Osteoarthritis, Pain
Conditions
Brief summary
The purpose of this research study is to test whether researchers can reliably measure the response pupils have when an acute painful stimulus is experienced. Changes in the size of the pupil of the eye can be an indicator of brain activity in a region of the brain that is important for feeling pain.
Detailed description
There is strong rationale to support a role for locus coeruleus (LC) responsivity to acute painful stimuli in regulating speed of recovery after surgery and for LC responsivity as a mechanistic link explaining the risks for slow recovery from weak Conditioned Pain Modulation (CPM), catastrophizing cognitive style, and low enzyme activity catecholamine-O-methyltransferase (COMT) genotype. Preliminary data show feasibility to perform the proposed study. Primary Hypothesis: An observational study of pupil responses to noxious stimuli shows strong intra-individual reliability over 8 weeks. Key secondary hypotheses: Compared to individuals homozygous for val at the val158met site of the catecholamine-O-methyltransferase (COMT) gene, those homozygous for met will show smaller pupil responses to noxious stimuli and weaker CPM.
Interventions
None listed
Sponsors
Wake Forest University Health Sciences
National Institute of General Medical Sciences (NIGMS)
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
* Adult (18-70) * Pain from hip or knee arthritis of moderate intensity * American Society of Anesthesiologists physical status 1-3
Exclusion criteria
* Inability to complete study questionnaires * Pregnancy * Litigation or workers compensation related to hip or knee pain * Taking \> 50 mg morphine equivalents/day * History of Raynaud's disease of the feet * Psychotic disorder or a recent psychiatric hospitalization * History of eye surgery or topical eye medications that would would directly affect pupil diameter
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Percentage of Change in Pupil Diameter | 8 weeks | pupil diameter in response to 5 second presentation of noxious heat stimuli |
| Pain Score on Visit 1 | Day 1 | Participants rated their pain intensity during 5 seconds of heating the skin surface to 50 degrees. They used a scale of 0-100, with 0 being no pain at all and 100 being the worst pain imaginable. The heat was applied 5 times over 7.5 minutes and these 6 scores were averaged as their individual score. |
| Pain Score on Visit 2 | Week 2 | Participants rated their pain intensity during 5 seconds of heating the skin surface to 50 degrees. They used a scale of 0-100, with 0 being no pain at all and 100 being the worst pain imaginable. The heat was applied 5 times over 7.5 minutes and these 6 scores were averaged as their individual score. |
| Pain Score on Visit 3 | Month 1 | Participants rated their pain intensity during 5 seconds of heating the skin surface to 50 degrees. They used a scale of 0-100, with 0 being no pain at all and 100 being the worst pain imaginable. The heat was applied 5 times over 7.5 minutes and these 6 scores were averaged as their individual score. |
| Pain Score on Visit 4 | Month 2 | Participants rated their pain intensity during 5 seconds of heating the skin surface to 50 degrees. They used a scale of 0-100, with 0 being no pain at all and 100 being the worst pain imaginable. The heat was applied 5 times over 7.5 minutes and these 6 scores were averaged as their individual score. |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATORJames C Eisenach, MD
Wake Forest University Health Sciences
Participant flow
Pre-assignment details
This was an observational study without assignment to arms or groups.
Baseline characteristics
| Characteristic | — |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 20 Participants |
| Age, Continuous | 55 years STANDARD_DEVIATION 5.8 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 0 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 20 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 1 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 19 Participants |
| Region of Enrollment United States | 20 participants |
| Sex: Female, Male Female | 14 Participants |
| Sex: Female, Male Male | 6 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 20 |
| other Total, other adverse events | 0 / 20 |
| serious Total, serious adverse events | 0 / 20 |
Outcome results
None listed