OVERVIEW
Reflex sympathetic dystrophy syndrome (RSDS) is a clinical syndrome characterized by severe pain in the distal extremities with autonomic dysfunction. It can occur at any age, but is more common in adults. The main symptoms are pain, autonomic dysfunction, edema, dyskinesia, and dystrophy and atrophy, which often appear rapidly within a few hours of injury, or gradually over several days or weeks, and last for several weeks to years. The pain is characterized by burning pain, which can be severe with light touch or repeated light stimulation, is not proportional to the severity of the injury, and lasts longer than the expected healing time. Pain in the affected limb is often accompanied by diffuse tenderness and swelling, and autonomic dysfunction, such as cold and hot limbs, red and white, dryness or sweating. The disease progresses slowly, with atrophy and contracture of the skin and subcutaneous tissue in the late stage.
Etiology
The etiology of the disease is unknown, most patients have a history of trauma, surgery, brain, spinal cord and peripheral nerve injury before the onset of the disease; some patients may be caused by local spread of the tumor involving the autonomic nerves; a small number of patients are prompted by drugs such as isoniazid, phenobarbital, ergotamine, cyclosporine, and so on.
Symptoms
1. Acute stage
Post-traumatic pain. The main manifestations of the affected limb burning pain and vasoconstriction disorders, the affected limb congestion, edema, skin temperature changes in the injury area, X-ray can be normal or show patchy bone density reduction, such as untreated for 3 to 6 months can be progressed to phase 2.
2. Dystrophy stage
The prominent manifestations are progressive aggravation of soft tissue swelling, skin and joint thickening, muscle wasting and development of skin stiffness.
3. Atrophic stage
Characterized by limited mobility, shoulder-hand syndrome, finger flexion, waxy dystrophic skin changes and friable nail ridges, with severe bone loss visible on X-ray.
Examination
1. Laboratory examination
No abnormality.
2. Other auxiliary examinations
(1) Radiological examination X-ray film usually shows segmental bone loss, and typical cases can see patchy decalcification of the long bones of the limbs and the short bones of the hands and feet, as well as soft tissue edema. High-resolution radiographs may also show subperiosteal resorption, streak formation, subperiosteal cavities and tunnel formation. CT and MRI of the affected extremities appear to be of little or no diagnostic value.
(2) Nuclide triphasic bone scanning After intravenous injection of nuclide (usually 99mTc) for 5 seconds, 1 to 5 minutes and 3 to 4 hours, the changes in blood flow imaging, blood pool imaging and delayed imaging can be observed, and it can be seen that the uptake of nuclide in the affected area is significantly higher than that in normal tissues, with a diagnostic sensitivity of 60% and a specificity of 80%, which is superior to that of X-ray examination, and it is suitable for people with early-onset limited RSDS or those who are negative on X-ray examination. It is suitable for those with early limited RSDS or negative X-ray examination.
Diagnosis
Internationally recommended diagnostic criteria: (1) distal limb pain and tenderness; (2) vasodilatory disorder symptoms and signs; (3) limb swelling, often most obvious around the joints; (4) often with dystrophic skin damage.
Treatment
1. Physical therapy
Cold and wet compression, heat therapy, wax therapy, stellate nerve ultrasound therapy, acupuncture and electro-acupuncture are simple and easy to implement, and can directly improve the function of limb movement. Percutaneous implantation of electrodes to stimulate the nerve can selectively stimulate the larger myelinated neurosensory fibers and stimulate the inhibitory system to relieve pain.
2.Drug or surgical treatment
(1) Sympathetic nerve block or amputation For patients with skin changes or persistent activity limitation with sympathetic nerve-dependent pain. Local anesthetics or epidural block The upper extremity involvement can be closed below the stellate ganglion. ② Drugs The first applied drug is guanethidine, local intravenous injection of guanethidine after 20 minutes on tourniquet, so that the middle and norepinephrine, all achieved efficacy. (iii) Surgery For those who have multiple sympathetic nerve blocks that are effective but have a short duration of action, sympathectomy can be considered.
(2) Glucocorticoids Corticosteroids have significant efficacy in RSDS, especially for those who refuse or cannot tolerate sympathetic blockade therapy.
(3) Nifedipine is a calcium antagonist that relaxes smooth muscle, increases peripheral blood circulation, and counteracts the effects of norepinephrine, which not only relieves pain but also stabilizes vasomotion.