Visual and motor cortex excitability: a transcranial magnetic stimulation study

Clin Neurophysiol. 2002 Sep;113(9):1501-4. doi: 10.1016/s1388-2457(02)00198-0.

Abstract

Objectives: Phosphene thresholds (PTs) to transcranial magnetic stimulation over the occipital cortex and motor thresholds (MTs) have been used increasingly as measures of the excitability of the visual and motor cortex. MT has been utilized as a guide to the excitability of other, non-motor cortical areas such as dorsolateral prefrontal cortex. The aims of this study were to compare the PTs to MTs; to assess their stability across sessions; and to investigate their relation to MTs.

Methods: PTs and MTs were determined using focal transcranial magnetic stimulation over the visual and motor cortex.

Results: PTs were shown to be significantly higher than MTs. Both PTs and MTs were stable across sessions. No correlation between PTs and MTs could be established.

Conclusions: Phosphene threshold is a stable parameter of the visual cortex excitability. MTs were not related to the excitability of non-motor cortical areas.

Publication types

  • Clinical Trial
  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Electric Stimulation / instrumentation
  • Electromagnetic Fields*
  • Electromyography
  • Evoked Potentials, Motor / physiology
  • Evoked Potentials, Motor / radiation effects
  • Female
  • Humans
  • Male
  • Motor Cortex / physiology*
  • Motor Cortex / radiation effects*
  • Phosphenes / physiology
  • Phosphenes / radiation effects
  • Reference Values
  • Sensory Thresholds / physiology
  • Sensory Thresholds / radiation effects
  • Transcranial Magnetic Stimulation
  • Visual Cortex / physiology*
  • Visual Cortex / radiation effects*