Reflex Sympathetic Dystrophy Prevention and Management
CRC Press, Boca Raton, Florida
H. Hooshmand, M.D.
" A syndrome of sustained
burning pain after a traumatic
nerve injury combined with
sudomotor dysfunction and later
Causalgias are divided into two forms:
1. Causalgia major
peripheral nerve injury with electrical "crosstalk" (ephapse) that causes severe
hyperactivity of sympathetic system (hyperpathia, vasoconstriction, and movement
disorder). The major form is severe, usually caused by injury with high velocity sharp
objects (e.g., butcher's knife), vibratory component major trauma (e.g., bullet), or
high-voltage nerve lesions (electrocution).
2. Causalgia minor
same principle as causalgia major, but milder injury, e.g., injury to the dorsum of hand
or foot, nerve root contusion, patient falling from a height on gluteal region resulting
in "guillotine" effect, bruising of nerve root caught at the narrowed
The difference between the two categories is a
matter of degree and severity. To classify causalgia as an independent illness is
artificial, and causalgia is nothing but a sever form of RSD.340,363-365
In this severe form of RSD, the course of the
disease is quite accelerated from stage 1 through 4 in a matter of weeks or months. S.
Weir Mitchell230 in 1872 first reported rapid development of atrophic changes in the skin,
nails, and soft tissues of the extremity in a matter of days to weeks.
Whereas in RSD of disuse the extremity is cold, in
ephaptic dystrophy the thermography reveals in the distal portion of the extremely cold
extremity that there is an isolated hot spot that points to the area of scar
formation and ephaptic peripheral nerve dysfunction (Figures 4-6). In this area the
vasoconstrictive capability of the sympathetic nerve is paralyzed, and there is a topical
hot spot. This hot spot can be appreciated only by thermography.289
This type of RSD is quite painful and very difficult
to treat. It demands multidisciplinary therapy as well as early diagnosis. The
form is characterized by increased heat emission
at the area of
ephaptic lesion (electric short). As the condition becomes chronic, the
distal portion of the extremity involved and the contralateral extremity becomes cold, but
the ephaptic spot stays hyperalgesic and warm (Figures 4,5, and 6b).
Sunderland363 in 1978 succinctly defined
causalgic pain as follows:
1. Usually pain occurs after the injury to a nerve
2. The severity of the injury to the soft tissues
other than the nerve does not play a role in the severity of the pain.
3. The pain is spontaneous, severe, and quite
4. There is a markedly lowered threshold for
aggravation of pain. This is the case in all RSD patients, but it is more exaggerated in
causalgics. So even a breeze over the skin or the touch of a bed sheet or a change of the
environment or a family argument and aggravation can markedly aggravate the pain. This
feature of emotional aggravation is common to all RSD patients, and it is nothing but the
role of the frontal lobe and the limbic system in aggravation of hyperpathic pain.
5. The pain is felt distal to the proximal nerve
injury, i.e., in the hand or foot. This is typical but not invariable. The pain does not
necessarily have to be a burning type of pain, and can be described in many other
6. Sunderland established the requirement that the
pain should be present at least 5 weeks. However, depending on the severity of the injury,
the pain can develop in a matter of days or weeks. What happens to an extremity in RSD of
disuse in a matter of several months can happen in a matter of a few weeks to a causalgic
In no case of RSD is the pain so severe, so
intolerable from burning, seering, aching, tingling, lightening, stabbing,
crushing, to a combination of the above, without burning pain in a matter of a
few hours to up to 7 to 10 days in close to 90% of the cases.374 However, it is
not unusual to see some patients who develop the pain as late as 3 to 4 weeks after the
Major causalgia is due to scar
formation of peripheral nerves but has a component of high-velocity or
high-vibration injury in its etiology. This is usually seen after bullet injuries
or high-velocity sharp objects such as a butcher knife or surgical instrument injury. This
is typically seen in war injuries, but it can also be seen in civilian trauma due to
amputation of an extremity or industrial injury to the extremity. It is not uncommon in
electrical injuries. Drilling steel against titanium in the aerospace industry causes
high-frequency vibration and makes the patient more susceptible to causalgia.
The difference between the minor and major
causalgias is a matter of degree and severity. For more detail on causalgia, see Chapters
1 and 12.
Major Causalgia and Motor Dysfunction
Major causalgia is the best example of efferent
dysfunction secondary to sensory nerve damage and RSD. This efferent dysfunction is quite
frequently present among causalgic patients (at least over 50% of the patients) and is in
the form of flexion deformity of the extremity, tremor, weakness of the extremity, and
The management of major causalgia requires a
multidisciplinary approach. Trigger point injections should be applied to referred pain
areas rather than the area of peripheral nerve damage. Repetitive sympathetic nerve blocks
can be quite effective. Sympathectomy should be used only for patients who have failed
with every other form of therapy and when the patient has a short life expectancy.
Even among patients who have has such a conservative
approach towards sympathectomy, there still may be the necessity for morphine pump after
failure of sympathectomy (Table 42). Morphine pump, a last resort in treatment, provides
good control of pain. As most causalgic patients in civilian (as opposed to war) practice
are involved in protracted litigation (especially worker's compensation cases), by the
time they are being evaluated for RSD several months or years have elapsed, and the only
effective treatment is morphine pump in this stage IV of the disease. For more detail on
causalgia, see Chapters 1 and 12.