Evaluation of mild-to-moderate COVID-19 through dual-task paradigm: a longitudinal case-controlled study.

Introduction: Coronavirus disease (COVID-19) was associated with cognitive alterations affecting everyday life activities. These need input integration of both motor and cognitive systems. The study aim is to evaluate cognitive-motor interference phenomenon in previously independent patients with mild-to-moderate COVID-19 (PwMCOVID-19) compared with healthy controls (HC), through dual-task (DT) paradigm.

Methods: PwMCOVID-19 were included if being independent at home, had no previous referred cognitive impairment, mechanical ventilation or oxygen need. They were assessed at admission and after 6 months with a motor-cognitive DT test (counting backward by twos while walking 2 min). HC were enrolled as control group. Differences between single-task (ST) and DT performance, DT effect (DTE) and task prioritization amongst groups and during time points were analyzed.

Results: One-hundred PwMCOVID-19 [mean age=67.32(12.08) years; 53 M/47 F] and 39 HC [mean age=63.11(9.90) years; 20 M/19 F] were recruited. Upon T0, PwMCOVID-19 showed lower cognitive and motor DT performances than ST and HC. Mutual interference pattern was predominant in PwMCOVID-19. At T1, 41 PwMCOVID-19 were examined [mean age=64.85(10.75); 22 M/19 F]. They had a worse DT performance compared to ST, although DT improved at T1. A stronger cognitive ST-DT difference was present at T0, compared to ST-DT difference at T1, while motor ST-DT difference was unchanged over time in PwCOVID-19.

Conclusion: In PwMCOVID-19, there is an impairment of DT counting while walking at baseline and after 6 months from hospitalization, with a more pronounced DT mutual interference pattern at T0. After 6 months, the motor and cognitive ST and DT performances ameliorated, not reaching the HC level.