Neuromodulation of Lidocaine and Capsaicin Cream Effects on Pain Experience

June 19, 2020 updated by: Jian Kong, Massachusetts General Hospital

Neuromodulation of Placebo and Nocebo Effects

The aim of this study is to use a brain stimulation tool called transcranial direct current stimulation (tDCS) to investigate the analgesic (reducing sensitivity to pain) effects of lidocaine cream and the hyperalgesic (increasing sensitivity to pain) effects of capsaicin cream using a neutral cream as a control. tDCS stimulation has been shown to temporarily influence the way the stimulated part of the brain functions. With this method, the involvement of specific parts of the brain can be investigated in the working of the brain as a whole.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

103

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Massachusetts
      • Charlestown, Massachusetts, United States, 02129
        • Massachusetts General Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

21 years to 50 years (ADULT)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Right handed healthy male and female adults aged 21-50
  • No contraindications to fMRI scanning
  • At least a 10th grade English-reading level; English can be a second language provided that the patients feel they understand all the questions used in the assessment measures.

Exclusion Criteria:

  • Current or past history of major medical, neurological, or psychiatric illness
  • Claustrophobia
  • History of head trauma
  • Instability of responses to experimental pain
  • Non-fluent speaker of English
  • Presence of any contraindications to fMRI scanning. For example: cardiac pacemaker, metal implants, fear of closed spaces, pregnancy
  • History of alcohol/substance abuse

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: BASIC_SCIENCE
  • Allocation: RANDOMIZED
  • Interventional Model: PARALLEL
  • Masking: TRIPLE

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
EXPERIMENTAL: tDCS Enhancement
In this group, the transcranial direct current stimulation (tDCS) stimulates the areas of the brain being examined in this study to increase their activity.
tCDS safely applies a weak electrical current to your scalp using two sponge electrodes that look like flat circular pads. The pads will be held in place on your head with a neoprene cap. The pads will be attached to a generator that will send a weak stimulus to your scalp. This current influences the way that your brain cells work. When the stimulus starts, you might feel a tingling sensation underneath the electrode pads. That sensation is not painful and goes away in seconds.
Lidocaine cream will be applied on the arm to reduce pain sensitivity (analgesia).
Capsaicin cream will be applied on the arm to increase pain sensitivity (hyperalgesia).
A neutral cream will be applied on the arm as a control.
EXPERIMENTAL: tDCS Inhibition
In this group, the transcranial direct current stimulation (tDCS) inhibits the areas of the brain being examined in this study to decrease their activity.
tCDS safely applies a weak electrical current to your scalp using two sponge electrodes that look like flat circular pads. The pads will be held in place on your head with a neoprene cap. The pads will be attached to a generator that will send a weak stimulus to your scalp. This current influences the way that your brain cells work. When the stimulus starts, you might feel a tingling sensation underneath the electrode pads. That sensation is not painful and goes away in seconds.
Lidocaine cream will be applied on the arm to reduce pain sensitivity (analgesia).
Capsaicin cream will be applied on the arm to increase pain sensitivity (hyperalgesia).
A neutral cream will be applied on the arm as a control.
SHAM_COMPARATOR: Sham tDCS
Sham transcranial direct current stimulation (tDCS) does not provide real stimulation though you will not know this until your debriefing at the end of the study. Sham will be used to determine if the results of this study are due to the tDCS or other reasons.
tCDS safely applies a weak electrical current to your scalp using two sponge electrodes that look like flat circular pads. The pads will be held in place on your head with a neoprene cap. The pads will be attached to a generator that will send a weak stimulus to your scalp. This current influences the way that your brain cells work. When the stimulus starts, you might feel a tingling sensation underneath the electrode pads. That sensation is not painful and goes away in seconds.
Lidocaine cream will be applied on the arm to reduce pain sensitivity (analgesia).
Capsaicin cream will be applied on the arm to increase pain sensitivity (hyperalgesia).
A neutral cream will be applied on the arm as a control.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Comparison of Functional Connectivity Changes of the DLPFC Before and After tDCS Stimulation
Time Frame: up to 2 weeks
We investigated the effects of cathodal (inhibition) and anodal (enhancement) tDCS on rDLPFC functional connectivity (FC) with the supplementary motor area (SMA) and anterior insula. Higher Fisher Z-scores represent greater resting-state functional connectivity.
up to 2 weeks
fMRI Resting States Functional Connectivity Changes During Pain Stimulation
Time Frame: up to 2 weeks
We measured changes in blood oxygen level-dependent (BOLD) activity in the brain during pain stimulation. In the outcome measure data table, "placebo contrast" indicates lidocaine - neutral and "nocebo contrast" indicates capsaicin - neutral.
up to 2 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Gracely Sensory Scale Pain Rating Changes in Response to Lidocaine and Capsaicin Creams and tDCS
Time Frame: up to 2 weeks
The Gracely Sensory Scale allows participants to rate the intensity of heat pain stimuli on a scale from 0 to 20, with 0 indicating no pain sensation and 20 indicating extremely intense pain. The outcome measure data table shows mean pain ratings for the lidocaine, capsaicin, and neutral creams after enhancement, inhibition, or sham tDCS stimulation.
up to 2 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (ACTUAL)

May 1, 2016

Primary Completion (ACTUAL)

March 1, 2019

Study Completion (ACTUAL)

March 1, 2019

Study Registration Dates

First Submitted

January 27, 2017

First Submitted That Met QC Criteria

April 5, 2017

First Posted (ACTUAL)

April 6, 2017

Study Record Updates

Last Update Posted (ACTUAL)

July 7, 2020

Last Update Submitted That Met QC Criteria

June 19, 2020

Last Verified

June 1, 2020

More Information

Terms related to this study

Other Study ID Numbers

  • 2015P000685

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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