Effect of transcranial DC sensorimotor cortex stimulation on somatosensory evoked potentials in humans.
OBJECTIVE
To study the after-effect of transcranial direct current stimulation (tDCS) over the sensorimotor cortex on the size of somatosensory evoked potentials (SEPs) in humans.


METHODS
SEPs were elicited by electrical stimulation of right or left median nerve at the wrist before and after anodal or cathodal tDCS in 8 healthy subjects. tDCS was applied for 10 min to the left motor cortex at a current strength of 1 mA.


RESULTS
Amplitudes of P25/N33, N33/P40 (parietal components) and P22/N30 (frontal component) following right median nerve stimulation were significantly increased for at least 60 min after the end of anodal tDCS, whereas P14/N20, N20/P25 (parietal components) and N18/P22 (frontal component) were unaffected. There was no effect on SEPs evoked by left median nerve stimulation. Cathodal tDCS had no effect on SEPs evoked from stimulation of either arm.


CONCLUSIONS
Anodal tDCS over the sensorimotor cortex can induce a long-lasting increase in the size of ipsilateral cortical components of SEPs.


CONCLUSIONS
tDCS can modulate cortical somatosensory processing in humans and might be a useful tool to induce plasticity in cortical sensory processing.
Matsunaga
Kaoru
K
Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, 8-11 Queen Square, London WC1N 3BG, UK.
Nitsche
Michael A
MA
Tsuji
Sadatoshi
S
Rothwell
John C
JC
D000328:Adult; D000704:Analysis of Variance; D001931:Brain Mapping; D004558:Electric Stimulation; D004566:Electrodes; D004569:Electroencephalography; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000502:physiology; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology; D011930:Reaction Time; D013003:Somatosensory Cortex / Q000502:physiology*; D013997:Time Factors