What is Complex Regional Pain Syndrome (Chronic Severe Pain Syndrome With Pain out of Proportion to the Original Injury)?
Complex Regional Pain Syndrome (CRPS) is a type of nerve-related pain. It is marked by a persistent pain that’s much more intense than what you’d expect from the injury and doesn’t ease even after the injury has healed. Along with this pain, the disorder can cause changes in how you sense things and how your body moves, as well as other factors like imbalances in body temperature regulation and physical appearance. Major triggers for CRPS are usually injuries, fractures or surgeries, with a few cases arising with no apparent reason.
This condition was first spotted in the 16th century, and since then, it has been called many names like ‘causalgia’ in 1872 and ‘reflex sympathetic dystrophy’ in 1946. Finally, in 1994, the International Association for the Study of Pain (IASP) coined the name ‘Complex Regional Pain Syndrome’ and proposed ways to diagnose it. A more comprehensive diagnostic criterion, known as the ‘Budapest Criteria’, was then proposed in 2010.
CRPS comes in two forms: Type I, which was previously known as reflex sympathetic dystrophy and develops without an apparent nerve injury, and Type II, which was called causalgia and develops due to a known nerve injury. Both forms can’t be distinguished simply through clinical examination and can affect any region, usually the far ends of the limbs. Occasionally, the pain also spreads to the nearest or opposite limb.
Living with CRPS can be quite challenging as it doesn’t only present physical symptoms but also affects sleep patterns and daily routines. It mounts significant mental stress on the patient. Its varied common symptoms and the lack of a clearly defined reason make optimal management of this disorder difficult.
What Causes Complex Regional Pain Syndrome (Chronic Severe Pain Syndrome With Pain out of Proportion to the Original Injury)?
Complex Regional Pain Syndrome (CRPS) can occur due to various types of bodily injuries or sometimes even without an injury at all, for example, during extended periods of inactivity. Fractures are a common cause, but it can also happen following other injuries like sprains, bruises, crush injuries, and after surgery. There have been cases where CRPS developed from seemingly insignificant events such as the insertion of an IV line. Sometimes, increased emotional distress during the physical injury that initiates CRPS could affect its severity and outcome.
Often, CRPS starts after fractures, especially those of the arm and leg bones. A large study found almost half of patients developed CRPS after suffering a single fracture and stayed symptomatic for a year. Some factors could heighten the risk of developing CRPS, such as rheumatoid arthritis and certain fractures. However, it usually doesn’t matter if the fracture occurred on an arm or leg. Symptoms often start to appear within 8 weeks after the injury. Some patients saw improvements after 3 months. Still, in many cases, significant improvements were not noted after a year.
Another study pointed out that older age, social or psychological factors, and co-existing psychiatric conditions could increase the risk of developing CRPS post-fracture. Yet, another study found no connection between psychological factors or depression symptoms and the chances of developing CRPS.
Surgeries could also lead to CRPS, specifically surgeries on the arms or legs. A study that looked retrospectively at 390 patients who underwent foot or ankle surgeries noted that around 4.36% developed CRPS. Additionally, it’s worth highlighting that surgical treatment of fractures seemed to come with a higher risk of developing CRPS. Surgeries like ones for carpal tunnel syndrome or Dupuytren contracture also came with varying chances of causing CRPS.
As for genetics, it isn’t exactly clear how genes might influence the development of CRPS. However, certain factors like a person’s human leukocyte antigen and changes in a protein called tumor necrosis factor-alpha (TNF-α) seem to play a role in CRPS. These factors might lead to CRPS starting at a younger age and even more severe symptoms. There are suggestions that CRPS might be inherited based on some retrospective studies.
Risk Factors and Frequency for Complex Regional Pain Syndrome (Chronic Severe Pain Syndrome With Pain out of Proportion to the Original Injury)
The occurrence of CRPS, or Complex Regional Pain Syndrome, seems to differ based on where you are in the world. For example, a study in Minnesota found the rate to be 5.46 cases per 100,000 people for CRPS type I, and 0.82 cases per 100,000 people for CRPS type II. On the other hand, a study in the Netherlands reported a much higher rate of 26.2 cases per 100,000 people. In both studies, it was found that females were more likely to be affected by CRPS than males.
In terms of age, the Netherlands study found the highest occurrence in people aged 61-70, while in the United States the most common age of onset was 46. The upper parts of the body were reported to be more commonly affected. Both studies identified fractures to be the most common trigger of CRPS, with 44-46% of cases being traced back to this cause. Among various symptoms, changes in swelling, temperature, and color were the most reported.
