Sociocultural Influences on Pain Assessment
Recruiting in Palo Alto (17 mi)
Overseen byLauren Y Atlas, Ph.D.
Age: 18 - 65
Sex: Any
Travel: May Be Covered
Time Reimbursement: Varies
Trial Phase: Academic
Recruiting
Sponsor: National Center for Complementary and Integrative Health (NCCIH)
Must not be taking: Opiates, Antidepressants, Anticonvulsants, others
Disqualifiers: Neurological conditions, Mood disorders, Chronic pain, others
No Placebo Group
Trial Summary
What is the purpose of this trial?Objective
The current proposal investigates behavioral, psychophysiological, and social processes that may help explain biases and disparate outcomes in pain. Health disparities, or health outcomes that adversely affect disadvantaged populations, are pervasive and apparent in many diseases and symptoms, including pain. Pain is the number one reason individuals seek medical treatment. Health disparities in pain encompass both differences in pain experience and treatment for pain. For instance, research indicates that Black individuals report increased pain and have reduced pain tolerance relative to White individuals, yet doctors are less likely to treat minority patients pain and underestimate their pain experience. This project aims to address this systemic discrepancy by focusing on interpersonal processes that may contribute to these disparities, including socially-relevant responses to pain (i.e. pain expression) and pain assessment (e.g. visual attention). The proposed research aims to determine whether the study of pain expressions and their assessment can yield insights on how social factors shape pain and its treatment. Further, we test the efficacy of potential interventions designed to improve accuracy and reduce biases in pain assessment. If successful, this work will form the foundation of a new research program that will link the field of pain research with the field of social neuroscience, and forge new insights on the critical problem of health disparities in pain.
Study population
We will accrue up to 700 total healthy volunteers to target 262 completers
Design
Our overall aim is to understand how social factors influence the assessment and management of pain, and to gain insight into psychosocial processes that may underlie health disparities in pain. We propose a series of studies designed to test these links. First, we will measure pain perception and physiological responses to painful stimuli in a diverse group of individuals to test for sociocultural and biological influences on pain and pain-related responses. In subsequent studies, new participants ("perceivers") will view images of these initial participants ("targets") and will provide estimates of 'targets' pain experience. We will measure a) whether perceivers can accurately estimate 'targets' pain experience; b) whether accuracy differs as a function of similarity between target and perceiver (ingroup vs outgroup); and c) whether individuals can improve accuracy through feedback.
Outcome measures
Primary outcome measures for all experiments will be decisions about pain (experienced by self or other) measured with visual analogue scales, reaction time, and/or categorical judgments (pain/no pain). We will also measure physiological responses (e.g., facial muscle response, skin conductance, pupil dilation) and brain responses using functional magnetic resonance imaging (fMRI) as secondary outcome measures. We will test whether pain and pain-related responses varies as a function of sociocultural/demographic factors (e.g. race, ethnicity, sex) and whether accuracy in assessing others pain is influenced by group similarity (i.e. ingroup vs. outgroup) and training (e.g. performance-related feedback)....
Do I need to stop taking my current medications for this trial?
Yes, if you regularly use prescription medications that significantly affect pain or heat perception, such as opiates, antidepressants, anticonvulsants, anxiolytics, hypnotics, antipsychotics, antimigraine agents, and muscle relaxants, you will need to stop taking them. However, using non-prescription pain relievers like ibuprofen or acetaminophen occasionally is allowed, as long as the last dose was not taken within 5 half-lives of testing.
What data supports the effectiveness of this treatment for pain assessment?
Research shows that alternating heat and cold therapy can improve muscle stiffness and subjective symptoms, while electrical stimulation is effective for controlling acute pain in many patients. These components suggest potential benefits for pain assessment and management.
12345Is the treatment generally safe for humans?
The treatments mentioned, such as electrical stimulation and thermal stimulation, have been used safely in humans for pain management and research. Safety features are often included to prevent harm, like avoiding burns during thermal stimulation, and electrical stimulation is a well-accepted method for controlling pain.
