FAQ Category: Pain

Complex regional pain syndrome (CRPS) is a disorder that can cause severe pain and disability. However, as painful and disabling as the condition is, there is not a lot that doctors know about it. More women get it than men. It occurs after about one to two percent of all bone fractures. It is most common (up to 35 percent) after certain types of wrist fractures.

CRPS more commonly affects the hand or foot, but may spread further up the affected limb and even into the opposite limb. The common symptoms of CRPS are unrelenting burning or aching pain, skin sensitivity, swelling, discoloration, sweating, and temperature changes. If the condition becomes chronic, dystrophy or deterioration of the bones and muscles in the affected body part may occur.

Many patients like a road map to help them navigate life’s many twists and turns. Having a painful condition like complex regional pain syndrome (CRPS) often puts people in the frame of mind of making comparisons. Finding out that others suffer as much (if not more) than we do helps the human mind accept and adapt to suffering.

There are several different tools doctors use to evaluate CRPS. Some just address the pain intensity. Others measure function, disability, and impairments caused by the pain and other symptoms.

Just recently, a group of rehabilitation researchers from around the world put together and tested a scale designed to measure severity of CRPS symptoms. They call it the Complex Regional Pain Syndrome Severity Score or CSS.

The CSS is a simple test that can be given easily yet still reflects diagnostic features of CRPS (e.g., pain, sweating, skin color changes). It was tested on 114 people with a known diagnosis of CRPS and compared with 41 patients with nerve pain that was not caused by CRPS. Most of the CRPS patients had a history of fracture or crush injury leading to the development of CRPS.

The test consisted of a checklist of signs and symptoms common with this condition. Self-reported symptoms included differences in temperature, skin color, sweating, and swelling from one side (involved side) to the other (uninvolved side). A second section of the test evaluates signs observed by the examiner such as exaggerated levels of pain with pinprick test, differences in skin temperature felt by the examiner, and decreased range-of-motion of the involved part (hand, foot).

Higher test scores meant more severe pain and other symptoms. Patients with CRPS had much higher test scores than the patients in the nerve pain but non CRPS group. Statistical analysis showed that this new scoring system for severity of CRPS is reliable and valid. In other words, it can be used dependably to identify people with CRPS and provide a picture of the severity of their condition. Used over time, it can also show changes or fluctuations in individual cases.

Many health care professionals are looking for ways to identify which treatment approaches work best. Sometimes it’s possible to even figure out who is most likely to benefit from each different type of treatment. That is a win-win situation for everyone.

Without the participation of people like yourself who already have a known diagnosis of complex regional pain syndrome (CRPS), it can be difficult to gather the evidence needed to support one method over another.

A recent study published results on the development of a severity score for CRPS. The test consisted of a checklist of signs and symptoms common with this condition. Self-reported symptoms included differences in temperature, skin color, sweating, and swelling from one side (involved side) to the other (uninvolved side).

A second section of the test evaluates signs observed by the examiner such as
exaggerated levels of pain with pinprick test, differences in skin temperature felt by the examiner, and decreased range-of-motion of the involved part (hand, foot).

Higher test scores meant more severe pain and other symptoms. Patients with CRPS had much higher test scores than the patients in the nerve pain but non CRPS group. Statistical analysis showed that this new scoring system for severity of CRPS is reliable and valid. In other words, it can be used dependably to identify people with CRPS and provide a picture of the severity of their condition. Used over time, it can also show changes or fluctuations in individual cases.

This type of tool may help health care professionals plan and modify treatment for patients with CRPS. Having a consistent severity score will help improve communication among all the health care professionals working with people who have CRPS.

Researchers involved in this project do not see this tool as a replacement for current pain scales in use to measure treatment outcomes. But the scoring system may be helpful when conducting research on this condition as it can show changes in symptoms with treatment. It may even function as a predictor of who will get better with different types of treatment.

Perhaps the proposed study at your center has similar goals and purposes. Consider asking the people who are conducting the study what the intent of the study is and how the results will be used. It may be something that doesn’t benefit you directly but could help others in the future.

Complex regional pain syndrome CRPS is a very painful disorder that affects people after a seemingly minor injury sometimes. The problem is not understood very well. Doctors don’t know what causes it or why it happens. That makes CRPS a difficult condition to treat effectively.

In recent years, anti-inflammatory medications have been used with mixed results. But the fact that this approach works for some patients makes it worth investigating further. If CRPS is an exaggerated response of the immune system to tissue injury, then inflammatory messengers and inflammatory cells must be part of the signaling system that bring on the painful symptoms.

