Diagnostic Considerations
Revised Complex Regional Pain Syndrome (CRPS) Criteria Proposed by the Budapest Consensus Group
General Features of the Syndrome:
CRPS describes an array of painful conditions that are characterized by a continuing (spontaneous and/or evoked) regional pain that is seemingly disproportionate in time or degree to the usual course of any known trauma or other lesion. The pain is regional (not in a specific nerve territory or dermatome) and usually has a distal predominance of abnormal sensory, motor, sudomotor, vasomotor and/or trophic findings. The syndrome shows variable progression over time.
There are two versions of the proposed diagnostic criteria: a clinical version meant to maximize diagnostic sensitivity with adequate specificity, and a research version meant to more equally balance optimal sensitivity and specificity.
Clinical Diagnostic Criteria for CRPS
- Continuing pain, which is disproportionate to any inciting event
- Must report at least one symptom in three of the four following categories:
- Sensory: Reports of hyperesthesia and/or allodynia
- Vasomotor: Reports of temperature asymmetry and/or skin color changes and/or skin color asymmetry
- Sudomotor/Edema: Reports of edema and/or sweating changes and/or sweating asymmetry
- 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 two or more of the following categories:
- Sensory: Evidence of hyperalgesia (to pinprick) and/or allodynia (to light touch and/or deep somatic pressure and/or joint movement)
- Vasomotor: Evidence of temperature asymmetry and/or skin color changes and/or asymmetry
- Sudomotor/Edema: Evidence of edema and/or sweating changes and/or sweating asymmetry
- Motor/Trophic: Evidence 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
*A sign is counted only if it is observed at time of diagnosis.
Research Diagnostic Criteria for CRPS
- Continuing pain, which is disproportionate to any inciting event
- Must report at least one symptom in each of the four following categories:
- Sensory: Reports of hyperesthesia and/or allodynia
- Vasomotor: Reports of temperature asymmetry and/or skin color changes and/or skin color asymmetry
- Sudomotor/Edema: Reports of edema and/or sweating changes and/or sweating asymmetry
- 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 two or more of the following categories:
- Sensory: Evidence of hyperalgesia (to pinprick) and/or allodynia (to light touch and/or deep somatic pressure and/or joint movement).
- Vasomotor: Evidence of temperature asymmetry and/or skin color changes and/or asymmetry.
- Sudomotor/Edema: Evidence of edema and/or sweating changes and/or sweating asymmetry.
- Motor/Trophic: Evidence 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.
*A sign is counted only if observed at time of diagnosis.
Interdisciplinary Management
Because the symptoms of CRPS patients encompass all the bio-psycho-social complexities of chronic pain, the best hope of helping our patients is the adoption of a systematic, stable, empathetic and, above all, interdisciplinary approach that addresses those symptoms. Drugs, psychotherapy, and interventions should be efficiently deployed for patients who either cannot begin or fail to progress using the interdisciplinary approach (outlined in sections three through five in the original guideline document). Many patients will require medication and psychotherapy from the beginning to be successful in the pivotal functional restoration algorithm (see "A Sample Stepwise, Functional Restoration Algorithm" below). Treatment guidelines that center on progressive functional restoration delivered by an interdisciplinary team are traditional, have substantial empiric and anecdotal support, and have been assessed and ultimately codified by three large, expert, consensus-building conferences. Although high level evidence supporting the rationale for interdisciplinary treatment of CRPS is fairly sparse (as it is for any treatment of CRPS), much stronger evidence exists for the efficacy of the interdisciplinary approach in other pain conditions, such as chronic low back pain. That functional restoration can and should be the central intervention and outcome standard in CRPS is a theory that must be tested. Until then, the interdisciplinary approach for treating patients with CRPS remains the most pragmatic, helpful, and cost-effective therapeutic approach available today.
