Wherever Is My Arm? Impaired Upper Limb Position Accuracy in Complex Regional Pain Syndrome

Date
2010
Authors
Lewis, JS
Kersten, P
McPherson, KM
Taylor, GJ
Harris, H
McCabe, CS
Blake, DR
Supervisor
Item type
Journal Article
Degree name
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier Inc.
Abstract

Knowledge of the position of one’s limbs is an essential component of daily function and relies on complex interactions of sensorimotor body schema-related information. Those with Complex Regional Pain Syndrome (CRPS) express difficulty in knowing where their affected limb is positioned. The aim of this study was to determine the degree to which experimental data supported the reported difficulty in limb position sense. A controlled experimental design was used to measure upper limb position accuracy amongst those with CRPS of one arm. Position accuracy was individually measured in both arms and compared to a known target position. Video captured each of 36 trials (half with arm in full view and half with vision obscured). The error in degrees between actual and known targets was determined using video analysis software. The Brief Pain Inventory measured pain. A subjective mental image representation of both upper limbs was documented. The CRPS group had moderate pain intensity and were significantly less accurate in positioning both the affected and unaffected limbs compared to controls (p<0.001). Position accuracy of the CRPS affected limb significantly improved with vision (8.3° in view, 10.7° not in view). Subjective mental representations of the affected limb were visualised as distorted. Evidence of bilateral arm positioning impairments in unilateral arm CRPS suggests that central mechanisms are involved. Cortical reorganisation in regions associated with the body schema (i.e. primary somatosensory and parietal cortices) is proposed as an explanation. The exact relationship between pain and limb position deficits requires further exploration.

Description
Keywords
Complex Regional Pain Syndrome , Reflex Sympathetic Dystrophy , Pain , Limb position sense , Limb position accuracy , Proprioception , Motor control , Experimental design , Vision , Body perception disturbance , Mental body representation , Central mechanisms
Source
Pain, vol.149(3), pp.463 - 469
Rights statement
Copyright © 2010 Elsevier Ltd. All rights reserved. This is the author’s version of a work that was accepted for publication in (see Citation). Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. The definitive version was published in (see Citation). The original publication is available at (see Publisher's Version)