Migraine and Transcranial Direct Current Stimulation (tDCS)

Previously, I href="http://scienceblogs.com/corpuscallosum/2007/01/transcranial_direct_current_st.php">wrote
about investigation of href="http://www.mindhacks.com/blog/2006/04/newsci_head_electric.html">tDCS
for treatment of href="http://www.mayoclinic.com/health/fibromyalgia/DS00079"
rel="tag">fibromyalgia.  Now there is
evidence that it may have a role in treatment of an entirely different
pain syndrome: href="http://www.nlm.nih.gov/medlineplus/migraine.html"
rel="tag">migraine.  

href="http://spectrum.ieee.org/oct07/5599">Researchers
Testing New Electric Treatment for Migraines

By Morgen E. Peck

First Published October 2007

Today, there are no fully satisfying
treatments for migraine symptoms. But researchers at Beth Israel
Deaconess Medical Center, in Boston, are testing a low-tech treatment
that could shock migraine patients back to their senses and provide a
cheap alternative to drugs. The technology
involved—transcranial direct current stimulation
(tDCS)—is simple: stimulate the brain with sudden, controlled
bursts of electricity to interrupt and modify the brain circuits
responsible for causing migraine pain.â©



The investigators, Dr. Felipe Fregni and Soroush Zaghi,
both of Harvard Medical School, have recruited 24 patients who suffer
migraine headaches at least 15 times per month. At scheduled intervals,
which may or may not coincide with migraines, Fregni attaches
electrodes to a subject’s scalp and passes 2 milliamps of
current through the brain, targeting the locus of pain. Two months into
the study, he is encouraged by what he is seeing. “In the
initial sample, the results went in the direction we
predicted,” he says.

This is interesting for a number of reasons.  Most obviously,
because migraine has no entirely satisfactory treatment.  The
development of an inexpensive, safe, and effective treatment would be
marvelous.  



Additionally, even if it does not turn out to be miraculous, or even
marvelous, we should learn something from it.  The effects of
tDCS, are complex despite
the simplicity of the treatment.



Finally, findings such as this can provoke thought about how the body
works.  Anticonvulsants such as href="http://en.wikipedia.org/wiki/Carbamazepine">carbamazepine
can have effects that are in some ways opposite to that of tDCS.
 Yet carbamazepine can help prevent migraine.  How
can two treatments that do opposite things, physiologically, each have
the same clinical effect?  Believe me, it happens.
 It is not a paradox, it just means that we do not fully
understand what is going on.  I tend to think that the effect
of tDCS is related to the phenomenon of cortical spreading depression,
but it is far to early to draw any conclusions.  (The link
between CSD and migraine is discussed at (the old) Neurophilosophy,
href="http://neurophilosophy.wordpress.com/2007/05/02/migraines-may-be-mini-strokes-that-cause-brain-damage/">here.)



We cannot carry the speculation too far in this case.  The
investigators are only two months into their study, the study is small,
and they are not even close to writing anything formal, much less
submitting it for peer review.