Correlation between quantitative sensory testing and questionnaires on neuropathic pain for chronic ischemic pain in peripheral arterial disease

A neuropathic component to chronic ischemic pain in peripheral arterial disease (PAD) has recently been shown using quantitative sensory testing (QST) and pain questionnaires. The aim of this study was to examine correlations between QST and pain questionnaires in patients with chronic ischemic pain. A total of 10 patients with severe PAD (Fontaine stages III and IV) without diabetes mellitus answered a questionnaire and were examined with QST. The questionnaire consisted of several validated instruments which were used to examine the intensity of pain, quality of pain and neuropathic pain (VAS, SF-MPQ, S-LANSS, NPSI). The results of the QST confirmed previously published data. Several terms of the SF-MPQ showed a correlation with parameters of the QST, such as Allodynia (QST) which correlated with the term tender (SF-MPQ) (Spearman's correlation coefficient 0.911; p< or =0.001) and the NPSI subscore evoked pain correlated with the QST parameter wind-up ratio (0.683; p=0.042). The results suggest that there might be correlations between psychophysical tests (QST) and pain questionnaires. Subjective perceptions of pain might be represented by a certain pattern in the QST. These connections could contribute to further clarify the pathophysiologic mechanisms leading to the perception of pain.