The Vagus Nerve Stimulator (NCP)
From A Patient's Point Of View

About the author

Preface

The vagus nerve: What is it?

The Device

The Generator

Location of the implants

Tunneling Tool

Magnets

Remote Programming Device

Programmable Options

Accessory Pack

Getting Acquainted with the VNS

Expectations

FDA MAUDE Report (adverse effects)

Statistics

Cost

What other VNS patients (and their families) have to say

Financial Aid

Depression

Other information resources

Bio

I am a 54 year old male with medically intractable temporal lobe epilepsy. I have both simple partial (sometimes called an "aura") and complex partial seizures. My epilepsy was diagnosed when I was 13. (I have had it a lot longer than that!)

Medically intractable means that although the number of seizures has been reduced with medication, attempts to control / eliminate seizures have been unsuccessful.

I was a candidate for epilepsy surgery at the University of Rochester's Strong Epilepsy Center in Rochester, New York, USA. After discovering that I have focii and triggers in both temporal lobes due to secondary epileptogenesis, surgery was no longer a feasible alternative.

I had the operation in 1999. After about 2 years I had the device turned off because it did not improve my seizure control and because it impeaded one of my basic joys in life -- singing!

About 2 years after the device was turned off I was diagnosed with sleep apnea. Since sleep is such an basic element when it comes to epilepsy; I thought that, in the spirit of following the scientific method, I would have the device turned back on again once I was able to get myself onto a consistant sleep schedule.

At this time (October 2004) I can say that there is a good possibility that the VNS has dramatically decreased my complex partial seizures. "Good possibility" is the best report that I can give due to the fact that I live alone. The only way I know for a fact that I have had a complex partial seizure is if I injure myself or if the seizure is witnessed by another person.

Neither has occurred for more than 9 months.

Due to past complex partials I have:

• a reconstructed ankle
• six skin grafts
• burned off two fingerprints
• burn scars on 23% of my body.

23 July 2007: The battery in my Model 100 died about 2 weeks ago.

I am scheduled to have surgery on 21 August, 2007 to get the generator replaced with a Model 102-R (with the two wire adapter.)

23 September 2007: Got my 102-R ("R" stands for a replacement with a 2 wire adapter.)

It was ramped up to thereputic capacity within 2 weeks.
The effect on the vocal chords is much less severe than it was with he Model 100.

Preface

There seems to be a lot of interest in the epilepsy community about the Vagus Nerve Stimulator. Since I am a technical writer and since I have a VNS implant, it seemed be a good idea for me to apply my profession and supply an information outlet.

Many of the descriptions used on this page are taken word for word from Cyberonics documentation. This is done in order to avoid the loss of technical accuracy that always accompanies paraphrasing. The device is alternately called a VNS (Vagus Nerve Stimulator) and an NCP Device (NeuroCybernetic Prosthesis). For the sake of consistency, I have decided to call it a VNS.

(For all of you in the United States: If you notice a grin on your doctor's face when you bring up the subject of the VNS, don't forget that VNS also stands for Visiting Nurse Service.)

The Vagus Nerve

Illustration from USC - Glossery of Neurosurgical Terms in Plain English
URL: http://uscneurosurgery.com/glossary/v/vagus nerve.htm

What is it?

• The 10th cranial nerve (one of 12 pairs of nerves that begin in the brain).
• The name vagus comes from Latin and means "wandering"

What does it do?

The vagus is a mixed nerve. It has a role in sensory, motor and secretory functions.

• It supplies sensory functions for:
  • Ear
  • Tongue
• It supplies motor functions for:
  • Larynx (voice box)
  • Diaphragm
  • Stomach
  • Heart
• It supplies both motor and sensory functions for:
  • Pharynx (sinuses)
  • Oesophagus
• It supplies secretory functions for:
  • Stomach
  • Intestine

More about the vagus nerve

Back to Quick Jump Index

---

The Device

The following illustrations (except for the cow magnet) are from Cyberonics and from The New York Hospital-Cornell Medical Center.

