FEATURE STORY/ WHEN THE NERVOUS SYSTEM PANICS
Modulating Central
Sensitization
C
C-Sens and Trigger Points
hronic degeneration or injury
to the spine is one of causes
of C-Sens, a maladaptive
process that may amplify disease and
spread discomfort. Could this serve as
a contemporary biomedical paradigm
supporting the spine’s key role in our
overall health and how we heal from
disease?
A sensitized nervous system
sends signals differently. “How these
aberrant signals are processed,”
writes Dr. Srbely, “and what role spinal
manipulative therapy plays in modulating
these signals, is an important area for
chiropractic research because these
concepts could form the foundation
for the neurophysiologic paradigm of
chiropractic.”:
I
n 2010, Dr. Srbely’s team studied the
connection between C-Sens and
trigger point sensitivity.
The C5 spinal segment supplies
nerves to a number of areas, including
some skin on the elbow and the
infraspinatus muscle in the shoulder.
This study experimentally evoked C-Sens
at the C5 spinal segment by exposing
the linked area on the right elbow to
45 degree heat for 10 minutes. The test
group then received a topical sensitizing
cream containing capsaicin, and the
control group received a topical placebo
cream.
The participants who received the
capsaicin cream showed significant
increases in brush allodynia, which
means that a harmless light brushing on
the skin felt painful. This indicated that
they had C-Sens.
Pressure pain sensitivity was
monitored in trigger points within the
infraspinatus muscle (in the shoulder)
which is innervated by the C5 segment,
and the gluteus medius muscle (in the
hip) which is not. Pain thresholds were
measured beforehand and then 10, 20
and 30 minutes afterwards.
Test subjects showed a significant
increase in pressure sensitivity in the
segmentally-linked infraspinatus trigger
point compared to the non-segmentallylinked gluteus medius trigger point. There
was no difference between these points
for control subjects.
These findings demonstrate a
strong segmental response in trigger
point sensitivity, suggesting that C-Sens
may play an important role in the
pathophysiology of myofascial trigger
points. If trigger points are a product
Like pain, what we see can be altered by the brain.
12
SPRING 2015