Complex regional pain syndrome

CRPS in English

Medical Words

According to abbreviationfinder, Complex regional pain syndrome is also known as complex regional pain syndrome or CRPS for short. The term replaces the synonymous terms Sudeck’s disease, reflex sympathetic dystrophy, Sudeck’s dystrophy and algodystrophy.

What is Complex Regional Pain Syndrome?

A diagnosis is made primarily on the basis of the clinical manifestations. Imaging methods such as X -rays or scintigraphy provide additional information.

Complex regional pain syndrome occurs after soft tissue or nerve injury. Often the syndrome develops after a fracture. Although the term is actually obsolete, CRPS is still referred to as Sudeck’s disease. The name goes back to the Hamburg surgeon Paul Sudeck, who discovered the disease. Sensory, motor, autonomic, and trophic disorders can develop in CRPS.

The course of the disease varies greatly depending on the patient. The diagnosis is also difficult. Therapy depends on the severity of the syndrome. Possible treatment methods include physical therapy, manual therapy, lymphatic drainage, or invasive procedures such as epidural spinal cord stimulation.


The exact origin of the complex regional pain syndrome has not yet been clarified. The healing process in the injured tissue is probably impaired. The syndrome occurs after external influences such as trauma, inflammation or surgery. The severity of the CRPS does not depend on the severity of the injury.

Complex regional pain syndrome occurs more frequently in the upper than in the lower extremities. Women are affected more often than men. The syndrome occurs particularly often after distal radius fractures, i.e. after fractures of the radius near the wrist. It is assumed that an inflammatory reaction occurs in which various inflammatory mediators are released.

These messenger substances are no longer completely broken down, so they prolong the neurogenic inflammatory reaction. The inflammatory mediators are also released in the central nervous system. This sensitizes the central pain-processing neurons. A centrally caused malfunction of the sympathetic nervous system also causes circulatory disorders and an increased tendency to perspire on the skin.

The vessels narrow and connections are formed between arterial and venous vessels (arteriovenous shunts). As a result, the tissue is not supplied with enough oxygen. Hypoxia develops, resulting in increased amounts of metabolic waste products. The resulting acidosis increases the pain.

Similar to phantom limb pain that can occur after limb amputation, complex regional pain syndrome involves cortical restructuring. Individual representational areas in the cerebral cortex change. As a result, the pain expands and occurs across different nerve supply areas.

There is also evidence of a genetic predisposition. A psychological component was also suspected for a long time. Whether this is really the case has not yet been conclusively clarified. However, studies show that CRPS occurs more frequently after stressful life events.

Symptoms, Ailments & Signs

Complex regional pain syndrome can be divided into two forms. In CRPS type I, there is trauma without nerve damage. Type II CRPS occurs after trauma involving nerve injury. Within the first three months, there are only non-specific symptoms such as swelling, redness, pain or warmth. The functionality of the affected extremity can also be limited.

After three to six months, joint stiffening dystrophy develops. The final stage of complex regional pain syndrome is atrophy. After six to twelve months, there is no longer any function. However, this classification is now very controversial, since many patients have a different course of the disease.

Many patients have weakness in the affected arm or leg. In the acute stage, the weakness is the result of pain and swelling. In the chronic stage, contractures and fibrosis limit mobility. Many patients also suffer from muscle tremors. Myoclonus is also observed.

Hyperalgesia also develops in most patients. Pain sensitivity is greatly increased. Patients also respond to nonpainful touch with pain. Three out of four patients also suffer from rest pain. Numbness or feelings of strangeness are also evident. At the beginning of the disease, there are almost always the typical signs of inflammation such as redness and swelling.

When it becomes chronic, the affected extremities turn blue and become cold. Half of all those affected have an increased tendency to sweat. This phenomenon is also known as hyperhidrosis. In the acute stage of the syndrome, hair and nails grow excessively in the affected area.

Later, the growth turns into the opposite. In particularly severe cases, the muscles can completely recede. Due to this atrophy, severe limitations in movement develop.

Diagnosis & course of disease

A diagnosis is made primarily on the basis of the clinical manifestations. Imaging methods such as X -rays or scintigraphy provide additional information. The X-ray shows patchy brightening caused by a reduced calcium salt content in the bone. With progressive chronification, these brightening increase.

However, the spot-like decalcifications appear eight weeks after the onset of the disease at the earliest and are therefore not suitable for early diagnosis. Soft tissue edema, thickening of the skin, fibrotic changes and joint effusions become visible in the MRI scan. However, many CRPS cases go undetected due to low sensitivity. Typical changes become visible relatively early on with skeletal scintigraphy. The band-like multiple storage near the joint is particularly noticeable.


Complex regional pain syndrome is usually a complication itself. It can result from a fracture. The syndrome, formerly known as Sudek’s disease, can also occur as a postoperative consequence of clubfoot surgery. In this case it is a postoperative complication. The treatment of such complications is complex, depending on the location of the discomfort and pain.

