Complex regional pain syndrome is a pathology that is usually diagnosed late, so it is common for patients to suffer from this pain for a long period of time. It is a syndrome triggered after a painful event and presenting spontaneous damage to stimuli such as friction, slight pressure or temperature change. It is located in an anatomical area that does not coincide with the distribution of a peripheral nerve or nerve root, in addition to being a disproportionate pain with respect to the triggering event.
It may be accompanied by edema, sweating and coloration alterations that may affect the motor capacity of the limb in question with a delay in functional recovery. Trophic disorders such as stiffness, skin alterations or nail and hair alterations may also occur, although there is no underlying pathology to explain the symptomatology. If there is no previous nerve injury it is referred to as type 1 syndrome, whereas if there is a nerve injury it is known as type 2.
Epidemiology of complex regional pain syndrome
It is a pathology that affects more women than men and is also more frequent in the upper extremities than in the lower extremities. In 65% of cases there is a previous trauma such as fractures, dislocations, sprains, thoracic contusions, slight abrasions or previous surgery on the affected limb.
Other causes may be myocardial infarction or neurological injuries and may even occur after venous puncture for venoclysis, intramuscular administration of drugs or prolonged orthopedic immobilization. It can occur at any age, from children to adults, although treatment results in children are better.
Symptoms of complex regional pain syndrome
The most evident symptom in this pathology is disproportionate pain in response to stimuli that in other circumstances would not be painful, such as rubbing or pressure. It is a pain that can worsen in situations of anxiety or stress and is accompanied by changes in the coloration of the skin with respect to the collateral limb.
These symptoms usually occur in three stages:
- Acute stage: it can last up to 3 months and starts with a burning, distal pain that increases with physical contact. It presents as edema, stiffness and swelling of the joints and even color changes.
- Dystrophic stage: can last from 3 to 12 months and increases swelling altering the affected limb. Skin temperature cools, nails break easily and pain is diffused, although stiffness and sensitivity to touch increase.
- Atrophic stage: after one year of age the skin becomes pale, dry and tight. Pain may have spread and mobility may have decreased.
Medical treatment and rehabilitation
Early diagnosis favors the results of treatment and rehabilitation is of vital importance to avoid stiffness and improve mobility, as well as to reduce edema. Rehabilitation should be carried out in a non-aggressive manner and after the pain has subsided by medical treatment or sympathetic blockade.
Among the pharmacological treatments, non-steroidal anti-inflammatory analgesics can be used, although their efficacy has not yet been demonstrated. In the initial phases and in the short term, corticosteroids can be used, as well as anticonvulsants and opiates. And treat the pathology with botulinum toxin and capsaicin and lidocaine patches.
One of the most effective treatments are sympathetic blocks because of their healing power in this disease and because they help to determine what percentage of the patient’s pain is due to the sympathetic system. On the other hand, the response to this treatment helps the specialist to determine the use of other techniques. An upper extremity sympathetic block is performed on the stellate ganglion and with a means of image control. For the lower extremity, a lumbar sympathetic block is used with radiological control and contrast.