People with complex regional pain syndrome (CRPS) often experience intense pain, swelling and skin changes (color, texture, hair growth, temperature). The net result is a loss of motion and function along with reduced quality of life.

Scientists hope that by cutting off immune cells like cytokines, chemokines, and mast cells, it might be possible to stop (or even prevent) these disabling symptoms. A recent report from The Netherlands published results on two types of antiinflammatory medications used with complex regional pain syndrome: corticosteroids and free radical scavengers.

These drugs are much more powerful than regular ibuprofen. Corticosteroids used often include oral prednisolone and piroxicam (CNT). Free radical scavengers include DMSO, vitamin C, and Mannitol.

Free radicals are unstable oxygen atoms that form when they lose an electron. Electrons like to be in pairs. The loss of one electron literally puts the atom into orbit. It becomes a scavenger looking for another oxygen atom so that it can rob or steal the necessary electron.

The result is a cascade of damage to the cells as new radicals are formed in order to salvage the damaged oxygen atoms. Compounds like DMSO, vitamin C, and Mannitol work by getting rid of free radicals. Inflammatory reactions are reduced by eliminating free radicals. The end-result is to limit the amount of tissue damage that occurs from inflammation. In some clinics, corticosteroids and free radical scavengers are used together.

Both classes of drugs (corticosteroids and free radical scavengers) have been shown to provide relief from painful symptoms. Patients receiving either medication show significant improvements. This tells us that it is possible to stop the inflammatory process in different ways (turning off inflammatory cells, getting rid of damaging free radicals).

Matching the most helpful drug to each individual patient is the next challenge. If you begin a course of medications that do not give you the results you are hoping for, don’t hesitate to go back to the prescribing physician. You may need a change in dosage or even a different drug.

Complex regional pain syndrome or CRPS is a very painful disorder that affects people after a seemingly minor injury sometimes. People with complex regional pain syndrome (CRPS) often experience intense pain, swelling and skin changes (color, texture, hair growth, temperature). The net result is a loss of motion and function along with reduced quality of life.

The problem is not understood very well. Doctors don’t know what causes it or why it happens. That makes CRPS a difficult condition to treat effectively. Scientists in The Netherlands have added a new piece to the mystery of treating complex regional pain syndrome (CRPS).

In recent years, anti-inflammatory medications have been used with mixed results — some studies show it works, others don’t. But the fact that this approach works for some patients makes it worth investigating further. If CRPS is an exaggerated response of the immune system to tissue injury, then inflammatory messengers and inflammatory cells must be part of the signaling system that brings on the painful symptoms.

The two types of medications being investigated in the Netherlands are corticosteroids and free radical scavengers. Corticosteroids included oral prednisolone and piroxicam (CNT). Free radical scavengers included DMSO, vitamin C, and Mannitol.

Free radicals are unstable oxygen atoms that form when they lose an electron. Electrons like to be in pairs. The loss of one electron literally puts the atom into orbit. It becomes a scavenger looking for another oxygen atom so that it can rob or steal the necessary electron.

The result is a cascade of damage to the cells as new radicals are formed in order to salvage the damaged oxygen atoms. Compounds like DMSO, vitamin C, and Mannitol work by getting rid of free radicals. Inflammatory reactions are reduced by eliminating free radicals. The end-result is to limit the amount of tissue damage that occurs from inflammation. In some studies, corticosteroids and free radical scavengers were used together.

After reviewing all the studies on the use of these medications for CRPS, here’s a quick summary of what they found. Both classes of drugs (corticosteroids and free radical scavengers) worked. Patients receiving either medication showed significant improvements. This tells us that it is possible to stop the inflammatory process in different ways (turning off inflammatory cells, getting rid of damaging free radicals).

But once again, there were just as many patients who didn’t get better as those who did improve. Naturally, the scientists wondered “Why”? (Or more appropriately, “Why not”?). There are no clear answers just yet. Researchers around the world will continue exploring the “whys” and “whats” of complex regional pain syndrome.

Whenever experiencing new symptoms that you suspect might be drug-related, it’s always a good idea to check with your pharmacist and/or the prescribing physician. Many people taking long-term opioids (narcotics) for non-cancer problems are also taking other medications. Some of those drugs have the ability to alter cognitive (mental) function.

