The effects of 10 Hz repetitive transcranial magnetic stimulation on resting EEG power spectrum in healthy subjects

Neurosci Lett. 2007 May 29;419(2):162-7. doi: 10.1016/j.neulet.2007.04.030. Epub 2007 Apr 18.

Abstract

10 Hz rTMS over the left prefrontal cortex may be useful in the treatment of depressive disorders. However, the effects of 10 Hz rTMS applied in potentially effective doses on electroencephalographic activity are not well studied. Using EEG, we aimed to investigate the neurobiological effects of the 10 Hz rTMS set of parameters currently used for depression treatment in a sample of healthy subjects. In 18 healthy subjects, either 10 Hz real rTMS or sham stimulation were given in a crossover design. Real rTMS stimulation was carried out with an intensity of 110% of motor threshold (MT) over the left dorsolateral prefrontal cortex. For the sham condition, the coil was angled over a parietotemporal position and the intensity was reduced to 90% of MT. EEG recordings were taken before and after a single rTMS session. EEG power spectrum was extracted using the complex demodulation method and changes in power were evaluated statistically. Real 10 Hz rTMS induced an overall increase in delta power. This increase prevailed throughout the sample, whereas effects on the power of the alpha, beta and theta EEG bands were highly variable. Sham stimulation had no substantial effects on the EEG power spectrum. Furthermore, no changes in EEG asymmetry were detected. Real 10 Hz rTMS applied at 2000 stimuli and 110% intensity may induce significant changes in resting EEG in healthy subjects.

MeSH terms

  • Adult
  • Depressive Disorder / physiopathology
  • Depressive Disorder / therapy*
  • Electroencephalography / radiation effects*
  • Female
  • Functional Laterality / physiology
  • Humans
  • Male
  • Middle Aged
  • Motor Cortex / physiology
  • Parietal Lobe / anatomy & histology
  • Parietal Lobe / physiology
  • Prefrontal Cortex / anatomy & histology
  • Prefrontal Cortex / physiopathology*
  • Prefrontal Cortex / radiation effects*
  • Reference Values
  • Sex Characteristics
  • Transcranial Magnetic Stimulation / methods*
  • Transcranial Magnetic Stimulation / standards
  • Treatment Outcome