Healthy participants
Conditions
Interventions
Group 1: Healthy volunteers will be exposed to pain induced by the cold pressor test in two experimental conditions (between-subjects design). The assessments take place over three days: the MRI scan
Sponsors
Universitätsklinikum Essen, Klinik für Neurologie
Eligibility
Sex/Gender
All
Age
18 Years to 45 Years
Inclusion criteria
Inclusion criteria: - Healthy - Voluntary, informed consent - German-speaking
Exclusion criteria
Exclusion criteria: - Past or present neurological conditions, such as pain disorders (e.g., migraines, back pain, irritable bowel syndrome), brain or spinal cord injuries (e.g., traumatic brain injury, brain hemorrhage), epilepsy, sleep disorders, cramp syndromes - Severe mental/psychiatric illnesses, past or present, such as depression, schizophrenia, addiction disorders (particularly alcohol and drug abuse), or personality disorders - Severe internal illnesses, past or present, such as diabetes, neoplasms, thyroid over-/underactivity, asthma, porphyria, cardiovascular diseases, kidney or liver diseases, and diseases affecting the hematopoietic system. Special attention is given to diseases that are contraindications for the study medication as well as for CPT-induced blood pressure fluctuations - Anamnestic evidence of or the presence of acute (flu, bronchopulmonary) or chronic infectious diseases (HIV, HCV, HBV, HDV) - Cold-associated conditions, such as anamnestic evidence of Raynaud's phenomenon, cryoglobulinemia, physical urticaria - Skin diseases for which the use of CPT is contraindicated (e.g., atopic dermatitis, eczema, wounds, bites, injuries, and ulcers in the affected limb) - Pregnancy and breastfeeding - Alcohol consumption the day before or on the day of the study - Substance use within four weeks before the study - Intolerance or allergy to components of the substances - Surgical procedure under anesthesia within the last 6 months - Participation in other medication-related studies within the last 6 months - Ongoing medication, except for dietary supplements and hormonal contraception - Use of pain medication (e.g., NSAIDs), anticoagulants, or CNS-active medication within the last 7 days Additional exclusion criteria for MRI measurements: - Claustrophobia - Pacemakers, cochlear implants, neurostimulators - Non-MRI-compatible metallic foreign bodies in or on the person, particularly: - Non-removable piercings - Dental implants, braces - Tattoos with known metal contamination or large-area tattoos - Osteosynthesis materials (bone screws, etc.)
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Decision for or against a retreatment (i.e., taking the medication again in the same experimental context), expressed as a probability and as a binary outcome (co-primaries) at the end of Day 1 of the experiment: - “How likely are you to take the pain medication again if you had to immerse your hand in cold water for 5 minutes?” (0 = not likely at all, 100% = very likely, measured on a VAS) - “Would you take the pain medication again if you had to immerse your hand in cold water for 5 minutes?” (yes/no) | — |
Secondary
| Measure | Time frame |
|---|---|
| Secondary outcomes: - CPT pain tolerance: The duration (in seconds) for which participants can keep their hand in a cold-water bath before removing it due to unbearable pain will be assessed. Additionally, the number of participants who remove their hand prematurely from the water bath will be compared between each group. - CPT pain intensity: Pain intensity ratings will be continuously assessed throughout the CPT using a computer-based Visual Analog Scale (0 = no pain at all, 100% = unbearably strong pain). The increase in ratings over time will be estimated as the Area Under the Curve (AUC) of the ratings over time. - Treatment expectations and treatment effects (GEEE) - Side effects (GASE and GEEE) - Pain experience before and after medication on Day 1 measured on a VAS (pain intensity expectation, pain-related fear, arousal. desire to avoid pain, average pain intensity, pain unpleasantness, distress induced by examination) - Physiological measurements before and after each CPT (systolic blood pressure, diastolic blood pressure, heart rate) Exploratory outcomes: - Explicitly stated influencing factors regarding treatment decisions on Day 1 (e.g. pain intensity, pain duration, drug efficacy, administration of medication, side effects) - Decision for or against a retreatment in two hypothetical scenarios expressed as a probability and as a binary outcome on Day 1: a) A clinical setting ("Please recall a past stressful situation in which you experienced physical pain. Based on your experiences in the study, how likely would you be to take/would you take the pain medication again if you had to go through that situation once more?) and b) A social setting ("How likely are you to recommend/would you recommend the pain medication to a person close to you who is in severe pain?") - Retrospective assessment of pain experience before and after medication on Day 8 measured on a VAS (pain intensity expectation, pain-related fear, arousal. desire to avoid pain, av | — |
Countries
Germany
Contacts
Public ContactKatharina Schmidt
Universitätsklinikum Essen, Klinik für Neurologie
Outcome results
None listed