ABSTRACT
Introduction: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was detected in Wuhan, China, in December 2019. The disease (Covid-19) is mainly associated with lung injury, although neuromuscular symptoms including muscle weakness and myalgia are encountered in up to 10.7% of hospitalized patients affected by Covid-19. Nevertheless, the extent of muscular involvement in infected subjects has never been assessed with neurophysiological investigations. Method(s): Over a 3-week period, from April 30 through May 20, 2020, a total of 70 patients were hospitalized in the Internal Medicine Ward of the Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico in Milan, Italy. After excluding patients who underwent invasive ventilation and steroid treatment, 12 patients were evaluated. The Covid-19 diagnosis was confirmed by 2 positive nasopharyngeal swabs performed before and after our evaluation. All patients were asymptomatic for muscular involvement. Result(s): A total of 12 patients were included in this study. None of the patients exhibited neuromuscular symptoms during the disease course. All patients showed mild to moderate respiratory symptoms and chest X rays were suggestive for pneumonia. Mean age was 69 (SD 12.80) years, and 5 patients were men. The main comorbidity was hypertension. Neurological examination was unremarkable, and all the subjects obtained an MRC sum score of 60. None of the patients showed an elevation of the serum creatine-kinase (CK) or serum lactate dehydrogenase (LDH) levels performed before the neurophysiological assessment. No NCS abnormalities were found except the absence of bilateral sural sensory action potential (SAP) in patient 12, which was already reported in a previous evaluation and likely due to diabetes. Needle electromyography showed a myopathic pattern in 6 out of 12 subjects. Such alterations were prominent in a patchy fashion, in particular in proximal muscles such as trapezius (6), iliopsoas (4) and deltoid (1). The levels of fibrinogen, CK, D-dimer, C reactive protein did not show relevant differences between the two groups. When compared to non-myopathic subjects, patients with skeletal muscle injury exhibited more severe respiratory conditions according to the need for non-invasive mechanic ventilation (NIMV) Conclusion(s): Our data show that in SARS-CoV-2 infection muscular involvement may occur despite the absence of clinical signs or symptoms and should be considered part of the disease spectrum. The application of muscle biopsy to unravel the mechanisms of myofiber damage on tissue specimen could help to clarify the pathogenesis and the treatment response of coronavirus-mediated injury. Copyright © 2022
ABSTRACT
Background and aims: Coronavirus disease 2019 (COVID-19) is associated to neuromuscular symptoms in up to 10.7% of hospitalized patients. The prevalence and the characteristics of intensive care unit acquired weakness (ICUAW) in patients affected by COVID-19 have been extensively assessed, although no distinctive pattern was found. ICUAW has been described as a potential confounding factor during the identification of severe acute respiratory syndrome coronavirus 1-related myopathy. In order not to incur this potential bias, we focused on a subset of non-severe cases. Our aim was to precisely assess the extent of primary neuromuscular involvement with neurophysiological investigation in COVID-19 patients. Methods: From April through May 2020 a total of 70 patients were hospitalized in the Internal Medicine Ward of the Fondazione IRCCS Ospedale Maggiore Policlinico in Milan, Italy. After excluding patients who underwent invasive ventilation and steroid treatment, 12 patients were evaluated. Neurological examination, nerve conduction studies (NCS) and concentric-needle electromyography (EMG) were performed. Results: While nerve conduction studies were unremarkable, needle electromyography showed myopathic changes in 6 out of 12 subjects. All patients were asymptomatic for muscular involvement. Clinical features and laboratory findings did not show relevant differences between patients with and without myopathic changes. [Formula presented] [Formula presented] Conclusions: Our data show that in SARS-CoV-2 infection muscular involvement can occur despite the absence of clinical signs or symptoms and should be considered part of the disease spectrum. The application of muscle biopsy to unravel the mechanisms of myofiber damage on tissue specimens could help to clarify the pathogenesis and the treatment response of coronavirus-mediated injury.