Post-COVID-19 Parkinsonism and Parkinson's Disease Pathogenesis: The Exosomal Cargo Hypothesis

Parkinson's disease (PD) is the second most prevalent neurodegenerative disease after Alzheimer's disease, globally. Dopaminergic neuron degeneration in substantia nigra pars compacta and aggregation of misfolded alpha-synuclein are the PD hallmarks, accompanied by motor and non-motor symptoms. Several viruses have been linked to the appearance of a post-infection parkinsonian phenotype. Coronavirus disease 2019 (COVID-19), caused by emerging severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, has evolved from a novel pneumonia to a multifaceted syndrome with multiple clinical manifestations, among which neurological sequalae appear insidious and potentially long-lasting. Exosomes are extracellular nanovesicles bearing a complex cargo of active biomolecules and playing crucial roles in intercellular communication under pathophysiological conditions. Exosomes constitute a reliable route for misfolded protein transmission, contributing to PD pathogenesis and diagnosis. Herein, we summarize recent evidence suggesting that SARS-CoV-2 infection shares numerous clinical manifestations and inflammatory and molecular pathways with PD. We carry on hypothesizing that these similarities may be reflected in exosomal cargo modulated by the virus in correlation with disease severity. Travelling from the periphery to the brain, SARS-CoV-2-related exosomal cargo contains SARS-CoV-2 RNA, viral proteins, inflammatory mediators, and modified host proteins that could operate as promoters of neurodegenerative and neuroinflammatory cascades, potentially leading to a future parkinsonism and PD development

Physical Fitness Differences, Amenable to Hypoxia-Driven and Sarcopenia Pathophysiology, between Sleep Apnea and COVID-19

Handgrip strength is an indirect indicator of physical fitness that is used in medical rehabilitation for its potential prognostic value. An increasing number of studies indicate that COVID-19 survivors experience impaired physical fitness for months following hospitalization. The aim of our study was to assess physical fitness indicator differences with another prevalent and hypoxia-driven disease, Obstructive Sleep Apnea Syndrome (OSAS). Our findings showed differences between post-COVID-19 and OSAS groups in cardiovascular responses, with post-COVID-19 patients exhibiting higher values for heart rate and in mean arterial blood pressure. Oxygen saturation (SpO2) was lower in post-COVID-19 patients during a six-minute walking test (6MWT), whereas the ΔSpO2 (the difference between the baseline to end of the 6MWT) was higher compared to OSAS patients. In patients of both groups, statistically significant correlations were detected between handgrip strength and distance during the 6MWT, anthropometric characteristics, and body composition parameters. In our study, COVID-19 survivors demonstrated a long-term reduction in muscle strength compared to OSAS patients. Lower handgrip strength has been independently associated with a prior COVID-19 hospitalization. The differences in muscle strength and oxygenation could be attributed to the abrupt onset of the disorder, which does not allow compensatory mechanisms to act effectively. Targeted rehabilitation focusing on such residual impairments may thus be indispensable within the setting of post-COVID-19 syndrome

Eight Weeks Unsupervised Pulmonary Rehabilitation in Previously Hospitalized of SARS-CoV-2 Infection

The aim of our study was to determine the impact of unsupervised Pulmonary Rehabilitation (uns-PR) on patients recovering from COVID-19, and determine its anthropometric, biological, demographic and fitness correlates. All patients (n = 20, age: 64.1 ± 9.9 years, 75% male) participated in unsupervised Pulmonary Rehabilitation program for eight weeks. We recorded anthropometric characteristics, pulmonary function parameters, while we performed 6 min walk test (6 MWT) and blood sampling for oxidative stress measurement before and after uns-PR. We observed differences before and after uns-PR during 6 MWT in hemodynamic parameters [systolic blood pressure in resting (138.7 ± 16.3 vs. 128.8 ± 8.6 mmHg, p = 0.005) and end of test (159.8 ± 13.5 vs. 152.0 ± 12.2 mmHg, p = 0.025), heart rate (5th min: 111.6 ± 16.9 vs. 105.4 ± 15.9 bpm, p = 0.049 and 6th min: 112.5 ± 18.3 vs. 106.9 ± 17.9 bpm, p = 0.039)], in oxygen saturation (4th min: 94.6 ± 2.9 vs. 95.8 ± 3.2%, p = 0.013 and 1st min of recovery: 97.8 ± 0.9 vs. 97.3 ± 0.9%), in dyspnea at the end of 6 MWT (1.3 ± 1.5 vs. 0.6 ± 0.9 score, p = 0.005), in distance (433.8 ± 102.2 vs. 519.2 ± 95.4 m, p < 0.001), in estimated O2 uptake (14.9 ± 2.4 vs. 16.9 ± 2.2 mL/min/kg, p < 0.001) in 30 s sit to stand (11.4 ± 3.2 vs. 14.1 ± 2.7 repetitions, p < 0.001)] Moreover, in plasma antioxidant capacity (2528.3 ± 303.2 vs. 2864.7 ± 574.8 U.cor., p = 0.027), in body composition parameters [body fat (32.2 ± 9.4 vs. 29.5 ± 8.2%, p = 0.003), visceral fat (14.0 ± 4.4 vs. 13.3 ± 4.2 score, p = 0.021), neck circumference (39.9 ± 3.4 vs. 37.8 ± 4.2 cm, p = 0.006) and muscle mass (30.1 ± 4.6 vs. 34.6 ± 7.4 kg, p = 0.030)] and sleep quality (6.7 ± 3.9 vs. 5.6 ± 3.3 score, p = 0.036) we observed differences before and after uns-PR. Our findings support the implementation of unsupervised pulmonary rehabilitation programs in patients following COVID-19 recovery, targeting the improvement of many aspects of long COVID-19 syndrome