If you are taking more than one medication, there can be drug interactions that can lead to adverse side effects. Memory loss is one of those possible side effects. Memory loss occurs when there is a disruption of the nervous system (brain). Memory loss can also be the result of many different factors (e.g., age, stress, presence of other problems such as high blood pressure, heart disease, diabetes).

And as is often the case, people who suffer from chronic pain become depressed. Altered mood or depression is also linked with changes in cognitive function (especially memory or the speed of mental). Sorting out which factor has the most power over mental abilities can be difficult.

Make time to see your physician and have this symptom evaluated. If it is drug-induced, you may benefit from a change in dosage of your current medication or even a switch to a different drug.

People who have severe, chronic pain may be given the option of taking opioid medications (narcotics) to help manage their pain and live some semblance of a normal life. For those who are not facing end-of-life issues with cancer, this can become a life-long management tool. Whenever opioids are discussed, there is always a concern raised about safety, especially physical dependency and addiction.

Experts agree that with the right drug and dosage, patients who are monitored carefully and consistently by their medical doctors can manage their pain effectively — and without the down side of addiction or physical dependency.

But as new evidence shows, addiction isn’t the only adverse effect of opioids. Difficulty concentrating, memory loss, slower physical reaction time, and slower processing of information are additional potential side effects of these powerful pain relievers.

Some experts in the area of pain research have suggested that anyone who is given a prescription for opioids should also be given a simple baseline test to assess cognitive function. Then if it turns out the prescription becomes a long-term event, retesting can be done. Any observed change(s) in cognitive function would signal the need to review the medication and possibly change the drug or drug dosage.

If you notice anything unusual, the onset of new (or different) symptoms, and any change in the intensity, duration, or frequency of your current symptoms, report these immediately to your physician. Otherwise, if you are experiencing good control of your pain without any compromising changes in your health, you are “good-to-go” as the modern phrase puts it so well.

Patients with complex regional pain syndrome (CRPS) are faced with some very unpleasant symptoms. The first is unrelenting burning or aching pain followed by skin sensitivity, swelling, discoloration, sweating, and temperature changes.

The most commonly affected area of the body is the hand or foot, but the symptoms can spread further up the affected limb and even into the opposite limb. If the condition becomes chronic, dystrophy or deterioration of the bones and muscles in the affected body part may occur.

Many patients do have a distorted sense of where the affected arm is. It can be mild or severe enough that they wish the arm could be cut off. They describe not knowing where their limb is even when touching something with that hand. It is difficult to use that arm/hand to insert keys into a lock and open a door, pick up a pen, or even use that hand to wipe themselves after going to the bathroom.

Therapists working with these patients refer to this phenomenon as a distortion of body image or distortion of body schema. The failure to recognize limb position is a problem with position accuracy.

Scientists think this distortion is a central processing problem — in other words, the problem lies in the nervous system (brain, spinal cord, peripheral nerves) rather than in the arm itself.

Efforts are being made to further explore this particular problem. Research can begin to look for the exact neural processing pathways that are affected by CRPS. Researchers hope to find ways to restore normal sensorimotor function.

Getting a handle on what kind of pain medications work best for back pain is not an easy task. There isn’t a one-pill-fits-all or one-dose-for-all that guides physicians prescribing medications. They do rely on the drug companies to give them an idea of what works best for the average patient based on research done during the development and testing of the drug.

But no matter where or how the research is done, there are just so many variables to consider and compare. Does the patient have back and leg pain or just back pain? Does the patient take the prescribed drug for four weeks? Six weeks? Longer?

Researchers try to look at all the studies and combine results for a better understanding of effects. But according to pain research done in Europe, the design of each study isn’t similar enough to really allow such a meta-analysis. For example, sometimes patients are given drug combinations rather than a single drug. The dosage might be increased until it reaches a point where it’s effective and the side effects are tolerable or patients may be given the same dose from day one.

There are other confounding factors. Patients may stop taking the drug and withdraw from the study for any number of reasons. It could be they experienced no pain relief or there might have been unpleasant side effects, so the patient(s) quit taking the medication. The data from discontinuation rates and patient withdrawals makes it difficult to compare one study to another.

And each patient presents with unique features. Age, sex (male or female), weight, and activity level (metabolism) are important factors. Location of pain, type of pain, and intensity of pain are also all taken into consideration when choosing a drug and prescribing dosage.

Even if you all went to the same physician, it’s possible there would be a wide range of differences in how you are treated based on all these (and probably other) individual factors.

Physicians and pharmacists know that every drug prescribed (and even over-the-counter medications that can be taken without a prescription) has both benefits and side effects.

