MRI study of human brain exposed to weak direct current stimulation of the frontal cortex

Clin Neurophysiol. 2004 Oct;115(10):2419-23. doi: 10.1016/j.clinph.2004.05.001.


Objective: To determine whether weak transcranial direct current stimulation (tDCS), which is an interesting new tool inducing prolonged cortical excitability shifts in humans, induces brain edema, disturbance of the blood-brain barrier or structural alterations of the brain detectable by magnetic resonance imaging (MRI).

Methods: In 10 healthy individuals, tDCS, which is known to alter cortical excitability for about 1 h, was applied over motor and pre-frontal cortices. contrast-enhanced t1-, t2-, and diffusion-weighted mri was performed immediately before, 30 and 60 min after tdcs.

Results: MRI performed 30 and 60 min after tDCS did not show pathological signal alterations in pre- and post-contrast-enhanced T1-weighted and diffusion-weighted MR sequences.

Conclusions: tDCS protocols which are known to result in cortical excitability changes persisting for an hour after stimulation do not induce brain edema or alterations of the blood-brain barrier or cerebral tissue detectable by MRI.

Significance: These results deliver further evidence for the safety of the currently applied tDCS protocols in humans.

Publication types

  • Clinical Trial

MeSH terms

  • Adult
  • Anisotropy
  • Blood-Brain Barrier / physiology
  • Body Water / physiology
  • Body Water / radiation effects
  • Brain / anatomy & histology*
  • Brain / physiology*
  • Brain Edema / etiology
  • Brain Edema / pathology
  • Electric Stimulation / adverse effects*
  • Electromagnetic Fields
  • Humans
  • Image Processing, Computer-Assisted
  • Magnetic Resonance Imaging
  • Male
  • Prefrontal Cortex / physiology*