Highlights
- •For tSMS, NdFeB magnet was settled over the sensorimotor cortex.
- •Amplitudes of the SEP at C3' significantly decreased after tSMS by up to 20%.
- •tSMS might be a useful tool for inducing plasticity in somatosensory processing.
Abstract
Background
The motor cortex in the human brain can be modulated by the application of transcranial
static magnetic field stimulation (tSMS) through the scalp. However, the effect of
tSMS on the excitability of the primary somatosensory cortex (S1) in humans has never
been examined.
Objective
This study was performed to investigate the possibility of non-invasive modulation
of S1 excitability by the application of tSMS in healthy humans.
Methods
tSMS and sham stimulation over the sensorimotor cortex were applied to 10 subjects
for periods of 10 and 15 min. Somatosensory evoked potentials (SEPs) following right
median nerve stimulation were recorded before and immediately after, 5 min after,
and 10 min after tSMS from sites C3′ and F3 of the international 10-20 system of electrode
placement. In another session, SEPs were recorded from 6 of the 10 subjects every
3 min during 15 min of tSMS.
Results
Amplitudes of the N20 component of SEPs at C3′ significantly decreased immediately
after 10 and 15 min of tSMS by up to 20%, returning to baseline by 10 min after intervention.
tSMS applied while recording SEPs every 3 min and sham stimulation had no effect on
SEP.
Conclusions
tSMS is able to modulate cortical somatosensory processing in humans, and thus might
be a useful tool for inducing plasticity in cortical somatosensory processing. Lack
of change in the amplitude of SEPs with tSMS implies that use of peripheral nerve
stimulation to cause SEPs antagonizes alteration of the function of membrane ion channels
during exposure to static magnetic fields.
Keywords
Abbreviations:
MEP (motor evoked potential), NdFeB (neodymium, iron, and boron), QPS (quadripulse stimulation), rTMS (repetitive transcranial magnetic stimulation), S1 (primary somatosensory cortex), SEP (somatosensory evoked potential), SMF (static magnetic field), TBS (theta-burst stimulation), tDCS (transcranial direct current stimulation), TMS (transcranial magnetic stimulation), tSMS (transcranial static magnetic field stimulation)To read this article in full you will need to make a payment
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Article info
Publication history
Published online: September 29, 2014
Accepted:
September 23,
2014
Received in revised form:
September 20,
2014
Received:
July 14,
2014
Footnotes
This work was supported in part by a Grant-in-Aid for Scientific Research (C) No. 25350631 from the Japan Society for the Promotion of Science and by a Grant-in-Aid for Developed Research (B) from Niigata University of Health and Welfare.
Identification
Copyright
© 2014 Elsevier Inc. Published by Elsevier Inc. All rights reserved.
