rasha s. jabri , md dubai anesthesia march 2012 tawam hospital-jhmi al ain abu dhabi, uae
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When is it Reasonable to Speak about CRPS?. Rasha S. Jabri , MD Dubai Anesthesia March 2012 Tawam Hospital-JHMI Al Ain Abu Dhabi, UAE. History. American Civil War: GSW near neves 1864 : term “causalgia” long years final reminder of the battle-field - PowerPoint PPT PresentationTRANSCRIPT
Rasha S. Jabri , MD
Dubai Anesthesia March 2012Tawam Hospital-JHMI Al Ain Abu Dhabi, UAE
When is it Reasonable to Speak about CRPS?
History
• American Civil War: GSW near neves
• 1864 : term “causalgia” long years final reminder of the battle-field
• Dr. Sudeck: trivial injuries result in osteoporotic changes near the site of injury (Sudeck’s atrophy)
History
• Rene Leriche : sympathetic nervous system as a mediating factor in the condition
• “Reflex sympathetic dystrophy” (RSD)
• Since the early descriptions of this painful condition many names have been applied to the syndrome
Terms for CRPS
• •Algodystrophy • •Algoneurodystrophy • •Causalgia • •Post-traumatic pain syndrome • •Post-traumatic dystrophy • •Post-traumatic osteoporosis • •Reflex sympathetic dystrophy • •Shoulder-hand syndrome • •Sudeck’s atrophy
Classification
• 1986 (IASP) formal description and classification of RSD but NO clear diagnostic criteria, NO specific underlying mechanisms.
• Many neuropathic pain conditions were included in the diagnosis of RSD, specifically those resistant to traditional treatments
Classification
• 1994 IASP new taxonomy of complex regional pain syndrome (CRPS), which would more accurately describe RSD and causalgia.
• New diagnostic criteria for CRPS which focused on clinical diagnosis from patient history, symptom description, physical signs and pain.
Classification
• CRPS : inciting events:– type I =RSD, follows a soft tissue injury – CRPS II= (causalgia) follows a well-defined
nerve injury
CPRS
• syndrome including,– complexity of the varied presentations– regionally, symptoms, which are typically non-
dermatomal– pain, usually out of proportion to the inciting trauma– syndrome, denoting the constellation of signs and
symptoms
• varied contribution of the sympathetic nervous system
Epidemiology•Overall incidence of CRPS to be 26.2 per 100,000 person
•CRPS I to be 5.46 per 100,000 person years at risk and a prevalence of 20.57 per 100,000.
• The incidence of CRPS II has been reported at 0.82 per 100,000 person years at risk and prevalence of 4.2 per 100,000 person years.
Risk Factors
• Extremities trauma/MVA↑
• Surgeries/Orthopedic↑( Knee, Ankle, CTS)
• Stroke, or unknown cause very rare
• Most cases between 50 and 70 years of age
• CRPS female predominance: 2.0-3.5:1.13
• Mainly Caucasian
Pathophysiology
• Theories peripheral mechanisms as well as central mechanisms for CRPS.
• In CRPS II biochemical, morphological (structural) and physiological changes of the injured and adjacent intact primary afferent neurons may occur
CPRS II
• The loss of DRG cells degeneration of the centrally projecting afferent axons and to denervation of dorsal horn neurons
• Secondary changes in the central representations changes in central representations (in the spinal cord, brain stem, thalamus and forebrain)
CPRS I• CRPS I central representations of the sensory,
autonomic, and somatomotor systems account for the clinical presentation in CRPS
• CRPS, particularly type I, is a systemic disease of neuronal systems: somatosensory, sympathetic, somatomotor, and peripheral (vascular, inflammatory) systems
Pathophysiology• Marked increase in alpha 1 adrenoreceptors which
appears in the injured extremity: skin muscle and nerve tissue
• Augment depolarization in nerve and muscle tissue resulting in an amplification effect of any stimuli
• Increase in pain w increase in either endogenous or exogenous catecholamines.
.
