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My office has seen a surge of clients diagnosed with chronic regional pain syndrome or CRPS after trauma of one kind or another. Although relatively obscure, the incidence and recognition of CRPS is beginning to gain attention, through understanding of the condition and treatment options at this time are still limited.
What is CRPS?
CRPS (complex regional pain syndrome), also known as RSD (reflex sympathetic dystrophy syndrome), is usually a life-altering condition, characterized by chronic, severe pain and commonly accompanied by other symptoms such as swelling and changes in the skin.
The condition is often precipitated by some form of trauma, typically of a seemingly minor nature in comparison to the problems that follow. There is no known cure, although experimental treatments continue to be conducted. (For an initial broad overview of experimental treatments see the Treatment discussion in the Wikipedia entry for Complex regional pain syndrome)
Until the 1990's, cases were often labeled as reflex sympathetic dystrophy or reflex sympathetic dystrophy syndrome (RSD or RSDS). The International Association for the Study of Pain (IASP) helped lead a name change in these cases, to complex regional pain syndrome (CRPS), in conjunction with the publication of diagnostic criteria for CRPS in 1993.
The name change was intended to move the syndrome away from association with a specific pathophysiology, because in truth various theories of pathophysiology have been proposed, and a definitive cause remains undetermined.
When was CRPS First Discovered?
In 1864, Drs. Mitchell, Moorehouse, and Keen, in a study of Civil War soldiers shot in the extremities, described a syndrome consisting of persistent burning pain with progressive trophic changes. In this same year, they described this condition as “erythromelalgia” changing the name to “causalgia” (Greek for “burning pain”) in 1867.
The syndrome has experienced a name-identity crisis since its beginning with numerous variations that have included the following:
- Erythromelalgia (1864 Mitchell, Moorehouse, Keen);
- Causalgia (1867 Mitchell, Moorehouse, Keen);
- Sudeck's Atrophy (1900 Sudeck);
- Peripheral Acute Trophoneurosis (1929 Zur Verth);
- Traumatic Agniospasm (1931 Morton and Scott);
- Post-traumatic Osteoporosis (1933 Fontaine and Herrman);
- Traumatic Vasospasm (1934 Lehman);
- Reflex Dystrophy of the Extremities (1937 DeTakats);
- Minor Causalgia (1940 Homans);
- Reflex Neurovascular Dystrophy (1947 Steinbrocker);
- Reflex Sympathetic Dystrophy Syndrome (1947 Evans);
- Reflex Aglodystrophy (1967 Serre); Mimocausalgis (1973 Patman).
Although a substantial portion of the medical literature has gradually shifted to the CRPS name in place of RSD as a descriptor for the syndrome, RSD is still commonly used,
What Causes CRPS?
The cause or pathogenesis of the syndrome is not clearly known but revolves about the sympathetic nervous system in some way. Trauma is often a precipitating factor (i.e. likely cause). Mandel and Rothrock's paper published in the June 1990 Postgraduate Medicine states:
Experimental evidence suggest that trauma, usually involving an extremity, results in C-fiber hyperactivity. Subsequently, large-diameter fibers in the dorsal horn become sensitized, resulting in sympathetic-fiber stimulation of peripheral nerve A-mechanoreceptors, which in turn, leads to spontaneous pain, hyperthesia, and allodynia.
Further extension of stimulation to the autonomic nuclei in the dorsal horn results in uninhibited sympathetic efferent activity sufficient to sustain the abnormal sensitizations of A-mechanoreceptors, resulting in persistent pain and physical changes.
It seems like the sympathetic nervous system turns on to help the body deal with the original trauma but then refuses to turn off. It remains “hyperactive.”
Trauma, even minor trauma, is the major precipitating factor in CRPS. Surgery, fractures, animal bites can all cause CRPS.
In one study, CRPS began following:
- Surgery (33.5%)
- Slip and Fall (19.8%)
- Fracture (18.8%)
- Sprain (14.6%)
- Crush Injury (14.2%)
- Contusion (12.3%)
- Auto Accident (3.9%)
- Other Trauma (3.2%)
- Lacerations (1.0%)
In that study, the time span between onset of symptoms and time of diagnosis was about 10 ½ months.
What Areas are affected by CRPS?
CRPS can occur in any area of the body, but the most common is in one or more of the extremities.