34678How does the treatment in the trial differ from other pain treatments?
This treatment is unique because it combines cold water immersion, electric shock stimulation, and thermal stimulation to assess pain, which is different from standard pain treatments that often rely on medications or single-method therapies. The use of these physical stimuli allows researchers to explore how different cultural backgrounds might influence pain perception and response.
13479Eligibility Criteria
Healthy adults aged 18-60 who speak English fluently and can consent to participate are eligible for this study. Excluded are those with chronic pain conditions, certain medical issues affecting sensation or pain perception, employees of NCCIH and NIMH, non-US residents, and individuals taking specific prescription medications.Inclusion Criteria
All Sub-Studies: Healthy
I am between 18 and 60 years old.
All Sub-Studies: Able to provide written informed consent
+1 more
Exclusion Criteria
I have scars, burns, or a recent tattoo in the test area that could affect skin sensitivity.
I don't regularly use meds that affect pain or heat feeling, except for occasional painkillers.
All Sub-Studies: Has a major-medical condition or medical history that in a clinician's assessment could affect ability to comply with study procedures, including neurological or psychiatric conditions (including stroke and blindness or deafness, a history of brain damage, substance or alcohol dependence or abuse or psychosis)
+11 more
Trial Timeline
Screening
Participants are screened for eligibility to participate in the trial
2-4 weeks
Initial Assessment
Measure pain perception and physiological responses to painful stimuli in a diverse group of individuals
4-6 weeks
Multiple visits (in-person)
Perception Study
New participants view images of initial participants and provide estimates of their pain experience
4-6 weeks
Multiple visits (in-person)
Feedback and Training
Participants receive feedback on their performance to improve accuracy in pain assessment
4-6 weeks
Multiple visits (in-person)
Follow-up
Participants are monitored for accuracy and biases in pain assessment after interventions
4 weeks
Participant Groups
The trial investigates how social and cultural factors influence the experience of pain and its assessment by others. It involves electric shocks, thermal stimulation via a thermode device, cold water immersion tests, facial expression recording during painful stimuli, heart activity monitoring, sweat measurement sensors on the hand, facial muscle electrical activity testing through electrodes attached to the skin.
4Treatment groups
Experimental Treatment
Active Control
Group I: Substudy 3: Feedback GroupExperimental Treatment1 Intervention
Participants in substudy 3's Feedback Group will be informed about their performance after every trial when making judgments about other people's pain.
Group II: Substudy 1: All participantsExperimental Treatment3 Interventions
Measuring facial response to painful stimulation.
Group III: Substudy 2: Healthy volunteersActive Control1 Intervention
Measuring pain assessment accuracy
Group IV: Substudy 3: ControlActive Control1 Intervention
Subjects will judge stimuli with the same instructions as Sub-Study 2 (which provides a test of replication).
Find a Clinic Near You
Research Locations NearbySelect from list below to view details:
National Institutes of Health Clinical CenterBethesda, MD
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Who Is Running the Clinical Trial?
National Center for Complementary and Integrative Health (NCCIH)Lead Sponsor
References
The viability of external electrical stimulation as a therapeutic modality. [2011]This study indicates that external electrical stimulation is a valuable tool for control of acute pain in about 80 percent of patients but, for significant relief of pain, in only about 25 percent of patients with chronic pain. The author recognizes that in order to increase its use, a system for delivery of this therapy under a doctor's prescription, rather than having to teach each individual practitioner the technique for using the device, must be developed. In chronic-pain patients when external electrical stimulation is inadequate, a more aggressive and comprehensive program of operant conditioning, progressive physical exercise, drug withdrawal, autogenic training, and biofeedback is advised.
Managing pain using heat and cold therapy. [2019]Evidence supports the use of superficial heating and cooling of tissues to provide pain relief in low to moderate levels of acute and chronic pain in adults, but there are no standards or guidelines in children's centres across the UK for administering these modalities in children, so a project was undertaken to develop these locally. Evidence from the literature was used to identify best practice in relation to equipment, safety and infection control. Implementation was supported by educational input and a detailed protocol for assessment and application of the devices. Three years after their introduction a review of the guidelines and an audit demonstrated that these modalities have been beneficial, providing cost-effective, holistic care for children experiencing pain in hospital.