Some side effects are barely noticeable. We say these are tolerable. Others can cause a wide range of symptoms (e.g., itching, headaches, difficulty breathing, loss of sex drive) that are considered intolerable — the affected patient is either unable or unwilling to suffer those effects.

The goal is to give the patient maximum benefit of the drug with the least amount of side effects. Sometimes medications are given in a standard dose, the effects are observed, and then the dosage and frequency (how often you take it) are tweaked a bit until you get the best response possible for that medication.

Pain relief is usually the main goal. Providing pain relief without affecting function and quality of life because of adverse side effects is the challenge. Often, it’s a wait-and-see approach to pain control knowing that every drug has its benefits and side effects that will become more apparent over time.

Limb position awareness is challenged in both arms of patients with complex regional pain syndrome (CRPS) even when only one arm has the CRPS. This phenomenon points to the possibility of what is called central processing errors. Central processing refers to the natural function of the nervous system (nerves, spinal cord, brain).

In the case of CRPS, errors occur in the nervous system’s ability to keep track of all body parts at any given time. A recent study published by researchers from England and New Zealand have shown that patients with this condition have a problem with general awareness of limb position. When one side is affected, both limbs respond as if they no longer know where they are in relation to the body or moving through space.

Many patients with complex regional pain syndrome have a mental picture of the affected arm that includes some distortion. For example, when they look at the arm, part of it is missing or a finger is oddly shaped. Some patients describe the arm as much larger than it actually is.

Having pain anywhere in the affected arm does not help patient find the arm. Being able to see the arm does help. Hand therapists who work with patients who have complex regional pain syndrome are beginning to use mirrors to help re-map the brain’s own image of the body. This is one way it may be possible to restore normal reach and function of limbs affected by this condition.

Older adults often find that managing the chores and activities of daily life are a challenge enough without pain being added to the mix. Suddenly, making a cup of tea can become impossible — much less preparing a nutritious meal.

Sleep is disrupted, thinking becomes cloudy, and the affected adult is no longer getting out with other people. Persistent pain in this age group can create a steady decline in physical and cognitive function.

Pretty soon, folks will try just about anything. But the good news is that capsaicin is safe and effective. This cream is designed to act as a counter irritant. It does cause a mild burning sensation and brings blood flow to the painful area. The result can be temporary relief from the pain.

There are other topical creams and gels that can provide pain relief by numbing the area (e.g., lidocaine). These medications are useful in controlling nerve pain. Patients with diabetic neuropathies or chronic musculoskeletal problems seem to benefit the most. Patients must avoid use around open wounds or mucous membranes and stop use if a skin rash develops.

If your mother is not getting the pain control or pain relief she needs, it may be time for a visit with the physician again. With patience and persistence, older adults can get the pain relief they need in order to stay active and functional. There are many different types of medications for pain relief available. Sometimes it takes a combination of drugs. This can take some time to sort out fully.

When you’re younger, it may be easier to shrug off pain or work through it. The old expression, No pain, no gain is the mantra of many athletes. But as we get older, pain has a way of getting us down faster and keeping us there longer. We don’t bounce back like we used to. This is especially true when pain is present.

What can be done about it? Medications are one possibility but knowing what to take and when to take it can be another difficult hurdle to jump. That’s why the American Geriatrics Society has published Guidelines for Pharmacologic Therapy. The specific focus is on medications for chronic pain in older adults. Chronic (or persistent) pain is defined as pain that lasts more than three months. Older adult refers to men and women 65 years old and older.

What medications are available and who should take them? Pain medications including acetaminophen (Tylenol), nonsteroidal antiinflammatories (NSAIDs), opioids (narcotics), adjuvant (additional other) analgesics, topical analgesics (rub on creams and gels), and other drugs are available. Here’s a brief summary of each class of drugs.

You are probably referring to something we call the pain body drawing. Patients draw lines, X’s, dots, and use letters like N for numbness or S for muscle cramps on a picture of the human body. The various markings show where pain is located and what kind of pain it is.

Some physicians, chiropractors, and physical therapists use these body maps routinely to assess any changes in patients’ pain levels and location. By looking at the pain pattern and how it changes over time, it’s possible to understand more about the patient’s experience.

Sometimes the pain drawings reveal aspects of the patient’s psychologic status, including how much emotional overlay is present. Emotional overlay refers to how much our emotions amplify (increase or magnify) the pain experience.