Tissue damage initiates a number of alterations of the peripheral and the
central pain pathways
Dahl, J. B. et al. Br Med Bull 2004 71:13-27; doi:10.1093/bmb/ldh030
Bruehl S. An Update on the Pathophysiology of CRPS Anesthesiology .September 2010;113(3):713-725
Bruehl S. An Update on the Pathophysiology of CRPS Anesthesiology .September
2010;113(3):713-725
Speculative Model of InteractingPathophysiologic Mechanisms in CRPS
Clinical Stages
• Classically: three distinct sequential progressive stages
• Disputes the traditional staging of CRPS
• Subtypes/subgroups exist in CRPS
Clinical Stages (Bonica)
I warm acute CRPS pain, sensory abnormalities, hyperalgesia, allodynia, vasomotor dysfunction, edema and sudomotor disturbance.
II (dystrophic stage) 3 to 6 mons more pain/sensory dysfunction and vasomotor dysfunction, with significant motor/trophic changes.
III (atrophic stage) cold extremity with decreased pain/sensory disturbance, continued vasomotor disturbance, increased motor/trophic changes.
General definition
• An array of painful conditions regional pain disproportionate in time or degree to the usual course of any known dz
• Regional: not in a specific nerve territory or dermatome usually has a distal predominance of abnormal sensory, motor, sudomotor, vasomotor, and/or trophic findings.
IASP CRPS subgroups NOT Sequential stages
(1) Relatively limited syndrome with vasomotor signs predominating
(2) Relatively limited syndrome with neuropathic pain/sensory abnormalities predominating
(3) Florid CRPS syndrome similar to ‘‘classic RSD’’ descriptions
Pattern and Spread
32. IE, et al. Signs and symptoms of reflex sympathetic dystrophy: prospective study of 829 patients. Lancet 1993;342:1012-1016.
Veldman PH.Signs and symptoms of RSD: prospective study of 829 patients. Lancet 1993;342:1012-1016.
Clinical Features
• CPRS is a painful and debilitating disorder primarily affecting one or more extremities.
key features
• Spontaneous pain, allodynia, hyperalgesia, edema, temperature change, abnormal vasomotor and sudomotor activity, trophic changes, and motor dysfunction
IASP
Diagnostic criteria to establish the diagnosis of CRPS (type I):
(1) initiating noxious event or immobilization
(2) continuing pain, allodynia, or hyperalgesia with pain disproportionate
(3) Edema, changes in skin blood flow, or abnormal sudomotor activity
• (4) the exclusion other medical conditions
CPRS II IASP
(1) continuing pain, allodynia, or hyperalgesia after an nerve injury
(2) Edema, changes in skin blood flow, or abnormal sudomotor activity
• (3) the exclusion other medical conditions
Sudomotor Changes & Edema
Trophic Changes
Trophic Changes
Conclusions and Clinical Implications
• IASP standardized, common methodology for making DX of CRPS or not
• Treatment for two distinct conditions
• CRPS and non-CRPS neuropathic
pain groups
IASP_
• Controversy about the value of consensus-based
dx criteria
• Absence of evidence-based information
• Necessity of validating in light of systematic validation research
Harden RN. Proposed new diagnostic criteria for CRPS. Pain Med. May-Jun2007;8(4):326-331
CRPS DX ?????
• “looser” vs “tighter” criteria?!!
• Validity dx of the criteria ?
• Sensitivity vs Specificity?
