Evidence for local inflammation in complex regional pain syndrome type 1.
BACKGROUND
The pathophysiology of complex regional pain syndrome type 1 (CRPS 1) is still a matter of debate. Peripheral afferent, efferent and central mechanisms are supposed. Based on clinical signs and symptoms (e.g. oedema, local temperature changes and chronic pain) local inflammation is suspected.


OBJECTIVE
To determine the involvement of neuropetides, cytokines and eicosanoids as locally formed mediators of inflammation.


METHODS
In this study, nine patients with proven CRPS 1 were included. Disease activity and impairment was determined by means of a Visual Analogue Scale, the McGill Pain Questionnaire, the difference in volume and temperature between involved and uninvolved extremities, and the reduction in active range of motion of the involved extremity. Venous blood was sampled from and suction blisters made on the involved and uninvolved extremities for measurement of cytokines interleukin (IL)-6, II-1beta and tumour necrosis factor-alpha (TNF-alpha), the neuropetides NPY and CRGP, and prostaglandin E2


RESULTS
The patients included in this study did have a moderate to serious disease activity and impairment. In plasma, no changes of mediators of inflammation were observed. In blister fluid, however, significantly higher levels of IL-6 and TNF-alpha in the involved extremity were observed in comparison with the uninvolved extremity.


CONCLUSIONS
This is the first time that involvement of mediators of inflammation in CRPS 1 has been so clearly and directly demonstrated. This observation opens new approaches for the succesful use and development of immunosuppressives in CRPS 1.
Huygen
Frank J P M
FJ
Department of Anesthesiology, Erasmus Medical Centre, Rotterdam, The Netherlands. fhuygen@anes.azr.nl
De Bruijn
Anke G J
AG
De Bruin
Martha T
MT
Groeneweg
J George
JG
Klein
Jan
J
Zijlstra
Freek J
FJ
D001768:Blister / Q000378:metabolism; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000032:analysis / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D012019:Reflex Sympathetic Dystrophy / Q000209:etiology*
D018836:Inflammation Mediators