VAGUS NERVE STIMULATION THERAPY AFTER FAILED CRANIAL SURGERY FOR INTRACTABLE EPILEPSY

Abstract OBJECTIVE: To determine the effectiveness of vagus nerve stimulation (VNS) therapy among patients with persistent or recurrent seizures after lobar resection, callosotomy, and other cranial operations for intractable epilepsy. METHODS: Data were obtained from the VNS therapy patient outcome registry, which was established after United States Food and Drug Administration approval of the VNS device in 1997 as a means of capturing open-label clinical data outside of protocol. The integrity of the systems for collecting and processing registry data was authenticated by an independent auditing agency. The effect of potential selection bias, however, remains uncertain. RESULTS: Two nonconsecutive cohorts were compared: patients tracked in the registry who had previously undergone cranial surgery for epilepsy (CS group, n = 921) and those who had not (non-CS group, n = 3822). For the CS group, the median reduction in seizure frequency was 42.5% after 3 months of VNS therapy, 42.9% at 6 months, 45.7% at 12 months, 52.0% at 18 months, and 50.5% at 24 months. For the non-CS group, analogous rates were 47.0%, 52.9%, 60.0%, 62.7%, and 66.7%, respectively. In the CS group, seizures were reduced by at least 50% in 55.1% of patients, at least 75% in 31.4% of patients, at least 90% in 17.3% of patients, and 100% in 5.1% of patients after 24 months of VNS therapy. Response rates were more pronounced in the non-CS group: at least 50% in 62.2% of patients, at least 75% in 43.7% of patients, at least 90% in 26.8% of patients, and 100% in 8.3% of patients. Patients in both groups experienced marked improvements in quality of life parameters. CONCLUSION: The effectiveness of VNS is maintained during prolonged stimulation, and overall seizure control continues to improve with time. Patients in whom prior cranial surgery had failed did not respond as favorably as all other patients receiving VNS therapy. Nonetheless, many of the former group improved substantially. Thus, on the basis of these open-label data, VNS therapy represents a potentially palliative treatment option for patients with refractory seizures after failed cranial surgery.

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Implanted vagus nerve stimulation in 126 patients: surgical technique and complications

Perspectives in Surgery ◽

10.33699/pis.2020.99.7.304-310 ◽

2020 ◽

Vol 99 (7) ◽

Keyword(s):

Vagus Nerve ◽

Vocal Cord ◽

Nerve Stimulation ◽

Vagus Nerve Stimulation ◽

Pulse Generator ◽

Operative Procedure ◽

Intractable Epilepsy ◽

Vagal Nerve ◽

University Hospital ◽

Nerve Stimulator

Introduction: Vagus nerve stimulation is a palliative treatment for patients with refractory epilepsy to reduce the frequency and intensity of seizures. A bipolar helical electrode is placed around the left vagus nerve at the cervical level and is connected to the pulse generator placed in a subcutaneous pocket, most commonly in the subclavian region. Methods: Between March 1998 and October 2019, we performed 196 procedures related to the vagal nerve stimulation at the Neurosurgery Department in Motol University Hospital. Of these, 126 patients were vagal nerve stimulator implantation surgeries for intractable epilepsy. The cases included 69 female and 57 male patients with mean age at the time of the implantation surgery 22±12.4 years (range 2.1−58.4 years). Results: Nine patients (7.1%) were afflicted by complications related to implantation. Surgical complications included postoperative infection in 1.6%, VNS-associated arrhythmias in 1.6%, jugular vein bleeding in 0.8% and vocal cord paresis in 2.4%. One patient with vocal cord palsy also suffered from severe dysphagia. One patient (0.8%) did not tolerate extra stimulation with magnet due to a prolonged spasm in his throat. The extra added benefit of vagus stimulation in one patient was a significant reduction of previously regular severe headaches. Conclusion: Vagus nerve stimulation is an appropriate treatment for patients with drug-resistant epilepsy who are not candidates for focal resective surgery. Implantation of the vagus nerve stimulator is a relatively safe operative procedure.

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Vagus Nerve Stimulation for Intractable Epilepsy

Youmans Neurological Surgery ◽

10.1016/b978-1-4160-5316-3.00069-1 ◽

2011 ◽

pp. 807-812

Author(s):

James E. Baumgartner ◽

Gretchen K. Von Allmen

Keyword(s):

Vagus Nerve ◽

Nerve Stimulation ◽

Vagus Nerve Stimulation ◽

Intractable Epilepsy

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Long term effect of vagus nerve stimulation in pediatric intractable epilepsy: an extended follow-up

Child s Nervous System ◽

10.1007/s00381-015-3004-z ◽

2016 ◽

Vol 32 (4) ◽

pp. 641-646 ◽

Cited By ~ 24

Author(s):

Ayse Serdaroglu ◽

Ebru Arhan ◽

Gökhan Kurt ◽

Atilla Erdem ◽

Tugba Hirfanoglu ◽

...

