Healthy Male and Female Subjects, Healthy Volunteer Study
Conditions
Keywords
auricular stimulation, functional near infrared spectroscopy
Brief summary
This is a single-visit non-invasive study of healthy volunteer subjects. Brain activity will be measured with infra-red light sensors attached to a cap worn on the head, while both ears are gently stimulated with plastic filaments.
Detailed description
The aim of this study is to localize and quantify brain activations from experimental stimulation of auricular points in pain-free volunteers. Investigators will stimulate auricular points for the shoulder, thumb, and lumbar spine with von Frey filaments and measure functional near-infrared spectroscopy (fNIRS) responses in the primary somatosensory (S1) and prefrontal cortex (PFC). This will test the hypothesis that stimulation across different points in the auricular cartography maps to distinct brain responses, an assumption underpinning AT theory. Stimulation of different ear points is anticipated to induce similar PFC responses, but activate distinct areas within the S1 homunculus, validating the concept of auricular cartography.
Interventions
Different points on both ears will be repeatedly stimulated with a plastic filament. This will be felt, but not be painful and should not result in lasting irritation.
Sponsors
University of Pittsburgh
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Intervention model description
Observational mechanistic study
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
Age of at least 18 years
Exclusion criteria
1. frequent or chronic pain requiring the use of pain-relieving medications more than twice per week, on average, in the last 3 months, 2. history or symptoms of neuropathy, 3. active lesions or skin disruptions to either ear, 4. recent (\< 3 mo) illicit drug use, 5. history of substance misuse/abuse, 6. current or recent (\<1 month) opioid or marijuana use, and 7. current regular use of psychoactive prescription medications
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| fNIRS response, Lumbar spine vs. thumb auricular points | 10 minutes | Calculated T-statistic for contrast of analyzed fNIRS signal change, comparing responses from stimulation of the ipsilateral ear at the auricular points corresponding to the lumbar-spine vs. thumb. A T-statistic of 0 indicates no difference; more positive scores mean stronger fNIRS signal change with stimulation of the lumbar point, compared to stimulation of the thumb point; more negative scores mean change with stimulation of the thumb, compared to the lumbar spine. This outcome is a number reflecting the overall magnitude of difference between stimulation points, calculated in one summary statistic. Dispersion measures cannot be calculated for the T-statistic in this analysis framework. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| fNIRS response, shoulder vs. thumb auricular points | 10 minutes | Calculated T-statistic for contrast of analyzed fNIRS signal change, comparing responses from stimulation of the ipsilateral ear at the auricular points corresponding to the shoulder vs. thumb. A T-statistic of 0 indicates no difference; more positive scores mean stronger fNIRS signal change with stimulation of the shoulder, compared to stimulation of the thumb point; more negative scores mean change with stimulation of the thumb, compared to the shoulder. This outcome is a number reflecting the overall magnitude of difference between stimulation points, calculated in one summary statistic. Dispersion measures cannot be calculated for the T-statistic in this analysis framework. |
| fNIRS response, lumbar spine vs. shoulder auricular points | 10 minutes | Calculated T-statistic for contrast of analyzed fNIRS signal change, comparing responses from stimulation of the ipsilateral ear at the auricular points corresponding to the lumbar-spine vs. shoulder. A T-statistic of 0 indicates no difference; more positive scores mean stronger fNIRS signal change with stimulation of the lumbar point, compared to stimulation of the shoulder point; more negative scores mean change with stimulation of the shoulder, compared to the lumbar spine. This outcome is a number reflecting the overall magnitude of difference between stimulation points, calculated in one summary statistic. Dispersion measures cannot be calculated for the T-statistic in this analysis framework. |
Countries
United States
Contacts
CONTACTCarly Riedmann, MPH
CONTACTAmy Monroe, MPH, MBA
PRINCIPAL_INVESTIGATORKeith Vogt, MD, PhD
University of Pittsburgh
Outcome results
None listed