Efeitos da estimulação transcraniana por corrente contínua e da estimulação magnética transcraniana na função cognitiva de indivíduos com Doença de Alzheimer: revisão sistemática e metanálise

Abstract

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive loss of memory and perception, with cognitive impairment. Treatment is traditionally carried out by drug therapy, but recent research indicates that brain stimulation techniques, including Transcranial Direct Current Stimulation (tDCS) and Transcranial Magnetic Stimulation (TMS), can modulate cognitive functions in individuals with AD . This study is justified by the need for a thorough investigation of experimental studies that address the effects of these techniques in the treatment of AD, seeking the consistency of the results found in them. Therefore, it has the general objective of evaluating the effects of tDCS and TMS on the improvement of cognitive function in individuals with AD. This is a systematic review and meta-analysis, that followed the recommendations of the PRISMA guideline for the construction of its structure. The study period took place from April 2019 to November 2020. Among the inclusion criteria, we selected: 1) Studies of the type randomized clinical trials; 2) Samples with clinical diagnosis of AD; 3) Both sexes; 4) Age group of 55 to 85 years; and 5) Studies that used tDCS and / or TMS in cognitive function. The primary outcome of this study was cognitive decline and its secondary outcomes were memory, functional capacity and performance in ADLs. The data extracted from the studies were used to analyze the risk of bias, the effect of treatment and the quality of the evidence. The results show that it is not possible to state that tDCD has the potential to promote improvement in cognitive function; for TMS, it is suggested that its use has promising and beneficial effects in the treatment of cognitive function related to AD. However, the quality of the evidence for the main outcome of this systematic review and meta-analysis was considered very low. Therefore, despite the results found, one must consider the heterogeneity of the results measures in the included studies. Given this scenario, there is a need for further research in the field of neurostimulation with greater methodological rigor.