Quantitative sensory testing: a comprehensive protocol for clinical trials

Abstract

We have compiled a comprehensive QST protocol as part of the German Research Network on Neuropathic Pain (DFNS) using well established tests for nearly all aspects of somatosensation. This protocol encompasses thermal as well as mechanical testing procedures. Our rationale was to test for patterns of sensory loss (small and large nerve fiber functions) or gain (hyperalgesia, allodynia, hyperpathia), and to assess both cutaneous and deep pain sensitivity. The practicality of the QST protocol was tested in 18 healthy subjects, 21-58 years, half of them female. All subjects were tested bilaterally over face, hand and foot. We determined thermal detection and pain thresholds including a test for the presence of 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 (pain to light touch), and pain summation (wind-up ratio) using repetitive pinprick stimulation. The full protocol took 27+/-2.3 min per test area. The majority of QST parameters were normally distributed only after logarithmic transformation (secondary normalization) except for the frequency of paradoxical heat sensations, cold and heat pain thresholds, and for vibration detection thresholds. Thresholds were usually lowest over face, followed by hand, and then foot. Only thermal pain thresholds, wind-up ratio and vibration detection thresholds were not significantly dependent on the body region. There was no significant right-to-left difference for any of the QST parameters; left-to-right correlation coefficients ranged between 0.78 and 0.97, thus explaining between 61% and 94% of the variance. This study has shown that a complete somatosensory profile of one affected area and one unaffected control area, which will be necessary to characterize patients with a variety of diseases, can be obtained within 1 h. Case examples of selected patients illustrate the value of z-transformed QST data for an easy survey of individual symptom profiles.

Analgesic Effect of Transcranial Direct Current Stimulation on Central Post-Stroke Pain

“…The quantitative sensory test was also used, as it is a standard psychophysical test for evaluating the wide-ranging somatosensory perception adjusted by the actions of the small and large fibers, and it is known as a method for determining loss of function of the diverse somatosensory pathways (Rolke et al 2006;Bachmann et al 2010b). …”

Foot control in incomplete SCI: distinction between paresis and dexterity

“…Muscle strength was determined according to the six level scale of ASIA standards 8 . Spasticity was assessed by a modified Ashworth test 16 , and perception of vibration was assessed by a tuning fork at both the malleolus medialis and carpometacarpal joint of the first toe (64 Hz, 8/8 scale) 17 . Active and passive range of motion (ROM) was determined using an electric goniometer (Biometrics Ltd, Gwent, UK), with the sampling rate set at 1000 Hz.…”

Quantitative sensory testing somatosensory profiles in patients with cervical radiculopathy are distinct from those in patients with nonspecific neck–arm pain

“…As QST parameters may vary significantly over body areas, comparative HC reference data have to be obtained for all body regions that are examined in patients [58,44]. Reference data were obtained in 31 HC.…”

“…HC subjects were tested bilaterally in the C6 (n = 13) and C7 (n = 13) dermatome. All patients and 26 HC underwent QST on the dorsum of the foot ipsilateral to the symptomatic side as a remote control site [57,58]. In HC, the 'symptomatic' side was determined randomly by rolling a die.…”

“…Standardised QST was performed according to the QST protocol of the German Research Network on Neuropathic Pain (DFNS) [57,58] by one investigator (BT) in a laboratory with a constant room temperature. This protocol comprises all of the somatosensory submodalities that are mediated by different primary afferents (C-, Aδ-, Aβ-) as outlined in the following sections.…”