Quantitative Sensory Testing (QST) - Does assessing ... - TI Pharma

5. QST in patients with tendinopathy
are adequate (Visentini et al 1998; Zwerver et al 2009).
Healthy control athletes were recruited from local sports clubs and through
advertisements on websites. Inclusion criteria for participation of this study were a
VISA-P score had to be above 90. All subjects were asked neither to take analgesics
24h before participation in the study nor to take part in sport activities on the day
of the study. Subjects with diseases or conditions associated with possible altered
somatosensory function, such as a knee surgery, diabetes, fibromyalgia or neurological
diseases were excluded. All participants signed an informed consent prior to their
inclusion QST testing was approved by the Medical Ethical Commission (Stichting
Beoordeling Ethiek Bio-Medisch Onderzoek Assen, The Netherlands).
2.2. Quantitative Sensory Testing
QST entails the measurement of the subjects’ responses to standardized thermal and
mechanical stimuli. QST is used to determine detection, disappearances and pain
thresholds. The German Research Network on Neuropathic Pain – DFNS has developed
a standardized QST protocol. This protocol consists of 7 different tests that measure
13 parameters, including various types of mechanical and thermal detection and pain
thresholds for the hand, foot and face (Rolke et al 2006a). QST was performed by
two research nurses, who had undergone a comprehensive training at the DNFS in
Germany. All tests were performed in the same research facility. Thermal QST tests
were performed using the Medoc Pathway System (Medoc, Israel) and consisted of
threshold assessments for warm and cold detection (WDT, CDT) and heat pain and
cold pain (HPT, CPT). Thermal measurements were obtained with ramped stimuli (1
˚C/s) that were terminated when the subject pressed a button. Minimal and maximal
temperatures were 0 and 50 ˚C. The baseline temperature was 32 ˚C. In addition, subjects
were asked about paradoxical heat sensations (PHS) during the thermal sensory limen
(TSL) procedure of alternating warm and cold stimuli.
Mechanical QST tests consisted of seven different parameters. The mechanical
detection threshold (MDT) was determined with a standardized set of modified von
Frey filaments (Optihair2-Set, Marstock Nervtest, Germany). The mechanical pain
threshold (MPT) was measured using a set of seven pinprick devices with fixed stimulus
intensities that exerted forces of 8, 16, 32, 64, 128, 256, and 512 mN. Mechanical pain
sensitivity (MPS) was assessed using the same set of seven weighted pinprick stimuli
to obtain a stimulus–response function for pinprick-evoked pain. Dynamic mechanical
allodynia (DMA) was assessed as part of the test above, using a set of three light tactile
stimulators as dynamic innocuous stimuli: cotton wisp, cotton wool tip fixed to an
elastic strip and a standardized brush (SENSElab No.5 Somedic, Sweden). Vibration
disappearance threshold (VDT) was performed with a Rydel–Seiffer graded tuning
fork (64 Hz, 8/8 scale) that was placed on the patellar tendon; the vibration is graded
from 0 to 8 (max). The wind up ratio (WUR) test was assessed with a pinprick intensity