EC Neurology

Background: Epilepsy is a neurological disorder caused by a discharge due to neuronal hyperexcitability, which causes seizures, affecting the quality of life in people who suffer from it, mainly because there is cognitive impairment due to seizures and physical limitations. Palliative treatment options for refractory patients are a ketogenic diet, Vagus Nerve Stimulation (VNS), and functional epilepsy surgery (resection surgery).

Aims: We Present the experience of the vagal stimulator implantation to reduce health expenses in the population with refractory epilepsy at the 20 De Noviembre National Medical Center, ISSSTE, in Mexico City; We sought to evaluate the percentage of improvement of patients with drug-resistant epilepsy to medical treatment, based on the percentage reduction in the frequency of seizures, quality of life, costs for medical services, and acquisition of antiepileptic drugs.

Materials and Methods: Data from patients treated with VNS at “20 de Noviembre” medical center, between January 2005 and December 2018, with a minimum follow-up time of 6 months, were included. The Vagal Neurostimulator was placed in 29 patients, of which 12 patients (41.4%) were female and 17 patients (58.6%) were male.

Results: The mean number of crises per day before implantation was 35; After implantation, the mean concerning the number of crises, was 12. The percentage reduction in the number of crises per day after the implantation of the VNS had a minimum of 33.3% and a maximum of 99.2%, the Mean was 65.2%, with a standard deviation of 16.4. The use of drugs in a general way by the 29 patients was reduced from 127 antiepileptic drugs before the placement of the vagus nerve stimulator (VNS), to 75 drugs used in a general way.

Conclusion: Results of the trials and the experience accumulated in recent years place the implant of the vagal neurostimulator (VNS), as an alternative in the treatment of refractory cases. It is now considered adjuvant, with few and transient adverse effects and a favorable impact on the frequency, duration of crises, and quality of life that justify its indication.

Keywords: Vagus Nerve Stimulation (VNS); Refractory Epilepsy; Antiepileptic Drugs

