Pain resulting from nerve entrapment syndromes is a common reason for clients to seek the care of a massage practitioner. However, there are numerous neurological disorders that, at first glance, might appear to be nerve entrapment but are an entirely different pathological condition. Complex regional pain syndrome (CRPS) falls into that category.

A brief review of fundamental neuroanatomy is helpful to properly understand what occurs in CRPS. The autonomic nervous system has efferent fibers that control activity in various smooth muscles, glands and cardiac muscle. Within the autonomic system there are two divisions, the sympathetic and parasympathetic. The primary function of the sympathetic branch is to stimulate activity, while signals from the parasympathetic branch serve to inhibit activity. Of these two, the sympathetic branch is more involved in CRPS.

The sympathetic nervous system has a vital role in protective reflexes as the body responds to stress. It is in high gear during the "fight or flight" response. However, excess sympathetic system activity can generate and maintain pain states in different regions of the body. It is this excess sympathetic activity that causes the symptoms of CRPS. While there still is not a complete understanding of how excess sympathetic branch activity causes these pain conditions, it appears there is some spillover of noxious input from the sympathetic efferents into various nociceptors, especially in the extremities.

The term complex regional pain syndrome has only recently been added to the medical lexicon. It includes two separate conditions that have similar symptoms, but are different in cause. The two conditions were formerly called reflex sympathetic dystrophy (now called CRPS 1) and causalgia (now called CRPS 2).⁵ The primary difference between them is how they occur. In CRPS 1, symptoms commonly occur as a result of some traumatic incident, but there is no evidence of specific nerve damage. In CRPS 2, there also is some event that initiated excess sympathetic activity, but this condition also involves identifiable damage to the nerve. Most of the symptoms of CRPS 1 and 2 are similar and are listed below:

Symptoms of CRPS

• some initiating event, often traumatic, but might be trivial - surgeries, fractures, dislocations;
• pain disproportionate to the inciting event;
• allodynia (painful response to a stimulus that usually is not painful);
• hyperalgesia (exaggerated sensory response to a stimulus that ordinarily would produce only mild discomfort);
• allodynia and hyperalgesia that extend beyond the distribution of a single peripheral nerve;
• evidence of autonomic dysfunction (edema, alteration in blood flow, sudomotor dysfunction such as excess sweating in the region);
• pain usually described as burning, searing or shooting;
• vascular abnormalities (more common in CRPS 1) - often start with vasodilation and skin warming in the early phase and progress to vasoconstriction in later stages;
• excess edema in the affected extremity;
• motor impairment including weakness, inability to initiate movement, tremor, muscle spasm or dystonia;
• changes in growth patterns of hair and nails on the affected limb; and
• trophic changes in the skin.

Distinguishing CRPS from other neurological disorders is aided by detailed evaluation of several clinical features in addition to those listed above. The condition can affect either the upper or lower extremity, but is more common in the upper extremity, and the pain usually is aggravated with moving the affected limb. Various myofascial dysfunctions also might accompany the extremity pain.¹ Women are affected more often than men by approximately a three-to-one ratio.² Some degree of depression or psychological dysfunction is common with CRPS. However, it is unclear if this psychological dysfunction is a causative factor or a result of the condition, because depression and similar psychological manifestations are common in severe and chronic pain conditions.⁴

Treatment for CRPS varies widely, but physical therapy is a primary component of most treatment protocols. The goal of most physical therapy treatments is to desensitize the area and restore normal function of the affected extremity. Massage might play a fundamental role in this process. Because myofascial dysfunction often is a part of the array of symptoms, addressing the myofascial component might interrupt the cycle of pain and dysfunction. In many cases, if the myofascial pain condition was properly addressed, the whole syndrome may resolve.³ Massage is also likely to be helpful because it is effective at decreasing overall sympathetic system activity.

If you have a client demonstrating signs and symptoms that indicate the possibility of CRPS, it is important to have them properly evaluated by a physician. There are a number of other treatment strategies such as nerve blocks and medications that are effective in addressing the problem, and it might be important to start these treatments as early in the rehabilitation process as possible.

CRPS can be a debilitating condition. Because it occurs more often in the upper extremity, it might be easy to dismiss many of the symptoms as arising from a peripheral compression neuropathy such as carpal tunnel syndrome. However, awareness of the variety of symptoms associated with CRPS allows the practitioner to look at a bigger picture and catch this condition early on, if present, so it can be most effectively treated.

References

1. Allen G, Galer BS, Schwartz L. Epidemiology of complex regional pain syndrome: a retrospective chart review of 134 patients. Pain, 1999;80:539-44.
2. Ghai B, Dureja GP. Complex regional pain syndrome: a review. J Postgrad Med, 2004;50:300-7.
3. Rashiq S, Galer BS. Proximal myofascial dysfunction in complex regional pain syndrome: a retrospective prevalence study. Clin J Pain, 1999;15:151-3.
4. Walker SM, Cousins MJ. Complex regional pain syndromes: including "reflex sympathetic dystrophy" and "causalgia." Anaesth Intensive Care, 1997;25:113-25.
5. Wasner G, Backonja MM, Baron R. Traumatic neuralgias: complex regional pain syndromes (reflex sympathetic dystrophy and causalgia): clinical characteristics, pathophysiological mechanisms and therapy. Neurol Clin, 1998;16:851-68.