The syndrome affects all levels of tissue:
What are the Symptoms of CRPS?
CRPS commonly results in spontaneous pain, often described as a burning or shooting pain, at times reaching unbearable levels.
Although the pain usually appears near the area of an injury, the extent of pain typically seems excessive in comparison with the level of any apparent tissue damage in the area of the pain. The pain is often accompanied by swelling, tenderness, increasingly brittle nails, changes in skin color and temperature, and increases in sweating and hair growth in the specifically affected extremity.
In some cases, the pain is repeatedly triggered by a light touch of soft clothing or even a breeze brushing across the skin. Decrease in the range of motion of an affected extremity and atrophy of the extremity can result, along with severe osteoporosis and thickening of joints.
The symptoms are varied and often contradictory, if not bizarre. Pain is the most common denominator but can include some or all of the following:
- Recent trauma to affected portion of the body
- Pain or persistent burning sensation
- Diminished motor function leading to dystrophy and/or atrophy
- Muscle spasms
- Skin changes (variations in temperatures, dryness, scaling, either too much hair growth [hypertrichosis] or too little hair growth [ambithichosis] skin and tissue atrophy, nail changes)
- Vasomotor instability (Raynaud's phenomenon, cool, cyanotic, pallid mottled color, vasoconstriction, warm erthyematous [red] vasodilation, either no sweat [ambihidrosis] or excessive sweat [hyperhidrosis])
- Bone changes (osteoporosis, increased vascularity, prominent osteoclastic activity)
- Joint tenderness and joint swelling (hystologic abnormality of synovial tissue, variations of synovial edema and proliferation of capillaries, fibrosis of the subsynovium, some perivascular infiltration with chronic inflammatory cells, mostly lymphocytes)
- Tapered digits
- Palmar fasciitis often involved with hand injuries
- Pain and limitation of movement in shoulder associated with injury or the upper extremity, bilateral involvement in up to 50% of the cases
Are there Different Types of CRPS?
CRPS is currently categorized as either Type I or Type II. Both types share common characteristics, but they are differentiated by the presence or absence of a known peripheral nerve injury.
Type I develops after an “initiating noxious event” which may or may not have been traumatic in nature, but without observable evidence of a nerve injury. Type II is defined by the presence of a nerve lesion.
The distinction between these two types of CRPS is of more than academic interest. You need to know which type is afflicting you because some of the diagnostic tools are useful with one type of CRPS but not both.
In addition, some of the older names now grouped under the CRPS label are generally descriptive of a specific category of CRPS. RSD, Sudek's atrophy, algoneurodystrophy causalgia, sympathetically maintained pain (SMP), reflex neurovascular dystrophy (RND), and shoulder-hand syndrome are commonly associated with CRPS Type I, while causalgia occupies the CRPS Type II category.
How is CRPS diagnosed?
CRPS can be diagnosed objectively. Diagnosis of the syndrome is based upon the following:
- Clinical evaluation of presenting symptoms
- A triple phase bone scan can be helpful for pinpointing abnormalities in bone growth and bone deterioration, but probably not with the extent of accuracy needed for a CRPS Type I diagnosis.
- Thermal imaging may reveal asymmetric body temperatures commonly observed with CRPS, but because of fluctuation of temperatures in the limbs, one test is insufficient proof of the condition.
- Histologic changes in synovial tissue
- A sympathetic block – to identify pain reduction associated with the selective blocking of sympathetic nerves – is no longer considered to necessarily be diagnostic of CRPS.
- An EMG to identify abnormal neural activity in the affected limb can aid in the diagnosis of a Type II injury, but not Type I.
There are other objective tests which may be helpful, such as sweat testing, an MRI scan, laser Doppler imaging, and even plain film x-rays (depending on the signs and symptoms being observed).
However, there is no single gold standard objective test to confirm CRPS. Although a test may support the diagnosis, it will not prove it, and even with a supportive test a defense expert will try to point to a high false positive rate for CRPS.
There are several other conditions that can be confused with RSDS which include the following:
- Rheumatoid arthritis
- Herpes simplex
- Herpes zoster
- Ischemic rest pain
- Tabes dorsalis
- Pancoat's syndrome
There are also several conditions that are known to occur simultaneously with RSDS and include the following:
- Myocardial infarction
- Degenerative joint disease
- Cervical spinal cord injury
- Protruding cervical discs
- Cerebrovascular accidents
- Multiple sclerosis
How painful is CRPS?