Keyword(s):

Vagus Nerve ◽

Nerve Stimulation ◽

Vagus Nerve Stimulation ◽

Intractable Epilepsy ◽

Term Effect ◽

Long Term Effect

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P.018 Forced normalization after vagal nerve stimulation in a case of intractable Lennox-Gastaut syndrome

Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques ◽

10.1017/cjn.2018.120 ◽

2018 ◽

Vol 45 (s2) ◽

pp. S20-S20

Author(s):

A Denton ◽

A Vitali ◽

K Waterhouse ◽

J Tellez-Zenteno

Keyword(s):

Vagus Nerve ◽

Nerve Stimulation ◽

Vagus Nerve Stimulation ◽

Psychiatric Symptoms ◽

Intractable Epilepsy ◽

Complex Case ◽

Drop Attacks ◽

Intractable Seizures ◽

Forced Normalization ◽

Clonic Seizures

Background: Forced normalization is the development of psychiatric symptoms in a patient experiencing remission of intractable seizures. The mechanism of this phenomenon is unknown. We present a complex case of Lennox Gastaut syndrome that experiences forced normalization after vagus nerve stimulation (VNS). Methods: This case details a 31-year-old male with seizures since early childhood. The patient has intractable epilepsy and failed AEDs, VNS, and a partial callosotomy. Results: The patient was in remission from 2-12 years old, when seizures returned at a frequency of 2-5 per day. He has multiple types of seizures including drop attacks, absences, and tonic-clonic seizures. Patient experienced status epilepticus multiple times. Twelve AEDs were failed before VNS was started in 2010, which helped curb the severity of seizures and the potential for clusters. Forced normalization developed over the course of treatment with VNS. The patient behavior was characterized by aggression, paranoia, and hallucinations. VNS was turned off late in 2010 and then re-started in January of 2011. Patient proceeded to cycle between several days of seizures without psychiatric symptoms and several days of psychosis without seizures. Conclusions: Vagus nerve stimulation gave way to forced normalization, characterized here as aggressive behaviour and psychosis. Forced normalization is seen commonly after epilepsy surgery, but rarely following VNS.

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Vagus Nerve Stimulation for Intractable Epilepsy: Outcomes in Children and Adults

Neuromodulation Technology at the Neural Interface ◽

10.1111/j.1525-1403.2009.00232.x ◽

2009 ◽

Vol 13 (1) ◽

pp. 44-49 ◽

Cited By ~ 3

Author(s):

Won Chul Namgung ◽

Tae Sung Ko ◽

Sang-Ahm Lee ◽

Joong Ku Kang ◽

Seok Ho Hong ◽

...

Keyword(s):

Vagus Nerve ◽

Nerve Stimulation ◽

Vagus Nerve Stimulation ◽

Intractable Epilepsy

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Vagus Nerve Stimulation in Intractable Epilepsy Associated With SCN1A Gene Abnormalities

Journal of Child Neurology ◽

10.1177/0883073816687221 ◽

2017 ◽

Vol 32 (5) ◽

pp. 494-498 ◽

Cited By ~ 11

Author(s):

Stephen P. Fulton ◽

Kate Van Poppel ◽

Amy L. McGregor ◽

Basanagoud Mudigoudar ◽

James W. Wheless

Keyword(s):

Vagus Nerve ◽

Nerve Stimulation ◽

Vagus Nerve Stimulation ◽

Seizure Control ◽

Intractable Epilepsy ◽

Myoclonic Epilepsy ◽

Dravet Syndrome ◽

Severe Myoclonic Epilepsy ◽

Scn1a Gene ◽

Myoclonic Epilepsy Of Infancy

Mutations in the SCN1A gene cause a spectrum of epilepsy syndromes. There are 2 syndromes that are on the severe end of this spectrum. The classic severe form, Dravet syndrome, is an epileptic encephalopathy of childhood, causing cognitive decline as well as intractable seizures. Severe Myoclonic Epilepsy of Infancy–Borderline (SMEIB) is a term used to include cases with similar severities as those with Dravet syndrome, but lacking a single feature of classic severe myoclonic epilepsy of infancy. Vagus nerve stimulation is a nonpharmacologic treatment for intractable epilepsy. A retrospective review was conducted of patients with deleterious SCN1A mutations who had vagus nerve stimulation placement for treatment of their intractable epilepsy. These children had onset of their epilepsy between 3 and 29 months of age. Seizure control was assessed 6 months after implantation. Twenty patients are included in the study, with 12 implanted at our institution. Nine of the 12 patients implanted at our institution, who had confirmed pre- and post-implantation seizure assessments, showed improvement in seizure control, which was defined as >50% reduction in generalized tonic-clonic seizures, and 4 of those 12 reported improvement in cognitive or speech development. Seven of the 8 patients not implanted at our institution reported subjective benefit, with 4 relating “marked improvement” or seizure freedom. Vagus nerve stimulation appears to impart a benefit to children with deleterious SCN1A gene abnormalities associated with intractable epilepsy.

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