>Eric E. Sabelman, PhD
>October 9
>Brain Control: Surgical Technology for Fixing the Malfunctioning Brain
> It is now possible to treat Parkinson’s Disease and similar movement
> disorders by implanting a multi-contact electrode into the region of
> the brain that causes tremor and stiffness.  Such Deep Brain
> Stimulation (DBS) electrodes do not cure the disease, but relieve
> symptoms when medication is no longer effective – the definition of a
> “neuroprosthesis.”  Unlike older surgical treatments that simply
> burned out the malfunctioning region, the stimulation parameters of
> the DBS pulse generator can be tuned (varying contact selection and
> polarity, pulse rate, width and amplitude) for best effect as the
> patient’s disease progresses.  Since DBS recipients may be given
> partial control over stimulation parameters, the patient’s
> participation in determining long-term outcome differs from other
> neurosurgery.
> DBS surgery can be beneficial whenever a precise causative location in
> the brain can be reached by a straight path without passing through
> life-dependent structures.  Thus, DBS is unsuitable for problems that
> afflict the whole brain, like Alzheimer’s Disease.  Surprisingly,
> besides movement disorders, DBS targets have been identified for
> neuropsychiatric syndromes: Tourette’s Disease, obsessive-compulsive
> disorder, and some forms of depression and behavioral addiction.  Does
> this mean that everyone with a treatable “illness” will be given a DBS
> implant?  Or that DBS surgery will be used to enforce “normal”
> behavior?  Not very likely, given the extreme difficulty of deep
> electrode implantation surgery, which requires accuracy an order of
> magnitude better than “routine” brain surgery.
> Dr. Sabelman is the founder of Pro-Zooics Research, which has been
> engaged in biomedical design & consulting since 1979. Eric has been on
> the core staff of the VA Palo Alto Rehabilitation R&D Center, where he
> investigated wearable computers for human body motion analysis, acute
> spinal cord injury patient care, and tissue engineering for nerve
> repair and reconstructive surgery. He is an Adjunct Lecturer in
> Mechanical Engineering at Santa Clara University, and affiliated with
> the Biodesign Program at Stanford. He will discuss his current work at
> Kaiser Permanente on Deep Brain Stimulation for treatment of
> Parkinson's Disease.

Eric began by explaining that a Deep Brain Stimulation system looks a lot like a heart pacemaker, and is installed in about the same place in the patient's body. The main difference is that there is a cable that extends up the patient's neck to the electrodes in the brain from there. Then he showed us a list of diseases that DBS is proven to be effective in treating, including Parkinson's which Kaiser employs him to install DBS equipment to treat.

Eric showed us a beautifully stained slide of a stem cell and explained that stem cell research could come up with competing treatments for Parkinson's and other diseases. However, at this point in time there is not the technology to precisely place the stem cells, and nobody has figured out how to encourage them to grow in exactly the directions desired. Placing the wires and probes from a surgical standpoint is easy by comparison.

Eric showed us a CAT scan of the human head, with these small almond shaped areas highlighted. He explained that for the surgery to have the desired effect, the probes must be placed within half a millimeter of the right location. Enormous care goes into this. After a patient has qualified for the surgery their head is extensively studied, to identify the exact path to insert the probe through and the exact location where it needs to end up. In planing the operation, care must be taken to keep from severing arteries, which could have the effect of a stroke.

Installing DBS equipment is an ordeal. The patient's head is held still for the procedure by a viselike apparatus on a steel post bolted to the floor. Because one way to get feedback on where the probe is to turn it on and ask the patient "how does that feel", patients are awake during surgery, which could take a full day. The other way to get feedback during surgery is to take X-rays to see where things are, and this is also done. Once that is done, they wait for the wounds to heal before powering it up.

Kaiser now installs DBS equipment in about a person a month here in Northern California. Parkinson's patients do show that the technique is a good therapy in many cases.

During Q&A the following points came up:

Brain stimulation signals range from 3 to 7 Volts, are pulses of only a few milliAmps for a few milliseconds, and are generally between 2-300 Hertz.

If surgery accidentally causes a patient to have a seizure, they have emergency procedures for cutting them out of the equipment that keeps them still during surgery. The same procedures are invoked when there is an earthquake during surgery.

It's hard to tell, but probably Kaiser spends $50,000 to $100,000 per DBS installation.

Most Parkinson's patients ready for DBS are in their '70s or later, although the number of patients as young as 40 is rising.

The URL list is below.  Thanks to Dave Jaffe for looking up reviews of the Wired article and Stanford MDs' profiles.

A Shock to the System
From: Wired Magazine - March 2007
By: Steven Gulie

“To slow the progress of Parkinson’s disease, doctors planted electrodes deep in my brain. …”
[First-hand report on DBS surgery at Stanford]

Deep brain electrodes - from the inside [review of Wired article]

A first-hand account of deep brain stimulation [review of Wired article]

photogallery of DBS surgery at Emory University

animation of the placement of DBS electrodes and pacemakers

Jaimie Henderson

Helen Bronte-Stewart

Gary Heit

Re-Wired for Life Foundation

WE MOVE -  resource for movement disorder information

American Society of Stereotactic and Functional Neurosurgery

Parkinson's Disease Research Web (NINDS Neurodegeneration Group)

American Parkinson Disease Association

Parkinson's Disease Resource Center (MedScape)

the Parkinson's Institute in Sunnyvale

Tian Harter