IS VAGUS NERVE STIMULATION MORE EFFECTIVE IN MALFORMATIONS OF CORTICAL DEVELOPMENT?
Abstract number :
1.391
Submission category :
Year :
2004
Submission ID :
4419
Source :
www.aesnet.org
Presentation date :
12/2/2004 12:00:00 AM
Published date :
Dec 1, 2004, 06:00 AM
Authors :
Genevieve Demarquay, Alexandra Montavont, Marc Guenot, Jean Isnard, Dominique Rosenberg, Sophie Gehin, Damien Dufournel, Catherine Fischer, Francois Mauguiere, and Philippe Ryvlin
In patients with drug resistant epilepsy associated with either multifocal malformations of cortical development (MCD) or a normal MRI, and not eligible for epilepsy surgery, intermittent chronic Vagus Nerve Stimulation (VNS) is a potential palliative treatment. The purpose of this study was to evaluate the efficacy of VNS therapy in these two populations. Among 31 patients with medically intractable focal seizures, treated with VNS in our center, we identified all cases with either a MCD or a normal MRI, and evaluated the responder rates to VNS at one and two years. There were 14 patients with a normal MRI and nine with a MCD, including 4 periventricular nodular heterotopias, 2 tuberous sclerosis, 2 multifocal dysgenesis and 1 occipital polymicrogyria.
Mean age at the time of VNS implantation in the MCD and cryptogenic groups was respectively 30,1 years and 41,2 years, and mean duration of epilepsy 22,5 and 27 years. Mean follow-up of VNS was 2,6 [plusmn] 2,5 years in the MCD group and 2,5 [plusmn] 1,06 in the cryptogenic group with a minimum of one year. Mean seizure frequency per month was 29,5 [plusmn] 32 and 29,2 [plusmn] 20 in the MCD and cryptogenic group respectively.
In the group with MCD, a 50 % or more reduction in seizure frequency was observed in 6 patients out of 9 (66,6%) at 1 year and in 5 patients out of 5 (100%) at 2 years, whereas in the cryptogenic group, the responder rates were 38,5 % at one and two years of VNS (5 out of 13). Thus, there was a trend towards better results in the MCD group at two years of follow-up, which did not prove significant in this small sample of patients (c 2=3,32; p[lt]0,1) VNS therapy represents a useful therapeutic option for individuals with refractory epilepsy, which might be more efficient in patients with MCD than in patients with cryptogenic partial seizures. A potential explanation for these results may be the implication of the serotoninergic system in both the pathophysiology of epileptogenic MCD, and the mechanisms of VNS. Further evaluation are needed to confirm these results.