Thursday, December 15, 2011

Why is the shoulder the most common first complaint in NA



If you are like me, you may have wondered why it is that the shoulder is the most common first noticed complaint in Neuralgic Amyotrophy attacks. Maybe it never crossed your mind after all.  I figure, if there is a causal agent in the bloodstream, and it finds the shoulder plexus site to attack, it is just as likely to find other nerves at other plexus sites.  It may be clever, but is it really smart enough to be that specific?  If you listen to most doctors, they would suggest “yes”, it is that specific.  If you have any other issues in other areas with weakness, it is either all in your head, or you have something else they can charge thousands of dollars to test for, and come up with nothing.  “Oh well, nothing wrong with you- got to scoot”.   

If you read the document (linked above), there are two things talked about which suggest a reason for the shoulder being the most common joint impacted with NA.  It begins with overall muscle loss, and ends with the efficiency of muscles to do work with impeded nerve connections.  The author first speaks of muscle loss, stating that

“In daily life, people generally do not notice that they are losing muscle strength
until they have lost around 30% of their maximum strength. The strength that lies
between 70% and the maximum of 100% is, as it were, ‘extra’ in case heavy exertion
must unexpectedly be made.”

So, you could have an attack of NA that leaves you with a gradual loss of muscle strength to say 75% of normal, and not even notice it.  I think this actually happened to me, looking back. I had had an attack that impacted my right hand and left my arm weak. But otherwise, I had no clue what was going on, except, on a long car trip, I noticed a bit of shaking at times getting into or out of the car.

Time passed, and one night I woke up on my right side and noticed that my shoulder popped, and collapsed a bit. There was no pain, just the sensation of settling that did not feel normal at all.  Why would this be important? Look to the document again. 

“For most of the muscles, one can say that they function well in daily life
once they have regained 70% of their former strength. However, some muscles
must truly be nearly 100% recovered before they can function normally again.
The muscle that, when it fails, causes a protruding shoulder blade, (the serratus
anterior) is the most important example of this. Because this muscle needs its
maximum strength and endurance in order to work well, it sometimes seems as
if recovery of the nerve to this muscle takes much longer than the recovery of the
other nerves.”

It would seem possible that the muscles surrounding the shoulder are a bit more sensitive to nerve loss than other sites in the body. So that may explain why the shoulder is the first noticed spot that NA impacted, when truly, it is everywhere to some extent.  They go on to say:

“With neuralgic amyotrophy, the strength in the affected muscles is often decreased
to (much) less than 50% of the maximum. It is often not even possible
anymore to carry – or lift – the weight of the arm itself, let alone an extra weight
(for example, a purse or bag). It also becomes difficult to maintain movement or
postures. It is sometimes possible to make a specific movement once (such as
extending the arm or putting something in the cabinet above your head) but it is
not possible to do that a number of times or to keep doing it for a specific period
of time. Both the loss of strength and the difficulty with maintaining movement
are serious impediments for NA patients in their daily work, sports or activities at
home.”

Add to that that any regained strength may be to a lesser amount than what existed prior to the attack. For HNA sufferers, this is augmented by having many more attacks over a lifetime.

Speaking of returning strength. . . Do not do as I did and force it to get better.  Heavy exercise prior to complete healing can lead to further nerve damage and make that nerve even more susceptible to further attacks in the future.

“If, within a nerve bundle, no more than two thirds of the axons are damaged, then
the remaining axons will take over the work of the damaged cables within three
to four months. This mechanism is called: ‘collateral reinnervation’. This repair
mechanism works well because the muscle can then again be completely controlled.
However, this is at the expense of some load endurance. That means that the
muscle can certainly provide maximum strength once but cannot maintain it well
or keep it up for long. In daily life, patients often notice that, after a time, they can,
in principle, carry out all of the movements with the arm, but that the arm becomes
heavy and tired after being used for awhile and they must stop and rest before
they can continue with what they were doing.”


“If the nerve has been affected a number of times, the chance of recovery decreases.
Also, nerves are not able to tolerate everything: If they become even more
damaged, they will be ‘broken’ for good. In practice, this means that the function
of, for example, the arm after an initial period of painful loss of function will still
recover for the most part, but that, after a second or third time, will not recover as
completely and, ultimately, will not be able to recover at all. The loss of strength,
but also the disorders in sensation and blood supply to the skin, then become
permanent.”



No comments:

Post a Comment