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

Aalborg University

Status: Completed

Conditions: Prolonged Pain, EEG, Resting State Functional Connectivity

Treatments: Other: 8% Capsaicin patch; Other: placebo patch

Study type: Interventional

Funder types: Other

Identifiers

NCT05158309

N-20190057

Details and patient eligibility

About

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).

Enrollment: 24 patients

Sex: All

Ages: 19 to 44 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

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

Exclusion criteria

1. Chili allergies
2. History of chronic pain or current acute pain
3. 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.
4. Present or previous musculoskeletal disorders such muscle/tendon strain, ligament sprain tension,tendonitis, degenerative disc disease, mechanical back syndrome, and ruptured/herniated disc.
5. Present or previous mental illnesses such as depression, bipolar disorder, and schizophrenia.
6. Pregnancy
7. Current use of medications that may affect the trial (e.g. pain relieving medication and anti-inflammatory medication)
8. Using hair products that may interfere with EEG conductance such as gel, except for shampoo, prior to the trial.
9. Drug addiction defined as the use of cannabis, opioids or other drugs
10. Consumption of alcohol, caffeine, or tobacco 6 hours before the experimental onset
11. Lack of ability to cooperate -

Trial design

Primary purpose: Basic Science

Allocation: Non-Randomized

Interventional model: Crossover Assignment

Masking: Single Blind

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24 participants in 2 patient groups, including a placebo group

Capsaicin

Experimental group

Description:

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.

Treatment:

Other: 8% Capsaicin patch

Placebo

Placebo Comparator group

Description:

Placebo condition: participants received no pain.

Treatment:

Other: placebo patch