Harden RN. Proposed new diagnostic criteria for CRPS. Pain Med. May-Jun2007;8(4):326-331
IASP/CRPS dx Criteria
Adequately Sensitive
(rarely miss a case of actual CRPS)
Problems of overdiagnosis due to Poor Specificity
Harden RN. CRPS : Are the IASP diagnostic criteria valid and sufficiently comprehensive? Pain 1999;83:211–9
Harden RN. Proposed new diagnostic criteria for CRPS. Pain Med. May-Jun2007;8(4):326-331
• The modified criteria requires the presence of both for CRPS diagnosis
Objective Objective signs on PE signs on PE
Subjective Subjective symptomsymptom
Clinical DiagnosticCriteria by the Budapest group
• 2/4 sign categories and ¾ symptom categories for diagnosis
• Sensitivity of 0.85
• Specificity of 0.69
• Clinical vs research purposes2/4+4/4 more sensitivity and specificity around 80, 90%
Diagnostic Examination
• No single objective test for diagnosis
• Diagnostic tests may assist in determining the likelihood of the syndrome
Diagnostic Examination
• Sympathetic Blockade – sympathetically maintained pain or sympathetic
independent pain
• Skin Temperature Measurement – Infrared thermography– Difference of more than 2.2°C has a sensitivity
of 76% and a specificity of 93% for diagnosis of CRPS
Quantitative Autonomic Function Testing
– The quantitative sudomotor axon reflex test (QSART)
– difference in sweat production between an affected extremity and an unaffected extremity
– QSART test may help predict response to sympathetic block
– Research needs to be conducted to further assess the utility of the test
Vasomotor Testing
– Acute CRPS increase in vascular flow to the affected extremity secondary to neurogenic inflammation
– Decrease in sympathetic activity at the extremity
– Measured by doppler flowmetry – Additional studies to assess the utility in the
diagnosis of CRPS
Trophic Change Measurement
• Chronic CRPS present with changes in skin, nails or bone
• Evaluation of trophic changes to the bone by triple-phase bone scintigraphy has been used to substantiate the diagnosis of CRPS, although distinguishing between CRPS and acute trauma may difficult
Therapy
Pharmacological Therapy
– Antidepressants (tricyclic & dual inhibitors) are effective agents for treating a variety of neuropathic pain condition
– SSRI + DPNP, PHN? CRPS
• Anticonvulsants (Antiepileptics) – The gabapentinoid group of drugs, gabapentin
(GBP) and pregabalin (PGB), are the most commonly used antiepileptics drugs (AEDs) for CRPS
• Opioids – There are no long-term studies– Considered in CRPS if pain limits the patient’s
participation in physical restorative therapies– Fent Patch VAS↓, fx (Agarwal, Pain Med 2007)
• Calcium Regulating Medications (Bisphosphonates)
• Effective agents for the treatment of CRPS– Mechanism of action is unknown– (alendronate, pamidronate, clodronate)– May inhibit bone resorption and their
effectiveness have been confirmed in randomized controlled studies
– Manicourt (Arthritis Rheum 2004)
• Calcitonin– Thyroid gland, inhibit osteoclastic bone
resorption – Gobelet ( Pain 1992)– Intranasal calcitonin in 63 pts with CRPS in a
double-blind randomized study – Significant reduction in pain at rest and with
motion and increased mobility – Meta-analysis_Perez concluded that calcitonin
could provide effective pain relief in CRPS patients (J Pain Symptom Manage 2001)
Free Radical Scavenger
• Dimethylsulfoxide (DSMO)
• N-acetylcysteine (NAC)
• Effective in treating CRPS• Perez (Pain 2003)
Interventional Procedures
• Sympathetic Nerve Blockade – Diagnosis and treatment for CRPS
• Epidural Infusion – local anesthetic and opioid – fluoroscopic guidance catheter tip on the
affected side at the appropriate spinal segmental level
– Tunneled 5 days to 12 wks physiotherapy
Neuromodulation
• Only one in five CRPS patients is capable of returning to a normal level of functioning
• Spinal cord stimulation (SCS) is an intervention modality that may be used in patients with refractory pain
• Symptoms of CRPS have been ranked the second most frequent indicator for SCS therapy in the USA after post-laminectomy pain syndrome
SCS
• Pain relief as high as 70%
• when conservative therapies fail
• Kemler (J Neurosurg 2008)
• -------------------long term effect
• Harke (Eur J Pain 2005)
Intrathecal Drug Delivery
• Data citing the benefits is limited
• Case reports/series
• Viable consideration for patients that do not respond to SCS or w multiple sites of pain
• Alternatively ziconitide a nonopioid analgesic, has shown some promise in the treatment of severe chronic nonmalignant pain, including CRPS
Summary
• CRPS is a painful and debilitating disorder primarily affecting one or more extremities
• No specific etiology identified
• ? underlying pathophysiology
• Difficulties in diagnosis and treatment
• No single diagnostic test or a single or combination of therapies that are universally effective for CRPS
Conclusions
• Treatment of CRPS focuses on an early aggressive multimodal approach targets pain reduction and functional restoration
• Medications CRPS are approved for the treatment of other pain conditions
• Continued research may reveal additional mechanisms of the disease leading to preventive measures and additional targets for drug activity