Is Complex Regional Pain Syndrome (CRPS)?
Who Gets CRPS?
What Is Happening in the Body to Cause CRPS?
Diagnosing and Treating CRPS
More Information on CRPS
Complex Regional Pain Syndrome (CRPS) is a chronic pain condition. A patient
with CRPS has pain as well as changes in blood flow, sweating, and swelling
in the painful area. Sometimes the condition leads to changes in the skin,
bones and other tissues. It may also become hard for a patient with CRPS
to move the painful body part.
The patient's arms or legs are usually involved, but CRPS may affect
any part of the body, such as the face or trunk. In some patients, many
different areas of the body are affected. CRPS can be progressive (meaning
that it gets worse at one site or spreads to other sites), or it can
stay the same for a long time or even improve on its own.
CRPS usually develops after an injury. The injury may be to the skin,
bone, joints or tissue. This type of CRPS has been called reflex
sympathetic dystrophy. CRPS can also develop after any
type of injury to major nerves. This type has been called causalgia.
The injury that leads to CRPS may be only minor, and sometimes a patient
cannot remember any injury or event that caused CRPS to start.
Like all human beings, patients who develop CRPS have had many other injuries that did not become CRPS.
Patients want to know: "Why did this injury result in my getting CRPS?" Unfortunately, no one knows
the answer to this question. Experts say that it might happen because:
||The chance of getting it might run in the family
||There is some type of stress in the person's life at the time
injured body part is not being used for a long time (either
because it is in a cast or sling, or because the person
is protecting it and not moving it normally)
Until recently, doctors thought that CRPS always involved a problem in
the sympathetic nervous system (a set of nerves that control the size
of blood vessels, sweating, and many other bodily functions). They now
think that only some patients with CRPS have these sympathetic nervous
system problems. Pain that comes from problems in the sympathetic nerves
is called sympathetically-maintained pain, or
SMP. The only way a doctor can find out if a patient has SMP is to do
a sympathetic nerve block. (Sympathetic nerve blocks are injections of
a numbing drug, called a local anesthetic, into different sites in the
body). A person suffering from CRPS can be said to have SMP only if he
or she has good pain relief from a sympathetic block.
If SMP does not explain the pain in most patients with CRPS, what is
the cause of the pain? Experts agree that there are problems in the
peripheral nervous system (the nerves in the body) and the central nervous
system (the brain and spinal cord) of patients with CRPS, but the details
are not known. There are other factors that can be involved in the development
of CRPS because they directly affect the activity of the nervous system,
muscles, and bones. Examples of these factors are emotional issues or
stress and not using a painful body part.
A doctor makes the diagnosis of CRPS based on how a patient describes
the symptoms and from what the doctor finds when he or she gives the patient
a physical exam. The patient does not need to have a nerve block to get
a diagnosis of CRPS. Laboratory tests or tests such as X-rays or bone
scans are usually not needed to make the diagnosis, either.
These are the symptoms that doctors use to decide whether or not a patient has CRPS:
|Pain that is constant or almost constant, with:
||pain caused by things that do not usually cause pain, such
as clothing, wind, cold or a light touch to the skin (called
||severe pain when only a slight pain would be expected, such as
when a doctor lightly pricks the skin with a pin (called
|Having some of the following in the painful area:
||changes in skin color (mottled, purple-bluish, red)
||skin temperature that is not normal (either hotter or colder
than other areas)
||either more or less sweating in the area
The following symptoms are also commonly experienced by CRPS patients:
||Problems moving the painful body part
||Depression or anxiety (common to all chronic pain disorders)
||Sleep problems (common to all chronic pain disorders)
Some patients with CRPS have changes in the area of the pain
that are known as trophic changes. These include:
||Wasting away of the skin, tissues, or muscle
||Thinning of the bones
||Changes in how the hair or nails grow, including thickening or
thinning of hair or brittle nails
No single treatment, such as a pill or nerve block, can cure
CRPS, but many CRPS patients do find that their pain and other symptoms
get much better with the right therapies. CRPS can improve when patients:
treatments that lessen the pain (such as nerve blocks,
medicines, and other treatments),
||take part in a physical therapy program, and
||get helpful psychological treatments (such as stress management
Every patient with CRPS responds differently to each therapy -- what
works well for one patient may not work at all for another. Because
of this, doctors may need to try many different medical therapies in
different combinations. It is often best for patients with CRPS to see
pain specialists, who are experienced in taking care of patients with
difficult pain problems.
Drugs. Doctors might prescribe
drugs like anti-inflammatory drugs, corticosteroids, antidepressants,
anticonvulsants, calcitonin,or opioids for patients with CRPS. Patients
may have to take several different drugs together to get the best pain
Sympathetic Block. Sympathetic
nerve blocks include stellate ganglion nerve blocks, lumbar sympathetic
nerve blocks and Bier blocks. For all of these blocks, doctors inject
numbing drugs (called local anesthetics) in
different nerves. For the Beir block, a drug is injected into a vein after
a cuff is inflated. The cuff keeps the drug in the painful area, so the
drug only affects the tissues in that area. Doctors may also use a phentolamine
infusion, in which a drug is given intravenously (through an IV). Phentolamine
infusions are thought to have a similar effect as a sympathetic nerve
Most patients with CRPS should receive at least one sympathetic block
because some patients will have dramatic pain relief. If a sympathetic
block does not provide good pain relief, the patient should probably stop
Sympathectomy. Some patients
with CRPS have good pain relief from sympathetic nerve blocks, but the
pain relief does not last long. For these patients, doctors might suggest
a sympathectomy (killing the sympathetic nerves leading to the painful
body part, either by using surgery or chemicals). Some patients get longer
pain relief after the sympathectomy, but others do not. Also, there is
the slight chance that patients who get a sympathectomy for CRPS of the
leg might develop a new pain syndrome, called post-sympathectomy syndrome.
Other Treatments. Some patients
get pain relief from acupuncture and transcutaneous electrical nerve stimulation
(TENS). With acupuncture, needles are placed in specific areas on the
skin to help relieve pain. With TENS, patients carry a small, box-shaped
device that sends electrical impulses into the body through electrodes.
These electrical impulses interfere with pain signals.
Sometimes, pain specialists recommend that a patient try a treatment called
spinal cord stimulation, or dorsal
column stimulation. This treatment provides low-voltage
electrical stimulation by placing an electrode inside the spine. Pain
specialists also sometimes recommend that a patient try intraspinal
infusion. Intraspinal infusion means that medications are
given through a catheter going directly into the spine. Drugs that prevent
or treat pain (called analgesics), such as morphine,
can be given in low doses through the catheter.
Physical and occupational therapists can help patients with CRPS begin
a program of stretching, strengthening, and aerobic conditioning. The
goal of this program is to help the patient get back range of motion,
strength and motor control. Physical and occupational therapists might
also try treatments like warm and cold baths, ultrasound, or electric
Desensitization is another important treatment that can be
used to help with allodynia (pain caused by things that do not normally
cause pain, such as clothing, wind, cold or a light touch to the skin).
The patient's painful skin is rubbed with different materials, starting
with soft, light textures and proceeding to rough, irritating surfaces.
Gradually, the painful skin gets used to the rough textures, until the
patient can easily deal with the touch of clothing, bed sheets, towels,
International Research Foundation for RSD/CRPS
Reflex Sympathetic Dystrophy Syndrome Association
National Guideline Clearinghouse: CRPS Treatment
NINDS CRPS Information Page
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