The purpose of this study is to obtain information for the design of a method to measure the behaviour of the ascending and descending pathways of the nociceptive system.
Source
Brief title
Condition
- Other condition
Synonym
Health condition
chronic pain development
Research involving
Sponsors and support
Intervention
No registrations found.
Outcome measures
Primary outcome
The main parameters are:
Experiment 1: Estimation method (ascending method or random stimulus method).
Experiment 2: Perturbation method (Perturbation temperature).
Experiment 3: Number of nociceptive thresholds.
Experiment 4: Stimulus settings (number of pulses, inter-pulse interval, pulse
width).
Experiment 5: Temporal nociceptive perturbations.
Experiment 6: Multilevel nociceptive perturbations.
The outcome measures are the estimated thresholds determined via logistic
regression analysis over time. Moreover, the ratio between felt and not felt
stimuli will be measured in the experiment 1.
Secondary outcome
na
Background summary
Persisting or chronic pain after surgical interventions is a frequently
occurring problem. Even minor surgical interventions may lead to postoperative
chronic pain development. Chronic pain severely restricts an individual*s
quality of life, but also increases costs of global health care and absenteeism
at work.
Mechanisms involved in chronic pain development may lie within ascending and/or
descending pathways of the nociceptive system. Sensitizing effects caused by
ascending mechanisms are normally counteracted by inhibiting effects of
descending mechanisms. An imbalance between both pathways increases the risk of
chronic pain development. Observation and identification of the state of these
nociceptive pathways might provide information for optimization of pain
management.
The sensitivity of mechanisms in the ascending pathway is reflected in
psychophysical nociceptive thresholds, estimated using electrical stimulation
of the skin (e.g. a decrease in nociceptive threshold indicates hyperalgesia).
Different stimulus properties (e.g. the number of electrical pulses) are known
to activate these mechanisms differently and result in different thresholds.
Therefore, it is expected that simultaneous estimation of multiple thresholds
reveals additional phenomena, enabling a more detailed observation and modeling
of ascending nociceptive processing.
The activation of descending inhibiting mechanisms normally is proportional to
the intensity of nociceptive input (i.e. the *pain inhibits pain* phenomenon).
The dynamics of the consequent threshold changes are still unknown, but may
contain important information for discrimination between ascending and
descending mechanism behavior. Tracking nociceptive thresholds during well
controlled nociceptive perturbations would be a first step to develop a method
for independent identification of the state of both pathways.
Study objective
The purpose of this study is to obtain information for the design of a method
to measure the behaviour of the ascending and descending pathways of the
nociceptive system.
Study design
This study consists of six experiments
1. Compare precision and efficiency of available algorithms for tracking of
multiple threshold; quasi-experimental one group pretest-posttest study
2. Observe dynamic changes of thresholds induced by nociceptive perturbations;
experimental cross-over study
3. Study how the number of simultaneously tracked thresholds affects the
observability of dynamic changes in the nociceptive system; quasi-experimental
one group pretest-posttest study
4. Assess measured thresholds from different electrical stimulus properties;
explorative longitudinal / one group pretest-posttest study
5. Study the effect of temporal nociceptive perturbation patterns on the time
course of tracked thresholds; experimental one-way repeated measures design
6. Study the effect of multilevel nociceptive perturbations on the time course
of tracked thresholds; experimental one-way repeated measures design
Study burden and risks
Experiment 1 will take approximately 50-60 minutes and includes a cold pressor
task lasting for a maximum time of three minutes.
Experiment 2 will take approximately 2 hours and includes two cold pressor
tasks lasting for a maximum time of two minutes each.
Experiment 3 will take approximately 50-60 minutes and includes a cold pressor
task lasting for a maximum time of 2 minutes.
Experiment 4 will take place on two consecutive days and each day will take
approximately 50-60 minutes. Moreover, experiment 4 contains two cold pressor
tasks (one at each day) lasting for a maximum time of 2 minutes.
Experiment 5 and 6 will take approximately 50-60 minutes and include two cold
pressor tasks, each lasting for a maximum time of two minutes.
The electrode used for electrical stimulation in all experiments can cause mild
skin irritation which disappears within 30 minutes after removal. The
perturbation task is known to may cause a subject to faint. The maximum allowed
nociceptive perturbation time, however, is set such that the chance of a
subject to faint is minimal. Subjects are also always able to remove their hand
from the water when pain is no longer tolerable.
Drienerlolaan 5
Enschede 7522 NB
NL
Drienerlolaan 5
Enschede 7522 NB
NL
Listed location countries
Age
Inclusion criteria
18 years and older, legally competent, able to communicate, cognitively competent, informed consent.
Exclusion criteria
pregnany, diabetes, MS, HIV/AIDS, not able to deal with used research methods, no compliance of instructions, loss of somatosensory function, deviating perception of pain, prolonged pain during the last three months, momentary pain-complaints, fatigue, fibromyalgia.
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
Register | ID |
---|---|
CCMO | NL35175.044.11 |
NTR-old | NTR2961 |