Transcranial Direct-current Stimulation (tDCS) Efficacy in Refractory Cancer Pain.

"tDCS consists of delivering a low-intensity (1 to 2 milliamperes) direct electrical current by means of a pair of electrodes (anode and cathode) applied to the scalp. Electrodes generally have a diameter (round electrode) or a diagonal (rectangular electrodes) ranging from 2 to 3.5 cm.~To stimulate a given cortical zone, the anode is placed over of the selected zone, generally identified by means of an EEG headset (10/20 System Positioning). For the treatment of pain, the anode is placed over the primary motor cortex (M1) on the contralateral side to the pain or on the left side in patients with diffuse pain. The cathode is placed over a supposedly neutral cortical zone, usually the contralateral supraorbital cortex with respect to the anode. In this study, the stimulation intensity will be 1.5 mA using round sponge electrodes 3.5 cm in diameter."

"The tDCS device has a Sham mode that allows for true placebo stimulation. A simulated session is thus designed as a real stimulation session without its effects. Sensations similar to tDCS are created by generating currents only at the start of the session.~Same modalities as for the Active tDCS procedure will therefore be put in place: a pair of electrodes (anode and cathode) are applied to the scalp.To stimulate a given cortical zone, the anode is placed over of the selected zone, generally identified by means of an EEG headset (10/20 System Positioning). For the treatment of pain, the anode is placed over the primary motor cortex (M1) on the contralateral side to the pain or on the left side in patients with diffuse pain. The cathode is placed over a supposedly neutral cortical zone, usually the contralateral supraorbital cortex with respect to the anode."