Effect of Topical Lidocaine on Warm and Cold Sensation in Healthy Individuals

University of Aarhus60 enrolled

Overview

The purpose of the present study is to systematically test the occurrence of paradoxical and illusory responses to cold and warm stimuli in healthy volunteers with artificial sensory loss.

Efficient thermal sensation is important for adequate behavioral response to cold or warm stimuli and early signs of neuropathy can be changes in the thermal sensation. Alterations in thermal perception can results in paradoxical heat sensation (a warm perception when the skin is cooled) or a peculiar/burning sensation when the skin is stiumlated with simultaneous warm and cold (a "thermal grill"). Clarifying the occurrence of these paradoxical and illusory sensations, may help understanding early signs of peripheral neuropathy as well as thermal sensory perception. The investigators plan to conduct a study on thermal sensory perception using a model of sensory loss in healthy volunteers and systematically test the occurrence of paradoxical heat sensations and responses to the thermal grill.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

DIAGNOSTIC

Masking

DOUBLE

Enrollment

Conditions

Neuropathy;Peripheral Thermal Hypesthesia

Interventions

Xylocaine spray 100mg/mlDIAGNOSTIC_TEST

Topical application

EthanolDIAGNOSTIC_TEST

Topical application

Eligibility

Sex: ALLMin age: 18 YearsMax age: 40 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Healthy subjects * Age between 18 and 40 years * Participant is able and willing to give informed consent. Exclusion Criteria: * Unable to understand and speak Danish * Non-cooperative * Chronic pain or acute pain the past week lasting more than 4 hours or pain on the day of investigation * Pain medication within the last week * Medication within the last week that can affect assessment * Psychiatric or neurological disease and diseases that may affect the assessment * Sensory disturbances * History or symptoms of significant diseases (e.g. psychiatric or neurological disease, diseases that may affect the assessment, sensory disturbances, cancer, diabetes mellitus, liver diseases, kidney diseases, cardiovascular diseases) * Pregnancy or lactation * Jetlag or sleep deprivation * Alcohol or drug abuse * Consumption of cannabis the last 4 weeks and consumption of alcohol in the last 48 hours * Any abnormality of the skin or of vascular origin at application site * History of hypersensitivity to lidocaine, other amide-type anesthetics, or other contents of the lidocaine or vehicle

Locations (1)

Danish Pain Research Center, Aarhus University, Aarhus University Hospital

Aarhus N, Denmark

RECRUITING

Outcomes

Primary Outcomes

Paradoxical heat sensation (PHS)

Number of PHS responders on arm treated with lidocaine 45 minutes after drug application and Number of PHS responders on arm treated with ethanol 45 minutes after drug application

Time frame: 45 minutes

Secondary Outcomes

Thermal Grill (TG)

Number of TG responders on arm treated with lidocaine 75 minutes after drug application and Number of TG responders on arm treated with ethanol 75 minutes after drug application

Time frame: 75 minutes

Quality of the Thermal Grill (TG)

The participants are asked whether the stimulus is burning, hot, warm, neutral, cold, or freezing cold after the TG-condition (warm and cold), only warm or only cold on arm treated with lidocaine 75 minutes after drug application The participants are asked whether the stimulus is burning, hot, warm, neutral, cold, or freezing cold after the TG-condition (warm and cold) or only warm or only cold on arm treated with ethanol 75 minutes after drug application

Time frame: 75 minutes

Pain intensity of the Thermal Grill (TG)

The participants are asked to rate the intensity of pain on a visual analog scale (VAS) 0-100 (0 no pain; 100 worst pain imaginable) after the TG-condition (warm and cold), only warm or only cold on arm treated with lidocaine 90 minutes after drug application The participants are asked to rate the intensity of pain on a VAS 0-100 (0 no pain; 100 worst pain imaginable) after the TG-condition (warm and cold), only warm or only cold on arm treated with ethanol 90 minutes after drug application

Time frame: 90 minutes

Intensity of unpleasantness of the Thermal Grill (TG)

The participants are asked to rate the intensity of unpleasantness on a VAS 0-100 (0 no unpleasantness; 100 worst unpleasantness imaginable) after the TG-condition (warm and cold), only warm or only cold on arm treated with lidocaine 95 minutes after drug application The participants are asked to rate the intensity of unpleasantness on a VAS 0-100 (0 no unpleasantness; 100 worst unpleasantness imaginable) after the TG-condition (warm and cold), only warm or only cold on arm treated with ethanol 95 minutes after drug application

Central Contacts

Ellen L Schaldemose, MD

CONTACT

+45 93501942 ells@clin.au.dk

Data from ClinicalTrials.gov

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