The pain patterns themselves are divided into two different classifications: organic and nonorganic. Organic pain is presented as a clearly identifiable pattern. It occurs in the thoracic spine (middle part of the spine). Nonorganic has a strange pattern of pain all over the body with no clear pattern.

Your physician may have a specific way in which he is evaluating or using the pain body drawings. To find out for sure: ask him! He will probably be happy to show you how he uses this information in preparing a plan of care for you.

Give your physician a call and explain what happened. It is known that some people require 10 to 40 times the standard dose to get the same effect. This difference in response to drugs has also been observed in animals, so we know it isn’t just a psychologic problem.

With any of the narcotic pain relievers, there is always a concern about addiction. But scientists have discovered that the need for a higher dose may be based on your genetic makeup. Research has uncovered a handful of these potential differences. It’s expected that there may be hundreds of genetic variations like this.

For example, some folks don’t have the CYP2D6 enzyme needed to activate the drug. Without this enzyme, the drug isn’t metabolized (broken down) and the patient gets no (or very minimal) pain relief. Another problem occurs when P-glycoprotein doesn’t function properly. This is the protein that transports the opioid across cell membranes. Without normal P-glycoprotein, there can be too little or too much opioid in the cells.

Here’s one more example of genetic mutations that affect how opioids work in the human body. When the COMT gene is mutated, it no longer makes the enzymes that break down neurotransmitters that carry chemicals around the body. Without proper COMT, the cell receptor sites for opioid are also affected.

These examples are really only the tip of the iceberg. The more scientists explore this direction of research, the more differences in genetic makeup are discovered. The cell receptor sites just mentioned? It turns out there are probably many different types of pain receptor sites — a change in any of these can affect how well opioids attach to the cell, transfer across the cell membrane, and have the intended effect to reduce pain messages.

Genetics isn’t the only factor in how people respond to opioids. There is still a significant effect of personality and psychology — some people tend to lean toward suffering rather than overcoming. And the source of the pain can also contribute to how well opioids work.

Your physician is the best one to evaluate all of these factors and determine what’s best for you. The information you give him or her about dose effectiveness will help. The pharmacist cannot refill a prescription for opioids early without your physician’s approval.

Definitely not. It is well-known that different people respond to different drugs differently. This concept is referred to as patient variability in responsiveness. There are many reasons this happens and it can affect many different drugs not just narcotic pain relievers.

Age, body fat and water content, sex (male versus female), and even race can contribute to ways in which the same drug is metabolized (broken down) differently. Drug metabolism determines (in part) how effective (sometimes how powerful) a drug can be. The reverse is true too. Undermetabolism and underabsorption of the medication results in no change (or minimal change) in symptoms.

In the case of pain medications, some people need a higher dose of the same drug to get the same effect as someone who responds well to the lowest dose prescribed. And some people simply don’t respond to the medication. In your case, even though the two drugs (Percocet and Vicodin) are very similar (they differ only in two atoms), the effect was very different.

You may want to let your physician know about this and make it a part of your medical record. This can save you time, pain, and money in the future. Should you need similar pain control, starting with Percocet — rather than trying Vicodin (or other drugs) first — may be the fastest and most direct treatment approach.

Complex regional pain syndrome, called CRPS for short, is a very real, very painful disorder that affects people after a seemingly minor injury sometimes. The problem is that CRPS is not understood and doctors don’t know what causes it or why it happens. They can’t even tell who would be at higher risk of developing it than others. Not only that, the symptoms and how the affect people can vary considerably from person to person.

As a result of so much that isn’t known, there is a good bit of confusion around the disorder, which used to be called reflex sympathetic dystrophy. In fact, it used to be thought that it was a mental disorder more than a physical one. Over the centuries, researchers tried to pin different causes, usually psychological, to CRPS because they couldn’t find any other way to explain it. Of course, as psychological thinking changed over time, so did the theories – but nothing really stuck and there still is no proof that CRPS is associated with a mental or psychological problem.

Complex regional pain syndrome, called CRPS, is a disorder that can cause severe pain and disability. However, as painful and disabling as the condition is, there is not a lot that doctors know about it. They do know that more women get it than men and that occurs after about one to two percent of fractures and after up to 35 percent of certain types of wrist fractures. What they don’t know is why it happens, who it will happen to, and how severe it will be. And, because treatment of CRPS depends on the symptoms, doctors often can’t tell you what may work and what may not.

Patients with severe, constant pain that has not responded to any other treatment may be candidates for pain pumps such as you are considering. There are various systems to provide long-term delivery of drugs into the spinal canal for fast action. The drug is delivered directly to the nervous system overriding pain messages to the brain.

