title: Repetitive transcranial magnetic stimulation: hearing safety considerations.
abstract: BACKGROUND
  The guidelines for use of repetitive transcranial magnetic stimulation (rTMS) advise frequent updating of rTMS safety guidelines and recommendations. Although rTMS can produce sound of more than 120 dB C, which is sufficient to induce hearing loss, the effect of rTMS noise on the hearing of both patients and rTMS practitioners is understudied.
  
  
  OBJECTIVE
  This study investigated the effects of rTMS noise on subjects' hearing using otoacoustic emissions evoked by clicks (transiently evoked otoacoustic emissions, TEOAEs), which is an objective and sensitive method of cochlear exploration.
  
  
  METHODS
  Hearing thresholds and TEOAEs were recorded in 24 normal-hearing healthy subjects before and after a real or sham rTMS session (a single 20-minute session applied to the superior temporal gyrus with 1200 pulses at 100% of the individual motor threshold).
  
  
  RESULTS
  No significant difference in hearing thresholds was observed between subjects exposed to real or sham rTMS. However, the difference in TEOAE amplitude between pre- and post-rTMS sessions increased significantly with rTMS noise for those subjects the least protected by earplugs, showing a post-rTMS slight decrease of TEOAE amplitude for high rTMS intensities and hence minor hearing function alteration. However, this correlation was no longer found 1 hour after the rTMS session.
  
  
  CONCLUSIONS
  These findings suggest that, even when rTMS is used within normal safety limits and with good hearing protection, rTMS noise can transiently disturb hearing mechanisms in normal-hearing healthy subjects. This transient effect of rTMS on hearing may be an important consideration for Institutional Review Boards when rTMS is used at higher stimulation intensities.
authors.affiliation: Université de Lyon, Lyon, France; INSERM U1028, CNRS UMR5292, Lyon Neuroscience Research Center, Brain Dynamics and Cognition Team, Lyon, France; University Lyon 1, Lyon, France; Department of ENT, Hospices Civils de Lyon, Centre Hospitalier Lyon Sud, Pierre-Bénite, France. Electronic address: stephane.tringali@chu-lyon.fr.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Tringali
authors.affiliation: Université de Lyon, Lyon, France; INSERM U1028, CNRS UMR5292, Lyon Neuroscience Research Center, Brain Dynamics and Cognition Team, Lyon, France; University Lyon 1, Lyon, France; Department of Audiology, Hospices Civils de Lyon, Centre Hospitalier Lyon Sud, Pierre-Bénite, France.
authors.forename: Xavier
authors.initials: X
authors.lastname: Perrot
authors.affiliation: Université de Lyon, Lyon, France; INSERM U1028, CNRS UMR5292, Lyon Neuroscience Research Center, Brain Dynamics and Cognition Team, Lyon, France; University Lyon 1, Lyon, France; Department of Audiology, Hospices Civils de Lyon, Centre Hospitalier Lyon Sud, Pierre-Bénite, France.
authors.forename: Lionel
authors.initials: L
authors.lastname: Collet
authors.affiliation: Université de Lyon, Lyon, France; INSERM U1028, CNRS UMR5292, Lyon Neuroscience Research Center, Brain Dynamics and Cognition Team, Lyon, France; University Lyon 1, Lyon, France.
authors.forename: Annie
authors.initials: A
authors.lastname: Moulin
mesh_terms: D000328:Adult; D001309:Auditory Threshold / Q000502:physiology* / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D011829:Radiation Dosage; D050781:Transcranial Magnetic Stimulation / Q000379:methods*; D055815:Young Adult