QST in Context With Conditioned Pain Modulation (CPM)
Conditioned Pain Modulation (CPM) is a phenomenon which isn't examined enough. Many factors of influence such as gender, age and psyche are already known - but the duration of such effects, their reliability and the correlation between standardized Quantitative Sensory Testing (QST) and CPM is still unknown.
In this study the investigators expect to find parameters in QST that correlate with the efficacy of Conditioned Pain Modulation. Knowing factors that indicate high or low potential CPM could help finding patients-at-risk and adapting their therapy.
|Healthy||Procedure: Quantitative Sensory Testing Procedure: Conditioned Pain Modulation Procedure: Repetition of four QST parameters|
|Study Design:||Observational Model: Case-Only
Time Perspective: Prospective
|Official Title:||Quantitative Sensory Testing in Context With Conditioned Pain Modulation (CPM)|
|Study Start Date:||May 2012|
|Study Completion Date:||December 2012|
|Primary Completion Date:||December 2012 (Final data collection date for primary outcome measure)|
26 healthy voluntary probands
Procedure: Quantitative Sensory Testing
following the standardized protocol of DFNS
Other Name: QSTProcedure: Conditioned Pain Modulation
test stimulus by hot thermode conditioned stimulus by cold water bath
Other Names:Procedure: Repetition of four QST parameters
Conditioned Pain Modulation was firstly found in rats by electrical stimulation of their spinal cord and called Diffuse Noxious Inhibitory Controls. In humans such experimental settings are impossible. That is why we need two noxious stimuli for provoking such an endogenous pain inhibition.
Before the CPM setting begins, we will investigate our 32 healthy probands by basic QST following the protocol of DFNS (German Research Network on Neuropathic Pain). This assessment helps us to create a sensory profile for every proband and to look for correlations between QST parameters and CPM efficacy. Then the CPM setting follows. In our experimental design we use a test stimulus (TS) on the dominant forearm by thermode (normally 45-47°C, depending on the pain rating, we need scores >NRS 60) and a conditioned stimulus (CS) on the other hand by cold water bath (10°C). Both stimuli must be rated on the numerical rating scale (NRS) 0-100 alone and in combination. A positive effect can be seen, if the difference between TS alone and TS in combination with CS is >0. To learn more about the duration of CPM effects we decided to repeat four QST parameters (cold detection threshold, warm detection threshold, mechanical detection threshold and mechanical pain threshold) within 30 minutes after finishing the CPM part to detect changes of time.
The whole study design will be repeated 24-72h hours later to increase the test-retest-reliability.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01618604
|Bergmannsheil, department for pain management|
|Bochum, Nordrhein-Westfalen, Germany, 44789|
|Study Director:||Christoph Maier, Prof. Dr. med||University hospital Bergmannsheil department of pain management|