Evaluation of the Potentiating Effect of tDCS on Opioid Analgesia of Pain Threshold in Humans

Hospital de Clinicas de Porto Alegre

Status and phase: Unknown; Phase 2

Conditions: Acute Pain

Treatments: Drug: Remifentanil; Drug: Placebo; Device: Active tDCS; Device: Sham tDCS

Study type: Interventional

Funder types: Other

Identifiers

NCT02432677

14-0217

Details and patient eligibility

About

The purpose of this study is to evaluate the potential additive effect of tDCS compared to placebo-sham in opioid analgesia on pain thresholds in nociceptive experimental model in healthy volunteers .

Full description

Pain is a prevalent symptom in medicine and the role of various opioids is valuable in the treatment of moderate to severe pain. Several technologies of brain stimulation , including transcranial direct current stimulation ( tDCS) are emerging as therapeutic options for many pain conditions. The effect of tDCS was demonstrated in sensory perception , decreasing the threshold for acute pain in healthy volunteers and in various chronic pain conditions . There is evidence about the use of tDCS with the participation through many mechanisms in cortical modulation , including the regulation of neurotransmitters, including opioids. In the context of neurostimulation, opioidergic system and cortical pain modulation, emerge the hypothesis of a possible potentiating effect of tDCS on clinical application of opioid analgesia.

Enrollment: 48 estimated patients

Sex: Male

Ages: 18 to 40 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Male
• Healthy
• Without medication
• Sign the informed consent

Exclusion criteria

• Patients who did not understand the Portuguese
• Acute or chronic pain conditions
• Medical or psychiatric disorders
• History of sleep disorders (apnea, hypersomnia, somnambulism...)
• History of alcohol or substance abuse
• Neurological disorder
• Use of anti-inflammatory drugs, steroids and non-steroids, opioid and non-opioid analgesics, psychiatric medications, anticonvulsants, alpha and beta blockers
• Traumatic brain injury
• Neurosurgery
• Metallic implant in the brain

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

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48 participants in 4 patient groups

Remifentanil + Active tDCS

Experimental group

Description:

* tDCS session: the procedure will initiate by placing an anode electrode on the primary motor cortex (contralateral to the dominant cortex) and the cathode electrode on the contralateral supra-orbital region. The current employed is 2mA of transcranial direct-current stimulation administered for 20 minutes. * Remifentanil - 0,06mcg.kg.min - Infusion 10min before the tDCS session, during the tDCS session and after the tDCS session, until the end of pain tests.

Treatment:

Drug: Remifentanil

Device: Active tDCS

Placebo + Active tDCS

Other group

Description:

* tDCS session: the procedure will initiate by placing an anode electrode on the primary motor cortex (contralateral to the dominant cortex) and the cathode electrode on the contralateral supra-orbital region. The current employed is 2mA of transcranial direct-current stimulation administered for 20 minutes. * Placebo: Saline infusion - Infusion 10min before the tDCS session, during the tDCS session and after the tDCS session, until the end of pain tests.

Treatment:

Drug: Placebo

Device: Active tDCS

Remifentanil + Sham tDCS

Other group

Description:

* Sham tDCS: consists in the same montage of the active tDCS, but the device is turned off 30 seconds after starting stimulation (without letting the patient notice it). The rest of the montage is kept identical to the active one during the 20 minutes session. * Remifentanil - 0,06mcg.kg.min - Infusion 10min before the tDCS session, during the tDCS session and after the tDCS session, until the end of pain tests.

Treatment:

Drug: Remifentanil

Device: Sham tDCS

Placebo + Sham tDCS

Other group

Description:

* Sham tDCS: consists in the same montage of the active tDCS, but the device is turned off 30 seconds after starting stimulation (without letting the patient notice it). The rest of the montage is kept identical to the active one during the 20 minutes session. * Placebo: Saline infusion - Infusion 10min before the tDCS session, during the tDCS session and after the tDCS session, until the end of pain tests.

Treatment:

Device: Sham tDCS

Drug: Placebo