A Sample, Stepwise, Functional Restoration Algorithm
Step 1 |
Reactivation
Contrast Baths
Desensitization
Exposure Therapy
|
Step 2 |
Flexibility
Edema Control
Isometric Strengthening
Correction of Postural Abnormalities
Diagnosis and Treatment of Secondary Myofascial Pain
|
Step 3 |
Range of Motion (ROM) (gentle)
Stress Loading
Isotonic Strengthening
General Aerobic Conditioning
Postural Normalization & Balanced Use
|
Step 4 |
Ergonomics
Movement Therapies
Normalization of Use
Vocational/Functional Rehabilitation
|
From the outset, in appropriate cases, the patient should have access to medications and/or psychotherapy and/or injections. If the patient cannot begin, or fails to progress, at any step or in any regard, the clinical team should consider starting (or adding) more or stronger medications (see Pharmacotherapy below) and/or more intensive psychotherapies (see Psychological Interventions below) and/or different interventions (see Interventional Therapies below).
Pharmacotherapy
Pharmacotherapy Guide. The Following Strategies Are Suggested for Patients Who Have Been Diagnosed with CRPS but Who Cannot Begin or Progress in the Functional Restoration Algorithm *:
Reason for inability to begin or progress |
Action |
Mild-to-moderate pain |
Simple analgesics and/or blocks (see section 5 in the original guideline document) |
Excruciating, intractable pain ** |
Opioids and/or blocks or later, more experimental interventions (see section 5 in the original guideline document) |
Inflammation/swelling and edema |
Steroids, systemic or targeted (acutely) or non-steroidal anti-inflammatory drugs (NSAIDs) (chronically); immunomodulators |
Depression, anxiety, insomnia |
Sedative, analgesic antidepressant/anxiolytics and/or psychotherapy (see section 3 in the original guideline document) |
Significant allodynia/hyperalgesia |
Anticonvulsants and/or other sodium channel blockers and/or N-methyl-D-aspartate (NMDA)-receptor antagonists |
Significant osteopenia, immobility trophic changes |
Calcitonin or bisphosphonates |
Profound vasomotor disturbance |
Calcium channel blockers, sympatholytics and/or blocks (section 5 in the original guideline document) |
*It is important to remember that these suggestions are overruled by individual patient presentation.
**It is also important to not that certain drugs, such as biphosphonates, may be associated with analgesia as well as the more primary action.
A methodical, patient approach to pharmacotherapy in CRPS is essential. To attempt to identify prominent mechanisms involved in the pain generation, and to try to match drug mechanisms of action to these is the sine qua non of the drug therapy of CRPS. It is often necessary to use more than one drug, or "rational polypharmacy," and the goal is often as much to relieve the pain as to allow progress in interdisciplinary rehabilitation. This is theoretically the best hope for comprehensive management of the syndrome, as drug therapy alone is never enough.
In most cases, no single drug will provide sufficient analgesia long term, nor will it completely prevent the need for abortive/rescue agents. This clinical reality usually requires two or even multiple medications to adequately manage the pain. Thus, the problem of drug-drug interaction is critical to consider, but unfortunately the literature is very weak in this regard. The traditional sources of information, such as the Physician's Desk Reference®, are somewhat helpful, but it is important to consider competitive metabolic or catabolic pathways, such as the liver cytochrome P450 catabolic systems. For instance, the 2D6 enzyme pathway catabolizes codeine, heterocyclic drugs, tramadol, mexiletine, and methadone (among others), and the prudent clinician would keep this in mind when combining these drugs. It is also important that if a drug-drug interaction is observed, this information should be reported and published.
Refer to the original guideline document for more information on individual drugs.
Psychological Interventions
There is no solid evidence that psychological factors are necessarily involved in the onset of chronic CRPS. However, there are theoretically plausible pathways through which psychological factors in some cases could affect the development of CRPS. Evidence is mixed that CRPS patients are in any way psychologically unique compared to other chronic pain patients, although the hypothesis that they are as a group more emotionally distressed has received some support. Once CRPS has developed, emotional factors may have a greater impact on CRPS pain intensity than in non-CRPS pain conditions, possibly through the impact of dysphoric psychological states on catecholamines. Meta-analytic reviews document the efficacy of various psychological interventions for many types of non-CRPS chronic pain, and suggest that such interventions are likely to be beneficial for CRPS patients as well. Adequate randomized controlled studies of psychological interventions in CRPS patients are not available to guide this aspect of CRPS management, although numerous uncontrolled studies suggest the likely utility of several approaches. These approaches include various forms of relaxation training, biofeedback, and cognitive and behaviorally focused interventions. Successful implementation of these interventions requires recognition of the unique issues in CRPS patients, particularly the pervasive learned (or centrally mediated) disuse often seen in such patients. Clinical experience using techniques like those described above in an integrated multidisciplinary context indicates that many CRPS patients can achieve significant improvements in functioning and ability to control pain.
