Pain measurement in reflex sympathetic dystrophy syndrome

The reflex sympathetic dystrophy syndrome (RSDS) consists of a triad of pain, edema and sympathetic dysfunction of an extremity following trauma, peripheral nerve injury or central nervous system disorder. Reflex sympathetic dystrophy syndrome is a difficult and costly pain syndrome to treat. One of the difficulties in evaluating treatment efficacy is the objectification and quantification of patient findings. The purpose of this investigation was to develop a simple, reproducible and systematic evaluation of pain and neurologic impairment in RSDS. The protocol evaluation included the following measures of pain and impairment: (1) objectification of distal joint pain by palpation (0-4 scale); (2) volumetric measurement by water displacement of the distal limb; (3) skin temperature measurement; (4) active range of motion assessment of the affected limb (AROM); (5) McGill Pain Questionnaire (MPQ); and (6) visual analogue pain scale (VAS). Seventeen subjects with definite or probable RSDS were evaluated. The mean age of patients was 35.6 years +/- 8.0 years (+/- 2 S.E.M.), and the mean duration of symptoms was 11.8 +/- 4.8 months. There were an equal number of subjects with upper and lower extremity involvement. The VAS had significant correlations with limb volume, AROM-lower extremity and joint pain indices (P less than 0.0005). The MPQ subscales had robust correlation with the joint pain indices alone (P less than 0.0001). Skin temperature was not predictive of changes in joint pain score, AROM, limb volume or subjective pain measures. However, there was internal consistency between volumetric and AROM measures and joint pain indices. This protocol is recommended for use in therapeutic trials for the treatment of the RSDS.