The study evaluated the effectiveness, tolerability and safety of VNS therapy for children after three months and six months of use in the largest reported group of children to receive VNS. The study found that VNS therapy was safe, well tolerated and highly effective in reducing the frequency of seizures over time:
- Average seizure reduction at six months was approximately 45%;
- Over half of patients experienced more than a 50% reduction in seizures at both three and six months.
Treatment with VNS therapy not only resulted in a decrease in seizure frequency but also in a striking improvement in various aspects of quality of life. After three and six months, improvements were reported in alertness, verbal communication, school performance, clustering of seizures and postictal (post-seizure) periods. These improvements occurred not only among patients who responded well to VNS, but also among patients who were considered non-responders (i.e., experienced less than 25% reduction in seizure frequency).
"Findings from this retrospective study reveal an even greater reduction in seizure frequency than in the initial clinical trials of VNS and are comparable with reductions reported in adolescents and adults," said Sandra L. Helmers, MD, Associate Professor, Department of Neurology, Emory University School of Medicine. “This is a very promising therapy for children with difficult-to-treat epilepsy. Other research recently published in the New England Journal of Medicine indicates that epilepsy patients who find more than three medications ineffective are unlikely to respond to further medication. Our research indicates VNS should be considered as a treatment for such individuals, even young children.”
Epilepsy is a chronic neurological disorder characterized by recurrent, unprovoked seizures. Nearly 2.3 million Americans are affected by the condition, including approximately 422,000 children aged 18 years and younger.
“The typical patient in this study was 12 years old, started having seizures at the age of two and had already tried nine antiepileptic drugs (AEDs) before trying VNS therapy," stated Helmers. “Uncontrolled seizures are not only linked with a poor quality of life, but can also put children at a greater risk of brain damage and increased mortality. Introducing effective seizure control treatments such as VNS earlier, rather than later, may help children avoid these negative outcomes."
About VNS
VNS stimulates the limbic system, a group of related brain structures that affect mood, motivation, sleep, appetite, alertness and seizures. VNS is delivered to the left cervical vagus nerve by a stopwatch-sized generator – the NeuroCybernetic Prosthesis (NCPâ) System – implanted just under the skin in the left chest area. VNS delivers pre-programmed, mild, intermittent electrical pulses to the left vagus nerve 24 hours a day. The implantation procedure takes approximately one hour and usually requires no overnight hospitalization.
VNS is safe and has not been reported to cause the type of side effects sometimes associated with AEDs (e.g., cognitive dysfunction, liver damage and blood disorders). Common side effects associated with VNS include hoarseness, sore throat, shortness of breath and coughing, all of which typically occur only during stimulation and diminish over time. VNS was first approved for people with epilepsy in Europe in 1994 and for use as an adjunctive therapy in reducing the frequency of seizures in adults and adolescents over 12 years of age with partial onset seizures which are refractory to antiepileptic medication in the United States in 1997. To date, more than 14,000 patients in 24 countries have been treated with VNS.
About Cyberonics
Cyberonics, Inc. was founded in 1987 to design, develop and market medical devices for the treatment of patients with epilepsy and other debilitating disorders using a unique therapy, vagus nerve stimulation (VNS). VNS therapy is delivered by the Cyberonics NeuroCybernetic Prosthesis (NCPâ) System, a pacemaker-like implantable medical device that delivers mild electrical stimulation to the left vagus nerve in the patient’s neck. VNS with the Cyberonics NCP System was approved by the FDA on July 16, 1997 for use as an adjunctive therapy in reducing the frequency of seizures in adults and adolescents over 12 years of age with medically refractory partial onset seizures. In addition to the U.S., the NCP System is currently approved for sale as a treatment for epilepsy in all the member countries of the European Union, Canada, Australia and other markets. VNS delivered by the NCP System is at various levels of investigational clinical study as a potential treatment for depression, anxiety disorders, Alzheimer's Disease, chronic migraine headache and obesity. VNS with the Cyberonics NCP System was recently approved for sale in the European Union and in Canada as a treatment of depression in patients with treatment resistant or treatment intolerant major depressive episodes including unipolar depression and bipolar disorder (manic depression). Cyberonics is headquartered in Houston, Texas, USA, with an office in Belgium. For additional information please visit www.cyberonics.com.
Journal
Journal of Child Neurology