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Vagus Nerve Stimulation for Epilepsy. Dr. Mark Spitz Dr. Edward Maa August 11, 2017. Conflict of Interest. Nothing to Disclose. VNS Aspire. Experience with VNS. Aspire. 8000 72 24 4. Total . World wide 120,000 University of CO (Dr. Spitz) 505
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Vagus Nerve Stimulation for Epilepsy Dr. Mark Spitz Dr. Edward Maa August 11, 2017
Conflict of Interest Nothing to Disclose
Experience with VNS Aspire 8000 72 24 4 Total • World wide 120,000 • University of CO (Dr. Spitz) 505 • Denver Health (Dr. Maa) 97 • Denver VA (since 2012*) 12 • * prior to 2012 implanted at center of excellence
History 1929 - EEG in Humans 1938 - Vagal nerve stimulation desynchronizes EEG Percival Baily and Fredrich Bremer 1985 - Termination of PTZ seizures Jacob Zabara 1987 - Cyberonics founded 1997 - FDA approval for Epilepsy 2015 – Aspire version approved
Implanting VNS improves efficacy similar to adding a new AED
Magnet gives patients and caretakers a sense of control to potentially abort a seizure
Many Patients are able to stop or decrease severity/duration of seizures with the magnet
VNS has unique problems Surgical Multiple follow up visits to titrate intensity Voice changes Battery life 6.7 years (Aspire)
Clinical and economic impact of vagus nerve stimulation therapy in patients with drug-resistant epilepsy.Helmers et al 2011 Analysis was conducted using multistate Medicaid data 1650 patients
New Aspire Technology FDA Approved 2015
Literature Review Eggleston et al 2014 82% of patient with seizures had an increase in heart rate Not just convulsions Anterior cingulate, insula, posterior orbito-frontal prefrontal cortex & amygdala all play roles in the autonomic nervous system to influence heart rate
Aspire Fischer et al 2015 US Pivotal Trial 10 Centers 20 patients – all adults Inpatient Data 89 Seizures in the EMU 74% had >20% increase in heart rate 61.3% of detected seizures were aborted Median time 35 seconds Outpatient Data At 12 months QOL improved Responder rate was 50% at 6 months
Commonly asked questions Mechanism of Action MRI Compatibility Vagal Nerve Complications
Mechanism of action Unknown in my opinion Neurotransmitter changes – Serotonin Aspartate, GABA, Norepinephrine Cerebral blood flow: Cortex, Thalamus EEG de-synchronization
MRI/VNS Compatibility • No special MRI equipment/coils required • 1.5, 3T magnets • Exclude C7 – L3 • Body coil and extremity coils OK
Vagal nerve side effects are rarely a problem Left vagus nerve is only 20% efferent Anode electrode on the VNS blocks most of efferent action potential
Final Comments Think resective surgery first. VNS is palliative, resective surgery is often curative Make sure patient has epilepsy