Effects of theta burst stimulation protocols on phosphene threshold

Clin Neurophysiol. 2006 Aug;117(8):1808-13. doi: 10.1016/j.clinph.2006.03.019. Epub 2006 Jun 21.

Abstract

Objective: We investigated the effects on occipital cortex, of two newly developed methods of repetitive transcranial magnetic stimulation (rTMS): continuous and intermittent theta burst stimulation (cTBS and iTBS), that lead to long lasting changes in excitability when applied over primary motor cortex.

Methods: Phosphene threshold to a single TMS pulse was measured before and after application of either continuous or intermittent theta burst stimulation (cTBS/iTBS; 600 total pulses at 80% phosphene threshold).

Results: In our cohort, cTBS increased phosphene threshold by an average of 10%. In contrast, iTBS, which transiently increases motor cortex excitability, had no effect on phosphene threshold.

Conclusions: cTBS can be applied successfully to non-motor areas of cortex, but iTBS may need modification to produce maximal effects.

Significance: cTBS maybe a new useful tool in disorders characterized by an abnormal state of activity of the visual cortex.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Female
  • Humans
  • Male
  • Phosphenes / physiology*
  • Theta Rhythm*
  • Transcranial Magnetic Stimulation / methods*
  • Visual Cortex / physiology*