What is VNS?

• A new type of therapy for medically intractable epilepsy.
• The Cyberonics NCP System consists of:
  • Pacemaker generator (3 to 5 year battery life)
  • Nerve stimulation electrode
  • Intermittent stimulation (adjustable stimulation parameters)
  • Magnet on-demand therapy
• Implanted device that electronically stimulates the left vagus nerve.
• Intermittent electrical stimulation of the Vagus Nerve.
• Why the Vagus?
  • Easy access
  • No pain fibers
  • 80% to brain
  • Widespread distribution in brain
• Stimulation parameters programmable & adjustable by computer.
• Improves seizure control and quality of life in a significant % of patients with chronic uncontrolled seizure disorders.
• Long-lasting relief from daily Quality of Life compromises which accompany epilepsy.
• Easy to use.
• Device Advantages
  • Long-lasting therapy
  • Targeted therapy
  • No "medication" interactions
  • Easy to use
  • Guaranteed compliance
  • Magnet activation = less fear, more control
    • "seize control"
• “Safe and Effective” per FDA.
• Long-lasting relief from recurrent symptoms.
• Daily Quality of Life improvements > Daily Quality of Life compromises for those with epilepsy.
  

 

• Overview: VNS Patient exposure:

 

• VNS: Animal Studies (Epilepsy Models)

• Historical Overview of VNS Therapy
  • 1985 First Animal Studies (J. Zabara, Temple University)
  • 1988 First Human Implant (Kiffin Penry)
  • 1992 First Randomized Active Control Study
  • 1994 Eruopean Community Approval
  • 1996 5 completed uncontrolled studies (N=454)
  • 1997 USA (FDA) Commercial Approval
  • 1999 5,000+ Patients treated worldwide
• VNS: Human Mechanism of Action Summary
  • Stimulation of the left vagus nerve is associated with widespread and bilateral activation and changes in blood flow in areas of the brain responsible for seizure activity
  • VNS: Modulates Blood Flow (BF) in Key Brain Structures in Humans via PET At Initiation and After 3 Months
    • Significant Bilateral Increase in BF in areas that prevent seizure onset or limit seizure spread:
      • Tractus Solitarius
      • Thalamus
      • Hypothalamus
    • Significant Bilateral Decrease in BF in areas associated with repetitive ictal firing:
      • Amygdala
      • Hippocampus
    • VNS: Prolonged and Progressive Blood Flow During PET Imaging
      • 9 VNS Patients were administered 12 PET Scans, Range of stimulation = 5-16 months, 6 Scans with stimulation, 6 Scans without stimulation
      • PET Scans revealed areas of activation, as well as areas of deactivation in blood flow
      • Statistical changes in blood flow seen in right fusiform gyrus
      • Statistical significance approached for changes in blood flow in right insular cortex, right temporal lobe and right cerebellum
  • Mechanism of action for VNS is as well (or as poorly) understood as most anticonvulsant medications currently prescribed.

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