Ignite Creation Date:
2024-05-06 @ 5:01 PM
Last Modification Date:
2024-10-26 @ 2:20 PM
Study NCT ID:
NCT05161286
Status:
COMPLETED
Last Update Posted:
2022-04-08
First Post:
2021-08-12
Brief Title:
The Influence of Expectations Attention and the Test Paradigm on the Efficacy of the Pain Processing System
Sponsor:
University Ghent
Organization:
University Ghent
Study Overview
Official Title:
The Influence of Expectations Attention and Test Paradigm on the Efficacy of the Pain Processing System
Status:
COMPLETED
Status Verified Date:
2021-02
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
CPM_AWARE
Brief Summary:
Conditioned pain modulation CPM is the endogenous pain relief mechanism responsible for the pain-inhibits-pain phenomenon This mechanism can be activated experimentally and its efficiency evaluated by experimental pain tests According to the pain-inhibits-pain principle during such an experimental testing paradigm a painful test stimulus is typically applied followed by a conditioning stimulus The effect of the conditioning stimulus on the test stimulus is examined to determine whether or not the conditioning stimulus elicits an inhibitory effect With this study the investigators want to examine in pain-free adults whether and to what extend the efficacy of CPM is influenced by 1 attention focus versus distraction 2 intrinsic expectations pain reduction versus no change versus pain increase with regard to pain due to the CPM paradigm used and 3 the order of application of the test stimulus and conditioning stimulus sequential versus parallel paradigm
Detailed Description:
Despite the widespread use of CPM by researchers there is still no gold standard for conducting this test Both a sequential and a parallel application of the test stimulus and the conditioning stimulus are often used interchangeably and side by side In both paradigms the pain intensity or pain threshold of the test stimulus is first determined Subsequently in the parallel protocol the test stimulus is reapplied while simultaneously applying the conditioning stimulus In the sequential protocol the conditioning stimulus is applied first and after removing the latter stimulus the test stimulus is reapplied the CPM effect is visible up to 5 minutes after removal of the conditioning stimulus The difference between the initial and repeated test stimulus during or after conditioning is quantified to express the CPM effect
Even the publication of an expert opinion which decided in favor of the sequential paradigm has so far changed little in the use of the two paradigms In that same publication international CPM experts considered the sequential order purer than the parallel order as the results of the latter can be attributed to a shift of attention to the conditioning stimulus However this claim has little support from the literature Some researchers even argue that cognitive mechanisms such as attentional shift might be part of the underlying mechanism of the CPM effect Existing research also shows that CPM effectiveness is influenced by expectations For this previous studies conditioned test subjects by telling them in advance that the conditioning stimulus would reduce or increase pain However when the experimental CPM paradigm is used to investigate the effectiveness of the pain-inhibiting system no such suggestions are made However this does not preclude that when the test protocol is explained to the subject he or she does not create intrinsic expectations regarding the pain that is provoked However few studies have investigated this and the results of these studies are inconsistent and therefore do not allow conclusions to be drawn
The aim of this study is to compare a sequential protocol with a parallel protocol on the one hand and to measure the influence of expectations attention and distraction on the CPM effect on the other
In this study the test stimulus of the CPM measurement will consist of a mechanical stimulus applied with an analog algometer Force Dial model FDK 10 and 40 Push Pull Force Gage Wagner instruments Greenwich Connecticut on the Brachioradialis and Quadriceps muscle of the dominant side The pressure pain threshold will be determined and used as an outcome measure The conditioning stimulus consists of immersing the hand up to 10 cm above the wrist of the non-dominant side in warm water at a temperature of 455C for 6 minutes This temperature has been proven to be a reliable stimulus eliciting solid effects
At the time of testing the CPM measurement will therefore be performed four times each time with a small variation The order of the variations is determined at random There is a break of 10 minutes between each performance so that the effect of the previous performance has worn off The four variations of the CPM paradigm are the following
1 Sequential protocol the test stimulus is applied before and after the conditioning stimulus
2 Parallel protocol the test stimulus is applied before after and during immersion at minute 4
3 Focus protocol this protocol works like the sequential protocol In addition the subject will be asked to give a pain score from 0 no pain to 100 excruciating pain every 30 seconds during immersion thereby focusing on the conditioning stimulus
4 Distraction protocol this protocol works like the sequential protocol During the immersion attention will be diverted away from the conditioning stimulus by having the subject perform a cognitive test known as the Paced Auditory Serial Addition Test PASAT The latter implies that the subject must listen to an auditory series of numbers memorize them and add them
Before the actual test begins a familiarization moment will take place in which the subject becomes acquainted with the test and the conditioning stimulus by undergoing it for the first time There will also be a practice session of the PASAT at that time
