What happens with this syndrome
After an injury, an inflammatory reaction is activated in the tissues and pain receptors are activated. Normally, as healing progresses, these processes fade. With Sudeck's syndrome, they become fixed: the nerve endings become overly sensitive, the work of the autonomic nerves that regulate blood vessels and sweating changes, and the spinal cord and brain rearrange the perception of signals from the limb. As a result, even a light touch is perceived as pain, the vessels either dilate or spasm, and immobility triggers a vicious circle: pain prevents movement, and lack of movement increases pain and stiffness.
- Excessive sensitivity of nerve endings
- Violation of autonomic regulation of blood vessels
- Changes in the perception of pain in the central nervous system
- Vicious circle of pain and immobility
- Bone loss from inactivity
Causes and risk factors
Most often, the syndrome develops after a fracture, especially of the radius in a typical location, as well as after operations, dislocations, sprains and even minor injuries. Sometimes there is no obvious injury at all. The risk is increased by a cast that is too tight, prolonged immobility, refusal to develop movements due to fear of pain, as well as concomitant anxiety. Of particular importance is how early rehabilitation is started: the longer the limb is inactive, the higher the likelihood of pain persisting. Not everyone has a predisposition, and it is impossible to predict in advance who will develop the syndrome.
- Fracture of the radius in a typical location
- Surgeries on the hand and foot
- Tight or excessively prolonged immobilization
- Dislocations and sprains
- Refusal of early development of movements
- Anxiety and fear of pain
- Sometimes there is no obvious injury
Symptoms and stages
The first stage, which lasts weeks, is dominated by burning pain, severe swelling, redness and increased skin temperature, increased sweating and pain from light touch. In the second stage, the swelling becomes dense, the skin turns pale or blue, becomes cold, stiffness of the joints increases, and spotty bone loss appears on x-rays. In the third stage, pain may decrease, but thinning of the skin, muscle atrophy, deformation and persistent limitation of movement remain. The division into stages is arbitrary, and the course varies from person to person, but the general trend is from inflammatory to irreversible changes.
- Burning pain out of proportion to the injury
- Pain from a light touch
- Swelling, redness, then paleness of the skin
- Change in skin temperature
- Excessive sweating
- Muscle stiffness and atrophy
- Changes in hair and nail growth
Diagnostics
There is no specific analysis or image confirming the diagnosis: it is made according to clinical criteria, assessing complaints and objective signs in comparison with the healthy side. Dynamic X-rays of the hand or foot may show characteristic spotty bone loss, but in the early stages it is usually normal, and this does not exclude the diagnosis. ENMG is performed to avoid missing damage to a specific nerve that requires other treatment. MRI and other studies are ordered to rule out infection, vein thrombosis, and undetected fracture. It is important that the diagnosis is made as early as possible.
- Examination according to diagnostic criteria
- Comparison with the opposite limb
- Dynamic X-ray of the hand or foot
- ENMG to exclude nerve damage
- MRI according to indications
- Rule out infection and venous thrombosis
Treatment and recovery
The main principle is to return the limb to movement as early as possible, ensuring sufficient pain relief. Rehabilitation is built from simple to complex: first, soft passive movements and work with sensitivity, then active exercises, restoration of support and everyday skills. Classes should be regular and daily. The doctor selects painkillers and agents that affect neuropathic pain; in persistent cases, therapeutic blockades are used. Physiotherapy, gentle massage, and contrast baths as prescribed are useful. Psychological support is also important: fear of movement significantly worsens the result.
- Early and sufficient pain relief
- Daily physical therapy with gradual complication
- Sensitivity work and desensitization
- Physiotherapy and gentle massage
- Medicines for neuropathic pain as prescribed by a doctor
- Therapeutic blockades for persistent pain
- Psychological support and overcoming fear of movement
- Refusal from prolonged limb immobility