RSD is now known as Complex Regional Pain Syndrome Type 1 (CRPS-1). It applies to a variety of seemingly unrelated disorders that have clinical features that are varied but manifest the same fundamental disturbance and underlying physiology. The condition has been termed a variety of names including shoulder-hand syndrome, Sudeck's atrophy, causalgia and algodystrophy. 

 

No matter what you call it, this very real syndrome refers to diffuse limb pain that is often burning in nature and often secondary to an injury or noxious stimulus. There are associated sensorimotor, autonomic and trophic changes that are in a non-dermatomal distribution. These patients are frustrating to treat, often manipulative and depressed, yet have a very real neurophysiologic problem that first needs to be recognized and then aggressively treated. Classically, there are signs of autonomic dysregulation including alterations in blood flow, which cause color, and temperature changes, as well as hyperhidrosis (increased sweating) and edema. There are also sensory abnormalities with hypo and usually hyperesthesia. Motor dysfunction is usually seen in later stages with weakness, joint stiffness and occasionally tremor. 

 

Certainly many of us can see that there are reactive psychological disturbances as well including anxiety, depression and a feeling of hopelessness. When it is not appropriately treated, trophic changes can occur including muscle atrophy, glossy or thin skin, brittle nails and alterations in hair growth along with osteopenia seen on x-ray. It is these trophic changes that can be irreversible. Hence, we must all be very aware to recognize this problem so that the medical specialists that are prepared to deal with this can appropriately treat it. It is of utmost importance that therapists recognize the early stages so it can be brought to the attention of the referring physicians. 

 

The earliest description of RSD comes from the 17th century where a surgeon recognized a severe, burning pain that resulted from a peripheral nerve injury. This was termed causalgia in 1864 by Mitchell who recognized this in soldiers who sustained a war injury. The earliest treatment was seen in the 1920s when sympathetic blocks relieved the pain from causalgia and a surgical sympathectomy could affect a permanent relief. The International Association for the Study of Pain later changed the term RSD to Complex Regional Pain Syndrome Type 1 and a causalgia by resulting from a nerve injury was termed Type 2. The clinical presentation for CRPS Type 1 is a pain localized initially to the site around the injury, but typically with time spreads to involve the entire extremity. It can often spread through the contralateral limb and even the ipsilateral extremity or the entire side of the body. 

 

Disturbances in vasomotor function are a common denominator that can produce either vasoconstriction or vasodilation, resulting in skin color and temperature changes as well as increased sweating. This is the foundation for the clinical diagnosis; however, there is a list of criteria that must be fulfilled in order to make the clinical diagnosis including a burning pain, hyperesthesia, temperature and color changes, edema, and hair and nail growth changes. There are both laboratory and imaging studies that may support the diagnosis, including bone scans and x-rays as well as a quantitative sweat test, but the diagnosis is best made by a positive response to sympathetic blockade. This is performed by a pain management specialist who will block the sympathetic flow to the extremity through either a stellate ganglion or axillary block using the appropriate anesthesia and then monitoring the response in the extremity. One must be aware of other conditions in the differential diagnosis including a peripheral nerve injury that would have a well-defined neurologic distribution. 

 

Other conditions such as inflammatory lesions (tenosynovitis or bursitis) or myofascial pain can often be confused for complex regional pain syndrome. Fortunately, the main hurdle in treating this condition is making the appropriate diagnosis and the patient being referred to the right specialist. Pain management is now a well-recognized subspecialty, usually practiced by anesthesiologists with further training in this area. There are now a variety of pain clinics available for treating patients with this and other difficult chronic pain conditions. The current treatment consists of diminishing the sympathetic flow to the extremity through either pharmacologic, sympathetic nerve blockade or chemical sympathectomy. Physical therapy to the affected area is critical and must always be done in conjunction with any type of blockade of sympathetic flow to the extremity. In early cases, when the condition is recognized in its initial stage, it may respond to physical therapy by itself. The majority of cases, however, require nerve blocks that are either performed as a block to the stellate ganglion, which is in the cervical spine region, or a brachial plexus block, which is performed in the axilla region. These are often performed with light sedation as many of these patients have anxiety as a complicating condition, and a series of these blocks is required in order to get the condition under control. It is best to perform these blocks in direct conjunction with physical therapy so that the patient can have the blockade performed and immediately go to the therapy center for active and active-assisted range-of-motion exercises with muscle strengthening and conditioning. Deep myofascial massage as well as heat is also helpful and this is often done in conjunction with whirlpool, paraffin or radiant heat treatments. Low-dose ultrasound (0.5 watts per centimeter squared x5 minutes) also has a beneficial effect as well as the use of a TENS unit. 

 

It should be noted that vigorous passive range-of-motion exercises or the use of very heavy, strenuous weights may re-trigger the symptoms and it is important that the physical or occupational therapist work closely with the pain management specialist and referring physician in this regard. Psychological treatment is often necessary in dealing with stress as well as teaching coping strategies for dealing with this pain and the underlying causes. It may be important to address underlying psychosocial factors that can predispose patients to this problem. It is important to emphasize to the patient that they are not crazy, although they may certainly have psychological disturbances, so that they know that the pain they are experiencing has a very real physiologic basis and that it is possible for us to help them. 

 

It is important to understand the characteristics of this condition as they are rarely seen by the pain management specialist in the early stages. Most of the time, they present to an orthopedic or hand surgeon with the complaints as previously mentioned, but the initial treating physician either may not recognize the diagnosis or may not realize its severity and the need for aggressive early treatment. It is in these cases where the therapist is particularly valuable as they work with the patient in a closer manner and can make the suggestion that these patients be referred to the appropriate pain management specialist to confirm their suspicions. 

 

Now that we understand so much more about this condition, we can begin erasing the medical stigma against it and concentrate on appropriate treatment. 

 

Authors:

Alejandro Badia, MD, Miami Hand Center, Hand and Upper Extremity Surgeon

Angel Saavedra, MD, Miami Hand Center, Anesthesiologist and Pain Management Specialist.