Re: Thalamic Stimulation (fwd)

[Barbara Patterson <patterso@xxxxxxxxxxxxxxxxxxx>]

---------- Forwarded message ----------
Date: Wed, 27 Dec 95 14:35:00 P
From: Andy L. Blatz <andyb@xxxxxxxxxx>
Subject: Re: Thalamic Stimulation

Dear Henry:

Re your recent query:
Date:    Sun, 24 Dec 1995 11:10:56 -0800
From:    HENRY GUTTENTAG <hgutt@xxxxxxxxxxxxx>
Subject: Thalamic stimulation (To all interested)

I have been told by some of the investigators who are involved in the
clinical trials of these devices that the results are good.  Please keep in
mind that this is by no means an EXTERNAL device.  The procedure involves
localizing (with microelectrode recording and stimulation) an appropriate
region of the thalamus for the permanent implantation of stimulating
electrodes which are then connected, much like a heart pacemaker with a
power supply and assorted electronics which are implanted somewhere else in
the body.  The stimulating electrodes then give an adjustable pulsatile
stimulation which has an effect similar to a pallidotomy.  There are
currently advantages and disadvantages to the procedure.  Advantages: 1)
Much less tissue is destroyed during the surgery because no lesion is made.
2) The neural tracts interconnecting the various regions of the brain are
left mostly intact. 3) The stimulation can be turned off, or the electrodes
removed, ie., the procedure is reversible.  Disadvantages: 1) There is a
higher degree of risk associated with implanted devices, than with
short-term surgery. 2) Higher cost. 3) Thalamic stimulation is still
considered highly experimental and is available only at certain centers.  4)
Long-term results are unavailable.

If you do decide to pursue the thalamic stimulation route, make sure that
you work with a surgical team that incorporates microelectrode recording and
microstimulation in their procedures to ensure the highest accuracy of
electrode placement.

Sincerely,
Andy Blatz, PhD
Axon Instruments, Inc. (Yes, we make microelectrode recording amplifiers.)