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medications such as meclizine
or scopolamine are not effective
with MdDS. Instead, clonazepam,
benzodiazepines or amitriptyline
may be beneficial. Additionally,
light physical activity such as
walking or yoga, taking naps,
and possibly acupuncture may
help strengthen the vestibular
system.
Resources for additional
information include the National
Institutes of Health, the National
Organization for Rare Disorders
and the MdDs Balance Disorder
Foundation.
— Frances Smith, EMT-P, DMT
Q:
In a recent DAN
article about exercise
and diving, I read
the following:
Intense physical activity —
generally with substantial
muscular forces and joint
loading (the application of
forces on joints) — is believed to
transiently increase micronuclei
activity, the presumed agent of
bubble formation.
Are these micronuclei
preexisting? Where do
micronuclei come from, and how
are they formed or created?
A:
The source point for
bubble formation is one
of the great mysteries in
diving science. We know that
bubbles form at relatively low
gas supersaturations, suggesting
some biological facilitation of the
process, but we do not yet have
the imaging tools to see the initial
formation. This technology will
come, but it’s not available yet.
Other methods to identify the
sites of formation also continue.
Micronuclei may comprise
multiple structures. Whatever
they are, they are preexisting, and
their activity of facilitating bubble
formation can be influenced
by acute events (most notably
recent pressure excursions that
act as preconditioning to alter
the responsiveness). Altered
responsiveness appears to be
transient, indicating a dynamic
state or ongoing replacement. If
you want to see micronuclei in
action, look at a glass of beer. You
can often see streams of bubbles
originating from apparently
singular points on the side of
the glass. These points are often
associated with defects in the glass,
effectively small cracks within
which micronuclei formation
points exist. It is thought that
the micronuclei are lodged in the
cracks and act to crank out bubble
after bubble. Even if this cannot
provide all the answers, it can
make for a pleasant interlude if
you enjoy beer.
Ultimately, we can see bubbles
best in the vascular system, and
we have a good idea when they
develop and what effects they can
have. When we are vague on the
specifics of the actual formation,
it is an honest acknowledgment of
understanding yet to come.
AD
— Neal W. Pollock, Ph.D.
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