Transcranial Magnetic Stimulation at Harvard: A Homecoming

Returning to Harvard is a homecoming of sorts.  I originally came here in 2006 for Dr. Alvaro Pascual-Leone?? course on Transcranial Magnetic Stimulation (TMS).   At that time, I knew virtually nothing about TMS other than it was a treatment that offered help to some of the nicest but most miserable patients I saw, those with a treatment resistant depression that my doctorate in psychology and doctorate in medicine offered little help.  Having two doctorates can be a humbling experience when you are so acutely aware of the limits both professions allow in helping others.

Now, as he was then, Dr. Pascual-Leone is a kind, and thoughtful pioneer of TMS. Today was the first of a week-long course on TMS and there was an honesty and thoughtfulness in our opening lecture. He begins by discussing the title of what we do, Transcranial Magnetic Stimulation and its increasing popularity in the news and how the name is in many ways quite confining. When we use the term ??/span>Transcranial?? it is accurate only in reference to the current FDA-approved treatment we psychiatrists use when focusing on the brain for the treatment of depression. But the clinical use of TMS came after many years of use by neurologists employing single pulse TMD for peripheral neuron evoked motor potentials and other diagnostic uses. In rehab, as an example, TMS is now used for treating pain in the spinal cord removing the treatment site from a transcranial position.

In a comparable manner, the second term ??agnetic??/strong> is also a misnomer. I think we clinicians are fortunate for this inaccuracy. It is not the magnetic condition of these pulses that depolarizes cells but the small electrical charge that the magnetic pulse induces that causes the neurons we are trying to stimulate to fire. This is Michael Faraday?? magnetic induction. But to have more accurately named it some variant of electrical therapy would to have shackled it to electroconvulsive therapy whose stigma is rivaled only by its effectiveness in treating depression. The public would have been scared off and the stigma would have doomed this non-invasive procedure.

Finally, the term ??timulation.??/strong>  When we hear the term stimulation we generally think of an increase in effect, like the use of stimulant drugs such as caffeine or amphetamines.  This can give an inaccurate impression because TMS stimulation can have an inhibitory effect depending on the frequency of the pulses and the location of stimulation.  Most of us will do 1 Hz stimulation of the right dorsolateral prefrontal cortex.  This reduces anxiety by stimulating inhibitory neurons.  This makes sense to us in the field but can certainly cause confusion in others.

What I found in these beginning comments was the essence of a giant in the field. These were not said in some form of iconoclastic discourse raging against the system but rather as the thoughtful observations of one of the true pioneers in the field for whom attention to detail has been an inherent aspect of his research. And I am blessed to have four more days with him. Antidepressants not giving you relief from depression? Or creating new problems with the side effects? Learn more by clicking on the button below.