The three-phase bone scan was the most useful test for diagnosing CRPS, helping in 85% of the cases, while autonomic testing was useful in 80% of cases. There are several risk factors for CRPS, including asthma, use of ACE inhibitors, menopause, osteoporosis, and a history of migraines. Cigarette smoking also appears to increase the risk of CRPS.
- The occurrence of CRPS varies based on geographical location.
- A Minnesota study found an occurrence of 5.46 cases per 100,000 people for CRPS type I and 0.82 for type II, whereas a Netherlands study found a rate of 26.2 cases per 100,000 people.
- Females tend to be more affected than males.
- The most common age of onset is 46 in the US, and 61-70 in the Netherlands.
- Fractures are the most common trigger of CRPS.
- Changes in swelling, temperature, and color are the most common symptoms.
- The three-phase bone scan is the most useful diagnostic tool for CRPS.
- Risk factors for CRPS include asthma, ACE inhibitor use, menopause, osteoporosis, and migraines.
- Cigarette smoking also increases the risk of CRPS.
Signs and Symptoms of Complex Regional Pain Syndrome (Chronic Severe Pain Syndrome With Pain out of Proportion to the Original Injury)
Patients suffering from Complex Regional Pain Syndrome (CRPS) may experience a variety of sensory, motor, and autonomic symptoms. Sensory issues could include allodynia, where usually non-painful stimuli cause pain, and hyperalgesia, where usually painful stimuli lead to exaggerated pain. Autonomic symptoms might involve changes in skin color and temperature, as well as alterations in swelling and sweating. Motor symptoms can range from weakness, reduced motion range to even tremor, and dystonia in the affected limb.
In addition, CRPS is often linked with depression, anxiety, and a lower quality of life. It’s important to note that while patients with significant psychological issues might express more pain-related behavior and catastrophic thinking, no specific personality or mental health issues are known predictors of CRPS.
CRPS can also be associated with a series of medical issues impacting various systems in the body. These may include:
- neuropsychological deficits, such as problems with executive functioning, memory, and word retrieval
- Constitutional symptoms, like lethargy, weakness, disruptions in sleep pattern
- cardiopulmonary involvement, including reflexive fainting, atypical chest pain, muscle stiffness in the chest leading to shortness of breath
- endocrine system issues, like low cortisol levels, and underactive thyroid
- urological problems, such as increased need to pee, inability to control urination
- gastrointestinal issues, like nausea, vomiting, diarrhea, constipation, and indigestion
Testing for Complex Regional Pain Syndrome (Chronic Severe Pain Syndrome With Pain out of Proportion to the Original Injury)
Complex Regional Pain Syndrome (CRPS) is a condition without a known cause or standard testing method. The diagnosis is mostly based on patients’ clinical signs and symptoms as defined in the Budapest criteria.
The Budapest criteria include constant pain that is more severe than what would be expected from the initial injury. Patients also need to report at least one symptom in three of the following four categories:
- Sensory: This refers to reports of extreme pain (hyperalgesia) or pain from something that does not typically cause pain (allodynia).
- Vasomotor: This refers to reports of uneven body temperature or changes in skin color.
- Sudomotor/Edema: This involves reports of swelling or changes in sweating.
- Motor/Trophic: This involves reports of limited motion, motor dysfunction (like weakness or shaking), and changes in hair, skin, or nails.
In addition to these symptoms, patients must also show at least one actual sign in two or more of these categories during their assessment.
The final part of the Budapest criteria states that there should be no other diagnosis that can better explain the patient’s signs and symptoms.
While additional tests, like thermography, triple-phase bone scan, and the quantitative sudomotor axon reflex test, can provide more data, they are not required for a diagnosis of CRPS. These tests are mainly used to rule out other potential diagnoses, such as nerve problems, inflammation of skin and blood vessels, blood flow problems, swelling of parts of the body, blood clots, and other issues.
Treatment Options for Complex Regional Pain Syndrome (Chronic Severe Pain Syndrome With Pain out of Proportion to the Original Injury)
Complex Regional Pain Syndrome (CRPS) can lead to long-term disability and impairment if not treated promptly and appropriately. Early and intensive treatment is crucial, as early CRPS is generally more responsive to therapy and carries a better prognosis. The best approach to treatment involves a combination of therapies, including physical and occupational therapy, medications, and certain procedures.
