Quantitative sensory testing in the German Research Network on Neuropathic Pain (DFNS): Standardized protocol and reference values

Abstract

The nationwide multicenter trials of the German Research Network on Neuropathic Pain (DFNS) aim to characterize the somatosensory phenotype of patients with neuropathic pain. For this purpose, we have implemented a standardized quantitative sensory testing (QST) protocol giving a complete profile for one region within 30 min. To judge plus or minus signs in patients we have now established age- and gender-matched absolute and relative QST reference values from 180 healthy subjects, assessed bilaterally over face, hand and foot. We determined thermal detection and pain thresholds including a test for paradoxical heat sensations, mechanical detection thresholds to von Frey filaments and a 64 Hz tuning fork, mechanical pain thresholds to pinprick stimuli and blunt pressure, stimulus/response-functions for pinprick and dynamic mechanical allodynia, and pain summation (wind-up ratio). QST parameters were region specific and age dependent. Pain thresholds were significantly lower in women than men. Detection thresholds were generally independent of gender. Reference data were normalized to the specific group means and variances (region, age, gender) by calculating z-scores. Due to confidence limits close to the respective limits of the possible data range, heat hypoalgesia, cold hypoalgesia, and mechanical hyperesthesia can hardly be diagnosed. Nevertheless, these parameters can be used for group comparisons. Sensitivity is enhanced by side-to-side comparisons by a factor ranging from 1.1 to 2.5. Relative comparisons across body regions do not offer advantages over absolute reference values. Application of this standardized QST protocol in patients and human surrogate models will allow to infer underlying mechanisms from somatosensory phenotypes.

Low pressure pain thresholds are associated with, but does not predispose for, low back pain

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The International Spinal Cord Injury Pain Basic Data Set

“…Neuropathic pain following SCI is often associated with evoked pain, such as allodynia or hyperalgesia 4 and examination of sensory abnormalities is therefore an important complement to the verbal assessment. 5,6 However, it is presently not possible to accurately link particular pain features to specific mechanisms. Because many of the pain types experienced after an SCI are relatively refractory to treatments, pain often persists and can even worsen over time 7 and interfere with cognitive, emotional and physical functioning.…”

Investigation of sensory thresholds in Cavalier King Charles Spaniels with and without Chiari‐like malformations and syringomyelia

“…However, a lack of association between normal dogs and dogs with chronic pain also has been noted using von Frey techniques 23. Additionally, vibration testing is used in humans with SM15 and neuropathic pain, as another form of mechanical stimulation 34. No data have been reported on vibration testing in dogs and this approach may be considered for future work.…”