Complex regional pain syndromes

Abstract

Complex regional pain syndromes (CRPS) (formerly reflex sympathetic dystrophy and causalgia) are neuropathic pain conditions that are initiated by an extremity trauma or peripheral nerve lesion. Clinical definition and scientific understanding of CRPS are still evolving; however, both the clinical picture and therapeutic options are significantly influenced by a dysfunction of the sympathetic nervous system. Recent investigations suggest functional central abnormalities and a peripheral inflammatory component in the pathophysiology of CRPS. Interdisciplinary treatment includes physical, pharmacologic, and invasive interventional therapy, as well as stimulation techniques.

Challenges in the development of novel treatment strategies for neuropathic pain

“…8 CPRS-II is defined by spontaneous pain and hyperalgesia or allodynia, along with the presence, or evidence of previously present, edema, abnormal blood flow, and autonomic, trophic, or sudomotor abnormalities, and is distinguished from type I by the clear indication of nerve trauma. 1,7,8,13 The signs and symptoms of CPRS-I are the same as those of CPRS-II, except that there is no verifiable damage to a peripheral nerve. 1,7,9,10 By definition, it is precipitated by a noxious event that might include fractures, joint sprains, strains, thoracic surgery, soft tissue injury, and cardiac ischemia.…”

“…1,7,8,13 The signs and symptoms of CPRS-I are the same as those of CPRS-II, except that there is no verifiable damage to a peripheral nerve. 1,7,9,10 By definition, it is precipitated by a noxious event that might include fractures, joint sprains, strains, thoracic surgery, soft tissue injury, and cardiac ischemia. [5][6][7]14 Idiopathic CRPS-I has been described as sequella to noxious events so trivial patients may not remember the occurrence, and include venipuncture, lacerations, and other types of minor trauma.…”

“…6 It has been reported that sympathetic blockade, including complete surgical sympathectomy, permanent chemical sympathectomy with phenol, or systemic sympatholytics abolish both the adverse pain condition and the trophic changes, especially when performed soon after the insult. 6,7 Although previously expressed as an independent form of neuropathic pain, it is now recognized that sympathetically maintained pain may be a component of neuropathic pain in some, but not all, patients, regardless of the initiating factor. A sympathetic component has been described in neuralgias including postherptic neuralgia (PHN), metabolic neuropathies, and phantom limb pain.…”

“…1,7,9,10 By definition, it is precipitated by a noxious event that might include fractures, joint sprains, strains, thoracic surgery, soft tissue injury, and cardiac ischemia. [5][6][7]14 Idiopathic CRPS-I has been described as sequella to noxious events so trivial patients may not remember the occurrence, and include venipuncture, lacerations, and other types of minor trauma. 6,7 Because of the absence of verified injury, the inclusion of CPRS-I as a neuropathic pain state has been challenged.…”

“…[5][6][7]14 Idiopathic CRPS-I has been described as sequella to noxious events so trivial patients may not remember the occurrence, and include venipuncture, lacerations, and other types of minor trauma. 6,7 Because of the absence of verified injury, the inclusion of CPRS-I as a neuropathic pain state has been challenged. 15 However, it has been strongly argued that the symptomology is consistent with neuropathic pain, and that the signs and symptoms, and not the etiology of the condition, should drive the therapeutic options.…”