---------- Forwarded message ----------
From: Hughes, James J. <[EMAIL PROTECTED]>
Date: 2008/10/9
Subject: [tt] FDA clears Transcranial Magnetic Stimulation for major
depression
To: [EMAIL PROTECTED], [EMAIL PROTECTED]



http://feeds.feedburner.com/~r/BrainStimulant/~3/415414063/transcranial-magnetic-stimulation-gains.html
Transcranial
Magnetic Stimulation Gains FDA
Clearance<http://feeds.feedburner.com/~r/BrainStimulant/~3/415414063/transcranial-magnetic-stimulation-gains.html>

Transcranial magnetic stimulation (TMS), a method of non-invasively
stimulating the brain, has just recently gained clearance for the treatment
of major depression <http://en.wikipedia.org/wiki/Clinical_depression>. This
is one of the first FDA clearances of TMS for a brain disorder. TMS has
actually been around quite some time (since 1985) and has shown considerable
promise for treating a variety of brain disorders. TMS has been used by
scientists to deactivate or activate specific regions of the brain's outer
layer (the neocortex) by sending multiple electromagnetic pulses through a
person's skull using a TMS device. These electromagnetic pulses are able to
create an electric current in a very targeted brain region. This electric
current can then cause either an inhibition or an excitation of the
underlying brain tissue depending on which frequency of the TMS pulse that
is used. High frequency electromagnetic pulses are able to excite brain
tissue while lower frequency pulses tend to decrease brain activity. So
specific brain regions may be selectively activated or deactivated. Brain
disorders often have hyperactive or hypoactive activity in specific regions,
and TMS is able to selectively adjust this brain activity non-invasively.

I think approval for other conditions will follow after this success.
Neuronetics <http://www.neuronetics.com/>, the company marketing the TMS
device, had actually tried in 2007 to get approval but failed quite
spectacularly <http://pn.psychiatryonline.org/cgi/content/full/42/5/2>.
Neuronetics has previously showed the results from a different TMS trial to
a board of several FDA advisors in 2007. For that specific trial, the
clinical outcome was measured by a reduction in major depression scores on
the Montgomery-Asberg Depression Rating Scale (MADRS) symptom score after
undergoing a treatment with TMS for six weeks. Symptoms for major depression
include profound sadness, apathy and an inability to experience pleasure.

In that previous trial the TMS failed to distinguish itself from the
sham/fake TMS for improving depression symptoms. The mean decrease in the
MADRS symptom scores was approximately 5.6 points in the active transcranial
magnetic stimulation group of patients and about 3.2 points in the sham/fake
TMS group of patients. Unfortunately for the company Neuronetics, the
p-value after 6 weeks was just .058. A p-value (see
statistics<http://en.wikipedia.org/wiki/P-value>)
that is less than .05 is the difference between the active and sham TMS that
is considered statistically significant. So the difference between fake and
real treatment was just not enough to prove efficacy. Neuronetics had also
tried to compare the efficacy of TMS to
ECT<http://en.wikipedia.org/wiki/Electroconvulsive_therapy>,
which is a bad move. ECT has a much greater mood elevating effect than TMS
and they are not comparable. TMS, though, has almost no side effects in
comparison to numerous side effects with ECT or antidepressants, which is a
huge plus. ECT causes a brain seizure and requires a person to undergo
anaesthesia. ECT has a drastic effect on the functioning of the entire
brain. TMS on the other hand can be performed on a person while they are
totally awake and is fairly painless. So TMS does have advantages to both
ECT and antidepressants. Neuronetics had to do another
trial<http://www.medpagetoday.com/Geriatrics/Depression/tb/7459>in
order to get better results and satisfy the FDA. It appears that they
were
successful 
(PDF)<http://www.neuronetics.com/FDA_Clears_NeuroStarTMS_Therapy_for_the_Treatment_of_Depression.pdf>in
convincing the FDA.



*Neuronetics, Inc., a privately-held medical device company and a leader in
the field of neuromodulation, announced today that the U.S. Food and Drug
Administration (FDA) has cleared its NeuroStar TMS (Transcranial Magnetic
Stimulation) Therapy system for the treatment of depression. NeuroStar TMS
Therapy(R) is specifically indicated for the treatment of Major Depressive
Disorder in adult patients who have failed to achieve satisfactory
improvement from one prior antidepressant medication at or above the minimal
effective dose and duration in the current episode. In clinical trials with
NeuroStar TMS Therapy, these patients had been treated with a median of 4
medication treatment attempts, one of which achieved criteria for adequate
dose and duration.*

* *

You can read the data from the clinical trial at this
website<http://www.neuronetics.com/scientificdata.html>.
The success from the new trial seems to be partially due to "adjusting" the
outcome parameters a little. Notice that the end point this time was 4 weeks
and not 6 weeks. However, it is possible that they amped up the amount of
TMS excitation that the patients received as well for a better effect.

*The primary efficacy measure, the Montgomery-Asberg Depression Rating Scale
(MADRS) symptom score change at 4 weeks, was statistically significantly
superior to placebo (p=0.0006), among NeuroStar-treated patients. Similar
results were observed with the Hamilton Depression Rating Scale (HAMD).*

*
NeuroStar TMS Therapy-treated patients had statistically significant
response and remission rates, which were approximately twice the rate of
placebo-treated patients. The response rate is the percentage of patients
who had a greater than or equal to 50% improvement in symptoms, and the
remission rate is the percentage of patients who achieved virtually complete
symptom resolution.*

*
NeuroStar TMS Therapy also produced statistically significant improvements
on the HAMD factor scores for core depression symptoms, anxiety symptoms,
somatization, and psychomotor retardation.*

* *

In the future, neuronetics will probably get competition from
brainsway<http://www.brainsway.com/>,
the company making the deep transcranial magnetic
stimulation<http://brainstimulant.blogspot.com/2008/02/deep-transcranial-magnetic-stimulation.html>device.
This recent Neuronetics TMS trial only targeted the left
dorsolateral prefrontal cortex, but researchers may also be able to target
the right dorsolateral prefrontal to gain an even greater antidepressant
response<http://brainstimulant.blogspot.com/2008/05/transcranial-magnetic-stimulation-and.html>.
So I think this treatment will end up getting better as scientists are able
to target more brain areas for activation/deactivation. I suspect
Neuronetics had to do a lot of data manipulation to get the right outcome
for this recent trial. However, TMS may still become more useful for brain
disorders as time goes on.



_______________________________________________
tt mailing list
[EMAIL PROTECTED]
http://postbiota.org/mailman/listinfo/tt

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups 
"Cosmology, Mathematics and Philosophy" group.
To post to this group, send email to 
[email protected]
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at 
http://groups.google.com/group/cosmology-mathematics-and-philosophy?hl=en
-~----------~----~----~----~------~----~------~--~---

Reply via email to