Effectiveness of vagal nerve stimulation in medication-resistant epilepsy. Comparison between patients with and without medication changes
Artículo de la doctora García-Pallero en la revista Acta Neurochirurgica
María A. García-Pallero [email protected]
Department of Neurosurgery, University Hospital La Princesa, C/ Diego de León 62, 28006 Madrid, Spain
Department of Neurophysiology, University Hospital La Princesa, C/ Diego de León 62, 28006 Madrid, Spain
Received: 9 August 2016 / Accepted: 9 November 2016 # Springer-Verlag Wien 2016
Background Vagal nerve stimulation (VNS) response is not immediate. A progressive decline in seizure frequency is usually found during a period of 12–18 months after implantation. During this time, the patient’s medication is usually modified, which can create doubts about whether their clinical improvement is due to medication changes or to VNS itself. Our goal is to compare two groups of patients treated with VNS, with and without changes in their medication.
Methods We prospectively analyze 85 patients who were treated with VNS in our hospital between 2005 and 2014. In 43 patients, changes in the antiepileptic drugs (EAD) were not allowed during the postoperative follow-up and they were compared with 42 patients who were left at the option of neurologist make changes in medication. We analyzed the clinical situation at 18 months and compared the two groups. Results Overall, 54.1% of patients had a reduction in seizures of 50% or higher (responders). In the group with no changes in medication, responders reached 63%, while in the group in which changes in medication were allowed, 45.2% were responders. Between responders and non-responders, there were no statistical differences in type of epilepsy, frequency, previous surgery, or intensity of stimulation.
We did not find a statistical difference in seizure frequency reduction between patients with or without changes in medication during their follow-up, so changes in
medication did not improve the outcome. Furthermore, the absence of changes in AED can help to optimize the parameters of the stimulator in order to improve its effectiveness.Keywords Antiepileptic drugs . Epilepsy surgery . Seizures . Vagus nerve