Pilot Study Using an NMDA Antagonist to Modulate Transcranial Direct Current Stimulation (tDCS) Effects on Sensory Discrimination

April 21, 2015 updated by: Dr. Verner Knott, University of Ottawa

A Pilot Study Using an NMDA Antagonist to Modulate Transcranial Direct Current Stimulation (tDCS) Effects on Auditory Sensory Memory Processing

Transcranial direct current stimulation (tDCS) is a non-invasive form of brain stimulation which uses a very weak constant current to temporarily excite the brain area of interest via small electrodes placed on the scalp. Currently, tDCS is being used as a tool to investigate mental processes (cognition) and motor function (movement) in healthy controls and to treat neurological (i.e. stroke) and psychiatric (i.e. depression and dementia) patients. tDCS has been found to improve motor processes and cognitive performance, including attention and memory functions. This study will attempt to examine the effects of tDCS on a specific aspect of short term memory to sounds measured from electrical activity (EEG) from the top of the scalp. This study will also assess the effect of a drug, dextromethorphan (DMO), commonly found in cough syrup, which is thought to regulate tDCS treatment through brain receptors. The study involves four laboratory test sessions. EEG assessments will be done in two sessions involving 'anodal' tDCS stimulation (to temporarily excite cortical activity locally), one session with DMO treatment and one with placebo treatment, and two sessions involving 'sham' tDCS stimulation (device is turned off), with the same DMO and placebo treatments. These findings will contribute to our understanding of the brain chemistry involved in tDCS treatment and its effects on cognitive abilities.

Study Overview

Status

Unknown

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Anticipated)

12

Phase

  • Phase 2
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • Canada
    • Ontario
      • Ottawa, Ontario, Canada, K1Z 7K4
        • University of Ottawa Institute of Mental Health Research

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 35 years (ADULT)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Healthy, medication free
  • Non-smoker
  • Right-handed

Exclusion Criteria:

  • Any current or past Axis I or Axis II disorder including a current or recent history of alcohol/substance abuse
  • A clinically significant medical illness or organic brain disorder known to cause psychosis or cognitive impairment
  • Any neurological diagnosis (including epilepsy)
  • Recent head trauma (<6 months)
  • Metallic implants or any electrical device (e.g., pacemaker) in the body
  • Major learning disability
  • Body mass index >38kg/m¬2
  • Use of illicit drugs
  • Abnormal hearing

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Allocation: RANDOMIZED
  • Interventional Model: CROSSOVER
  • Masking: DOUBLE

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Direct Current Stimulation active
Electrodes will be placed on the scalp overlying the left auditory cortex (anodal electrode) and on the contralateral forehead above the orbit (reference/cathode). Stimulation will be applied using a battery-driven constant-current regulator (Oasis Pro, Edmonton). In active tDCS sessions, the DC current will be initially increased in a ramp-like fashion over 10 s until reaching 2 mA and will be similarly decreased at the end of stimulation. In active tDCS, stimulation will be maintained for a total of 20 minutes. This will occur in two separate sessions, occurring within weeks.
Device: Direct Current Stimulation

Comparison between active Direct Current Stimulation (2 mA, 20 minutes) and Sham stimulation (the device is set up, but only turned on for 30 seconds).

Conductive saline-soaked rubber electrodes super-imposed on sponge plates will be placed on the scalp overlying the left auditory cortex (anodal electrode) and on the contralateral forehead above the orbit (reference/cathode). Stimulation will be applied using a battery-driven constant-current regulator (Oasis Pro, Edmonton). In active tDCS sessions, the DC current will be initially increased in a ramp-like fashion over 10 s until reaching 2 mA and will be similarly decreased at the end of stimulation. In active tDCS, stimulation will be maintained for a total of 20 minutes. This will occur in two separate sessions, occurring within weeks. For 'sham' stimulation, the device will only be turned on for 30 seconds. This will occur in two separate sessions, occurring within weeks.
Sham Comparator: Direct Current Stimulation sham
In sham sessions, the device will have the same placement and intensity, but will only be turned on for 30 seconds. The DC current will be initially increased in a ramp-like fashion over 10 s until reaching 2 mA and will be similarly decreased at the end of stimulation. This will occur in two separate sessions, occurring within weeks.
Device: Direct Current Stimulation

Comparison between active Direct Current Stimulation (2 mA, 20 minutes) and Sham stimulation (the device is set up, but only turned on for 30 seconds).

