Pain: Reflex Sympathetic Dystrophy Prevention and Management
Boca Raton, Florida
H. Hooshmand, M.D.
CAUSE OF FAILURE AFTER
1. Sympathectomy is analogous to
the act of killing the messenger. The sympathetic nervous system has the
critical job of properly controlling and preserving the circulation in
different parts of the body, especially in the extremities. By paralyzing
the system, the extremity will be more apt to have disturbance of
circulation and is left unprotected from fluctuation in circulation.
Sympathectomy is similar to permanently removing the
central heat and air-conditioning system and never replacing it because of
Sympathectomy permanently damages the temperature
regulatory system. The reason sympathectomy does not cause side effects
other than ineffective control of pain as well as impotence and
orthostatic hypotension is because it is invariably partial and
2. Even after "complete" removal of
the sympathetic plexus for the upper or lower extremities, the sympathetic
nerves in the wall of the blood vessels are left intact.
3. As shown in Table 6, the most
common form (over 80%) of RSD is disuse RSD. In this situation, the
sympathetic system is temporarily hyperactive. Proper conservative
treatment would prevent any unnecessary invasive surgery (such as
sympathectomy) in such patients.
4. Usually the patients that end up
needing sympathectomy are the ones who suffer from ephaptic
dystrophy. Sympathectomy in such cases cause a classic
Cannon phenomenon. This physiological phenomenon refers to the
fact that the end organ that is controlled by sympathetic nerve fibers
will become uninhibited in its chemical dysfunction. As a result, even
though the sympathetic fibers are not contributing to acetylcholine or
become uninhibited with resultant increase of pain input.
In diabetic neuropathy RSD, sympathectomy
dramatically relieves the pain for the first 1 to 3 years. Then
deafferentation can Cannon phenomenon set in. As a result, invariably by
the second to fifth year the patient ends up with a lot more pain.
Sympathetic blocks repeated every 6 to 12 months yield similar results.
In patients who have had sympathectomy,
thermography shows an increase of temperature in the focus of
ephaptic nerve damage (Cannon phenomenon) with secondary increase of pain
5. There is a significant overlap
in the border areas of sympathetic nerve dermatomes. As a result, the
adjacent intact sympathetic nerves try to overcome the lack of sympathetic
input. This contributes to the failure of long-term effects of
6. Whereas the neiospinothalamic
tract is quite consistent in its anatomical pattern, the sympathetic
nerves and plexi are phylogenetically old, and show a marked individual
variability in humans. This causes a problem at the time of surgery and
results in the gray rami branching off and entering in a few adjacent
areas of the sympathetic paravertebral chain. As a result, the removal of
part of this chain does not guarantee a "complete" sympathectomy.
7. The sympathetic nervous system
functions symmetrically and bilaterally. So the removal of a portion of
this system on one side does not achieve a "total sympathectomy.
8. At times when patients undergo
lumbar sympathectomy, we have noted that they may develop Horner's
syndrome on the same side or marked vasoconstriction of the hand on the
same side, reflecting the complex and primitive connections of the
sympathetic nervous system. Cooper has shown vasoconstriction in the hand
during electrical stimulation of the lumbar sympathetic chain. We have
noted development of de novo RSD in the ipsilateral hand in two
patients after lumbar sympathetic block.
9. Repeated sympathectomies are no
guarantee of success.
10. Another side effect of
sympathectomy is that the patient loses motivation for physiotherapy and
exercise. Because sympathectomy results in immediate relief in the first
few months, the patient has less inclination or motivation to exercise and
help improve the circulation of the extremity.
11. Even in the cases of rare and
severe major causalgias, it makes more sense to resort to a morphine pump
than to sympathectomy.
The application of
sympathectomy in management of RSD should be strongly discouraged.
If the patient suffering from RSD has a short
life expectancy (less than 5 years), then sympathectomy makes sense and
should be done.
FACTORS CONTRIBUTING TO
|Sympathetic nervous system is
bilaterally and symmetrically innervated. Unilateral sympathectomy cannot
Bilateral sympathectomy has too
many side effects (e.g., hypotension, impotence).
SNS is anatomically primitive and
structurally inconsistent. Amoebic-type connections of the ganglia makes
"total sympathectomy" impossible.
Overlapping SNS thermatomal
innervation results in postsympathectomy regeneration.
Cannon's phenomenon (topical
noradrenergic autonomy) at the area of ephapse perpetuates the
Spread of RSD to adjacent
structures results in new manifestations of RSD in remote areas,
e.g., Horner's syndrome or de novo RSD of hand after lumbar sympathectomy.
The permanent destruction of
thermoregulatory function of SNS causes latent complications, e.g., RSD in
War and peace RSD and war and peace
medical(e.g., dibenzyline treatment results in Lebanese war) and surgical
results are not identical and comparable.
The war casualties are more likely
to be stress-induced analgesia (SIA) than peacetime trauma (e.g., a work
injury is more likely to be stress-induced pain- SIP - because of legal
complications). SIA pain responds better to treatment.
Repeated sympathectomies are
invariably doomed to fail.