Psychological Intervention Treatment Algorithm
Step 1 |
Patient and Family Education about CRPS
Pathophysiology (lay language)
Disuse Issues
Reactivation
Self-Management Focus
Possible Psychophysiological Interactions
If patient has chronic CRPS or acute CRPS unresponsive to initial treatments
|
Step 2 |
Psychological Evaluation
Comorbid Axis psychiatric disorders
Cognitive, behavioral, emotional response to CRPS
Ongoing life stressors
Responses of significant others to CRPS
|
Step 3 |
Psychological Pain Management Intervention
Relaxation training with feedback
Cognitive intervention
Reframing for active patient role
Challenge dysfunctional cognitions
Catastrophic cognitions
Inaccurate beliefs about CRPS or treatment
Cognitions underlying fear of movement
Practice constructive self-talk
Behavioral intervention
Realistic pain-limited incremental reactivation
Family intervention
Address barriers to reactivation
Increase constructive social support
|
Step 4 |
If Axis I disorders or major life stressors are identified, conduct focused cognitive behavioral therapy targeting these issues |
Interventional Therapies
With a new understanding of CRPS as encompassing both sympathetically independent pain (SIP) and sympathetically maintained pain (SMP) in varying degrees among different patients, sympatholysis remains an important diagnostic (SMP vs. SIP) and therapeutic modality (in the SMP subgroup). Because of the considerable difficulty in "clinically assessing" the successful sympathetic block, and because "clinically successful" blocks provide varying degrees of sympatholysis, the role of local anesthetic injection sympathetic blockade versus intravenous regional anesthesia (IVRA), intravenous (IV), or epidural sympatholysis is unknown and largely based on local practice patterns. Additionally, with the notable paucity of good quality supportive outcomes studies, the clinician is left to utilize these blocks or sympathectomy-inducing infusions within the context of a broad algorithm of interdisciplinary treatment, while awaiting further pathophysiological data and outcomes research to guide our practice to the most beneficial treatments.
The decision to proceed with radiofrequency (RF) ablative techniques versus other nondestructive alternatives is a complex one, with less evidence for the ablative versus augmentative treatments. Due to the adverse long-term post sympathectomy syndromes, this author currently recommends against surgical ablative sympathectomy. Future studies may expand on the role of pulsed RF (cold RF) techniques or such unstudied techniques as cryosurgery as alternative therapies to treat SMP.
Our recommended strategy (and tactic) is to use interventional treatments for CRPS patients who are having difficulty either starting or progressing in the functional restoration/interdisciplinary algorithm. If patients are not progressing because of high pain levels (especially associated with autonomic dysfunction), then a stepwise progression — from the less invasive blocks, to infusions or catheter infusion therapies, and ultimately perhaps to neurostimulation — is recommended in order to facilitate the patient's functional improvement and pain control. One suggested algorithm developed by an expert panel for the integrated use of these procedures is shown below and has been previously published.
Interventional Pain Treatment Algorithm for CRPS*
Step 1 |
Minimally Invasive Therapies
Sympathetic Nerve Blocks
Intravenous Regional Nerve Blocks
Somatic Nerve Blocks
|
Step 2 |
More Invasive Therapies
Epidural and Plexus Catheter Block(s)
Neurostimulation
Intrathecal Drug Infusion (e.g., Baclofen)
|
Step 3 |
Surgical and Experimental Therapies
Sympathectomy
Motor Cortex Stimulation
|
Inadequate or partial response to any given therapy should lead to a stepwise progression down through these modalities (moving from less to more invasive) in conjunction with other noninterventional treatments.
*Adapted from Stanton-Hicks M, Burton A, Bruehl S, et al. An updated interdisciplinary clinical pathway for CRPS: report of an expert panel. Pain Practice. 2002;2:1-16.