Transcranial stimulation in patients with Parkinson's disease: A systematic review

Abstract

Introduction. Parkinson's disease is a neurodegenerative condition that primarily affects individuals over 50 years of age. It is characterized by the loss of dopaminergic neurons in the substantia nigra, leading to motor and cognitive symptoms. Objective.  This review focused on analyzing the effects of transcranial direct current stimulation in patients with Parkinson's disease. Methodology.  The study employed a descriptive methodology with a qualitative approach, following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Six investigations involving patients at various stages of Parkinson's disease were included, and they utilized different Transcranial electrical stimulation protocols. Patients received transcranial direct current stimulation in specific brain areas, sometimes combined with physical and cognitive exercises. Results. The results obtained in these studies demonstrated significant improvements in gait speed, step length, and cognitive function in some cases. These improvements were more pronounced when transcranial direct current stimulation was applied in combination with physical and cognitive exercises. Conclusion. However, it's worth noting that the exact electrode placement and stimulation intensity varied among the different studies, indicating some heterogeneity in the approaches used.