Title
Patterns of cortical reorganization parallel impaired tactile discrimination and pain intensity in complex regional pain syndrome.
Abstract
In the complex regional pain syndrome (CRPS), several theories proposed the existence of pathophysiological mechanisms of central origin. Recent studies highlighted a smaller representation of the CRPS-affected hand on the primary somatosensory cortex (SI) during non-painful stimulation of the affected side. We addressed the question whether reorganizational changes can also be found in the secondary somatosensory cortex (SII). Moreover, we investigated whether cortical changes might be accompanied by perceptual changes within associated skin territories. Seventeen patients with CRPS of one upper limb without the presence of peripheral nerve injuries (type I) were subjected to functional magnetic resonance imaging (fMRI) during electrical stimulation of both index fingers (IFs) in order to assess hemodynamic signals of the IF representation in SI and SII. As a marker of tactile perception, we tested 2-point discrimination thresholds on the tip of both IFs. Cortical signals within SI and SII were significantly reduced contralateral to the CRPS-affected IF as compared to the ipsilateral side and to the representation of age- and sex-matched healthy controls. In parallel, discrimination thresholds of the CRPS-affected IF were significantly higher, giving rise to an impairment of tactile perception within the corresponding skin territory. Mean sustained, but not current pain levels were correlated with the amount of sensory impairment and the reduction in signal strength. We conclude that patterns of cortical reorganization in SI and SII seem to parallel impaired tactile discrimination. Furthermore, the amount of reorganization and tactile impairment appeared to be linked to characteristics of CRPS pain.
Year
DOI
Venue
2006
10.1016/j.neuroimage.2006.03.045
NeuroImage
Keywords
Field
DocType
Functional magnetic resonance imaging,Complex regional pain syndrome,Tactile perception,Pain,Cortical reorganization
Tactile discrimination,Secondary somatosensory cortex,Neuroscience,Threshold of pain,Functional magnetic resonance imaging,Somatosensory evoked potential,Psychology,Somatosensory system,Neuroplasticity,Complex regional pain syndrome
Journal
Volume
Issue
ISSN
32
2
1053-8119
Citations 
PageRank 
References 
2
0.45
1
Authors
9