REFLEX SYMPATHETIC DYSTROPHY (RSD)
Part 1 of 2
Over the past 9 years, I received several emails from people suffering from Reflex Sympathetic Dystrophy (RSD). A recent email from a very desperate and concerned reader looking for information about (RSD) caused me to pause and reflect. For those unfamiliar with this disorder, it is one of the most frustrating, frightening and misunderstood neuromuscular problems one can experience. I have had patients develop RSD after a simple ankle sprain, major trauma or prolonged casting. It is speculated that the body seems to overreact to this trauma and the neuromuscular system goes haywire. The person can experience severe pain, burning, tingling, numbness, weakness, swelling, stiffness, warmth, excessive perspiration, excessive hair growth and more – all from a relatively minor trauma.
The current wisdom in pain management now classifies RSD as chronic regional pain syndrome (CRPS). CRPS is a malfunction of the nervous and immune systems as they respond to tissue damage from trauma or after a period of immobilization. A number of precipitating factors have been associated with CRPS including: sprain, contusion, fracture, heart attack, stroke, irritation or injury to a single spinal nerve, injury to the spinal cord, diabetic neuropathy, cancer, multiple sclerosis, poor circulation, infections, surgery, repetitive motion disorders (carpal tunnel syndrome), and cumulative trauma.
The sympathetic nervous system seems to assume an abnormal function after the incident. The original injury initiates a pain impulse carried by sensory nerves to the central nervous system. The pain impulse in turn triggers an impulse in the sympathetic nervous system which returns to the original site of injury. The sympathetic impulse triggers the inflammatory response causing the blood vessels to spasm, leading to swelling and increased pain. The pain triggers another response, establishing a cycle of pain and swelling. Even a minor injury might trigger CRPS causing nerves to misfire, sending constant pain signals to the brain.
CRPS is divided into two categories: Type I (Reflex Sympathetic Dystrophy) and Type II (Causalgia). Pathology of causalgia is damage to a major nerve trunk. In RSD, there is usually damage to some very minor nerves. The symptoms and clinical presentation of the conditions overlap as do the treatments. The contents of this article will focus on RSD.
Some experts believe there are three stages associated with RSD, marked by progressive changes in the skin, muscles, joints, ligaments, and bones of the affected area. The “staging” of RSD is a concept that is somewhat speculative because progression has not yet been validated by clinical research studies. Also, the course of the disease seems to be so unpredictable between various patients that staging is not helpful in the treatment of RSD. Not all of the clinical features listed below for the various stages of RSD may be present and speed of progression varies greatly in different individuals:
RSD is diagnosed primarily through observation of the signs and symptoms. Since there is no specific diagnostic test for RSD, the most important role for testing is to help rule out other conditions. However, there are a couple of tests which can be useful in providing evidence for RSD.
The backbone test for this disease is a sympathetic block. In over 95% of patients, the blockade will take away their pain. The sympathetic block will not only provide diagnostic and prognostic information, but may also provide a cure or partial remission of RSD.
1. Thermography: A non-invasive means of measuring heat emission from the body surface using a special infrared video camera.
2. Quantitative sweat test
3. Triple phase bone scan
4. Cold and mechanical allodynia: applying a stimulus to the area to see if it causes pain.
5. IV phentolamine test: a pharmacologic test for changes in blood pressure.
6. X-rays, EMG, Nerve Condition Studies, CAT scan, and MRI studies: All of these tests may be normal in RSD/CRPS. These studies may help to identify other possible causes of pain; for example, RSD plus a carpal tunnel syndrome.
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Contributor: Janet Caputo, PT, DPT, OCS: Clinic Director at Mackarey & Mackarey Physical Therapy Consultants, LLC in Scranton, PA.
NEXT MONDAY – Read Dr. Paul J. Mackarey “Health & Exercise Forum! in the Scranton Times-Tribune. Next Week RSD- Part 2.
This article is not intended as a substitute for medical treatment. If you have questions related to your medical condition, please contact your family physician. For further inquires related to this topic email: drpmackarey@msn.com
Paul J. Mackarey PT, DHSc, OCS is a Doctor in Health Sciences specializing in orthopaedic and sports physical therapy. Dr. Mackarey is in private practice and is an associate professor of clinical medicine at The Commonwealth Medical College.