Repetitive Transcranial Magnetic Stimulation (rTMS) and P50 Evoked Potential Component (rTMS-P50)

March 30, 2026 updated by: University Hospital, Caen

Evaluation of Effect of Low and High-frequencies of Repetitive Transcranial Magnetic Stimulation (rTMS) by the Suppression of P50 Evoked Potential Component (rTMS-P50)

The repetitive transcranial magnetic stimulation (rTMS) is a recent technique that has demonstrated its efficiency in both depression and schizophrenia. However if its efficiency has been recognized by the scientific community and the clinicians, its action on neurons and cerebral networks remains debated.

In the motor regions, the different rTMS studies generally use frequencies of stimulation of 1 to 40 Hz with differential effects; the low frequencies being associated with an inhibitory effect whereas highest frequencies have rather some facilitator effects as attested by the motor responses. What is valid for the motor system is not however necessarily applicable to other cerebral regions that have different neuronal organizations. If it is easy to observe these opposite effects of rTMS on the motor system (presence or absence of movements), these potential effects on more integrated cortex involved in high level functions have not been proved.

One of the possibilities to interpret the effects of the rTMS in no-motor cerebral regions would be to study the modifications of the EEG before and after rTMS and to see if a differential effect of the high and low frequencies of stimulation exists. Up to now, the studies having coupled these two techniques have observed modifications of the brain electric activity only during some seconds to minutes after rTMS, what appears in contrast with the clinical effects observed after a long delay (several days).

The contribution of our research resides in the use of the paradigm of suppression of P50 evoked potential component before and after rTMS tested with low and high frequencies of stimulation. This paradigm consists in two identical auditory stimuli presented at a very short interval (generally 500 milliseconds), the second sound generating a P50 wave of weaker amplitude than the first or being completely abolished in healthy subjects. However, this effect that has been well studied could result from an inhibitory action due to the gabaergic interneurons on the pyramidal neurons of the cortex. Thus, the investigators hypothesize that high frequency rTMS would have a facilitator effect on temporal lobe and so would induce no suppression of the P50 after-rTMS whereas low frequency rTMS would induce an inhibitory effect marked by a greater suppression of the P50.

Methods: 30 healthy subjects (of which 16 women) will be included after written consent. They will receive after randomization 2 sessions of rTMS in cross over at 1Hz and 20Hz at 30 days interval. An EEG and a P50 evoked potential will be done before and after rTMS. The site of stimulation will be determined by neuronavigation and will correspond to the maximal activation cluster generated by a language task during functional magnetic resonance imaging. The main judgment criterion is the S2/S1 ratio of the P50. The potential secondary effects will be evaluated (UKU adapted). The secondary criteria are the comparisons before and after rTMS of EEG spectrums in the alpha, beta and gamma bands.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

30

Phase

  • Phase 2

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

  • France
      • Caen, France
        • Caen University Hospital, department of psychiatry and explorations fonctionnelles neurologiques

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 60 years (Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • healthy subjects, right-handed, aged from 18 to 60 years
  • written consent
  • with social security

Exclusion Criteria:

  • pregnancy, breastfeeding
  • brain tumor or epilepsy
  • psychiatric, neurological or ear-nose-throat disorders, current or past
  • healthy subjects with psychotropic drugs or with substance abuses
  • healthy subjects with tabacco weaning
  • protected major with tutor
  • counter-indication to MRI and rTMS

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

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: high frequency rTMS
Procedure: high-frequency of repetitive transcranial magnetic stimulation (rTMS)
frequency of stimulation of 20 Hz
Other: low frequency rTMS
Procedure: low frequency of repetitive transcranial magnetic stimulation (rTMS)
frequency of stimulation of 1 Hz

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
P50 Ratio Stimulation 2/S stimulation 1
Time Frame: day of stimulation (day 1)
day of stimulation (day 1)

Collaborators and Investigators

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

Sponsor

University Hospital, Caen

Investigators

  • Principal Investigator: Pr Sonia Dollfus, MD, PhD, University Hospital, Caen

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.

General Publications

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

May 1, 2011

Primary Completion (Actual)

June 1, 2012

Study Completion (Actual)

June 1, 2013

Study Registration Dates

First Submitted

October 19, 2011

First Submitted That Met QC Criteria

November 7, 2011

First Posted (Estimated)

November 8, 2011

Study Record Updates

Last Update Posted (Actual)

April 2, 2026

Last Update Submitted That Met QC Criteria

March 30, 2026

Last Verified

June 1, 2013

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 09-181

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

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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