Transcutaneous Auricular Vagus Nerve Stimulation Improves Inflammation but Does Not Interfere with Cardiac Modulation and Clinical Symptoms of Individuals with COVID-19: A Randomized Clinical Trial

Transcranial auricular vagus nerve stimulation (taVNS) has shown effectiveness in reducing inflammation and depression. Thus, this study evaluated its effect on inflammation, cardiac autonomic modulation, and clinical symptoms in individuals affected by COVID-19. Methods: There were 52 randomized participants hospitalized with COVID-19 diagnosis who were to receive active (a-taVNS) or sham taVNS (s-taVNS) for 90 min twice a day for seven consecutive days. Interleukin 6 (IL-6), 10 (IL-10), cortisol, C-reactive protein (CRP), heart rate variability (HRV), and clinical symptoms were assessed before and after seven days of treatment. There were also seven- and fourteen-day follow-ups for clinical symptoms, including anxiety and depression levels, as well as a six-month follow-up for memory and attention levels. Results: There was significant reduction in CRP −23.9%, (95% CI −46.3 to −1.4) and IL-6 −37.7%, (95% CI −57.6 to −17.7) for the a-taVNS group. There were no changes in IL-10, cortisol levels, or in HRV results (p > 0.05) in both groups. There were no changes regarding clinical symptoms, except for a significant decrease in depression level (−2.85, 95% CI −5.44 to −0.27) in the a-taVNS group. Conclusion: taVNS showed effects on CRP, IL-6, and depression levels; however, it did not affect other clinical symptoms.

Effect of transcranial direct current stimulation and multicomponent training on functional capacity in older adults: protocol for a randomized, controlled, double-blind clinical trial

Introduction

When physical activity contains training of at least three components such as balance, coordination and strength, among others, it is called multicomponent training. This type of training is recommended for improving the functional capacity in elderly individuals but has no lasting effects. The association of transcranial direct current stimulation (tDCS) with other types of therapy has been shown to facilitate the enhancement and prolongation of therapy outcomes.

Aim

The objective of this study is to evaluate the effect of multicomponent training associated with active or sham tDCS on the performance of functional capacity in the elderly before treatment, after treatment and 30 days after the end of treatment. The secondary objective will be to correlate the performance of the primary outcome (functional capacity assessed by the Glittre Daily Life Activity Test) with walking capacity (by 6-min walk test), balance (with the mini-Balance Evaluation Systems Test), functional independence (by the Functional Independence Measure) and quality of life (with the World Health Organization Quality of Life Instrument).

Methods

Twenty-eight elderly people from the community will participate in the study, and will be randomized into two groups: 1) multicomponent training associated with active tDCS; and 2) multicomponent training associated with sham tDCS. The multicomponent training sessions will be held twice a week for 12 weeks, totaling 24 sessions. The tDCS will be administered over the dominant dorsolateral prefrontal cortex at the same time as multicomponent training, with an intensity of 2 mA, for 20 min. The evaluations will be made pretraining, after 24 training sessions and 30 days after the end of the training.

Discussion

We hypothesize that tDCS, when associated with multicomponent training, can potentiate and prolong the effects of this training on the functional capacity of the elderly. If this hypothesis is confirmed, this protocol may contribute to a longer-lasting physical rehabilitation of the elderly, encouraging them to maintain their independent daily activities for longer.

Trial registration

The study was registered in the Brazilian Clinical Trial Registry (RBR-2crd42) and received approval from the Human Research Ethics Committee of University Nove de Julho, São Paulo, Brazil (process number 3.077.953).