Neural and Psychological Mechanisms of Pain Perception

Launched by NATIONAL CENTER FOR COMPLEMENTARY AND INTEGRATIVE HEALTH (NCCIH) · May 15, 2015

Keywords

ClinConnect Summary

This clinical trial, titled "Neural and Psychological Mechanisms of Pain Perception," is exploring how our brains process pain and how emotions and expectations can influence our experience of pain. The researchers want to understand what happens when people anticipate different levels of pain and how various treatments might change how we feel it. Healthy volunteers aged 18 to 50 who speak English can participate in this study.

Participants will visit the clinic once or twice for 1 to 3 hours. They will undergo health screenings, and some may have MRI scans of their brains while they experience different types of sensations, like heat or mild electric shocks, to see how their bodies react. There will also be taste tests and questionnaires to fill out. It’s important to note that individuals with certain medical conditions, chronic pain, or those taking specific medications may not be eligible. The study lasts for three years and aims to provide insights into the complex nature of pain.

Gender

ALL

Eligibility criteria

• * INCLUSION CRITERIA:
• • Healthy
• • Between 18 and 50 years old
• • Fluent in English
• • Able to provide written informed consent.
• EXCLUSION CRITERIA (all sub-studies):
• • Unable to comply with study procedures or follow-up visits.
• • Has a major medical condition or medical history that in a clinician's assessment could affect heat sensitivity, pain thresholds, or ability to comply with study procedures. This may include cardiovascular, autonomic, or neurological conditions, including stroke, blindness, deafness, a history of brain damage, or a chronic systemic disease (e.g., diabetes).
• • Has a current mood disorders, anxiety disorders, or substance use disorders, or has a history of psychosis, hospitalization for a mental health condition, or recurrent psychiatric episodes.
• • Has a medical condition that in a clinician's assessment might affect somatosensation (e.g., Raynaud s disease, peripheral neuropathy, or circulatory disorder).
• • Has a current chronic pain condition or has had chronic pain in the past (painful condition lasting more than six months).
• • Has a dermatological condition affecting the testing region such as scars, burns, or recent tattoos that might influence cutaneous sensibility.
• • Regular use of prescription medication that has a significant effect on pain or heat perception. Excluded medications include central-acting agents such as opiates (morphine, tramadol), antidepressants (amitriptyline, duloxetine, milnacipran), anticonvulsants (gabapentin, pregabalin), anxiolytics (barbituates, benzodiazepines), hypnotics (zolpidem, sodium oxybate), antipsychotics (valproate, lithium, olanzapine), antimigraine agents (sumatriptan, ergotamine), and muscle relaxants (cyclobenzaprine, carisoprodol). Use of analgesic medications, such as non-steroidal anti-inflammatories, salicylates, and acetaminophen, taken on an "as needed" basis is acceptable as long as the last dose taken was within 5 half-lives of testing.
• • Is pregnant.
• • NCCIH and NIMH employees.
• EXCLUSION CRITERIA (fMRI sub-studies):
• * Individuals with conditions that could pose a risk relating to the safety of the fMRI procedure or pain stimulation will be excluded from the MRI portion of the protocol, but may participate in the non-fMRI sessions (with the exception of pregnant women). Such conditions include:
• • Those with ferromagnetic metal in the cranial cavity or eye, e.g. aneurysm clip, implanted neural stimulator, cochlear implant, ocular foreign body.
• • Those with an abnormality on a structural MRI.
• • Those with an implanted cardiac pacemaker or auto-defibrillator.
• • Those with an insulin pump.
• • Those with an irremovable body piercing.
• • Pregnant women (based on urine test completed within 24 hours prior to scan).
• • Individuals who are left-handed (based on self-report or score on handedness questionnaire) will be excluded from fMRI substudies.
• EXCLUSION CRITERIA (placebo analgesia sub-studies):
• • -Participation in an NIH study of analgesia, as gleaned from CRIS.