Transcutaneous cranial electrical stimulation (TCES): a review 1998

The Transcutaneous Cranial Electrical Stimulation (TCES) technique appeared at the beginning of the 1960s and is aimed to act at the level of the central nervous system. The current, composed of high frequency pulses interrupted with a repetitive low frequency, is delivered through three electrodes (a negative electrode placed between the eyebrows while two positive electrodes are located in the retro-mastoid region). Due to the characteristics of the current delivered, shortcomings encountered with previous electrical stimulation techniques are avoided. The main property of TCES is to potentiate some drug effects, especially opiates and neuroleptics, during anesthetic clinical procedures. This potentiation effect permits drastic reduction of pharmacological anesthetic agent and reduces post-operative complications. Animal studies performed with TCES demonstrated that this stimulation releases 5-hydroxy-indol-acetic acid and enkephalins. Despite numerous clinical and animal studies performed with this technique for several decades, TCES mechanisms are not completely elucidated but results obtained without undesirable effect are encouraging signs to continue investigations of this particular technique.