Changes in Electrical Brain Activity and Cognitive Functions Following Mild to Moderate COVID-19: A one-Year Prospective Study After Acute Infection.

The coronavirus disease 2019 (COVID-19) can disrupt various brain functions. Over a one-year period, we aimed to assess brain activity and cognitive function in 53 COVID-19 patients and 30 individuals without COVID-19 (or asymptomatic). The Montreal Cognitive Assessment, Trail Making Test Parts A and B (TMT-A and B), and Digit Span Test were used to assess cognitive function. Cognitive variables and electroencephalography (EEG) data (activity, mobility, and complexity) were compared between the groups at rest and during cognitive demand (F3-F7, Fz-F3, Fz-F4, and F4-F8). There was a reduction in F3-F7 activity during the TMT-B in the COVID-19 group at 6-12 months compared to the controls (p = 0.01) at baseline (p = 0.03), a reduction in signal complexity at F3-F7 at rest in the COVID-19 group at baseline and 6-12 months compared to the controls (p < 0.001), and a reduction in Fz-F4 activity at rest from 6-12 months in the post-COVID group compared to baseline (p = 0.02) and 3-6 months (p = 0.04). At 6-12 months, there was a time increase in TMT-A in the COVID-19 group compared to that in the controls (p = 0.04). Some correlations were found between EEG data and cognitive test in both groups. In conclusion, there was a reduction in brain activity at rest in the Fz-F4 areas and during high cognitive demands in the F3-F7 areas. A reduction in signal complexity in F3-F7 at rest was found in the COVID-19 group at 6-12 months after acute infection. Furthermore, individuals with COVID-19 experience long-term changes in cognitive function.

Effects of transcranial direct current stimulation on balance after ischemic stroke (SANDE trial): Study protocol for a multicentric randomized controlled trial.

BACKGROUND: Among the tools used for motor rehabilitation after stroke, transcranial direct current electrical stimulation (tDCS) aims to modify cortical excitability and improve motor function. Despite promising results, the effects of tDCS on balance after stroke have not yet been assessed using specific protocols. Therefore, this study will aim to evaluate the effects of tDCS and rehabilitation on balance after stroke. METHODS: Eighty-two ischemic stroke patients across two inpatient rehabilitation sites in Brazil will be randomized into one of two treatment programs (anodic tDCS and sham tDCS), both associated with balance training, each 2 days/week, for six weeks and monitored for exertion, repetition and quality of movements. The primary outcome measure is the balance. Secondary outcomes will include clinical and functional measures. Outcome data will be assessed at two time points. DISCUSSION: This trial will contribute to clarify if anodal tDCS is effective when associated with balance training to stroke recovery.