Impact of Anodal tDCS and Virtual Reality on Cognitive Dysfunction in Patients With Multiple Sclerosis

"Patients in the EG group will undergo a simultaneous A-tDCS over the left DLFPC. The tDCS will be delivered by a battery-driven, constant current simulator, two holding bags of plant cellulose (7x5 cm) and two electrodes of conductive silicone. The active (anodal) electrode will be placed by means of a cap on the scalp overlying the left DLPFC (46 Brodmann Area). The reference electrode will be located over the right shoulder. The choice of the left DLPFC as the site of stimulation relies upon the evidence that this region has a critical role in the top-down control of the task-relevant stimuli processing (Miller 2001).The DLPFC contributes to increase cognitive control through its connections with the anterior cingulate cortex and has been shown to enhance working memory and executive function. During the cognitive training (on-line procedure), A-tDCS (current of 1,5 mA) will be delivered for 20 minutes, while maintaining the current density (0.06 mA/cm2) below the safety limits."

CG will receive a S-tDCS over the DLPFC. In the S-tDCS session, the current will be turned off 30 sec after the beginning of the stimulation and turned on for the last 30 sec. By doing this, the patient feels an itching sensation below the electrodes at the beginning and at the end of stimulation, making this condition indistinguishable from the real A-tDCS stimulation. Doing this, all the subjects will be blinded on the type of stimulation. As well as in the EG, CG performs cognitive training including motor and cognitive exergames that incorporate enjoyment, technology, and health care.