The DBS System Components:
What lies beneath the skin
 

The Implanted Components

The Medtronic deep brain stimulation system has three main components, all of which are surgically placed inside your body.  Most of them will be just under the skin where you will be able to feel them.  This photo shows a Soletra with all three components connected together.  You can see more details about each component below.






The Electrode

This is is the electrode (also called the lead), which passes into the brain through a small hole which the surgeon makes in the skull.  This electrode is 1.3 mm in diameter, about the size (and flexibility) of a piece of cooked spaghetti.  The electrode is very limp and may be difficult to feel under the scalp.  It is about 15 inches long.  One end of this electrode is placed into a target deep in the brain; the other extends out of the skull and is connected to a "lead extension". 




Here is a close-up of the four contacts at the end of the electrode.  These are what conduct the electrical stimulation into the brain.  This is the “3387” electrode, the “3389” electrode contacts are spaced closer together, otherwise the electrodes are identical. 


Most DBS of STN is with 3389s, most DBS of GPi is with 3387s.




The lead extension 

The lead extension connects to the electrode and extends the wires from the head down into the chest, where it connects to the implanted pulse generator.  Some patients prefer to have the pulse generator implanted in the belly, just above the belt line.  We use a longer lead extension for that. 

The lead extension is a bit bigger and stronger than the electrode because it needs to flex and move as you move your head. You will probably be able to feel it where it goes beneath the skin of the neck to connect to the pulse generator. 


The pulse generator

This is the "brains" of the system, and includes the battery, the microprocessor computer and the other circuitry to produce the electrical impulses that go into the brain. 

On the right is the Soletra, which will control stimulation to one electrode to treat one side of the body.  On the left is the Kinetra, which can control two electrodes. 


Most patients need to treat both sides of the body, so they will have Kinetras. 


The programmer

The pulse generator has a special communication circuit, which uses radio signals to communicate with this programmer device, which is also a microprocessor computer.

The radio signals are very weak and only travel about an inch, so the programmer has a communication head that is placed on the skin (or clothing) over the pulse generator in order to communicate.  The radio signals go through skin and clothing, which makes programming the pulse generator a simple office procedure. 


Access Review

The Kinetra can be controlled by a “remote control” device called the Access Review.

With the Access Review you can actually turn the stimulation voltage up or down yourself.  This can be very useful in the first few months after the DBS surgery when you may be changing your doses of medicine and while your brain is still healing.  Sometimes a change in your medication will result in a need for more DBS, and using the Access Review can sometimes save a trip to our clinic.



The Next Generation!

Medtronic has a new implant technology for DBS- The Activa series.  The new devices include a rechargeable as well as a “regular” battery option. 


In this photo, the new rechargeable device is at the lower right, the new dual-channel non-rechargeable device is on the lower left, and the Soletra and Kinetra are on the upper left and right, respectively, for size comparison. 


The new devices are slightly smaller and thinner, but most importantly, they have some new features that will add flexibility to the therapy they provide.  Battery life of the new Activa PC is expected to be about the same as with the Kinetra.  We will be using the new devices from this point forward with our DBS patients.

All of our current DBS patients (except for a few who have been in a clinical trial of new devices) have systems made by Medtronic, Inc.  St. Jude Medical-ANS has recently completed a successful clinical trial of a DBS system, and we expect to also offer their system within the next year or so.  On this page we will describe the Medtronic systems we are using now.  At the bottom of the page you will find photos of the newly released Medtronic devices and the soon-to-be-released St. Jude Medical-ANS DBS system. 

The St. Jude Medical-ANS DBS System

This system is based on a family of “constant current” pulse generators.  The system is roughly similar to the Medtronics system, with a pulse generator, lead extension and electrode.  The surgery to implant the systems is identical, and the electrodes are targeted to the same parts of the brain (STN or GPi) to treat symptoms of Parkinson’s Disease.  The clinical trial of these devices has recently been extended, and we anticipate that they will be available for use with patients within the next few years.

Pulse Generator

Lead Extension

Electrode

This is the controller for the Libra system.  It enables the patient to turn the device on or off, and to change the strength of the stimulation on the two sides of the body.