tDCS in the Management of Post-COVID Disorders

tDCS deliver low-intensity electrical currents (2 mA) through electrodes placed on the scalp. It is used to influence brain function, modulating the neuronal activity in specific areas, in a non-invasive way, as the stimulation may not be perceived sensorially due to the low intensity. In some cases, it can provide mild tingling and bring minimal discomfort. It has the ability to increase or decrease the cortical excitability of neurons, influencing the polarization of neuronal membranes, with the anodal pole (positive) facilitating depolarization that results in increased neuronal excitability in the area, and the cathodal pole (negative) promoting a hyperpolarization of the neuronal resting membrane potential that reduces cortical excitability, used to inhibit activity in a particular cortical area.

Motor training will be performed on the treadmill with the speed respecting the limits of the patient's maximum heart rate. To determine the maximum heart rate, the calculation must be performed: maximum heart rate = 208 - (0.7\*age). For participants who use beta-blockers, the following formula will be used: maximum heart rate = 164 - (0.7\*age). Just for the arms of fatigue and pain.

an n-Back task will be performed online at PsyToolkit (https://www.psytoolkit.org/). Just for the arms of cognitive impairment and depressed mood.