REFLEX SYMPATHETIC

SUMMARY Complex Regional Pain Syndrome is an uncommon and unpredictable complication of neck and limb injury. Both physical and psychological factors have been identified.

Prognosis for rehabilitation is mainly influenced by severity of the syndrome.

Reflex Sympathetic Dystrophy (RSD), now known¹ as Complex Regional Pain Syndrome (CRPS), comprises² (Stage I) pain, autonomic dysfunction (malfunctioning of the nerves that serve functions mainly under involuntary control) and edema (swelling of the affected part.)

In Stage II³, dystrophy (tissue distortion from faulty nutrition), atrophy (loss of tissue), and movement disorders become more prominent. CRPS I (RSD) is diagnosed if specific nerve injury is not recognised, CRPS II (causalgia) if it is.

As evidenced by response to treatments that temporarily abolish or reduce its activity, the sympathetic component of the autonomic nerve supply may or may not be involved in maintaining the chronic pain of CRPS⁴. However, subsequent doubt about a central role for the sympathetic nervous system in mediating CRPS was a major factor in the change¹ from the previous term, Reflex Sympathetic Dystrophy.

Complex Regional Pain Syndrome is an uncommon and unpredictable complication of neck⁵ and limb injury. Severity of injury does not predict the occurrence of CRPS , and the "thin skull" causal factors are little understood. A genetic predisposition⁶ remains unconfirmed. A remarkable study⁷ of muscles from legs amputated for severe, intractable CRPS found changes similar to those in severe diabetes mellitus, where the local blood supply is compromised.

Both physical and psychological factors have been identified. A recent Belgian clinical research paper⁸ describing the typical patient profile is of interest to personal injury litigators.

PRACTICE POINT

RSD "thin skull":

1. Age more than 30 years
2. Chronic Depression
3. Evidence of alcohol abuse (50%)
4. Inactivity, or opportunity for

In this⁸ case series he clinicians noted a material response of the CRPS to antidepressant medication in the later cases that were routinely offered the treatment. Since the sympathetic nervous system - "fright, fight, flight" - is overactive in anxiety states a causal connection with chronic depression is not surprising.

However, there is considerable evidence that anxiety and depression are the consequence^9, ¹⁰ rather than a causal factor in RSD, and that psychological profiles are indistinguishable^9, ¹¹ from those of other chronic pain sufferers.

Prognosis for rehabilitation is mainly influenced by severity of the syndrome. A Polish researcher found¹² no difference in outcome according to the type of treatment - regional intravenous blocks with local anesthetic and corticosteroid medication, intravenous free-radical scavenger (mannitol), the hormone calcitonin or an exercise programme. Out of many factors studied, only 3 accounted for the treatment failures.

PRACTICE POINT

RSD Poor Prognosis for Rehabilitation

1. Symptoms more than 1 year
2. Advanced Stage II and III
3. Specific Nerve injury

There is little to no evidence for the proposition that early intervention alters the long-term outcome^{13
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Referenced Articles:

Chronic Pain 1998 - Personal Injury News - Volume 5, Issue 1
Evaluating research - Personal Injury News - Volume 4, Issue 1
Venepuncture - Medical Litigation News -Volume 3, Issue 1
Evaluating Research, Personal Injury News - Volume 4, Issue 1
MVA Psychiatry, Personal Injury News - Volume 4, Issue 6