Neuromodulation of Lidocaine and Capsaicin Cream Effects on Pain Experience

Not Applicable

Completed

• Conditions: Pain

• Registration Number: NCT03102710
• Lead Sponsor: Massachusetts General Hospital

Brief Summary

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.

Detailed Description

Not available

Study Timeline

• Study Start: 2016-05
• Study First Submitted: 2017-01-27
• Study First Submitted QC: 2017-04-05
• Study First Posted: 2017-04-06
• Primary Completion: 2019-03
• Study Completion: 2019-03
• Results First Submitted: 2020-05-13
• Status Verified: 2020-06
• Results First Submitted QC: 2020-06-19
• Last Update Submitted: 2020-06-19
• Results First Posted: 2020-07-07
• Last Update Posted: 2020-07-07

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 103

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 & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
fMRI Resting States Functional Connectivity Changes During Pain Stimulation	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.
Comparison of Functional Connectivity Changes of the DLPFC Before and After tDCS Stimulation	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.

Secondary Outcome Measures

Name	Time	Method
Gracely Sensory Scale Pain Rating Changes in Response to Lidocaine and Capsaicin Creams and tDCS	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.

Trial Locations

Locations (1)

Massachusetts General Hospital; 🇺🇸 Charlestown, Massachusetts, United States