This is an article that is on one of the Fibromyalgia sites that was
published last week. Reading all the emails from many who have it and
are also I like to read a lot online and continue to see what is out
there
I really am very thankful for the internet and the information and
support it has given me all these years being ill
I was surprised when my doctor told me that it is not uncommon to see
them together ( PA and RA also have fibromyalgia) and that I learned I
had another disease was devastating The good news is they are
learning more and more about it all the time
I ind this group the best for education and growth and also the tolerance
I am not on line as much as would like so I am not able to contribute
as much as I would like.. Especially with two diseases that sometime
effect me separately and also together at times
below is some information:
I belong to a couple fibro groups that help me stay informed...
Many conditions can lead to permanent changes in the pain transmission
mechanism and result in chronic pain that overwhelms the body's pain
defense mechanisms. One such condition is Fibromyalgia.
Fibromyalgia may not cause destruction along the pain pathways as
other conditions I have mentioned can [rheumatoid arthritis, carpal
tunnel syndrome, shingles, multiple sclerosis, for example]. However,
Fibromyalgia does cause chronic abnormal changes along all the pathway
components and this results in chronic pain via both peripheral (from
skin, muscles and nerves) and central (from spinal cord and brain)
neurological mechanisms.
The end result of Fibromyalgia's abnormal changes appears to be a
state of pain amplification that cause severe generalized pain.
Fibromyalgia is ultimately a disease of amplified pain.
Dr. Robert Bennett has written and presented excellent information
that explains why we hurt with Fibromyalgia (e.g., "Emerging Concepts
in the Neurobiology of Chronic Pain: Evidence of Abnormal Sensory
Processing in Fibromyalgia," Mayo Clinic Proceedings). If we trace the
pain signals through the various parts of the pain pathway (from the
nociceptors - or specialized pain nerve endings to the nerves to the
spinal cord to the brain) in people with Fibromyalgia, we find various
abnormalities along the way. Many studies have shed light on different
points along the complete pain pathway.
I want to briefly summarize some of these different abnormalities and
possible problems encountered by Fibromyalgia pain signals on the path
to the brain.
NOCICEPTORS - Pain originates from the nociceptors
Trauma is a common trigger of Fibromyalgia. Tissue injury - damage to
the muscles and soft tissues activates the nociceptors. Some studies
have suggested that microscopic injury occurs in specific parts of the
muscles (for those who want the medical names: muscle spindles,
intrafusal fibers, and calcium pumps).
Localized tissue injury probably activates arachidonic acid (a
biological protein), which turns into "bad" prostaglandans (called
Cox-II prostaglandins), and cause inflammation and pain.
In addition to trauma, autoimmune factors may be another pain nerve
activator. Perhaps autoimmune processes create compounds which act as
irritants and activate the nociceptors chronically to the point where
they become "permanently" sensitized and irritated. As a result,
biochemical, hormonal, and red blood cell changes occur that interfere
with the cells' ability to receive adequate supplies of oxygen,
glucose, and other nutrients. Blood flow, energy formation, and the
cells' electrical and neurological harmonies are all disrupted.
Since the nociceptors remain "faulty," the electrical and neurological
balance remains abnormal, and nociceptors continue to be activated.
Pain-producing neurotransmitters are released and accumulate as long
as the nociceptors stay activated at the peripheral level (skin and
muscles, especially).
These persistent pain signals we experience may be interpreted as an
itching, burning, swelling, or tingling at one end of the spectrum, or
at the other end knife-stabbing, burning, or throbbing. One
nociceptor can signal different pain signals and sensations depending
on its level of irritation the more irritated it is, the more severe
the pain.
These changes can become permanent and cause the nerves to become
sensitized to the point where they are easily activated to send pain,
even in the absence of any noxious stimulus.
In other words, persistent pain signals can spontaneously arise from
peripheral nerve endings and bombard the rest of the pain pathway. So,
instead of waiting for outside stimulation such as trauma, pressure,
temperature, or touch to signal the nociceptors, these nociceptors
send pain signals on their own, without any outside help. This
"spontaneous" pain is what we complain about the most!
NERVES
The nerves, especially the sensory nerves and the autonomic nerves,
"wonder what is happening" because they are getting bombarded by all
of these signals from the nociceptors. At first, they try to diminish
these painful signals by using accommodation and gate mechanisms.
However, the signals persist and they, too, undergo a sensitization
process. They become hypersensitized and react with an exaggerated
response instead of a normal or diminishing response (accommodation).