The Model 101 NCP Pulse Generator & the Model 300 NCP Bipolar Lead	The Model 100 NCP Pulse Generator & the Model 300 NCP Bipolar Lead
Size:  10.3 mm thick	Size:  13.2 mm thick
Weight:  38 grams	Weight:  55 grams
Battery Life1:  8-12 years	Battery Life1:  4-8 years
1Depending upon parameters selected by physicians

The NEW Model 102 NCP Pulse Generator

Titanium case Size:  6.9 mm x 52.2 mm x 51.6 mm

Weight:  25 grams

Battery Life1:  6-11 years

Lead compatability: Model 302 single pin

1Depending upon parameters selected by physicians

I have been informed that a new adapter is available that will allow a person who has a Model 100 or 101 (which has 2 leads) to get a new Model 102 or one of the new 300 series that are in the works.

(The Model 102 and the 300 series have a single wire connection to the device and the lead wire to the vagus nerve has only one connection to the nerve.)

Back to Quick Jump Index

---

Lead Connections
        Close Up.

Location of the implant

Back to Quick Jump Index

---

The Model 400 NCP Tunneling Tool is used during implantation to create a subcutaneous path between the device in the chest and the vagus nerve in the neck. It is also used to place the NCP Lead in the tunnel. The Tunneling Tool is supplied non-sterile.

Back to Quick Jump Index

---

Cyberonics has put two new magnets on the market:
Model 220-3 and 220-4.


Actually, it's only one new type of magnet with two different attachment devices.

One has a belt clip and is worn like a pager.

The other has a black velcroe strip and is worn around the wrist like a watch. The second style must be worn on the right wrist in order to swipe it in front of the VNS for activation. (It can actually be worn on either wrist but wearing it on the left wrist will activate your VNS whenever you get your wrist too close to your implant.)

The Model 220-1 Block Magnet and Model 220-2 NCP Horseshoe Magnet

block magnet -- 1" x 5/8 " x 2" = 26mm x 17mm x 51 mm
horseshoe magnet -- 2" x 3/4" x 2" = 52mm x 20mm x 51mm

For anybody of a technical mindset, the bar magnet's field strength is 65 gauss (0.0065 Tesla).



If anybody wants to obtain an inexpensive extra magnet for him/herself:

• Go to the nearest farmer's supply store and purchase a cow magnet for yourself. Mine cost $3.75 US.

• The cow magnet is easy to carry and not as obvious as the block magnet or wrist magnet when you have to activate your VNS. As a matter of fact, it is so easy to palm the cow magnet that most people will not even be aware of the fact that you have just activated your device (except for the voice change, of course.)

• FYI: It is called a cow magnet because farmers force cows to swallow it. The magnet stays in the stomach and prevents any barbed wire, nails or anything else that the cow might swallow from causing damage by going all the way through the digestive tract.

The Cyberonics Model 201 NeuroCybernetic Prosthesis (NCP�) Programming Wand is a hand-held device that transmits programming and interrogation information between a computer and the NCP Pulse Generator. The NCP Programming Software, in conjunction with a personal computer and the Programming Wand, can store and retrieve telemetry data and revise programmable parameters in the Pulse Generator.

The programming wand converts the digital output from a personal computer to the radio-frequency required for communication with the Pulse Generator and vice versa. The wand receives and sends signals to the personal computer via a cable connected to the wand by a phone plug and to the computer by a standard serial connector. Two standard 9-volt alkaline batteries power the wand.

To communicate with the Pulse Generator, position the programming head of the Programming Wand directly over the center of either flat surface of the Pulse Generator. Successful programming and communication are most likely if the surface of the programming head is within one inch of either of the flat surfaces of the VNS Pulse Generator.

PRODUCT SPECIFICATIONS:
POWER SOURCE: Two standard 9-volt alkaline batteries.

DIMENSIONS:
Housing: 19.1 cm x 10.2 cm x 3.3 cm
Programming Head Cover: 6.9 cm x 6.9 cm c 3.2 cm
Weight: 638 grams
Housing Material: ABS Plastic
Communication Range: 1 inch
Cable: 5-foot Cord (extendable to 9 feet)

I received the following information from Cyberonics about suggested programmable parameters:

The average output current used during the clinical studies was about 1.0 mAmps. Other standard treatment settings were 30 Hz, 500 pulse width, 30 seconds ON time, and five minute OFF time.

