According to the Epilepsy Foundation of America, epilepsy is the third leading neurological disorder, affecting more than 3 million Americans, and more than 200,000 new cases are diagnosed each year. The estimated annual cost of epilepsy is $15.5 billion in direct and indirect costs. For some patients, antiepileptic drugs (AEDs) will effectively control seizures, allowing them to lead independent lives. However, not all patients will benefit from AEDs. Nearly 1 million individuals suffer from drug-resistant epilepsy in which seizures are not controlled by drugs, or side effects of these medications are intolerable. Additionally, AEDs can be harmful if taken during pregnancy.
Without effective treatment, the visible nature of epileptic seizures—muscle twitches, convulsions, massive muscle spasms, tongue-biting and staring spells, to name a few—can make it difficult for patients to live normal lives. Children find it difficult to concentrate in school, and the unpredictable nature of seizures can make extracurricular activities and bonding with peers extremely challenging. For adults, epilepsy can force patients not to drive or work, and building and maintaining relationships can be difficult.
Some alternative treatments can free patients from the side effects of AEDs and allow them to enjoy greater quality of life. Some of these options include the ketogenic diet, which is high in fat and low in carbohydrates and protein. Other options include brain surgery and vagus nerve stimulation (VNS). In epilepsy surgery, a portion of a specific region in the brain thought to be causing seizures is removed. Patients are candidates for brain surgery if the source of seizures can be identified, accessed, and removed safely. VNS is much less invasive than brain surgery and does not require the strict adherence and planning necessary in the ketogenic diet. For patients with drug-resistant epilepsy, in particular, VNS can be quite effective.
First approved by the FDA as an adjunctive therapy for epilepsy in 1997, more clinicians are now considering use of VNS for drug-resistant epilepsy. The device is the size of a small pocket watch and clinicians often refer to it as a pacemaker for the brain. It’s implanted in the left chest and sends mild electrical impulses to the brain via the vagus nerve in the neck. VNS offers an added bonus in that the devices come with a magnet that, when swiped over the site of the implant, can lessen a seizure or abort it completely. Procedures to implant VNS devices typically take between 45 and 60 minutes to complete. Most patients can leave the hospital the same day they have the procedure. Using an external programming system, much like a personal digital assistant and wand, physicians can adjust the timing and amount of stimulation for patients.
Unlike the debilitating side effects associated with AEDs, common side effects of VNS are minor and include voice alteration, tickling in the throat, cough, and shortness of breath. Most patients have noted, however, that these side effects typically occur only when the device is stimulating the vagus nerve and often diminish over time. Most patients with VNS continue with the treatment and report experiencing improvements in seizure control over time. Some patients who still require AEDs even after VNS are able to reduce the number or dosage of their AEDs. To date, more than 50,000 patients worldwide have received VNS, helping patients enjoy greater quality of life and live with fewer seizures or seizure-free.
Readings & Resources (click to view)
Epilepsy Foundation of America. Epilepsy Fact Sheet. Available at www.epilepsyfoundation.org/about/factsfigures.cfm. Accessed November 19, 2007.
Vonck K, De Herdt V, Boon P. Vagal nerve stimulation–a 15-year survey of an established treatment modality in epilepsy surgery. Adv Tech Stand Neurosurg. 2009;34:111-146.
Boon P, Raedt R, de Herdt V, Wyckhuys T, Vonck K. Electrical stimulation for the treatment of epilepsy. Neurotherapeutics. 2009;6:218-227.
Kuba R, Brázdil M, Kalina M, et al. Vagus nerve stimulation: longitudinal follow-up of patients treated for 5 years. Seizure. 2009;18:269-274.
Balabanov A, Rossi MA. Epilepsy surgery and vagal nerve stimulation: what all neurologists should know. Semin Neurol. 2008;28:355-363.