The role of the coil click in TMS assessed with simultaneous EEG

Clin Neurophysiol. 1999 Aug;110(8):1325-8. doi: 10.1016/s1388-2457(99)00070-x.


Objective: We have used EEG to measure effects of air- and bone-conducted sound from the coil in transcranial magnetic stimulation (TMS).

Methods: Auditory-evoked potentials to TMS were recorded in three different experimental conditions: (1) the coil 2 cm above the head, (2) the coil 2 cm above the head but rigidly connected by a plastic piece to the scalp, (3) the coil pressed against the scalp over the motor cortex.

Results: The acoustical click from the TMS coil evoked large auditory potentials, whose amplitude depended critically on the mechanical contact of the coil with the head.

Conclusion: Both air- and bone-conducted sounds have to be taken into account in the design and interpretation of TMS experiments.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustic Stimulation
  • Adult
  • Brain / physiology*
  • Brain Mapping
  • Electroencephalography
  • Evoked Potentials, Auditory / physiology*
  • Female
  • Humans
  • Magnetics*
  • Male