Brain stimulation for movement difficulties

Intervention: This is a randomized, controlled, four-arm clinical trial, without blinding. Participants will be allocated to one of the intervention groups with non-invasive cortical electrical stimulation (ANODE or CATHODE or PLACEBO) or transcranial magnetic stimulation, according to randomization. Each group will contain 50 volunteers of both sexes, totaling 200 volunteers, aged between 30 and 60 years, all with mild to moderate conditions according to the Yoeh & Har scale (1-3) of Parkinson's Disease. The current intensity of the transcranial stimulator will be configured according to the tolerance and safety limits of the technique, in this case, 2 mA. Randomization will be in blocks: participants are allocated to fixed-size blocks, ensuring that each group receives an equal number of participants in each block; the intervention will take place over a period of 10 days. All volunteers must be off medication at the time of the intervention. The experimental design basically consists of collecting outcome measures before, during, and after the intervention (with variations depending on the experimental group/disease). Under tDCS (anode and cathode) conditions, participants received stimulation at an intensity of 2 mA for 20 minutes. Under TMS conditions, stimulation of the primary motor cortex (M1) was performed for 15 minutes, using a frequency of 10 Hz, with the application of single or paired pulses according to the experimental protocol. Primary outcome: It is expected that some statistical power will be found through the analysis of the data that can validate our hypothesis over a period of 2 years, verification will be through the variation in the MDS-UPDRS Part III score (motor examination), calculated as the difference between the post-intervention and pre-intervention values, we will observe using a paired t-test if the distribution of differences meets the assumptions of normality, or, alternatively, by the non-parametric Wilcoxon test for paired samples when such assumptions are not met. Additionally, a descriptive analysis of the magnitude of the effect will be performed, including the mean of the variation, 95% confidence interval, and effect size (Cohen's d for paired measures). The interpretation of the results will consider as a reference the minimum clinically important difference (MCID) for the MDS-UPDRS Part III, adopted as approximately 5 points. Secondary outcome: It is expected that some statistical power will be found through the analysis of the data that can validate our hypothesis over a period of 2 years, verification will be through the variation in the MDS-UPDRS Part III score (motor examination), calculated as the difference between the post-intervention and pre-intervention values, we will observe using a paired t-test if the distribution of differences meets the assumptions of normality, or, alternatively, by the non-parametric Wilcoxon test for paired samples when such assumptions are not met. Additionally, a descriptive analysis of the magnitude of the effect will be performed, including the mean of the variation, 95% confidence interval, and effect size (Cohen's d for paired measures). The interpretation of the results will consider as a reference the minimum clinically important difference (MCID) for the MDS-UPDRS Part III, adopted as approximately 5 points.;It is expected that some statistical power will be found through the analysis of the data that can validate our objective over a period of 2 years;in the case of accelerometry verification, derived variables such as mean tremor amplitude, dominant frequency, and temporal variability may be analyzed, according to the acquisition protocol;we will observe whether it will be necessary to adopt a significance level of a = 0.05 (two-tailed). Considering the exploratory nature of the study, no formal adjustment for multiple comparisons in the secondary outcomes will be performed, and its results will be interpreted as hypothesis-generating.;It is expected that some statistical power will be found through the analysis of the data that can validate our objective over a period of 2 years; in the case of accelerometry verification, derived variables such as mean tremor amplitude, dominant frequency, and temporal variability may be analyzed, according to the acquisition protocol, we will observe whether it will be necessary to adopt a significance level of a = 0.05 (two-tailed). Considering the exploratory nature of the study, no formal adjustment for multiple comparisons in the secondary outcomes will be performed, and its results will be interpreted as hypothesis-generating.