1. Ropper AH., et al. “Adams y Victor Principios de neurología (10^th edition)”. Ciudad de México, México: McGraw-Hill (2017).
2. Hauptman JS. “Vagal nerve stimulation for pharmacoresistant epilepsy in children”. Surgical Neurology International (2012).
3. Campos A Ulate. “Vagus nerve stimulator implantation for epilepsy in a paediatric hospital: outcomes and effect on quality of life” (2015).
4. Fisher RS., et al. “Assessment of vagus nerve stimulation for epilepsy: report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology”. Neurology1 (1997): 293-297.
5. Hauptman JS. “Vagal nerve stimulation for pharmacoresistant epilepsy in children”. Surgical Neurology International (2012).
6. Morris GL. “Evidence-Based Guideline Update: Vagus Nerve Stimulation for the Treatment of Epilepsy”. Epilepsy Currents6 (2013): 297-303.
7. Chen CYi. “Short-term Results of Vagus Nerve Stimulation in Pediatric Patients with Refractory Epilepsy”. Pediatrics and Neonatology3 (2012): 184-187.
8. Campos A Ulate. Vagus nerve stimulator implantation for epilepsy in a paediatric hospital: outcomes and effect on quality of life (2015).
9. Fisher RS. “Evaluación de la estimulación del nervio vago para epilepsia” (1997).
10. Elliott RE. “Vagus nerve stimulation for children with treatment-resistant epilepsy: a consecutive series of 141 cases”. Journal of Neurosurgery Pediatrics5 (2011): 491-500.
11. Henry TR. “Brain Blood-flow Alterations Induced by Therapeutic Vagus Nerve Stimulation in Partial Epilepsy: II”. Prolonged Effects at High and Low Levels of Stimulation (2004b).
12. Ben-Menachem E. “Vagus-nerve stimulation for the treatment of epilepsy”. The Lancet Neurology8 (2002): 477-482.
13. Morris GL. “Evidence-Based Guideline Update: Vagus Nerve Stimulation for the Treatment of Epilepsy”. Epilepsy Currents6 (2013): 297-303.
14. Hauptman JS. “Vagal nerve stimulation for pharmacoresistant epilepsy in children”. Surgical Neurology International (2012).
15. Fisher RS. Evaluación de la estimulación del nervio vago para epilepsia (1997).
16. Campos A Ulate. Vagus nerve stimulator implantation for epilepsy in a paediatric hospital: outcomes and effect on quality of life (2015).
17. Kwan P. “Definition of drug resistant epilepsy: Consensus proposal by the ad hoc Task Force of the ILAE Commission on Therapeutic Strategies”. Epilepsia6 (2009): 1069-1077.
18. Fisher RS., et al. “Operational classification of seizure types by the International League Against Epilepsy: Position Paper of the ILAE Commission for Classification and Terminology”. Epilepsia4 (2017): 522-530.
19. Manford M. “Recent advances in epilepsy”. Journal of Neurology8 (2017): 1811-1824.
20. Rugg-Gunn F., et al. “Epilepsy surgery”. Practical Neurology1 (2020): 4-14.
21. Begley C., et al. “The global cost of epilepsy: A systematic review and extrapolation”. Epilepsia4 (2022): 892-903.
22. Orosz I., et al. “Vagus nerve stimulation for drug-resistant epilepsy: a European long-termstudy up to 24 months in 347 children”. Epilepsia10 (2014): 1576-1584.
23. Morris GL 3rd., et al. “Evidence-based guideline update: vagus nerve stimulation for the treatment of epilepsy: report of the Guideline Development Subcommittee of the American Academy of Neurology”. Neurology16 (2013): 1453-1459.
24. Chen CY., et al. “Taiwan child neurology society VNS study group. Short-term results of vagus nerve stimulation in pediatric patients with refractory epilepsy”. Pediatrics and Neonatology 53 (2012): 184-187.
25. Révész D., et al. “Complications and safety of vagus nerve stimulation: 25 years of experience at a single center”. Journal of Neurosurgery: Pediatrics1 (2016): 97-104.
26. Takamichi Yamamoto. “Vagus Nerve Stimulation Therapy: Indications, Programing, and Outcomes”. Neurologia Medico-Chirurgica5 (2015): 407-415.
27. A Ulate-Campos., et al. “Resultados de la colocación del estimulador del nervio vago en epilepsia y calidad de vida en un hospital pediátrico”. Sociedad Española de Neurología8 (2015): 461-528.
28. Uthman BM., et al. “Treatment of epilepsy by stimulation of the vagus nerve”. Neurology7 (1993): 1338-1345.
29. Ben-Menachem E., et al. “Vagus nerve stimulation for treatment of partial seizures: 1. A controlled study of effect on seizures. First International Vagus Nerve Stimulation Study Group”. Epilepsia3 (1994): 616-626.
30. Labar D., et al. “Vagus nerve stimulation for medication-resistant generalized epilepsy. E04 VNS Study Group”. Neurology7 (1999): 1510-1512.
31. Handforth A., et al. “Vagus nerve stimulation therapy for partial-onset seizures: a randomized active-control trial”. Neurology1 (1998): 48-55.
32. Hornig GW., et al. “Left vagus nerve stimulation in children with refractory epilepsy: an update”. Southern Medical Journal 90 (1997): 4848.
33. Lundgren J., et al. “Vagus nerve stimulation in 16 children with refractory epilepsy”. Epilepsia 39 (1998): 80913.
34. Murphy JV., et al. “Left vagal nerve stimulation in six patients with hypothalamic hamartomas”. Pediatric Neurology 23 (2000): 1678.
35. Ohemeng KK and Parham K. “Vagal Nerve Stimulation: Indications, Implantation, and Outcomes”. Otolaryngologic Clinics of North America1 (2020): 127-143.