Effects of Flumazenil on Brain Excitability

Effects of Flumazenil on Cortical Excitability in Humans

This study will investigate the effects of the drug flumazenil on brain excitability and the drug's relationship to a natural brain chemical called GABA. Flumazenil is commonly used in hospitals to reverse the effects of a group of drugs called benzodiazepines, one of which is Valium. Benzodiazepines act by enhancing the effects of GABA.

Healthy volunteers 21 years of age and older may be eligible for this study. Candidates will be screened with a medical history and physical and neurological examinations.

Participants will have transcranial magnetic stimulation (TMS) four times on two different days, before and after receiving an intravenous (through a vein) infusion of either flumazenil or placebo (an inactive sugar solution), as follows:

TMS study 1

Drug or placebo infusion

TMS study 2 - 15 minutes after infusion

TMS study 3 - 60 minutes after infusion

TMS study 4 - 120 minutes after infusion

In transcranial magnetic stimulation, a very brief electrical current is passed through an insulated coil wire placed on the scalp. These currents stimulate the cortex (outer part of the brain). They may cause muscle, hand, or arm twitching if the coil is near the part of the brain that controls movement, or they may affect other reflexes or movements. During the study, subjects may be asked to make movements, do simple tasks or tense muscles. To record the electrical activity of muscles, electrodes will be taped to the skin over the muscles tested. In some cases, the studies will be videotaped.

Flumazenil will be infused through a catheter (thin plastic tube) attached to a needle placed in an arm vein. On one day, subjects will receive a 1-mg injection of flumazenil followed by a continuous infusion of 0.5 mg of the drug for about 30 minutes. On the other day, they will receive placebo, administered in the same manner.

Study Overview

Status

Completed

Conditions

Detailed Description

The purpose of this study is to investigate the effects of flumazenil on cortical excitability in healthy human volunteers. Flumazenil acts as a potent benzodiazepine (BZP)-specific antagonist by competing at the central synaptic gamma-aminobutyric acid (GABA) receptor site. However, the relationship between GABA and flumazenil without BZPs is not well known. We plan to determine if intravenous (IV) administration in therapeutic dosage alters cortical excitability as measured by transcranial magnetic stimulation (TMS). The long-term plan is to identify a pharmacological method to reduce cortical inhibition that might be useful in stroke rehabilitation.

Study Type

Observational

Enrollment

7

Contacts and Locations

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

Study Locations

    • Maryland
      • Bethesda, Maryland, United States, 20892
        • National Institute of Neurological Disorders and Stroke (NINDS)

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

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Only healthy volunteers, who are age 21 or older.

No history of surgery with metallic implants or known metallic particles in the brain.

Patients cannot be pregnant (as tested with a pregnancy test).

Patients with a psychiatric illness are not eligible.

No history of seizures.

No cardiovascular disease or drug therapy for chronic depression.

No hypersensitivity to benzodiazepines and related drugs.

No history of drug abuse and/or chronic alcoholism.

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?

Collaborators and Investigators

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

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

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, 2001

Study Completion

April 1, 2002

Study Registration Dates

First Submitted

April 28, 2001

First Submitted That Met QC Criteria

April 28, 2001

First Posted (Estimate)

April 30, 2001

Study Record Updates

Last Update Posted (Estimate)

March 4, 2008

Last Update Submitted That Met QC Criteria

March 3, 2008

Last Verified

April 1, 2002

More Information

Terms related to this study

Other Study ID Numbers

  • 010164
  • 01-N-0164

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.

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