Effects of theta burst stimulation protocols on phosphene threshold.
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.


CONCLUSIONS
cTBS maybe a new useful tool in disorders characterized by an abnormal state of activity of the visual cortex.
Franca
Michele
M
Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK. michele.tfr@katamail.com
Koch
Giacomo
G
Mochizuki
Hitoshi
H
Huang
Ying-Zu
YZ
Rothwell
John C
JC
D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D010719:Phosphenes / Q000502:physiology*; D013826:Theta Rhythm; D050781:Transcranial Magnetic Stimulation / Q000379:methods*; D014793:Visual Cortex / Q000502:physiology*