The
cover story of the October 7, 2002 issue of TIME simply suggests there is "new
hope" in the prevention of headaches. Unfortunately, the
story was a re-hash of the current state of affairs in the pharmaceutically
supported headache and migraine management industry.
Presented
as the most encouraging research was the anti-epilepsy drug topiramate.
From the article: Dr. Stephen Silberstein of Thomas Jefferson University
in Philadelphia presented a study of nearly 500 patients showing that topiramate
significantly reduced both the occurrence and duration of migraines—offering
hope that a whole class of existing antiseizure drugs could someday help
migraine sufferers put an end to attacks before they occur. No
mention was made as to the side
effects of topiramate. In its clinical trials, for example, 28%
of subjects taking topriamate had to drop out of the study because the
side-effects were intolerable.
The most
revealing aspect of the article was the observation of the trigeminal nerve, a
complex network of nerve fibers that ferries sensory signals from the face,
jaws and top of the forehead to the brain. During the course
of a migraine, scientists discovered, the trigeminal nerve practically
floods the brain with pain signals. The more researchers learn about the
trigeminal nerve, the more they believe that it is involved in all types
of primary headaches, including tension and cluster headaches. The differences
in the headache types seem to stem from what activates the trigeminal nerve
and how it responds.
The
hypothesis for the method of action of the NTI device for headache and
migraine prevention involves both the trigeminal nerve and the sympathetic
nervous system. Specifically, when hyperactive spindle fibers (which
are innervated by the sympathetic nervous system) reside within a trigeminally
innervated muscle (like the temporalis, for example), a sympathetic input
(that is, a "trigger"), may cause the intrafusal fibers of the spindle
to contort or spasm. One of the effect of the NTI device
is described by it's name, NTI: Nociceptive Trigeminal Inhibition (meaning
inhibitory signals are sent to disrupt trigeminal activity). Currently,
the only known method of disrupting hyper-trigeminal activity is with
the NTI device. As the TIME article describes, What seems clear,
however, is that the brain of a migraineur (as sufferers are called)
is primed to
overreact to all sorts of stimuli that most people can easily tolerate. "The
brain receives input from a wide variety of triggers—stress, hormones,
falling barometric pressure, food, drink, sleep disturbances," says Dr.
David Buchholz, a neurologist at the Johns Hopkins University School
of Medicine in Baltimore, Md. "Each of us has his own stack of triggers
and his own personal threshold at which the migraine mechanism activates.
The
higher the trigger level climbs above the threshold, the more fully activated
the migraine system—and the more pain", which perfectly describes
a heightened sympathetic tone, as is seen in the spindle fibers of migraine
and headache sufferers.
There was
no mention of the NTI device, the only non-drug, non-surgical method
approved for marketing by the FDA for the prevention of medically diagnosed
migraine pain. However, Botox was mentioned, but curiously, as a "surprise": One
of the surprises of the past couple of years is the effectiveness of
Botox, which is now being injected into facial muscles to temporarily
erase wrinkles. Migraineurs have reported that botox seems to banish
their
headaches as well. Studies are under way to see if those observations
hold up. Botox studies continue to show efficacy in
migraine prevention (results vary greatly, due mostly to an unstandardized
protocol
of injection placement). One of the leading hypotheses of the
efficacy of Botox involves "re-normalization
of excessive muscle spindle activity".
As more
is learned and accepted by the pharmaceutically supported migraine
and headache management industry about the trigeminal and sympathetic nervous
system, "alternative" modalities such as the NTI may become more widely
accepted. |