Measuring and Modulating Changes in EEG Resting State Functional Connectivity During Short-term and Long-term Pain

NCT05158309 | Completed

• 1 other identifier: N-20190057
• Study Type: interventional
• Target: 24
• Locations: 1 country
• Sites: 1

Brief Summary

Background and aims: Experimental prolonged pain models can shed more light on the cortical mechanisms involved in the transition from acute to chronic pain including changes in resting state functional connectivity (rsFC). This experiment aimed at examining the effect of 24-hour-capsaicin application on the rsFC of the default mode network (DMN), a prominent network in the dynamic pain connectome. Methods: Electroencephalographic (EEG) rsFC measured by Granger causality was acquired at baseline, 1-hour, and 24-hour following the initial patch application (placebo or capsaicin). After 24 hours, the patch was cooled down then heated up to assess rsFC changes in response to pain relief and facilitation. Pain was induced using a topical capsaicin patch (or placebo as control) on the right forearm and assessed on a 0-10 numerical rating scale (NRS).

Conditions

Prolonged Pain, EEG, Resting State Functional Connectivity

Outcome Measures

Primary Outcomes (2)

• Change in resting state functional connectivity

  resting state functional connectivity is assessed using Granger causality. It can take on any value starting with "0" representing no connectivity. Higher granger causality scores indicate higher connectivity.

  Granger causality is assessed at 5 time points for each condition (capsaicin or placebo): baseline, 1 hour, 24 hours, 24 hours, cooling at 24hours, and heating at 24 hours.

• Change in Subjective pain intensity

  Intensity rated by the participants on a numerical rating scale anchoring from 0 "no pain" to 10 "the worst imaginable pain" . Higher numerical rating scores indicate higher pain intensity.

  Intensity is assessed at 5 time points for each condition (capsaicin or placebo): baseline, 1 hour, 24 hours, cooling at 24hours, and heating at 24 hours.

Secondary Outcomes (11)

• Change in Pain sensitivity (Warmth detection threshold)

  Warmth detection threshold is assessed at 3 time points for each condition (capsaicin or placebo): baseline, 1 hour, and 24 hours.

• Change in Pain sensitivity ( Cold detection threshold).

  Warmth detection threshold is assessed at 3 time points for each condition (capsaicin or placebo): baseline, 1 hour, and 24 hours.

• Change in Pain sensitivity ( Heat pain threshold).

  Heat pain threshold is assessed at 3 time points for each condition (capsaicin or placebo): baseline, 1 hour, and 24 hours.

• Change in Pain sensitivity ( Cold pain thresholds).

  Cold pain threshold is assessed at 3 time points for each condition (capsaicin or placebo): baseline, 1 hour, and 24 hours.

• Change in Pain sensitivity ( Mechanical pain thresholds).

  Mechanical pain threshold is assessed at 3 time points for each condition (capsaicin or placebo): baseline, 1 hour, and 24 hours.

Study Arms (2)

Capsaicin

EXPERIMENTAL

Capsaicin condition: in this condition participants received pain using a (5x10 cm) 8% topical capsaicin patch on the volar part of the dominant right forearm.

Other: 8% Capsaicin patch

Placebo

PLACEBO COMPARATOR

Placebo condition: participants received no pain.

Other: placebo patch

Interventions

8% Capsaicin patch OTHER

Cutaneous pain was induced using a (5x10 cm) 8% topical capsaicin patch (transdermal patch, 'Qutenza', Astellas) on the volar part of the dominant right forearm (5 cm from the wrist) of each participant.

Capsaicin

placebo patch OTHER

A transparent patch with no formulation or effect but the same size of the capsaicin patch was applied to the same location.

Placebo

Eligibility Criteria

• Age: 19 Years - 44 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Healthy men and women, age 19-44, right-handed (assessed using the Edinburgh Handedness Inventory, speak and understand English.

You may not qualify if:

• Chili allergies
• History of chronic pain or current acute pain
• Present or previous neurologic such as epilepsy, Alzheimer disease, dementia, stroke, migraine and other headache disorders, multiple sclerosis, Parkinson's disease, neuroinfections, brain tumours and head trauma.
• Present or previous musculoskeletal disorders such muscle/tendon strain, ligament sprain tension,tendonitis, degenerative disc disease, mechanical back syndrome, and ruptured/herniated disc.
• Present or previous mental illnesses such as depression, bipolar disorder, and schizophrenia.
• Pregnancy
• Current use of medications that may affect the trial (e.g. pain relieving medication and anti-inflammatory medication)
• Using hair products that may interfere with EEG conductance such as gel, except for shampoo, prior to the trial.
• Drug addiction defined as the use of cannabis, opioids or other drugs
• Consumption of alcohol, caffeine, or tobacco 6 hours before the experimental onset
• Lack of ability to cooperate -

Sponsors & Collaborators

• Aalborg University: lead
• Danish National Research Foundation: collaborator
• European Commission: collaborator

Study Sites (1)

Aalborg University, Department of Health Sciences and technology

Aalborg, 9220, Denmark

Location

Study Officials

• Thomas Graven-Nielsen, DMSc, PhD

  Aalborg University

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal investigator

Model Details: Participants experienced both experimental (capsaicin) condition and placebo conditions. Due to the long-lasting effects of capsaicin after 24 hours of application, placebo condition always preceded the capsaicin condition.

Study Record Dates

• First Submitted: December 13, 2021
• First Posted: December 15, 2021
• Study Start: May 31, 2021
• Primary Completion: November 6, 2021
• Study Completion: November 6, 2021
• Last Updated: March 15, 2022

Record last verified: 2022-03

Locations

DK (1)