% reduction of generalized tonic-clonic seizures (P = 0.0020), 58% of absences (P = 0.0003) and 40% of myoclonic seizures (P = 0.0156). Eight patients were considered responders (>50% seizure reduction); two of these patients became seizure-free. Five out of seven patients with juvenile myoclonic epilepsy were responders. At the last follow-up visit, the patients had reduced the anti-epileptic drug (AED) usage from an average of 2.3 to 1.7 AED per patient (P = 0.0625). Two patients are currently being treated with VNS therapy only. Nine patients reported side effects, which were mostly mild and tended to diminish over time. CONCLUSION: Our results indicate that adjunctive VNS therapy is a favourable treatment option for patients with drug-resistant IGE. Rapid cycling seems worth trying in some of the non-responders.