Complex Regional Pain Syndrome
Complex regional pain syndrome (CRPS) is a chronic (long-term) disorder of the nervous system. It is a collection of signs and symptoms typically including pain of a burning type, changes in skin and bone tissue, excessive sweating (hyperhidrosis), swelling of an extremity, and extreme sensitivity to touch.
CRPS was first recorded in the 19th century during the American Civil War. Doctors noted veterans were experiencing pain after their wounds had healed. It commonly occurs at the site of injury to an arm or leg. CRPS may also be referred to as reflex sympathetic dystrophy syndrome (RSDS), “causalgia”, “the shoulder-hand syndrome” and “Sudeck’s atrophy”.
Although it can start at any age it is most common between the ages of 40 and 60. CRPS occurs more frequently in women than in men.
Causes
The exact cause of CRPS is unknown but may result from irritated and damaged nerves of the sympathetic nervous system. Even relatively minor trauma to a body part may lead to CRPS.
The sympathetic nervous system is a division of the autonomic nervous system (ANS) which controls unconscious bodily functions including digestion, regular beating of the heart, blood flow, sweating and salivation.
In CRPS dysfunctional sympathetic nerves are thought to send inappropriate messages to the brain. These interfere with normal messages regarding sensation, temperature and blood flow.
A number of different events can trigger the condition. These include:
- Trauma (injury)
- Surgery
- Some forms of arthritis
- Heart attack
- Stroke
- Nerve entrapment conditions eg: Carpal Tunnel Syndrome
- Shingles.
In approximately one third of all cases, no trigger can be identified.
Signs and Symptoms
CRPS can affect the nerves, skin, muscles, blood vessels and bones simultaneously. Symptoms can be gradual or rapid in onset and can vary in severity. They normally occur in three stages: acute, dystrophic and atrophic. Signs and symptoms occurring in these three stages may include:
Acute phase (1-3 months)
- Burning pain
- Swelling of an extremity
- Vasospasm (constriction of blood vessels) affecting skin colour and temperature.
- Excessive sweating
- Tenderness.
Dystrophic (3 to 9 months)
- Intensified pain
- Shiny skin
- Thickened skin
- Contracture development (tightening and shortening of muscles)
- Diminished swelling.
Atrophic (9 months or longer)
- Skin changes become irreversible
- Significant osteoporosis can be shown on x-ray
- Thinning of the fatty layers under the skin
- Restricted movement due to contractures
- Pain unyielding and may have spread to other areas of body.
Diagnosis
CRPS is poorly understood and often misdiagnosed. Diagnosis is usually made based on pain symptoms and clinical signs.. A doctor will usually make a diagnosis of CRPS based on the following:
- A full medical history
- Discussion of current pain symptoms
- X-rays to assess bone changes
- Blood tests to rule out other causes.
Treatment
Treatment is generally most effective in the first three months of the condition. If left untreated the disorder can spread to other areas of the body. The usual pattern of spread is up the affected extremity and on to the same side of the body. It may also spread to the opposite side of the body. Specialist intervention early on is the key to a successful outcome.
A doctor may need to try a variety of treatments. Least invasive is the application of cold or heat. Most invasive is chemical or surgical sympathectomy (removal of affected sympathetic nerves). Surgical sympathectomy involves cutting the nerves and while this can stop pain almost immediately other sensations may be destroyed as well.
Other treatments include:
- Sympathetic block (injection of a local anaesthetic into affected sympathetic nerves to block pain)
- The use of low dose tricyclic antidepressants and anticonvulsants to relieve pain sensitivity.
- Medications including analgesics (pain relievers), vasodilators (increase diameter of blood vessels) and corticosteroids (reduce inflammation)
- Desensitisation of affected area using techniques such as TENS (transcutaneous electrical nerve stimulation), massage and brushing of the skin.
- Physiotherapy (exercising affected limb to prevent contractures, maintain muscle strength and movement, and build aerobic fitness)
- Psychological counselling and education regarding the condition.
- Regular aerobic exercise eg. swimming / brisk walking.
Recovery
Recovery is variable in CRPS. The prognosis is better with early treatment. Approximately 50 per cent of patients with CRPS suffer pain for longer than six months. Some patients with severe symptoms may not respond to treatment. For these individuals a pain management programme aimed specifically at chronic pain can be beneficial. This is usually done through a hospital based multidisciplinary pain clinic involving medical practitioners, physiotherapist, occupational therapists, psychologists and other health professionals.
Support and Information
For further information or support, contact your GP or practice nurse.
Community support groups that may be able to assist include:
Pain Action in New Zealand Inc. (PAINZ)
PO Box 32 074
Christchurch
Ph: (03) 366 0716
Fax: (03) 366 0736
The Chronic Pain Support Foundation
Contact person: Rod Goss
E-mail: argoss@kol.co.nz
References
American Academy of Family Physicians (2001) Complex regional pain syndrome Leawood, KS: AmericanAcademy of Family Physicians -
http://www.familydoctor.org/handouts/238.html
Brukner, P. and Khan, K. (2001) Reflex sympathetic dystrophy. In P. Brukner and K. Khan Clinical sports medicine (2nd ed.) Sydney: McGraw-Hill Book Company
Everitt, W. (2001) Help exists for painful condition The Evening Post, 26 November (Ed.3, p4)
MayoClinic (2001) Reflex sympathetic dystrophy syndrome Rochester, MN: Mayo Foundation for Medical Education and Research http://www.mayoclinic.com/findinformation/ conditioncenters/invoke.cfm?objectid=8F3237C2-D7C0-4063-AE87DC86D78085FE
MedicineNet (2006) Reflex sympathetic dystrophy (RSDS) San Clemente, CA: MedicineNet, Inc - http://www.focusonarthritis.com/script/main/art.asp?articlekey=468&rd=1
National Institute of Neurological Disorders and Stroke (2001) Reflex sympathetic dystrophy syndrome Bethesda: National Institutes of Health http://www.ninds.nih.gov/health_and_medical/pubs/rsds_ fact_sheet.htm
Sloman, L. (2002) Treating CRPS in children New Zealand GP, 20 February, p18
Last Reviewed - 21/02/07