Introduction
Complex Regional Pain Syndrome (CRPS), formerly known as Reflex Sympathetic Dystrophy (RSD) or shoulder-hand syndrome, is a chronic pain disorder that often affects an arm or leg. It is characterized by severe burning pain and, if untreated, can lead to the deterioration of the affected limb. Though the exact cause is unknown, CRPS often develops after an injury, stroke, or heart attack. Early treatment is crucial for better outcomes, as prolonged untreated cases can lead to irreversible damage.
Anatomy
The sympathetic nervous system plays a vital role in regulating involuntary bodily functions essential for life, such as heart rate, blood vessel constriction, and body temperature control. It prepares the body for emergency situations, often referred to as the "fight or flight" response, by increasing heart rate, raising blood pressure, and redistributing blood flow to essential organs.
Causes
The exact cause of CRPS is still unclear, but it is believed that disruptions in the sympathetic nervous system may interfere with normal regulation of blood flow, sensation, and temperature in the affected limb. This dysfunction could lead to issues involving skin, nerves, muscles, bones, and blood vessels. Another hypothesis suggests an immune system response may contribute to the condition. CRPS often develops after an injury, but it can also follow events like heart attacks, strokes, cancer, or nerve compression.
Symptoms
CRPS symptoms vary but often include intense burning pain, joint stiffness, and swelling. It typically affects one arm or leg and progresses through three stages:
- Stage I: Lasts up to three months, with symptoms such as burning pain, stiffness, excessive sweating, and rapid nail and hair growth. Skin changes like dryness, thinning, and discoloration are common.
- Stage II: Lasts three to twelve months. Swelling increases, the skin becomes cooler and more sensitive, and pain spreads. Muscle stiffness worsens.
- Stage III: Occurs after one year and may involve irreversible damage. Pain may affect the entire limb, joints become extremely stiff, and muscle atrophy or contractures may develop.
Diagnosis
Early diagnosis is critical for effective treatment. A doctor will review your medical history, symptoms, and progression, and perform a physical exam to check for skin changes, swelling, blood flow irregularities, and mobility issues. While imaging tests such as X-rays, bone scans, or nerve studies may be ordered, no specific test can definitively diagnose CRPS.
Treatment
The best outcomes are achieved when treatment begins early. While there is no cure for CRPS, early-stage treatment can prevent disease progression or even reverse symptoms. Treatment aims to relieve pain and improve function, particularly in later stages. Options include:
- Medications such as pain relievers, antidepressants, steroids, and blood pressure medications
- Pain relief through spinal cord stimulation, medication injections, or implanted medication pumps
- Rehabilitation therapy, such as hand therapy, to regain limb function
Surgery
Surgery is rarely recommended for CRPS but may be necessary in cases involving nerve injury or compression. Resolving these issues surgically can alleviate symptoms in some cases.
Recovery
CRPS treated in its early stages has a favorable outlook, often leading to a regression of symptoms or an inactive disease state. Delayed diagnosis and treatment, however, may result in irreversible changes to the affected limb.
Prevention
There is no known way to prevent CRPS, but prompt treatment can stop the progression of symptoms and potentially improve outcomes.
