Impacto da estimulação transcraniana por corrente continua e do treinamento físico na adaptação autonômicas no acidente vascular cerebral: ensaio clínico, controlado, randomizado, duplo cego

Abstract

Introduction: Dysautonomy of the Autonomic Nervous System is a frequent consequence after a stroke resulting from changes in the connection between the brain-heart axis, with increased cardiac risks in these patients. Thus, studies have been growing for cardiovascular recovery and control, such as aerobic exercise (AE) and the possible use of Transcranial Direct Current Stimulation (tDCS) as a supporting technique in autonomic modulation. Objective: To investigate the effect of tDCS associated with aerobic training on the autonomic nervous system, physical performance, and cognitive performance after chronic stroke during the 1st, 12th, 24th, 36th sessions and after a 30-day follow-up without interventions. Methods: Clinical trial, double-blind, controlled, and randomized in two groups, being group 1 (tDCS anodal + AE with nine individuals) and group 2 (tDCS sham + AE with eight individuals), totaling 17 individuals, in a mean age range of 53 ± 10 years of both sexes. Assessments: Heart Rate Variability (HRV) 15 minutes before and after the 1st, 12th, 24th, and 36th sessions of anodal or sham tDCS + EA and a 30-day post-follow-up without interventions; cognition by the ADDENBROOKE (ACE) questionnaire by the total score and by the domains and physical performance by the distance covered for 30 minutes on the ergometric bicycle for three months of AE three times a week interspersed, with an intensity of 50 to 70% of the reserve heart rate. The tDCS applied for 20 minutes during AE, the anode in the left dorsolateral prefrontal cortex (DLPFC) and cathode in the contralateral, supraorbital region (Fp2), the intensity of 2mA. Results: There was no statistical difference in intergroup and intragroup HRV in sessions and after follow-up. But Intragroup, we observed that the parasympathetic performance after the 24th session in the active, increased 50% compared to the post from the 1st session and 11% compared to the baseline by the rMSSD index, showing the Variance Index value, which represents the total variation of the RR intervals analyzed in a time range, after the 24th session, of 17% above the index of the 1st session (1075.9 – 1262.3ms2) and 7% above the baseline condition (1184.2 – 1262.3ms2), indicating a better prognosis, however, this effect was not significant. Cognition showed levels of evidence inactive, where it was better in the language subscale at baseline p=0.041 and follow-up p=0.002. Better memory at follow-up p=0.005 compared to sham. There was a non-significant increase in physical performance in both groups. Conclusion: tDCS applied on left DLPFC plus AE did not change HRV and physical performance for three months and after follow-up between groups. However, there was an improvement in cognitive performance, especially in language and executive memory, after using anodic tDCS on the left DLPFC associated with AE.