Physical and occupational therapies are not limited to just exercises and manual therapy. Treatment modalities like electrical nerve stimulation, ultrasound, laser therapy, pain education, mirror therapy, and graded motor imagery (GMI) can all play a part. The aim of these different therapies is not only to increase motion and function but also to reduce pain by altering the way our brains perceive and process pain.
Medications used to manage CRPS can include anti-inflammatory drugs, anticonvulsants, antidepressants, lidocaine patches, opioids, NMDA antagonists, and bisphosphonates. Patients often receive a combination of these medications to optimize treatment results. It’s important to note, however, that the evidence for the effectiveness of some of these medications in treating CRPS is limited.
In some cases, treatments known as sympathetic nerve blocks may be used for managing symptoms in the upper or lower extremities. These procedures involve the injection of local anesthetic agents near the affected area to block the transmission of pain signals. However, the data on their effectiveness in decreasing CRPS-related pain is not definitive.
Another treatment option is spinal cord stimulation (SCS), which involves the delivery of electrical stimulation to the spinal cord to help alleviate pain. The treatment has shown potential in terms of improving pain and quality of life for many CRPS patients.
A more recent approach is the stimulation of dorsal root ganglion (DRG), another part of the nervous system that plays a vital role in carrying pain signals. DRG stimulation offers a more focused application of neurostimulation than traditional SCS and has been proven to be safe and effective in managing CRPS.
CRPS is a complex condition, and successful treatment often requires a team approach involving different healthcare professionals. Combining therapies from different areas may provide the best chance for improvement and help to prevent disability.
What else can Complex Regional Pain Syndrome (Chronic Severe Pain Syndrome With Pain out of Proportion to the Original Injury) be?
- Shortage of blood supply due to blockages in the arteries (Arterial insufficiency)
- A rare neurological disorder that affects the nerves (Gillian Barre syndrome)
- An outdated term usually referring to a range of psychological disorders (Hysteria)
- A type of muscle weakening condition, especially in the hands (Monometric amyotrophy)
- A chronic disease involving damage to the protective covering of nerve cells in the brain and spinal cord (Multiple sclerosis)
- A narrowing and hardening of the arteries that supply the legs and feet, leading to decreased blood flow (Peripheral atherosclerotic disease)
- A condition where a blood clot forms inside a vein, most commonly in the legs (Phlebothrombosis)
- A group of genetic disorders affecting the nervous system and skin (Porphyria)
- An uncommon viral infection affecting the spinal cord causing muscle weakness and paralysis (Poliomyelitis)
- A condition caused by damage to the spinal cord resulting in the loss of movement and sensation (Tabes dorsalis)
What to expect with Complex Regional Pain Syndrome (Chronic Severe Pain Syndrome With Pain out of Proportion to the Original Injury)
The future outcomes for those suffering from CRPS, or Complex Regional Pain Syndrome, can greatly vary. Some individuals might experience spontaneous recovery, while others continue to face persistent symptoms. However, beginning treatment early can often lead to better outcomes.
Possible Complications When Diagnosed with Complex Regional Pain Syndrome (Chronic Severe Pain Syndrome With Pain out of Proportion to the Original Injury)
Long-standing Complex Regional Pain Syndrome (CRPS) can lead to several complications, including:
- Dystonia, a condition that involves involuntary muscle contractions
- Cognitive executive dysfunction, which disrupts brain processes like memory and focus
- Adrenal insufficiency, a condition where the adrenal glands don’t produce enough hormones
- Gastroparesis, which slows down or stops the movement of food from the stomach to the small intestine
- Irritable bowel syndrome, a disorder that affects the large intestine and can cause stomach pain, cramping, bloating, gas, diarrhea, and constipation
Preventing Complex Regional Pain Syndrome (Chronic Severe Pain Syndrome With Pain out of Proportion to the Original Injury)
It has been suggested that taking vitamin C supplements could potentially lower the chances of developing CRPS (a type of chronic pain that usually affects an arm or leg) after fractures, due to its antioxidant capabilities. However, a large review study conducted in 2015, which included three separate trials, found that the current information couldn’t definitely confirm that vitamin C succeeded in preventing CRPS after fractures in the lower arm. It’s worth noting that the quality of the evidence from this study was not very high.
In 2017, another comprehensive review and analysis was performed investigating if vitamin C could prevent CRPS after fractures in the wrist. The study showed that taking 500 mg of vitamin C each day for 50 days seemed to reduce the risk of developing CRPS within one year.