PT Classroom - Reflex Sympathetic Dystrophy ׀ by Kostandinos Tsoulfas, MD

Reflex sympathetic dystrophy (RSD) is a complex form of neuropathic pain (pain from nerves). It is also known as complex regional pain syndrome (CRPS). This syndrome is characterized by increased sensitivity to normal stimuli, vascular instability, inflammatory changes, emotional responses. RSD typically involves an extremity (an arm or a leg). It is thought to occur because of the over sensitization of sensory nerves and receptors. This leads to changes in other structures including the sympathetic nervous system and spinal cord, as well as the limbic system in the brain.

What are some of the causes of RSD?
RSD is usually preceded by some sort of minor trauma. Traumatic events such as repetitive stress injuries, joint sprains, surgery, crush injuries and fractures. In some cases, no traumatic event can be identified.

Symptoms
Pain is typically described by patients as being intensely burning and regional pain. The extremity is more sensitive to painful stimuli as well as non-painful stimuli. Patients often report that putting a glove or stocking on an affected extremity will induce an excessive amount of pain as compared to a non-affected extremity. Patients will typically avoid gloves, cold weather and windy conditions because of this phenomenon. Patients may also have other sensations such as numbness and tingling.

Clinical signs and symptoms of RSD
The clinical course of RSD is usually divided into four phases:
1) In the first phase, patients usually complain of increased sensitivity to light touch, increased sensitivity to painful stimuli, muscle weakness, muscle spasms, temperature changes, sweating.
2) The second phase can include features of the first phase with the addition of symptoms such as swelling, loss of hair, nail bed changes, skin changes.
3) The third stage is characterized by muscle wasting, ulcers, rash, increased color changes due to vascular instability.
4) The fourth stage is characterized by increased swelling, blood pressure changes, autonomic nervous system changes.

Conditions such as diabetic neuropathy, vascular disease, peripheral neuropathies, nutritional neuropathies, thoracic outlet syndrome, carpal tunnel syndrome, other compressive neuropathies, disc herniations, radiculopathy, myofascial pain syndrome and fibromyalgia present similarly to RSD.

Diagnosis
To date, there is not one gold standard test that can diagnose RSD. A careful history and physical examination is needed to help rule out other conditions as mentioned above. Additional diagnostic testing to rule out these other conditions may also include EMG/NCV, laboratory evaluation, and radiographic imaging such as MRI or CT scans. Tests that help to rule in the diagnosis of RSD include three phase bone scan, diagnostic nerve blocks, quantitative sensory testing and infrared thermal imaging. It is important to remember that this condition varies among patients. Not every patient will have a positive test or exhibit all of the clinical signs and symptoms.

Treatment
Treatment is tailored to the patient and the severity of the patient's condition. In some cases, when treated early, RSD can respond to a series of diagnostic/therapeutic nerve blocks. When the condition has progressed, a multidisciplinary approach may be required. It is important to understand that for all stages adequate pain relief is required as well as mobilization of the involved extremity.
 

Specific Treatments for RSD
1) Physical Therapy. Physical Therapy is key at all stages for patients with RSD. It is important for patients to mobilize the affected extremity to help reduce long-term changes such as muscle weakness and decreased blood flow.
2) Pain relief is also a top priority for patients. Medical management, nerve blocks, electrical stimulation techniques (TENS unit), acupuncture and spinal cord stimulation are examples of commonly used modalities. Medical management will typically include low dose antidepressants, nonsteroidal anti-inflammatory medications, anti-convulsants and alpha blockers. Narcotic medical management is only indicated in select cases.
3) Because RSD can be a very debilitating condition, patients will often experience depression and other emotional disturbances. Psychological and psychiatric evaluation in treatment is necessary for patients who exhibit depressive and emotional disturbances or who have had the condition for a long period of time without improvement. Stress management techniques such as pacing, hypnosis, relaxation and cognitive and behavioral therapy can be very useful in helping patients to better deal with their pain. In addition, patients being considered for narcotic management should also receive psychological evaluation.