Complex Regional Pain Syndrome (CRPS) is a condition that is frequently disputed in personal injury and compensation claims. Even for clinicians who regularly see cases of CRPS it can represent diagnostic difficulties.
CRPS is a disorder of the nervous system in which pain is accompanied by disturbances in the sensory, motor and regulatory nervous system, producing a variable clinical picture characterised by one or more of the following
| Sensory Nerve Disturbances | Movement Abnormalities | Regulatory Changes |
| Hypersensitivity (increased sensation to a normally pain- ful stimulus e.g.heat or pin prick ) | Weakness | Temperature abnormalities |
| Allodynia (pain in response to a normally non-pain- ful stimulus e.g. light touch) | Stiffness | Perspiration (pseudo motor) changes |
| Hyperpathia (pain in response to a repeated stimulus eg vibration) | Muscle wasting | Changes in skin, hair and nail growth |
| Tremor | Blood flow changes (pale or mottled skin) | |
| Swelling |
Pathophysiology of CRPS
While the exact mechanism of CRPS in humans is uncertain, research underpinned by functional MRI scanning suggests that CRPS is the result of nervous system re-wiring in response to injury or immobilisation.
Diagnostic Difficulties
Diagnostic difficulties arise because there is no single test or investigation specific for CRPS and a diagnosis is reliant upon the presence or absence of various combinations of symptoms and signs. Historically, clinicians have changed their consensus opinion as to what combination of clinical signs and symptoms are necessary to diagnose this condition.
Treatments for Complex Regional Pain Syndrome
- Corticosteroid medication
- Vitamin C
- Antineuropathic pain medications
- Nerve blocks
- Neuromodulation
- Mirror box therapy
- Graded motor imagery
CRPS is usually managed in multidisciplinary pain clinics by Pain Medicine Physicians
| AMA Guides to Evaluation of Permanent Impairment 5th Edition criteria to diagnose CRPS | Budapest Consensus Criteria for the diagnosis of CRPS | AMA Guides to Evaluation of Permanent Impairment 6th Edition criteria to diagnose CRPS |
| A. Vasomotor changes: • Skin colour mottled or cyanotic; • Skin temperature cool; • Oedema. B. Pseudomotor changes: • Skin dry or overly moist. C. Trophic changes: • Skin texture smooth, non- elastic; • Soft tissue atrophy; • Joint stiffness and decreased passive motion; • Nail changes: blemished, curved, talon-like. • Hair growth changes: falls out, longer, finer. D. Radiographic Changes: • Radiographs: trophic bone changes, osteoporosis; • Bone scan: findings consistent with CRPS. < 8 of the above signs present at time of examination = no CRPS. 8 of the above signs present at time of examination = CRPS probable. | Continuing pain which is disproportionate to any inciting event. Must report at least one symptom in 3 of the 4 following categories A. Sensory (pain). B. Vasomotor. C. Psueudomotor/oedema. D. Motor /trophic. Must display at least one sign at the time of examination in 2 or more of the following categories A. Sensory: evidence of hyperalgesia or allodynia. B. Vasomotor: evidence of temperature asymmetry and/or skin colour changes and/or asymmetry. C. Pseudomotor/oedema: evidence of oedema or sweating changes and/or sweating asymmetry. D. Motor/trophic: evidence or decreased range of motion and/or motor dysfunction and or trophic changes (hair, nail, skin). There is no other diagnosis that better explains the signs and symptoms. | Must report at least one symptom in 3 or 4 of the following categories: A. Sensory: reports of hyperaesthesia and or allodynia. B. Vasomotor: reports of temperature asymmetry and or skin colour changes and or skin colour asymmetry. C. Pseudomotor/oedema: reports of oedema and or sweating changes and or sweating asymmetry. D. Motor/trophic: reports of decreased range of motion and or motor dysfunction (weakness tremor dystonia and or trophic changes (hair, nail, skin). Must display at least one sign at time of evaluation in 2 or more of the following categories: A. Sensory: reports of hyperaesthesia and or allodynia. B. Vasomotor: reports of temperature asymmetry and or skin colour changes and or skin colour asymmetry. C. Pseudomotor/oedema: reports of oedema and or sweating changes and or sweating asymmetry. D. Motor/trophic: reports of decreased range of motion and or motor dysfunction (weakness tremor dystonia and or trophic changes (hair, nail, skin). There is no other diagnosis that better explains the signs and symptoms. |