Electrical stimulation for the control of pain. [2019]Electrical stimulation for the control of pain is now a well accepted therapeutic modality. Transcutaneous application of electrical stimulation is the most common technique employed and has been used to treat chronic pain, acute surgical pain, and acute pain of other origins. Percutaneous application of electricity to the nervous system through needles electrodes is useful in predicting the efficacy of implantable stimulators and has served the same function as diagnostic nerve block. Implantable stimulators have been used for stimulation of peripheral nerves, the anterior and posterior surfaces of the spinal cord, and the brain. Peripheral nerve stimulators are the most efficacious of the implantable devices. They are used specifically for pain of peripheral nerve injury origin. Their use for pain outside the distribution of the nerve stimulated is not yet proved.
TNS-evoked long loop effects. [2019]Local analgesia can be produced by transcutaneous electrical stimulation of peripheral nerves. This is used in the treatment of chronic pain states. Its clinical effectiveness depends on two points; namely (1) the stimulation has to be perceptible, and (2) paresthesias elicited by TNS must be localized in the area of pain. To verify this in healthy subjects we produced an experimental pain by radiant heating of the skin and tested the analgesic effect of TNS. TNS stimuli parameters (duration, amplitude and frequency) were determined so that double blind conditions were given. Stimulation with small rectangular pulses showed the best analgesic effect especially at a stimulation rate of 100 Hz. The stimulation of various nerves showed that most of the analgesic effects depend on spinal level mechanisms but probably long loop effects are involved.
Effects of alternating heat and cold stimulation at different cooling rates using a wearable thermo device on shoulder muscle stiffness: a cross-over study. [2022]A small, wearable thermo device that uses Peltier elements for programmed heat and cold stimulation has been developed recently and is expected to be applied in conventional contrast bath therapy. This study was aimed to examine improvements in trapezius muscle hardness and subjective symptoms resulting from alternating heat and cold stimulation, with different rates of cooling.
A contact thermal stimulator for neurobehavioral research on temperature sensation. [2019]A thermal stimulation system is described which is suitable for use in psychophysical, behavioral and neurophysiological studies of temperature sensation. Skin temperature over a restricted area can be maintained at temperatures of 30 to 60 degrees C. Heating from this initial temperature can be achieved at rates from 1.0 degrees C to 30 degrees C/second, up to a maximum temperature of 70 degrees C. Stimulus duration can be varied from 1-15 sec. Safety features are employed to avoid accidental burning of subjects. The system can be used during electrophysiological recording with no electronic interference.
Lasers and other thermal stimulators for activation of skin nociceptors in humans. [2019]Pain can be induced by thermal, chemical, and mechanical stimulation in animals and man. Of the thermal stimulation modalities, heat is the most commonly used, as a variety of reliable stimulation techniques are available. Heat is a natural stimulus modality to evoke pain, and it has been used to study animal nociception and human pain perception for (a) examining the mechanisms of tissue injury and sensitisation and (b) quantifying the therapeutic effects of pharmacological, physical, and psychological interventions. This paper summarises the current understanding of the physiology and psychophysical response to painful heat stimulation in humans. By understanding the underlying mechanisms, new methods of heat stimulation may be developed for basic and clinical applications. Traditionally, contact heat, indirect thermal heat by focused light bulb, and laser pulses have been the methods used to induce heat pain in humans for experimental and clinical studies. The following lasers have been used in pain research: argon (488-515 nm), copper vapour (510-577 nm), semiconductor (e.g. 970 nm), neodymium-YAG (1064 nm), thulium-YAG (2000 nm), and CO(2) (10,600 nm).
