Modulatory Effects of Multichannel tDCS During Prolonged Experimental Pain

Aalborg University

Status: Completed

Conditions: Brain Modulation; Neuroplasticity; Prolonged Pain

Treatments: Device: transcranial direct current stimulation

Study type: Interventional

Funder types: Other

Identifiers

NCT04165980

VN-20180092

Details and patient eligibility

About

Corticomotor excitability, pain sensitivity, descending pain control and somatosensory evoked potentials (SEPs) is often altered in acute and chronic pain.

Topical capsaicin generates stable, long-lasting hyperalgesia and ongoing tonic pain in healthy participants, which significantly inhibits corticomotor excitability in the primary motor cortex (M1).

Recent studies (by Fischer et al 2017) indicated that multifocal Transcranial Direct Current Stimulation (tDCS) administered to brain regions linked to the resting state motor network (network-tDCS) could enhance corticomotor excitability in healthy participants compared to single site M1-tDCS.

It remains unknown whether network-tDCS has also the potential to modulate the inhibitory effects on motor cortex excitability, pain sensitivity, descending pain control and SEPs associated with prolonged pain

Full description

To date, pain modulation to M1 rs-network tDCS during 8% capsaicin induced pain has not been assessed (Mylius, Borckardt and Lefaucheur, 2012). Further, it is unknown how multichannel tDCS acts on tonic cutaneous pain for approximately 24 hours.

The main objective of these projects are to study and characterize quantitatively the effects of multichannel tDCS in the development of prolonged pain.

It is hypothesized that multichannel tDCS of left M1 resting-state network will reduce the severity of experimentally prolonged pain over the m. first dorsal interosseous (FDI), will increase descending pain control, might possibly increase pain thresholds and simultaneously will modulate the peak-to-peak amplitude of SEPs to electrical painful stimulation. Further, it is hypothesized that descending pain modulation of M1 tDCS will be related to interference with the suppression of cortical excitability

Enrollment: 38 patients

Sex: All

Ages: 21 to 50 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

-Right-handed healthy men and women in the age 21-50 years who speak and understand English

Exclusion criteria

• Lack of ability to cooperate
• History of chronic pain or current acute pain
• Pregnancy
• Drug addiction defined as the use of cannabis, opioids or other drugs
• Present and previous neurologic, musculoskeletal or mental illnesses
• Chili allergies (subproject 1 and 2)
• Current use of medications that may affect the trial
• Previous experience with rTMS and tDCS
• Contraindications to rTMS application (history of epilepsy, metal implants in head or jaw, etc.)
• Failure to pass the questionnaire for tDCS
• Failure to pass the "TASS questionnaire" (TASS = Transcranial Magnetic Stimulation Adult Safety Screen) (Rossi et al., 2001)

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

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38 participants in 2 patient groups

Sham transcranial direct current stimulation (sham tDCS)

Sham Comparator group

Description:

This study has a parallel design and 2 groups: Active tDCS and Sham tDCS. Sham tDCS applies a standard sham protocol consisting of ramping up and down during 30 seconds at the beginning and at the end of each tDCS session. Each tDCS session lasts 20 minutes and applies a total current of 4mA.

Treatment:

Device: transcranial direct current stimulation

Active transcranial direct current stimulation (activetDCS)

Active Comparator group

Description:

The active comparator is the Active tDCS group. The active tDCS will target the resting-state motor network and will apply a distributed direct current during the whole session. (The TIME during the direct current is applied is the only difference with Sham tDCS) Each tDCS session lasts 20 minutes and applies a total current of 4mA.

Treatment:

Device: transcranial direct current stimulation