Before the start of the CPM test two questionnaires are taken a general questionnaire assessing sociodemographic and health-related characteristics and the Hospital Anxiety and Depression Scale HADS which provides an indication of feelings of anxiety and depression that the subject might experience as such factors may have an influence ie known confounders on the CPM effect
Finally for each variation on the CPM paradigm it will be briefly explained what the protocol to be undergone entails This involves assessing the subjects expectations with regard to the related protocol The subject will have to indicate whether he she expects the immersion to have an influence on the pressure threshold measurement yes pain increase yes pain reduction no no effect If the participants answer yes the subjects are asked to quantify the expected impact by indicating how much more or less pressure is expected to be tolerated in percentages
This study has a cross-sectional design and the familiarization and the experimental CPM assessments take place during during a single test session of about 2 hours
Even the publication of an expert opinion which decided in favor of the sequential paradigm has so far changed little in the use of the two paradigms In that same publication international CPM experts considered the sequential order purer than the parallel order as the results of the latter can be attributed to a shift of attention to the conditioning stimulus However this claim has little support from the literature Some researchers even argue that cognitive mechanisms such as attentional shift might be part of the underlying mechanism of the CPM effect Existing research also shows that CPM effectiveness is influenced by expectations For this previous studies conditioned test subjects by telling them in advance that the conditioning stimulus would reduce or increase pain However when the experimental CPM paradigm is used to investigate the effectiveness of the pain-inhibiting system no such suggestions are made However this does not preclude that when the test protocol is explained to the subject he or she does not create intrinsic expectations regarding the pain that is provoked However few studies have investigated this and the results of these studies are inconsistent and therefore do not allow conclusions to be drawn
The aim of this study is to compare a sequential protocol with a parallel protocol on the one hand and to measure the influence of expectations attention and distraction on the CPM effect on the other
In this study the test stimulus of the CPM measurement will consist of a mechanical stimulus applied with an analog algometer Force Dial model FDK 10 and 40 Push Pull Force Gage Wagner instruments Greenwich Connecticut on the Brachioradialis and Quadriceps muscle of the dominant side The pressure pain threshold will be determined and used as an outcome measure The conditioning stimulus consists of immersing the hand up to 10 cm above the wrist of the non-dominant side in warm water at a temperature of 455C for 6 minutes This temperature has been proven to be a reliable stimulus eliciting solid effects
At the time of testing the CPM measurement will therefore be performed four times each time with a small variation The order of the variations is determined at random There is a break of 10 minutes between each performance so that the effect of the previous performance has worn off The four variations of the CPM paradigm are the following
1 Sequential protocol the test stimulus is applied before and after the conditioning stimulus
2 Parallel protocol the test stimulus is applied before after and during immersion at minute 4
3 Focus protocol this protocol works like the sequential protocol In addition the subject will be asked to give a pain score from 0 no pain to 100 excruciating pain every 30 seconds during immersion thereby focusing on the conditioning stimulus
4 Distraction protocol this protocol works like the sequential protocol During the immersion attention will be diverted away from the conditioning stimulus by having the subject perform a cognitive test known as the Paced Auditory Serial Addition Test PASAT The latter implies that the subject must listen to an auditory series of numbers memorize them and add them
Before the actual test begins a familiarization moment will take place in which the subject becomes acquainted with the test and the conditioning stimulus by undergoing it for the first time There will also be a practice session of the PASAT at that time
Before the start of the CPM test two questionnaires are taken a general questionnaire assessing sociodemographic and health-related characteristics and the Hospital Anxiety and Depression Scale HADS which provides an indication of feelings of anxiety and depression that the subject might experience as such factors may have an influence ie known confounders on the CPM effect
Finally for each variation on the CPM paradigm it will be briefly explained what the protocol to be undergone entails This involves assessing the subjects expectations with regard to the related protocol The subject will have to indicate whether he she expects the immersion to have an influence on the pressure threshold measurement yes pain increase yes pain reduction no no effect If the participants answer yes the subjects are asked to quantify the expected impact by indicating how much more or less pressure is expected to be tolerated in percentages
This study has a cross-sectional design and the familiarization and the experimental CPM assessments take place during during a single test session of about 2 hours
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
False
Is a FDA Regulated Device?:
False
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None