Abstracts

Vagus nerve stimulation (VNS) is accepted as an effective and safe treatment for refractory partial epilepsy. Its value for treating patients with refractory idiopathic generalized epilepsy (IGE) is not well documented., All patients with medically refractory IGE, with EEG/video documented seizures, implanted with VNS in our epilepsy surgery program between 1995 and 2006 were included. A total of 12 patients (2 M, 10 F) from 11 to 48 years (mean age: 30.7 [plusmn] 14.4 years) were identified. Mean follow-up period was 18 months ([plusmn] 14; range, 3 - 48). Patients were treated with an average of 2.25 AEDs/patient at implantation time. Wilcoxon[apos]s paired signed rank test was used for statistical analysis., There was 62% seizure reduction for generalized tonic-clonic seizures (p = 0.0020), 58% for absence seizures (p = 0.0003) and 40% for myoclonic seizures (p= 0.0156). Eight patients were considered responders ([ge] 50% seizure reduction); two of these patients became seizure-free. Two patients had [lt] 50% seizure reduction, and two patients showed no change in seizure frequency. At the last follow-up visit, the patients were receiving an average of 1.67 AEDs (-0.58 AEDs/patient; p = 0.0625). Two patients (both responders) are currently being treated with VNS therapy only. Most commonly used stimulations parameters were: pulse width 250 [mu]s, frequency 20 Hz, 30 seconds on and 5 minutes off. Median output current at the last follow-up was 1.5 mA. Due to lack of response in four patients, parameters were changed to rapid cycling (7 sec. on and 0.2/0.3 min off); two of these patients became then responders. An improvement in alertness ([ldquo]better[rdquo] or [ldquo]much better[rdquo]) was observed in 6 of the patients. According to 5 patients, the magnet was always or most times effective. Nine patients reported some side effects, which were mild and tended to decrease over time., In this patient population, VNS therapy was effective and safe for the treatment of medically refractory IGE. Rapid cycling seems to be effective for some of the non-responders. There was an improvement in alertness in half of the patients, and a trend towards a reduction in the number of AEDs/patient.,