title: Basic knowledge of transcranial direct current stimulation.
abstract: BACKGROUND
  Transcranial direct current stimulation (tDCS) was a neurophysiologic technique using weak electrical currents (1-2 mA) to modulate the activity of neurons in the brain. It was discovered in the 1960s, and then reintroduced by the reasonably well-controlled experiments 12 years ago. They suggested that electrodes placed on the head can produce noticeable neurological changes depended on the current direction.
  
  
  OBJECTIVE
  To review a basic technique of the instrument, mechanism of action, and application in clinical researches of tDCS.
  
  
  METHODS
  The tDCS studies were thoroughly reviewed in MEDLINE database using the key words "Transcranial direct current stimulation, tDCS, noninvasive brain stimulation, neurophysiologic technique" from 1998 to 2010.
  
  
  RESULTS
  The basic technique of the instrument, mechanism of action, application in clinical researches such as stroke, pain syndrome and craving; safety, side effect, and precaution of tDCS are described.
  
  
  CONCLUSIONS
  tDCS study is rapidly increasing and accepted as a noninvasive technique. It is easy to use and safe. The outcomes of tDCS in clinical researches are preferable with very little side effects.
authors: Department of Physiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand. aparad@kku.ac.th
authors: Paradee
authors: P
authors: Auvichayapat
authors: Narong
authors: N
authors: Auvichayapat