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HealthyNCT00054990

Effects of Antiepileptic Drugs on Brain Excitability

An observational study of Healthy, run by National Institute of Neurological Disorders and Stroke (NINDS) 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

This study will evaluate the usefulness of transcranial magnetic stimulation (TMS) in measuring cortical excitability. The cortex is the outer part of the brain. Patients with seizures have increased cortical excitability and are often treated with antiepileptic drugs to reduce this excitability. Read more about this study

Who is it for?
Any ageHealthy volunteers can take part
Conditions the study is for
Healthy
How many people
40 participants
Where
1 siteUnited States
Study dates
Feb 2003to Mar 2004
Phase
Observational
Are there results?
None posted in the registry

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 Any age
  • All sexes
  • Healthy volunteers accepted
  • Child, Adult, Older adult

Who may be able to join

  • Normal volunteers will be male or female, aged 18 to 55 at protocol entry without any of the exclusion criteria described below.

Who cannot join

  • Patients will be excluded from this study if they:
  • are pregnant (tested with urine pregnancy test).
  • have severe coronary disease.
  • have metal anywhere in the cranium except the mouth.
  • have intracardiac lines.
  • have increased intracranial pressure as expressed by the presence of papilledema.
Show all 12Show fewer
  • have cardiac pacemakers.
  • take neuroleptic or antidepressant medications.
  • any neurologic disease including epilepsy.
  • taking any psychiatric drugs.
  • any other documented systemic illness.
  • history of drug allergy.

Trial locations and contacts

1 site in 1 country.

United States1 site
  • National Institute of Neurological Disorders and Stroke (NINDS)

    Bethesda, Maryland, 20892

Other trials in United States

About this study

Official title: The Effects Of Antiepileptic Drugs On Cortical Excitability

This study will evaluate the usefulness of transcranial magnetic stimulation (TMS) in measuring cortical excitability. The cortex is the outer part of the brain. Patients with seizures have increased cortical excitability and are often treated with antiepileptic drugs to reduce this excitability. The therapeutic effects of antiepileptic drugs are usually tracked with blood tests that measure their blood levels. However, these blood tests may not always correctly reflect the effects of the drugs on the brain.

TMS has been used successfully to measure cortical excitability in many neurological diseases, including epilepsy, and may be helpful in measuring drug effects on the brain directly. For this procedure, a wire coil is held over the scalp. A brief electrical current is passed through the coil, creating a magnetic pulse that stimulates the brain. This may cause a pulling sensation on the skin under the coil and twitching in muscles of the face, arm, or leg. During the stimulation, the participant may be asked to tense certain muscles slightly or perform other simple actions.

Read more

Healthy normal volunteers between 18 and 55 years of age may be eligible for this study. Candidates will be screened with a medical history, physical and neurological examination, electroencephalogram (EEG), and blood tests.

On the first day of the study, participants will have a baseline TMS and will be randomly assigned to take one of two antiepileptic drugs: group A will take the carbamazepine; group B will take lamotrigine. If they wish, participants may be admitted to the NIH Clinical Center for the first 5 days of drug administration while the proper dosage is being determined. They will then be discharged and continue taking the drug for a total of 36 days. During this time, they will have daily blood tests and TMS from days 2 through 5, and again on days 12 and 36. Group A will have additional blood sampling and TMS on days 37, 39, 44, and 53; Group B will have blood tests and TMS on days 38, 40, 45, and 53.

Read the detailed description

Objectives. Epilepsy is a condition characterized by abnormally increased cortical excitability, and antiepileptic drugs (AEDs) control epilepsy by reducing cortical excitability. Serum blood levels presently represent the standard measure utilized to track the therapeutic effects of AEDs. However, peripheral blood levels do not always reflect brain levels, or provide direct information on cortical excitability. Transcranial magnetic stimulation (TMS) is a non-invasive technique that allows accurate measures of this parameter. The purpose of this protocol is to test the hypothesis that TMS measures of cortical excitability will correlate with serum blood levels of AEDs, and reflect clinical effects on cortical function directly in healthy volunteers. This information is crucial to reach the ultimate goal of developing a reliable quantitative measurement of central physiological effects of AEDs in epileptic patients.

Study Population. 40 normal volunteers aged 18 to 55 years will be recruited for this study.

Design. Subjects will be assigned to either of two groups, with each group receiving one of the following drugs; carbamazepine (CBZ), and lamotrigine (LTG). Measures of cortical excitability will be performed using TMS in various drug treatment phases: at baseline (before drug intake); during the AED induction period (once a day for the first 5 days), after 12 days of drug intake at the maximum dose during steady state; and 3, 7, and 14 half-lives after, and finally three weeks after abrupt drug withdrawal. Blood sampling for drug levels will be performed at each TMS study.

Outcome Measures. The primary outcome variables will be MEP size, measured from recruitment curves. MEP size difference from baseline will be compared to the serum drug level for each drug.

Conditions
Healthy
Keywords
Antiepileptic Drugs, Cortical Excitability, Transcranial Magnetic Stimulation, Epilepsy, TMS, Healthy Volunteer, HV
Medical subject headings
Epilepsy

Timeline

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

  1. First posted17 Feb 2003 (estimated)
  2. Study startFeb 2003
  3. Study completionMar 2004

Resources

More details

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

Study design
Study type
Observational
Enrolment
40 participants
IDs, dates and publications
ClinicalTrials.gov ID
NCT00054990
Sponsor's protocol ID
030107
Other IDs
03-N-0107
Status last verified
Mar 2004
First submitted
15 Feb 2003
Last updated
4 Mar 2008
Results posted
No

Publications

  • Burstein AH, Horton RL, Dunn T, Alfaro RM, Piscitelli SC, Theodore W. Lack of effect of St John's Wort on carbamazepine pharmacokinetics in healthy volunteers. Clin Pharmacol Ther. 2000 Dec;68(6):605-12. doi: 10.1067/mcp.2000.111530.

    PubMed 11180020
  • Cantello R, Civardi C, Cavalli A, Varrasi C, Tarletti R, Monaco F, Migliaretti G. Cortical excitability in cryptogenic localization-related epilepsy: interictal transcranial magnetic stimulation studies. Epilepsia. 2000 Jun;41(6):694-704. doi: 10.1111/j.1528-1157.2000.tb00230.x.

    PubMed 10840401
  • Chen R, Samii A, Canos M, Wassermann EM, Hallett M. Effects of phenytoin on cortical excitability in humans. Neurology. 1997 Sep;49(3):881-3. doi: 10.1212/wnl.49.3.881.

    PubMed 9305361

Questions about this trial

What is this clinical trial studying?

An observational study of Healthy, run by National Institute of Neurological Disorders and Stroke (NINDS) 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 1 inclusion and 12 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 4 Mar 2008. 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. 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?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

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.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT00054990, which also lists 3 linked publications.

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 4 Mar 2008.

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