Unfortunately, CRPS is considered the most painful conditions known. The McGill Pain Index rates pain from 0 (no pain) to 50 (worst possible pain). To give you an idea of how painful CRPS really is, childbirth and the amputation of a finger/toe have a pain rating of between 30 and 40. Chronic back pain and phantom limb pain are rated 30, while a fracture or toothache have a rating of 20. CRPS has a rating of 42. Now consider that CRPS lasts a lot longer than any of the other conditions mentioned and you will understand why it's often called the “suicide disease”
Here is a chart from one study regarding the pain at onset of CRPS:
Here are the responses for how frequently the pain occurred:
Constant 80-100% of the time 70.8%
Nearly constant 50-80% of the time 17.5%
Intermittent 25-50% of the time 6.7%
Occasional less than 25% of the time 5.0%
Can CRPS spread?
Unfortunately, CRPS can spread. Usually it will spread up or down, or left or right. So someone who is experiencing it in her left hand may have it spread to her right hand or left foot. Very seldomly it will spread diagonally (the right foot in this example).
In one study, almost 70% of the participants reported CRPS had spread to more than one area. The majority of the participants (71.6%) could not identify a reason for the spread while surgery and falls were a distant second and third leading cause.
How long does CRPS last?
CRPS is considered a permanent condition. Sometimes remission will occur, but usually it is temporary. Although doctors may routinely tell patients in pain that their condition will improve, CRPS is permanent in the majority of patients. The pain may subside for periods of time, but these are simply periods of remission. Any further trauma (including minor surgery or less) can cause a recurrence of pain that is worse than before.
What are the Treatments Options for CRPS?
The most single important factor in treatment of CRPS is early diagnosis. As CRPS progresses in severity, it becomes more difficult to treat successfully. Treatments can range from analgesics to lobotomy. At one point in medical history the offending extremity was amputated. In some cases today patients may still prefer amputation to the intractable pain and other severe symptoms that current modalities cannot resolve. Many of my clients have tried either a Ketamine infusion, a neural stimulator, or a dorsal ganglion stimulator to reduce the pain.
Early onset may be treated by simply immersing the affected area into cool water. Elevation of the area to relieve edema can also be helpful. Splinting can control contractures but extended immobilization is harmful. Range of motion exercises may be helpful and are sometimes combined with both ice water and hot water baths. Corticosteroids are occasionally effective.
If those treatments do not work, further treatment may include simple nerve stimulators (Tens unit), and anti-inflammatory agents, antiadrenergic agents (such as phenoxybenzamine and propranolol) and ultrasonography. Application of heat may be helpful for vasoconstriction. Even biofeedback has been successful in some cases. Nerve blocks are a principle modality. Temporary pain relief is offered during which time physical therapy can be accomplished. Periarterial sympathectomy has been demonstrated to be effective in some patients. Surgical sympathectomy has been successfully utilized in patients who responded to local sympathetic blocks. Hard narcotics such as morphine may also have to be used for pain relief.
What are the Effects of Suffering from CRPS?
It's not surprising that people suffering from extreme pain extending for a lifetime will also suffer severe psychological overlays. Failure by the physicians to make a proper diagnosis often compounds the problem by labeling it as a psychological problem. CRPS will interrupt all phases of a person's life: family, work (over 75% change jobs due to CRPS), sleep, rest, quality of life, and suicide is a possibility to be aware of. Medical treatment is expensive (which can be aggravated by unnecessary treatments based upon erroneous diagnosis).
From a study of CRPS, the following table shows how much the pain has interfered with life:
|All of the Time||Most of the Time||Some of the Time||Not at All|
|Marriage & Family Life||30.6%||28.9%||32.8%||7.7%|
|Social Activities/ Friendships||35.2%||30.5%||28.9%||5.4%|
CRPS involves inordinate pain and neuromuscular disability that is initiated by sometimes seemingly minute traumatic events that are coupled with conflicting symptoms and complaints. These often lead to unfortunate and erroneous conclusions that the pain is of psychogenic origin and that the patient is simply imagining. As the condition progresses, it becomes more difficult to treat successfully and the patient and the patient's family develop feelings of frustration, anger, and hopelessness.