Elsevier

The Journal of Pain

Volume 12, Issue 10, October 2011, Pages 1095-1101
The Journal of Pain

Original Report
Impaired Hand Size Estimation in CRPS

https://doi.org/10.1016/j.jpain.2011.05.001Get rights and content
Under an Elsevier user license
open archive

Abstract

A triad of clinical symptoms, ie, autonomic, motor and sensory dysfunctions, characterizes complex regional pain syndromes (CRPS). Sensory dysfunction comprises sensory loss or spontaneous and stimulus-evoked pain. Furthermore, a disturbance in the body schema may occur. In the present study, patients with CRPS of the upper extremity and healthy controls estimated their hand sizes on the basis of expanded or compressed schematic drawings of hands. In patients with CRPS we found an impairment in accurate hand size estimation; patients estimated their own CRPS-affected hand to be larger than it actually was when measured objectively. Moreover, overestimation correlated significantly with disease duration, neglect score, and increase of two-point-discrimination-thresholds (TPDT) compared to the unaffected hand and to control subjects’ estimations. In line with previous functional imaging studies in CRPS patients demonstrating changes in central somatotopic maps, we suggest an involvement of the central nervous system in this disruption of the body schema. Potential cortical areas may be the primary somatosensory and posterior parietal cortices, which have been proposed to play a critical role in integrating visuospatial information.

Perspective

CRPS patients perceive their affected hand to be bigger than it is. The magnitude of this overestimation correlates with disease duration, decreased tactile thresholds, and neglect-score. Suggesting a disrupted body schema as the source of this impairment, our findings corroborate the current assumption of a CNS involvement in CRPS.

Key words

Complex regional pain syndrome
body schema
cortical reorganization
neuropathic pain
hand size

Cited by (0)

Supported by the German Research Network “Neuropathic Pain Syndromes” (German Federal Ministry of Education and Research, BMBF) and the German Research Foundation (DFG; KFO 130).