Mechanism-based treatment in complex regional pain syndromes

• Published in: Nature reviews. Neurology Vol. 10; no. 9; pp. 518 - 528
• Main Authors: Gierthmühlen, Janne, Binder, Andreas, Baron, Ralf
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-09-2014; Nature Publishing Group
• Subjects: 692/1807/1447; 692/1807/410; 692/420/256; 692/699/375/1692; Care and treatment; Complex regional pain syndromes; Complex Regional Pain Syndromes - drug therapy; Complex Regional Pain Syndromes - physiopathology; Ganglionic Blockers - therapeutic use; Humans; Medicine & Public Health; Neurology; Occupational Therapy; Pain; Pathogenesis; Patients; Physical Therapy Modalities; Psychotherapy; review-article
• ISSN: 1759-4758; 1759-4766
• DOI: 10.1038/nrneurol.2014.140

Key Points
Complex regional pain syndromes (CRPS) are multifactorial disorders; the heterogeneity of clinical signs and symptoms reflects different underlying pathophysiological mechanisms
Peripheral mechanisms of CRPS include inflammation, peripheral sensitization and sympatho-afferent coupling
Central mechanisms include neuroplastic changes, such as cortical reorganization, afferent–efferent feedback conflicts and central autonomic dysregulation
Individual variation in pathophysiological mechanisms offer the opportunity for several mechanism-based treatment options
To date, only a few clinical trials have assessed the long-term efficacy of therapies specifically for CRPS
In complex regional pain syndromes (CRPS), pain—typically of neuropathic type—in the affected limb is accompanied by a variety of sensory, motor and autonomic signs and symptoms. Treatment for CRPS has been largely adapted from therapies for neuropathic pain states, but a better understanding of CRPS pathologenesis might provide opportunities for mechanism-based treatment. Here, the authors discuss available and emerging mechanism-based treatments in CRPS, including pharmacotherapy targeting central and peripheral sensitization and aberrant inflammatory response; sympathetic ganglion block interventions; and alleviation of symptoms by reversing body perception disturbances.
Complex regional pain syndromes (CRPS) are multifactorial disorders with complex aetiology and pathogenesis. Management of CRPS is challenging, partly because of a lack of clinical data regarding the efficacy of the various therapies, and partly because successful treatment of CRPS requires a multidisciplinary, patient-tailored approach. The pain in CRPS is often described as typical 'burning' neuropathic pain, and is accompanied by a variety of sensory, motor and autonomic signs and symptoms. Because research into therapies specifically in CRPS has been scarce, treatment for these syndromes has been largely based on therapeutic strategies adapted from neuropathic pain states; however, increased understanding of the pathogenesis of CRPS has provided the opportunity to develop mechanism-based treatments. The interactions between the multiple pathophysiological mechanisms that contribute to the development, progression and maintenance of CRPS remain poorly understood. This Review describes the challenges in linking the current theories and knowledge of pathophysiological mechanisms to the mode of actions of the different treatment approaches. We discuss the current treatment strategies for CRPS, including pharmacotherapy, sympathetic ganglion block interventions, psychological support, physiotherapy and occupational therapy, and establish the concept of mechanism-based treatment for CRPS.