As a result of the complex regional pain syndrome, numbness, restricted movement and chronic symptoms can occur. In the chronic course, high-grade inactivity osteoporosis can occur. The affected bones progressively degrade. They become porous. The muscle tissue can also break down as a result of a chronification of the complex regional pain syndrome. This also causes movement restrictions.

The problem is that a doctor can often only notice the changes in the bone structures when they have already reached a certain degree of severity. As a result, many of the CRPS cases go undetected at first. This in turn has consequences. These manifest themselves as long-term consequences of a trauma, often lifelong. However, since sequelae such as complex regional pain syndrome are relatively rare, the risk of untreatable complications is statistically rather small.

In addition, the treatment of surgical trauma can already prevent a complex regional pain syndrome from occurring. Complex regional pain syndrome appears to develop less frequently under regional anesthesia.

When should you go to the doctor?

If pain persists after an injury, it must be evaluated and, if necessary, treated by a general practitioner or a sports medicine specialist. Pain at rest and pressure pain in the joints indicate a complex regional pain syndrome. In individual cases, this resolves by itself, but medical treatment is usually required. The affected person should consult a doctor and have the symptoms clarified before serious complications develop. Medical advice is required at the latest when the pain is accompanied by swelling or circulatory disorders.

Weakness and stiffness indicate that the disease is already more advanced. The affected person should immediately consult the general practitioner. Psychological side effects must be treated by a therapist. Morbus Sudeck occurs mainly after sprains, bruises, bruises or injuries caused by surgery. The disease can also occur after vascular occlusions and dislocations. Anyone who belongs to the risk groups must inform the responsible doctor immediately. In addition to the family doctor, a sports doctor or an internist can be involved.

Treatment & Therapy

The therapy of the complex regional pain syndrome is very lengthy. Therapy is based on physiotherapeutic interventions adapted to the stage. Occupational therapy can also be used to restore everyday function. Bisphosphonates, corticoids, tricyclic antidepressants, non- opioid analgesics or opioids are often used for drug therapy.

Outlook & Forecast

The assessments regarding the prognosis for the complex regional pain syndrome are not yet clear due to a lack of data. Until now, physicians have assumed that a complex regional pain syndrome develops post-traumatically as a result of injuries to an extremity caused by surgery or other causes. The premise was that such damage should be avoided or that early multimodal pain therapy made sense.

Trauma, bandages that are too tight, fractures that have not healed well or other factors are the causes of complex regional pain syndrome. But the pain that persists cannot be adequately explained by this damage. Today, doctors assume that a regression of the pain syndrome is only possible with early diagnosis and therapy. However, complex regional pain syndrome often takes a chronic course with a poor prognosis. The pain becomes more or less independent without being able to be explained by who caused it.

It is discussed whether a genetic disposition, a disturbed perception of pain, psychological comorbidities or a painful therapeutic intervention are responsible for this. As long as physicians do not understand the complex regional pain syndrome, the prognosis for chronic pain cannot be improved. It is obvious that the cause of a complex regional pain syndrome is often attributed to psychological factors. According to current medical paradigms, the symptom should disappear when its cause is removed.


Complex regional pain syndrome cannot be prevented. The earlier the disease is detected, the better the prognosis. Therefore, if CRPS is suspected, a specialist should be consulted as soon as possible.


With this syndrome, the options for aftercare are limited in many cases, since the cause of the pain must first and foremost be treated correctly and, above all, sustainably. Self-healing cannot occur here, so that the patient should consult a doctor at the first sign of the disease in order to prevent further complications and a further deterioration of the symptoms.

An early diagnosis usually has a very positive effect on the further course of the disease. Most people affected by this disease are dependent on taking various medications. It is always important to ensure that the medication is taken regularly and that the dosage is correct. Likewise, all instructions directed by the doctor should be followed.

If anything is unclear or if there are side effects, consult a doctor first. Physiotherapy measures can also be very helpful in this disease. Many of the exercises can also be performed at home, speeding up treatment. In general, support and help from family members also has a positive effect on the progression of this syndrome and can also prevent depression and other psychological problems.

You can do that yourself

The measures that those affected by complex regional pain syndrome can take to reduce the symptoms depend on the cause and the type of medical treatment.

Basically, the pain can be reduced by acute measures such as cooling pads and rest. Naturopathy offers various painkillers that can also be used to relieve the symptoms. For example, marigold ointment or gentle infusions with chamomile have proven effective. Homeopathic medicines include belladonna and arnica. Physiotherapy is always an accompaniment to CRPS displayed. Treatment by a therapist or sports medicine doctor can be supported at home with targeted exercises. The patient should create a training plan together with the specialist and implement it in a targeted manner.

Further measures depend on the cause of the complaints. Occupational therapy can be carried out after a stroke, which can also be continued at home. In severe cases, aids such as crutches or a wheelchair must be organized. In addition, regular visits to the doctor are indicated, because the state of health can only be checked and rapid intervention in the event of complaints and complications can only be carried out with close medical supervision.

Complex regional pain syndrome