Testing Protocol for Cold-sensing Fibers

Study Overview
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Brief Summary
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This project aims to evaluate whether electrical stimulation can modulate the cold detection threshold and the cold pain threshold. The hypothesis is that different electrical stimulation will either decrease or increase the cold threshold depending on the shape of the electrical stimulus. If a combination of electrical stimuli and cold stimuli could be used, this could lead to a novel method for estimating the excitability properties of cold-sensing fibers. The sub-project takes place in 1 session (1.5 hours).

Official Title
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Nerve Excitability Testing Protocol for Cold-sensing Fibers

Conditions
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Pain

Intervention / Treatment
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* Other: Electrical stimulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy men and women 18-80 years Speak and understand English Exclusion Criteria: Pregnancy or breast feeding Drug addiction defined as the use of cannabis, opioids or other drugs Previous and present neurologic, musculoskeletal or mental illnesses (e.g., epilepsy, neuropathy, fibromyalgia and depression) Skin diseases Past history of conditions possibly leading to neuropathy Inability to cooperate Current use of medications that may affect the study, e.g., analgesics Previous traumatic experience of an electrical accident Consumption of alcohol or painkillers within the last 24 hours Participation in other pain studies throughout the study period Patients with cardiac diseases (e.g., pacemaker).

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Study group<br> | Other: Electrical stimulation<br>* At the beginning of the session, an electrode will be attached to the participant's ankle. Electrical stimulation will be applied to estimate the electrical perception threshold. This threshold will be used as condition stimuli when different thermal thresholds are assessed.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cold detection threshold | The cold detection threshold will be estimated by reducing the temperature until the subjects perceive a cold sensation. | During session 1. The estimation of the outcome measurement take approximately 3 minutes. | 
| Cold detection threshold with conditioning electrical stimuli | The cold detection threshold will be estimated by reducing the temperature until the subjects perceive a cold sensation. Simultaneous will electrical stimulation be applied. | During session 1. The estimation of the outcome measurement take approximately 3 minutes. | 
| Warm detection threshold | The warm detection threshold will be estimated by increasing the temperature until the subjects perceive a warm sensation. | During session 1. The estimation of the outcome measurement take approximately 3 minutes. | 
| Warm detection threshold with conditioning electrical stimuli | The warm detection threshold will be estimated by increasing the temperature until the subjects perceive a warm sensation. Simultaneous will electrical stimulation be applied. | During session 1. The estimation of the outcome measurement take approximately 3 minutes. | 
| Warm pain threshold | The warm pain threshold will be estimated by increasing the temperature until the subjects perceive a painful warm sensation. | During session 1. The estimation of the outcome measurement take approximately 3 minutes. | 
| Warm pain threshold with conditioning electrical stimuli | The warm pain threshold will be estimated by increasing the temperature until the subjects perceive a warm painful sensation. Simultaneous will electrical stimulation be applied. | During session 1. The estimation of the outcome measurement take approximately 3 minutes. | 
| Cold pain threshold | The cold pain threshold will be estimated by reducing the temperature until the subjects perceive a painful warm sensation. | During session 1. The estimation of the outcome measurement take approximately 3 minutes. | 
| Cold pain threshold with conditioning electrical stimuli | The cold pain threshold will be estimated by reducing the temperature until the subjects perceive a cold painful sensation. Simultaneous will electrical stimulation be applied. | During session 1. The estimation of the outcome measurement take approximately 3 minutes. | 
| The sensation of pulse 1 | The investigator will ask the participant to rate the sensation by a questionnaire. The scale will be 0-10, where 0 indicates no sensation and 10 is the worst imaginable sensation. | During session 1. The estimation of the outcome measurement take approximately 3 minutes. | 
| The sensation of pulse 2 | The investigater will ask the participant to rate the sensation by a questionnaire. The scale will be from 0-10 where 0 indication no sensation and 10 the worst imaginable sensation. | During session 1. The estimation of the outcome measurement take approximately 3 minutes. | 
| Perception threshold | The Perception threshold for the cutaneous electrical stimulation will be estimated for two different pulse shapes of the electrical stimulus. The perception threshold is defined as the electrical current needed for the participant to perceive the stimulus. The perception threshold will be estimated by the method of limits. | During session 1. The estimation of the outcome measurement take approximately 15 minutes. |