1. What is Complex Regional Pain Syndrome?
2. What causes it?
3. What can I do about it?

WHAT IS COMPLEX REGIONAL PAIN SYNDROME-CRPS I (RSD)?

The disease, which was formerly called reflex sympathetic dystrophy (RSD), is now termed Complex Regional Pain Syndrome-CRPS I. This disease may be characterized by significant pain complaints, changes in skin blood flow resulting in a warm or cool extremity, discoloration, sweating and swelling. The individual typically shields the limb from contact and use. With time, and particularly without adequate treatment, the syndrome progresses to include changes in the skin, hair, nails and soft tissue along with muscle wasting and loss of motion.

Different names have been promoted to assist in classifying patients based on their clinical presentations in hopes of defining subgroups that respond in a similar and predictable pattern to various treatments. The variability in diagnostic impression seen from one evaluator to the next relates to a combination of factors including individual training and experience along with the most recent name changes for these syndromes.

In 1994, the International Association for the Study of Pain (IASP) published the second edition of Classification of Chronic Pain. The term RSD was replaced by complex regional pain syndrome (CRPS) type I. There had been dissatisfaction with the term "reflex sympathetic dystrophy" because not all cases seemed to have involvement of the sympathetic nervous system, and not all were dystrophic.

WHAT CAUSES COMPLEX REGIONAL PAIN SYNDROME-CRPS I (RSD)?

The condition is initiated by a wide variety of factors, including nerve injury or minor trauma. Symptoms can be seen in orthopedic patients post-operatively, after stroke or head trauma and following myocardial infarction, chest surgery or infection. It has been reported with cancer, arthritis, burns, nerve entrapments, herpes zoster ("shingles") and a number of other diseases. We do not yet understand how these events trigger the abnormal healing response of CRPS I.

WHAT CAN I DO ABOUT IT?

Therapeutic approaches include physical rehabilitation, psychological care, medications, and a variety of techniques which, directly or indirectly, are aimed at blocking or interrupting the abnormal activity in the nervous system. Aggressive medical management is recommended for successful treatment. Conventional medical treatments have primarily focused around sympathetic blockade and oral analgesics.

As mentioned earlier in this article, abnormal functioning of the sympathetic nervous system appears to be associated with CRPS, but some individuals present with sympathetic independent pain (SIP). Thus, while a sympathetic block may provide a useful adjunct to aggressive medical therapy, it should not be considered as a sensitive or specific diagnostic test for the diagnosis. Usual procedures employed in diagnosis and treatment include:

1. Stellate ganglion block (upper extremity RSD)
2. Thoracic sympathetic block (upper extremity RSD)
3. Lumbar sympathetic block (lower extremity)
4. IV regional sympathectomy (upper or lower extremity)
5. Phentolamine infusion (upper or lower extremity)
6. Intravenous lidocaine infusion (upper or lower extremity)