A double-blinded randomized clinical trial will be carried to analyse the EEG as neurobiological predictor marker of HD-tDCS 4x1 in patients in long COVID-19. This study is in accordance with the CONSORT guidelines, which will investigate the effectiveness of treatment with HD-tDCS.~Patients who had a medical diagnosis of COVID-19, clinically stable, able to respond to simple commands, able to walk for six minutes and who sign study consent form will be enrolled. Those who present associated neurological diseases, pregnant, users of psychoactive drugs, patients who have metallic implants, electronic devices, pacemakers, or epileptic patients will be excluded.~Patients will be allocated randomly to the experimental group or sham control. Sessions for experimental group consist of anodal HD-tDCS on Left diaphragmatic primary motor cortex associated to respiratory training (10 sessions, 3mA, 20 minutes/session). In the sham condition, the device provided a 30-second ramp-up period to the full 3 mA, followed immediately by a 30-second ramp down.~Patients will be assessed in three moments: pre-treatment, post-treatment and after 30 days treatment ending (follow-up).
COVID-19 is an infectious disease which presents a heterogenous clinical presentation. Recent investigations suggest that people who were infected by COVID-19 often develop physical disabilities (i.e. pain, fatigue) and neurological complications after hospital discharge. Many therapeutic approaches such as transcranial direct current stimulation (tDCS) have been proposed to minimize functional and structural impairments. Electroencephalogram (EEG) has been used in this population to assess electrophysiological changes in the brain. However, evidences about EEG utilization as efficacy predictor of tDCS in COVID-19 people rest inconclusive.Our objective is to evaluate EEG as neurobiological predictor marker of tDCS efficacy on fatigue, pain, quality of life, self-efficacy and functional capacity in the chronic phase of COVID-19.