Now we get even more pain, numbness, swelling, burning, and other
sensations.
Some of the hypersensitization may be mediated by nerve growth factor,
which has been found in higher levels in Fibromyalgia. A high nerve
growth factor may indicate the nerves are trying to regenerate or
repair themselves. But instead of repairing the nerves so they act
normal again, the opposite seems to happen. Nerve growth factor is
probably enhancing the nerves' abilities to transmit pain to the
spinal cord. More pain results, not less.
SPINAL CORD Amplification, wind-up, allodynia, Substance P,
generalization
At the spinal cord level, the Fibromyalgia begins to take control.
It is here that additional changes occur to perpetuate the pain and
spread it to different levels. When pain generators first start
firing, the spinal cord pain processing centers may act at first like
a dry sponge and easily soak up all the signals. Our bodies may have
many pain generators at any given time, but if they are slowly and
intermittently firing, drug sponges can soak up the signals and not
cause any bothersome symptoms.
From time to time there may be an acute exacerbation of a problem
leading to a lot of pain signals being generated, and if a lot of pain
signals are dumped at once into the spinal cord sponge, only a little
bit gets absorbed and a lot gets passed through and perceived as acute
pain.
In Fibromyalgia, however, the different pain generators continue to
send signals and eventually the dry sponges becomes a wet sponge and
it can't soak up any more. The additional oncoming continuous signals
will spill over the wet sponge, and this leads to persistent pain.
The two main changes that occur at the spinal cord include:
* Pain amplification (by specialized nerves called NMDA receptors)
* And loss of pain filtering (by the diffuse noxious inhibitory
control system).
Spinal cord nerves are bombarded by continuous stimulation from the
peripheral nerves, causing a progressive increase in electrical
signals to be sent up to the brain. This phenomenon is called
"wind-up," and is the neurological mechanism for the amplification of
pain.
Once this wind-up phenomenon occurs, a central sensitization results
in which various types of sensory signals - not just pain - will
arrive in the spinal cord, become amplified, and be sent to the brain
as pain. The spinal cord becomes more sensitized to sending pain, lots
of it. Once this happens, the spinal cord is not able to properly sort
out and filter various sensory signals.
As a result, different sensory signals such as touch, pressure,
temperature, and joint movement all become amplified and sent up the
pain pathways, resulting in pain signals instead of the appropriate
touch, pressure, temperature, or joint motion signals.
This defect in pain transmission where there is increased sensitivity
to all stimuli even those which normally do not evoke pain is
called allodynia. Unfortunately for the person with Fibromyalgia, the
spinal cord is now "wired" to interpret nearly all sensory signals as
pain severe pain! We can still appreciate touch, pressure,
temperature, joint movement, and other non-pain signals, but pain
contaminates these signals, and we feel the pain.
Another key change at the spinal cord level is an increased formation
of Substance P and other neurotransmitters.
Substance P's primary role at the spinal cord level is to transmit
pain signals and to sensitize the spinal cord so it is readily
available to transmit pain. When Substance P reaches high
concentrations (as it does in Fibromyalgia), it can migrate up and
down the spinal cord, away from the initial location of the pain
signal. As a result, multiple levels of the spinal cord undergo
sensitization and send increased pain signals, leading to a
"generalization" of the Fibromyalgia.
This spreading of pain explains how one can develop generalized
Fibromyalgia from an initial regional area of pain. A common example
of this occurs following a motor vehicle accident where a particular
body part, such as the neck, was injured. Over time, the pain begins
to involve the mid-back, low back, and ultimately the whole body, even
though these areas were never injured. The Substance P-induced spinal
cord changes can explain this migration of pain from the neck to the
entire body.
BRAIN
Our poor brains have no chance, do they? Any pain memory stored in the
past will be re-awakened by this process. Fibromyalgia is notorious
for causing previously injured areas to hurt more once it develops.
This previously injured area may have settled down and become
essentially pain-free, but the pain memories remained, although
inactive. Thanks to the Fibromyalgia pain amplification process, the
inactive memories are reactivated.
The pain centers of our brain, the limbic system and the cerebral
cortex, are continuously fed these amplified signals from the spinal
cord. Changes occur:
* Serotonin levels decrease,
* Brain waves change,
* Sleep stages are affected,
* Blood flow and glucose [blood sugar] metabolism are affected.
The brain gets overwhelmed with these pain signals and spends a lot of
attention and energy monitoring the pain. Fibrofog occurs. Emotional
components are "attached" to pain, including f