There are no data to verify that these are optimal parameters. *

There is no proven correlation at present between high output current and device effectiveness, nor is there a standard treatment level that needs to be achieved during treatment ramping. The NCP System treatment should not be uncomfortable, nor should it cause bothersome side effects. Although Cyberonics recommends adjusting output current as necessary, there are no controlled data at this time to indicate that higher current levels are associated with better efficacy.

Patients whose seizures are well controlled at follow-up should not have their settings changed unless they experience uncomfortable side effects. The subsequent follow-up schedule and the nature of each examination should be determined by the physician on the basis of patient response to and tolerance of the implant.

* Italics my own.

The Model 500 NCP Accessory Pack contains replacement components for the NCP System. These components (screws, screw plugs, a hex scredriver, and extra silastic tie-downs) are back-ups for items that may become unusable during routine surgery. The hex screw-driver can also be used during an explantation in which a new Pulse Generator will not be implanted.

Getting Acquainted With The VNS

• THE VNS IS NOT A CURATIVE! A patient may still have seizures after the system has been activated.

• There are 2 different ways that the VNS may be activated.
  • The VNS automatically generates a charge at preset time intervals.

  • If the patient senses an aura or the onset of a seizure, a magnet can be waved over the chest implant to activate the VNS and deliver an immediate "extra burst".

• Implanting the VNS is a 2 hour operation and is usually performed on an outpatient basis. (Since I am also diabetic, I was kept in hospital overnight to monitor my blood sugar.)

• Since I live alone and I am unaware of my complex partial seizures, the people at the Rochester Comprehensive Epilepsy Program will probably want to put me in the hospital for long term monitoring (same as LTM for surgery candidates) to see if there are any immediate, noticeable effects caused by the VNS.
  • LTM: Patient is videotaped and has an EEG recorded 24 hours a day for several days.

• I thought that since I have focci and triggers in both temporal lobes I might need the VNS to be connected to both vagus nerves. I was told that this is not the case. The VNS is connected to the left vagus nerve. Communication between the two hemispheres of the brain is such that charges to one nerve will suffice.

• The VNS can not be used in patients who have had a bilateral or left cervical vagotomy.

• Your doctor may choose to have you wear a neck brace for the first week to help ensure proper lead stabilization.

• Holding the magnet steady over the implant will shut the device down until the magnet is removed. This piece of information is extremely helpful to those of us who are singers.

Back to Quick Jump Index

---

Expectations

In the words of Cyberonics:

• The NCP System is indicated 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 medications.

In other words:

• Adjunctive therapy: the device is designed to be used along with medications, not in place of them
• Reducing the frequency of seizures: Nobody should expect the device to totally eleminate their seizures
• Cyberonics advises that the device should not be used in children less than 12 years old.

I have not set my expectations too high; after all --

THE VAGUS NERVE STIMULATOR DOES NOT STOP SEIZURES!

• The VNS may reduce seizures although there is a fairly hefty percentage of people who experience no reduction in the number of seizures that they have after the device has been implanted. (As a matter of fact, the number of seizures has actually increased in a few cases!)

• The way I'm looking at this is: "Gee, it would be nice if the number of seizures could be reduced, I'd even be satisfied if the only thing the VNS did for me was to give me an aura before every seizure."

• The VNS is not a miracle machine, so I will not be absolutely crestfallen if I don't show any improvement after the implant.

• I believe that this is the only psychologically sound outlook that a prospective patient can adopt for him/herself.

Back to Quick Jump Index

---

The FDA MAUDE Report

MAUDE is an acronym for "Manufacturer and User Facility Device Experience Database - (MAUDE)."

The FDA describes the MAUDE reports as follows:

"MAUDE data represents reports of adverse events involving medical devices. The data consists of all voluntary reports since June, 1993, user facility reports since 1991, distributor reports since 1993, and manufacturer reports since August, 1996."

