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PainNCT01643798

Role of the Supraspinal Opioidergic Circuit in Prefrontal TMS-Induced Analgesia

A study testing Real rTMS in people with Pain, run by Medical University of South Carolina at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Studies have shown that transcranial magnetic stimulation (TMS), a non-invasive form of brain stimulation, can reduce pain in the laboratory and in the clinic. The purpose of this study is to investigate how TMS relieves pain and affects pain circuitry in the brain. Read more about this study

Who is it for?
Ages 18 to 45 yearsHealthy volunteers can take part
Conditions the study is for
Pain
What is being tested?
Real rTMS
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
15 participants
Where
1 siteUnited States
Study dates
Jan 2011to Jun 2012
Phase
Interventional
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 45 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • healthy volunteers
  • no history of depression or pain
  • no metal in body
  • no medications that lower seizure threshold

Who cannot join

  • history of depression or pain
  • history of seizures or epilepsy
  • metal implants in body
  • medications that lower seizure threshold
  • psychiatric medications

Trial locations and contacts

1 site in 1 country.

United States1 site
  • Medical University of South Carolina

    Charleston, South Carolina, 29414

Other trials in United States

About this study

Studies have shown that transcranial magnetic stimulation (TMS), a non-invasive form of brain stimulation, can reduce pain in the laboratory and in the clinic. The purpose of this study is to investigate how TMS relieves pain and affects pain circuitry in the brain. One of the primary study hypotheses is that opioid blockade will significantly reduce the pain relief produced by left prefrontal cortex TMS.

Read the detailed description

Non-invasive forms of brain stimulation such as transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS) are currently being investigated as alternative or adjunctive therapies for pain. Clinical interest in these techniques continues to grow because of rising opiate abuse and inadequate pain management strategies. Despite this enthusiasm, studies on the efficacy of repetitive TMS (rTMS) for pain have produced mixed results. Some of the most promising and informative research has focused on rTMS for perioperative pain. In two different postoperative studies, a single session of left dorsolateral prefrontal cortex (DLPFC) rTMS after gastric bypass surgery reduced morphine self-administration by 40% when compared to sham stimulation. These data are particularly fascinating given the role of the DLPFC in top-down pain processing.

Centered at the juncture of Brodmann Areas (BAs) 9 and 46, the DLPFC remains a popular therapeutic target for rTMS given its accessible location and presumed role in high-order cognition and emotional valence. Animal and human studies suggest that cingulofrontal regions like DLPFC may modulate pain perception via recruitment of opioidergic midbrain and brainstem structures like the periaqueductal gray (PAG) and the rostroventromedial medulla (RVM), respectively. These data outline the functional circuitry that might be involved in the analgesic effects of DLPFC rTMS.

While many studies aim to evaluate the clinical efficacy of DLPFC rTMS for pain management, few have examined how it affects pain processing. Imaging the cerebral signature of pain before and after left DLPFC rTMS might reveal information about pain circuitry and help to elucidate the mechanism by which prefrontal rTMS may produce analgesia. Previous studies suggest that opioid blockade abolishes left but not right DLPFC rTMS-induced analgesia. In this study, our a priori hypothesis was that left DLPFC rTMS would attenuate blood oxygenation-level dependent (BOLD) signal response to painful stimuli in pain processing regions. More specifically, we anticipated that midbrain and medulla BOLD signal changes induced by left DLPFC rTMS would be abolished by pretreatment with the μ-opioid antagonist naloxone.

Conditions
Pain
Being tested
Sham rTMS, Real rTMS
Medical subject headings
Pain

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Sham rTMSProcedure or surgery

    Also called Neuronetics Model 2100 Therapy System

    The eSham system was implemented in conjunction with a specialized Neuronetics sham TMS coil. This coil has a metal plate hidden inside of it that blocks the magnetic field from affecting the brain. Scalp electrodes were used to mimic the feel of real rTMS. This approach has been validated in previous studies.

  • Real rTMSProcedure or surgery

    Also called Neuronetics Model 2100 Therapy System

    An iron-core, solid-state figure-of-8 coil was used to stimulate the dorsolateral prefrontal cortex. The site of stimulation was estimated using the Beam F3 method based on the 10-20 EEG system.

Study groups in NCT01643798
Study groupRoleWhat they receive
SalinePlacebo comparatorParticipants received intravenous saline immediately prior to sham and real rTMS of the left dorsolateral prefrontal cortex. The parameters of the stimulation paradigm are as follows: 10 Hz, 5 seconds on, 10 seconds off, 20 minutes, 4000 pulses).
Receives: Procedure: Sham rTMS; Procedure: Real rTMS
NaloxoneActive comparatorParticipants received intravenous naloxone (0.1mg/kg) immediately prior to sham and real rTMS of the left dorsolateral prefrontal cortex. The parameters of the stimulation paradigm are as follows: 10 Hz, 5 seconds on, 10 seconds off, 20 minutes, 4000 pulses).
Receives: Procedure: Sham rTMS; Procedure: Real rTMS

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Pain Rating

    There are two experimental visits separated by one week. During each experiment, pain ratings will be measured every 30 minutes. "Preliminary testing" will be done 30 minutes into the experiment. The purpose of preliminary testing is to select the temperature that will be used to induce pain throughout the experiment. "Baseline testing" will be done 60 minutes into the experiment. "After sham rTMS" will be done 90 minutes into the experiment. "After real rTMS" will be done 120 minutes into the study. The pain scale used in a Visual Analog Scale (VAS). There was an 11-point rating system where "0" represented no pain and "10" represented unbearable pain.

    Measured: Baseline (60 minutes into experiment), Post-Sham (90 minutes), Post-Real (120 minutes)

  2. Change in BOLD Signal in Pain Processing Regions During Pain, Including Supraspinal Opioidergic Structures

    There are two experimental visits separated by one week. During each experiment, blood oxygen level dependent (BOLD) signal will be measured at baseline (60 minutes into the experiment), post-sham rTMS (90 minutes into the experiment) and post-real (120 minutes into the experiment).

    Measured: Baseline (60 minutes into experiment), Post-Sham (90 minutes), Post-Real (120 minutes)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted18 Jul 2012 (estimated)
  2. Study startJan 2011
  3. Primary completionMay 2012
  4. Study completionJun 2012

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Basic science
Allocation
Randomised
Intervention model
Crossover
Masking
Triple blind
Who is masked
Participant, Investigator, Outcomes assessor
Enrolment
15 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT01643798
Sponsor's protocol ID
1F30DA033748
Other IDs
1F30DA033748-01
Status last verified
Jun 2012
First submitted
22 Jun 2012
Last updated
15 Apr 2014
Data monitoring committee
No

Questions about this trial

What is this clinical trial studying?

A study testing Real rTMS in people with Pain, run by Medical University of South Carolina at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 4 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 15 Apr 2014. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

Yes. Results are posted in the registry (first posted 15 Apr 2014). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Pain Rating (time frame: Baseline (60 minutes into experiment), Post-Sham (90 minutes), Post-Real (120 minutes)). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Apr 2014.

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