The effect of transcranial direct current stimulation on the cortical activation by motor task in the human brain: an fMRI study.
OBJECTIVE
We attempted to evaluate whether cortical activation resulting from hand movements is changed by transcranial direct current stimulation (tDCS) applied on the primary motor cortex for the hand in the human brain, using functional MRI (fMRI).


METHODS
Fourteen normal subjects were recruited; subjects were randomly assigned to either the tDCS group (n=7) or the sham group (n=7). fMRI was performed with hand grasp-release movements at 1Hz before and after 20 min of intervention (the tDCS group: anodal tDCS, the sham group: sham stimulation).


RESULTS
The activation of the tDCS underlying primary sensorimotor cortex (SM1) was significantly increased in the tDCS group (p<0.05). By contrast, the SM1 was significantly decreased in the sham group in terms of the voxel count and intensity (p<0.05). No subjects complained of any adverse symptoms or signs.


CONCLUSIONS
We demonstrated that anodal tDCS increased the cortical excitability of the underlying motor cortex in the human brain. It seems that tDCS is an effective modality to modulate brain function.
Jang
Sung Ho
SH
Department of Physical Medicine and Rehabilitation, College of Medicine, Yeungnam University, Republic of Korea.
Ahn
Sang Ho
SH
Byun
Woo Mok
WM
Kim
Chung Sun
CS
Lee
Mi Young
MY
Kwon
Yong Hyun
YH
D000328:Adult; D001931:Brain Mapping; D004558:Electric Stimulation / Q000379:methods*; D019054:Evoked Potentials, Motor; D005260:Female; D018737:Hand Strength / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009044:Motor Cortex / Q000098:blood supply* / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D011597:Psychomotor Performance; D050781:Transcranial Magnetic Stimulation; D055815:Young Adult
D010100:Oxygen