Conductive saline-soaked rubber electrodes super-imposed on sponge plates will be placed on the scalp overlying the left auditory cortex (anodal electrode) and on the contralateral forehead above the orbit (reference/cathode). Stimulation will be applied using a battery-driven constant-current regulator (Oasis Pro, Edmonton). In active tDCS sessions, the DC current will be initially increased in a ramp-like fashion over 10 s until reaching 2 mA and will be similarly decreased at the end of stimulation. In active tDCS, stimulation will be maintained for a total of 20 minutes. This will occur in two separate sessions, occurring within weeks. For 'sham' stimulation, the device will only be turned on for 30 seconds. This will occur in two separate sessions, occurring within weeks.
Active Comparator: NMDA antagonist active
Dextromethorphan (DMO), a non-competitive NMDA antagonist, will be delivered in the form of generic Life Brand Clear Cough Syrup DM (Trillium Healthcare Products Inc, Brockville, ON). Each subject will receive a dose of 50 ml DM with no-sugar cranberry juice (100 ml) to drink. This same dose will be delivered in two separate sessions, occurring within weeks.
Drug: Dextromethorphan
Comparison between Dextromethorphan and a no-sugar placebo. Dextromethorphan (DMO), a non-competitive NMDA antagonist, will be delivered in the form of generic Life Brand Clear Cough Syrup DM (Trillium Healthcare Products Inc, Brockville, ON), which has high dose of DMO (15 mg/5 ml) with no other major additives. Each subject will receive a dose of 50 ml DM with no-sugar cranberry juice (100 ml) to drink from a mug, while wearing a nose plug. This same dose will be delivered in two separate sessions, occurring within weeks. Each subject will receive a dose of a placebo (150 ml of no-sugar cranberry juice) to drink from a mug, while wearing a nose plug. This same dose will be delivered in two separate sessions, occurring within weeks.
Other Names:
  • Life Brand Clear Cough Syrup DM
Placebo Comparator: NMDA antagonist placebo
Each subject will receive a dose of a placebo (150 ml of no-sugar cranberry juice) to drink. This same dose will be delivered in two separate sessions, occurring within weeks.
Drug: Dextromethorphan
Comparison between Dextromethorphan and a no-sugar placebo. Dextromethorphan (DMO), a non-competitive NMDA antagonist, will be delivered in the form of generic Life Brand Clear Cough Syrup DM (Trillium Healthcare Products Inc, Brockville, ON), which has high dose of DMO (15 mg/5 ml) with no other major additives. Each subject will receive a dose of 50 ml DM with no-sugar cranberry juice (100 ml) to drink from a mug, while wearing a nose plug. This same dose will be delivered in two separate sessions, occurring within weeks. Each subject will receive a dose of a placebo (150 ml of no-sugar cranberry juice) to drink from a mug, while wearing a nose plug. This same dose will be delivered in two separate sessions, occurring within weeks.
Other Names:
  • Life Brand Clear Cough Syrup DM

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
MMN ERP amplitudes as a measure of sensory processing changes
Time Frame: 1 year
Acute effects of DMO (vs. placebo) and tDCS (vs. sham) on MMN-indexed auditory sensory memory processing
1 year
Adverse Events Scores as measure of treatment side effects
Time Frame: 1 year
Adverse Events and self-reported symptoms after treatment
1 year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Ottawa

Investigators

  • Principal Investigator: Danielle Impey, Ph.D. (cand.), University of Ottawa Institute of Mental Health Research

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

April 1, 2015

Primary Completion (Anticipated)

September 1, 2015

Study Completion (Anticipated)

April 1, 2016

Study Registration Dates

First Submitted

April 13, 2015

First Submitted That Met QC Criteria

April 21, 2015

First Posted (Estimate)

April 27, 2015

Study Record Updates

Last Update Posted (Estimate)

April 27, 2015

Last Update Submitted That Met QC Criteria

April 21, 2015

Last Verified

April 1, 2015

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2013008

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Schizophrenia

Clinical Trials on Direct Current Stimulation

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Belarus

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

3
Subscribe