The MAUDE Report for this device can be found at:

MAUDE Database Search for CYBERONICS

OR

Do a search for "MAUDE" on the FDA site at:
www.fda.gov

Go to the MAUDE search engine and do a search on: "Cyberonics"

Statistics

Change in # of seizures per day	:	% of patients		After 2 years
Total elimination of seizures	:	next to nil
More than 50% reduction	:	~20% of patients		43% of patients
Up to 50% reduction	:	~55% of patients		not available
No reduction	:	~25% of patients		not available

$$ COST $$

• The following breakdown is what it cost (US $) to have the VNS implanted at Strong Memorial Hospital - Rochester, New York, USA in February, 1999:
  • Vagus Nerve Stimulator Device:
    • $20,200

  • Operating Room Services:
    • $1,915

  • Anesthesia:
    • $550

  • Recovery Room:
    • $333

  • EKG-ECG:
    • $66

  • Med-Sur-Gy-2 Bed (They kept me overnight for observation):
    • $700

  TOTAL:

  • $23,764

A note to anybody in the USA planning to use Medicaid to pay for your surgery:

• Here in New York State, Medicaid has a spend down schedule for In-patient care that is different than the normal monthly spend down schedule.The patient is responsible for 6 times their monthly spend down (6 months payment in advance) before Medicaid will pay anything for In-patient expenses. Once the payment has been made, all of your spend downs for the next 6 months are covered.

• For example:
  • If you have a monthly Medicaid spend down of $100, you would be responsible for the first $600 of your hospital bill.

• Make sure you know the Medicaid policy in your state!

• Having the implant operation performed as Out-patient surgery will probably circumvent the Medicaid problems. Look into it! A word to the wise.

What Others Have To Say

---

The following article about the Vagus Nerve Stimulator appeared in The Houston Press on April 7, 2005:

EXPOSED NERVE
By: Craig Malisow

---

• Patients & families of patients who have already had the VNS implant.

• See stories.

• I am always looking for information for this section (positive OR NEGATIVE reports).

  E-mail your story.

FYI: I have not verified any claims or statistics submitted by other people. Dave

Financial Aid

Cyberonics will donate $1million of VNS(TM) NCP� Systems (approximately 100) per year to candidates for the NCP System who are without medical insurance coverage and who do not have the financial resources to otherwise pay for it. The NCP� Systems will be distributed on a first-come, first-served basis.

More information

Back to Quick Jump Index

---

The VNS and Depression

Other Information Resources

***WIRED*** is an outstanding series of articles that were posted by Gregg Hartenstine to the MGH (Massachusetts General Hospital) Forum under the catagory of Epilepsy. Unfortunately I do not have enough memory to put them on my site. They may be found at:

• MGH Forum/Epilepsy

Publication dates are (all 1998): 3/10 - 3/20 - 3/30 - 4/17 - 4/23 - 4/27 - 5/8 - 6/19 - 6/29 - 8/5 - 9/8 - 10/27 - 10/30 and 12/3. The URLs are:

Wired 0.5

WIRED 1.0

WIRED 1.5

WIRED 2.0

WIRED 3.0

WIRED 3.5

WIRED Info Update

WIRED 4.0

WIRED 5.0

WIRED 6

WIRED 7

WIRED 8

WIRED 9

WIRED 10

WIRED 11

WIRED 11.0

I would STRONGLY suggest that anybody considering the VNS implant read this series of articles.

---

Resource Links

Suggest a site.

If you have any unanswered questions contact Cyberonics, the manufacturer of the VNS:

• Epilepsy..? So What?! An outstanding information resource!
• Article in Doctor's Guide Oct. 2002
• Vagal Nerve Stimulation - Cornell
• VNS Research - U of Arizona
• VNS - National Society for Epilepsy (UK)
• VNS - International
• Epilepsy: Implant Device (Houston Acadamy of Medicine)
• F.A.B.L.E. - Cyberonic Devices
• VNS - Rush Epilepsy Center Newsletter
• Article in Doctor's Guide April, 1998

My thanks to Patricia D. Sheldon, Rose Vella and all of the people at Cyberonics for their assistance in obtaining information and proofreading for technical content.

Thanks also go to Dr. Robert Fink for medical information.