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Trial record 6 of 33575 for:    Placebo AND placebo effect

The Interaction Between Conditioned Pain Modulation and Expectation in Understanding the Placebo Effect of Pain Reduction

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ClinicalTrials.gov Identifier: NCT03484728
Recruitment Status : Active, not recruiting
First Posted : April 2, 2018
Last Update Posted : April 10, 2019
Sponsor:
Information provided by (Responsible Party):
Rambam Health Care Campus

Brief Summary:
The interaction between conditioned pain modulation and expectation in understanding the placebo effect of pain reduction

Condition or disease Intervention/treatment Phase
Healthy Behavioral: placebo manipulation Not Applicable

Detailed Description:

Conditioned pain modulation (CPM) has recently been coined for the psychophysical protocols that assess the functioning of descending pain inhibitory pathways in humans. There is a growing body of evidence points to the important role of spinal serotonin (5-HT) and noradrenaline (NA) in mediation of pain inhibition via CPM. On the other hand, there is also evidence on synergistic modulatory effect of the opioidergic control on CPM, however this issue is under debates. It seems therefore, that pre-treatment CPM assessment may be relevant for prediction of analgesic drug interaction and additive effects.

Placebo effects are inherent to every treatment and significantly contribute to clinical outcomes even in the presence of strong verum analgesic effects. From a psychological point of view, a series of recent studies supported the nature of the placebo effect as a learning phenomenon wherein verbally-induced expectations, cued and contextual conditioning or social learning are considered as the core mechanisms to produce a benefit. Placebo analgesic effects can be elicited by verbal instructions that generate anticipation for a benefit, thus creating expectations of analgesia. The effect of placebo is, primarily mediated by mu-receptors associated opioidergic neurotransmission. Alike brain structures activated by placebo manipulations, prefrontal cortex, cingulate cortex, PAG and RVM are the most important brain structures involved in initiating of opioid-mediated anti-nociception.

An interesting question that emerges is the extent of overlap between the serotono-noradrenergic analgesia represented by CPM, and opioidergic analgesia represented by expectation-based placebo manipulation, for pain reduction. It seems that the final pathway for the two systems is the descending analgesia tract(s). It is unclear, though, if such final common pathway dictates a limited analgesic effect, i.e., it can only be activated to a certain extent, regardless of which system activates it, and therefore additive effects of expectation and CPM are limited to a certain ceiling. Alternatively, different tracts of descending pain inhibition are activated by each system, and the analgesic effect is additive.

Cognitive cortical brain potentials (especially, a P300 waveform) evoked in response to a combination of rare and frequent innocuous sensory stimuli represent a neurophysiological tool for assessment attention. As this test bases on uncertainty and the expectation of upcoming stimuli, the recording of P300 may be relevant for evaluation cognitive processes associated with expectation-related placebo analgesia.

The main aim of this study is to explore the interaction between serotono-noradrenergic and opioidergic systems of analgesia in healthy subjects. More specifically, the investigator will study whether these two systems work in an additive or a complementary way, and whether the neurophysiological assessment of individual expectation capabilities can predict the placebo magnitude.


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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 35 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Intervention Model Description: CPM was tested before and after the placebo manipulation (body cream application on forearm); based on the expectation of the cream analgesic response (high or low), two types of placebo manipulations were performed for each participant.
Masking: Double (Participant, Investigator)
Masking Description: The participants were told that the cream has poweful analgetic effect in one session; and that the cream has minmal analgesic effect in another session.
Primary Purpose: Basic Science
Official Title: The Interaction Between Conditioned Pain Modulation and Expectation in Understanding the Placebo Effect of Pain Reduction
Actual Study Start Date : March 27, 2018
Estimated Primary Completion Date : December 2019
Estimated Study Completion Date : June 2020

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Drug Reactions

Arm Intervention/treatment
Placebo Comparator: High-expectation placebo manipulation
application of nonactive body cream on forearm for 10 minutes
Behavioral: placebo manipulation
application of nonactive body cream on forearm

Low-expectation placebo manipulation
application of nonactive body cream on forearm for 10 minutes
Behavioral: placebo manipulation
application of nonactive body cream on forearm




Primary Outcome Measures :
  1. Change in pain perception [ Time Frame: up to 2 weeks ]
    pain units on a scale of 0-100. 0 no pain. 100 = the maximum pain

  2. Change in conditioned pain modulation (CPM) [ Time Frame: up to 2 weeks ]
    change in pain units on a scale of 0-100. 0 no pain. 100 = the maximum pain



Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 40 Years   (Adult)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • healthy subjects

Exclusion Criteria:

  • attention deficit.
  • pain disorders.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03484728


Locations
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Israel
Rambam Medical center, Neurology Department
Haifa, Israel
Sponsors and Collaborators
Rambam Health Care Campus

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Responsible Party: Rambam Health Care Campus
ClinicalTrials.gov Identifier: NCT03484728     History of Changes
Other Study ID Numbers: 574-17_RMB_CTIL
First Posted: April 2, 2018    Key Record Dates
Last Update Posted: April 10, 2019
Last Verified: April 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No

Keywords provided by Rambam Health Care Campus:
Conditional pain modulation
pain
placebo