It’s really a last resort effort to gain control of pain when everything else has been tried and failed. You would have to be evaluated as a possible candidate for this kind of pain management. A team of pain specialists will review what steps have already been taken and what pain control measures have been tried. Even these implantable pumps aren’t used without a trial first. Electrodes are placed on the outside of the spine first to see if the patient can get good pain relief this way. The external (outside) unit is left on for one to two weeks before considering implantation.

There can be a trial and error period when different drugs (or combination of drugs) are used to get the desired results (pain relief) with the fewest side effects. Common side effects with any of the opioid medications include nausea, dizziness, confusion, difficulty walking, and problems with memory.

Patients considering a pain pump should be told that complete pain relief is rare. They can expect some improvement (up to 50 per cent reduction in pain) — enough that they can function better. They may be able to tolerate their pain enough to complete daily activities and participate in life more comfortably.

Besides the side effects mentioned, there can be problems with low blood pressure that can suddenly switch to dangerous high blood pressure. It’s possible to develop a tolerance to the drug. This means the patient no longer gets the same pain relief with the standard prescribed dosage and must start taking more of the medication — and that can lead to even more problems.

Too strong of a reaction to a medication may require a switch to another drug. Even the process of withdrawing from one drug to try another can cause problems. Then the catheter used to deliver the drug can get blocked or kinked. And patients run out of their drugs. That’s just the short list of things that can go wrong with this type of drug therapy.

Pain pumps can be a very helpful tool for the right person. Talk to your doctor about your need for better pain control. There may be a far simpler solution to your problem than a pain pump. But if you have indeed explored all other options with no success, then this may be the next step to consider.

Complex regional pain syndrome (CRPS) is a common problem after trauma to an arm or leg. The injury could be as a result of surgery or bone fracture. Distal radial (wrist) fractures are the most common injury leading to CRPS, but no one knows why exactly. CRPS can occur without any known trauma or injury. Non-traumatic cases of CRPS make up about 10 per cent of all affected patients.

The patient develops wrist and hand pain, swelling, and skin color changes. The pain and swelling are accompanied by a loss of motion and function. There can even be changes in skin temperature (warm or cold) and increased hair growth on the arm compared to the other (healthy) side. In one-third of all cases, more than one extremity (arm or leg) is affected. CRPS occurs in women much more often than men (75 to 85 per cent of all cases).

The question of whether there is a genetic link with CRPS has been raised by medical researchers. Are siblings of patients with CRPS at increased risk for CRPS as well? A group of Dutch scientists who specifically study CRPS say there’s no overall increased risk. But younger patients (under 50 years old) seem more likely to have siblings who also develop CRPS.

There have been case reports of families with multiple siblings who developed CRPS. Only one study has been done to look at this connection more closely. The age factor points to a possible genetic link but there can be other environmental factors since siblings usually grow up together in the same household. More study is needed before an answer to this question of genetic susceptibility among siblings can be answered.

Complex regional pain syndrome (CRPS) is a chronic (long lasting) painful condition, usually affecting the arm or leg. Patients with CRPS develop severe pain, swelling and changes in skin texture, hair growth, and temperature. Loss of motion accompanied by pain can lead to a loss of function and disability in daily activities, work, and recreation.

The International Association for the Study of Pain (IASP) has divided CRPS into two types based on the presence of nerve lesion following an injury. The injury could be as a result of surgery or bone fracture. Distal radial (wrist) fractures are the most common injury leading to CRPS, but no one knows why exactly. CRPS can also occur without any known trauma or injury. Non-traumatic cases of CRPS make up about 10 per cent of all affected patients.

Type I CRPS was formerly known as reflex sympathetic dystrophy (RSD), Sudeck’s atrophy, or reflex neurovascular dystrophy (RND). There is no known or obvious nerve lesion in this type. Type II, formerly known as causalgia, occurs when there is obvious nerve damage.

Women are affected three times more often than men. Although it can occur at any age, adults between the ages of 50 and 70 years old seem to develop CRPS most often. One in three patients has symptoms in more than one limb. One in three patients develops dystonia, a movement disorder that contributes to even more dysfunction. The arm, wrist, and/or hand are affected slightly more often than the leg.

Although the exact cause remains largely unknown, it is suspected that there are multiple factors, possibly including genetic, nongenetic, and environmental contributions. Scientists from around the world are studying this problem in hopes of finding a way to treat it more effectively and perhaps even prevent it someday.