Effects of Transcranial Direct Current Stimulation of the Cerebellum (ctDCS) Associated with Cognitive Training in the Working Memory on Healthy Elderly

Abstract

The present research presents a study with the intention of advancing the knowledge of the repercussions of the cerebellum stimulations. The study investigated the acute and cumulative effects of transcranial cerebellum current (ctDCS) stimulation associated with cognitive training for working memory in healthy elderly. A total of 30 volunteers, aged 60 to 72 years, underwent five sessions consisting of the application of the following protocols on the entire cerebellum hemisphere: the Experimental Group (15 participants) received an anodic electric current (anodic ctDCS) and the Control Group (15 participants) received a sham current (simulated ctDCS), both of whom underwent cognitive training while receiving transcranial anodyne cerebellar current or sham (online) stimulation. Participants' performances were measured through specific neuropsychological tests to assess working memory (Digit Span test in direct and indirect order and Letter-Number Sequencing test). After a week and three months of the last stimulation session, the participants performed the neuropsychological tests again to check for possible remnants of the intervention (follow-up). The results suggest that there was no difference between the performance of Experimental Group (anodic ctDCS) and Control Group (sham ctDCS) in different neuropsychological tests, regardless of the time of application (p>0,05). While the anodic ctDCS improved the performance of the Experimental Group in the intra-group analysis Digit Span test in direct order when compared to baseline and the follow-up three-month (p<0,05).