Complex Interaction of Sensory and Motor Signs and Symptoms in Chronic CRPS

Volker Huge,Walter Magerl,Patrick Moehnle,Wibke Kaufhold,Antje Beyer,Shahnaz Christina Azad,Meike Lauchart,Gustav Schelling

doi:10.1371/journal.pone.0018775

Abstract

Spontaneous pain, hyperalgesia as well as sensory abnormalities, autonomic, trophic, and motor disturbances are key features of Complex Regional Pain Syndrome (CRPS). This study was conceived to comprehensively characterize the interaction of these symptoms in 118 patients with chronic upper limb CRPS (duration of disease: 43±23 months). Disease-related stress, depression, and the degree of accompanying motor disability were likewise assessed. Stress and depression were measured by Posttraumatic Stress Symptoms Score and Center for Epidemiological Studies Depression Test. Motor disability of the affected hand was determined by Sequential Occupational Dexterity Assessment and Michigan Hand Questionnaire. Sensory changes were assessed by Quantitative Sensory Testing according to the standards of the German Research Network on Neuropathic Pain. Almost two-thirds of all patients exhibited spontaneous pain at rest. Hand force as well as hand motor function were found to be substantially impaired. Results of Quantitative Sensory Testing revealed a distinct pattern of generalized bilateral sensory loss and hyperalgesia, most prominently to blunt pressure. Patients reported substantial motor complaints confirmed by the objective motor disability testings. Interestingly, patients displayed clinically relevant levels of stress and depression. We conclude that chronic CRPS is characterized by a combination of ongoing pain, pain-related disability, stress and depression, potentially triggered by peripheral nerve/tissue damage and ensuing sensory loss. In order to consolidate the different dimensions of disturbances in chronic CRPS, we developed a model based on interaction analysis suggesting a complex hierarchical interaction of peripheral (injury/sensory loss) and central factors (pain/disability/stress/depression) predicting motor dysfunction and hyperalgesia.

Highlights

Complex Regional Pain Syndrome (CRPS), mostly regarded as a neuropathic pain disorder, is typically evolving after a minor trauma of the limb [1]
It is still unclear to which degree the underlying pathophysiological mechanisms predict the clinical presentation of CRPS and the resulting outcome of the disease, recent studies suggest an interdependency between the clinical presentation, the underlying pathophysiology and possible consequences in terms of resulting impairments
Chronic CRPS was characterized by chronic pain at rest and during exercise, combined with substantially limited hand force and impaired motor function

Summary

Introduction

Complex Regional Pain Syndrome (CRPS), mostly regarded as a neuropathic pain disorder, is typically evolving after a minor trauma of the limb [1]. It has been suggested that the pathophysiological mechanisms of CRPS follow a distinct time course, with a preponderance of peripheral inflammation and beginning of small fiber degeneration in the acute phase, and progression of small fiber degeneration as well as central pathomechanisms dominating the chronic phase of the disease [13]. Many clinical studies focused on the characterization of different specific aspects of the disease, for example the degree of neurological changes or the description of motor impairments [15,16]. In order to expand the knowledge of clinical characteristics of chronic CRPS and the level of concomitant stress and depression, as well as to characterize the degree of resulting hand impairment and disability, this study was performed

Methods

Results

Conclusion