Interventions: tDCS and follow-up intervention
paraesthesia, pain
CHRONIC PAIN, HEAT, CORTEX, PARAESTHESIA
tDCS was tested in healthy subjects from 2000 until 2005, at the time of the first clinical applications in the treatment of chronic pain. tDCS consists of delivering a low-intensity (1 to 2 mA) 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 2 mA using round sponge electrodes 3.5 cm in diameter. As in the case of rTMS, stimulation of M1 is thought to be active by means of the connections between the motor cortex and numerous structures situated away from M1 involved in pain modulation [A tDCS session generally lasts 20 minutes. The patient may experience a feeling of heat or paraesthesia at the site of the electrodes for the first 30 seconds, but subsequently does not experience any sensations, which is why active stimulation will be delivered for the first 30 seconds of the sham procedure [This study will be conducted in patients hospitalised in a unit experienced in palliative care. tDCS will be delivered daily for 5 consecutive days (from Monday to Friday) with the patient either sitting or lying down.