Neuromuscular electrostimulation techniques: historical aspects and current possibilities in treatment of pain and muscle waisting. [2022]Application of electricity for pain treatment dates back to thousands of years BC. The Ancient Egyptians and later the Greeks and Romans recognized that electrical fishes are capable of generating electric shocks for relief of pain. In the 18th and 19th centuries these natural producers of electricity were replaced by man-made electrical devices. This happened in following phases. The first was the application of static electrical currents (called Franklinism), which was produced by a friction generator. Christian Kratzenstein was the first to apply it medically, followed shortly by Benjamin Franklin. The second phase was Galvanism. This method applied a direct electrical current to the skin by chemical means, applied a direct and pulsed electrical current to the skin. In the third phase the electrical current was induced intermittently and in alternate directions (called Faradism). The fourth stage was the use of high frequency currents (called d'Arsonvalisation). The 19th century was the "golden age" of electrotherapy. It was used for countless dental, neurological, psychiatric and gynecological disturbances. However, at beginning of the 20th century electrotherapy fell from grace. It was dismissed as lacking a scientific basis and being used also by quacks and charlatans for unserious aims. Furthermore, the development of effective analgesic drugs decreased the interest in electricity. In the second half of the 20th century electrotherapy underwent a revival. Based on animal experiments and clinical investigations, its neurophysiological mechanisms were elucidated in more details. The pain relieving action of electricity was explained in particular by two main mechanisms: first, segmental inhibition of pain signals to the brain in the dorsal horn of the spinal cord and second, activation of the descending inhibitory pathway with enhanced release of endogenous opioids and other neurochemical compounds (serotonin, noradrenaline, gamma aminobutyric acid (GABA), acetylcholine and adenosine). The modern electrotherapy of neuromusculo- skeletal pain is based in particular on the following types: transcutaneous electrical nerve stimulation (TENS), percutaneous electrical nerve stimulation (PENS or electro-acupuncture) and spinal cord stimulation (SCS). In mild to moderate pain, TENS and PENS are effective methods, whereas SCS is very useful for therapy of refractory neuropathic or ischemic pain. In 2005, high tone external muscle stimulation (HTEMS) was introduced. In diabetic peripheral neuropathy, its analgesic action was more pronounced than TENS application. HTEMS appeared also to have value in the therapy of symptomatic peripheral neuropathy in end-stage renal disease (ESRD). Besides its pain-relieving effect, electrical stimulation is of major importance for prevention or treatment of muscle dysfunction and sarcopenia. In controlled clinical studies electrical myostimulation (EMS) has been shown to be effective against the sarcopenia of patients with chronic congestive heart disease, diabetes, chronic obstructive pulmonary disease and ESRD.
Thermosensitivity of muscle: high-intensity thermal stimulation of muscle tissue induces muscle pain in humans. [2022]Small-calibre afferent units responding to thermal stimuli have previously been reported to exist in muscle. The question as to whether these receptors in humans mediate subjective thermal sensations from muscle remains unresolved. The aims of the present study were to determine in humans whether intramuscular injection of warm and cold isotonic saline elicits temperature sensations, muscle pain or any other sensations. In 15 subjects, no thermal sensations assessed on a temperature visual analogue scale (VAS) could be detected with intramuscular injections of isotonic saline (1.5 ml) into the anterior tibial muscle at temperatures ranging from 8 to 48 degrees C. The same subjects recorded strongly increasing scores on a temperature VAS when thermal stimuli in the same intensity range were applied to the skin overlying the muscle by a contact thermode. However, I.M. isotonic saline of 48 degrees C induced muscle pain with peak scores of 3.2 +/- 0.8 cm on a VAS scale ranging from 0 to 10 cm. Using the the McGill pain questionnaire a subgroup, of subjects qualitatively described the pain using the 'thermal hot' and 'dullness' word groups. Temperature measurements within the muscle during the stimulating injections showed that the time course of the pain sensation elicited by saline at 48 degrees C paralleled that of the intramuscular temperature and far outlasted the injection time. The present data show that high-intensity thermal stimulation of muscle is associated with muscle pain. High-threshold warm-sensitive receptors may mediate the pain following activation by temperatures of 48 degrees C or more. Taken together, the data indicate that thermosensation from a given volume of muscle is less potent than nociception.