Neuromuscular Complications of SARS-CoV-2 and Other Viral Infections

Abstract

In this article we review complications to the peripheral nervous system that occur as a consequence of viral infections, with a special focus on complications of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). We discuss neuromuscular complications in three broad categories; the direct consequences of viral infection, autoimmune neuromuscular disorders provoked by viral infections, and chronic neurodegenerative conditions which have been associated with viral infections. We also include discussion of neuromuscular disorders that are treated by immunomodulatory therapies, and how this affects patient susceptibility in the current context of the coronavirus disease 2019 (COVID-19) pandemic. COVID-19 is associated with direct consequences to the peripheral nervous system via presumed direct viral injury (dysgeusia/anosmia, myalgias/rhabdomyolysis, and potentially mononeuritis multiplex) and autoimmunity (Guillain Barré syndrome and variants). It has important implications for people receiving immunomodulatory therapies who may be at greater risk of severe outcomes from COVID-19. Thus far, chronic post-COVID syndromes (a.k.a: long COVID) also include possible involvement of the neuromuscular system. Whether we may observe neuromuscular degenerative conditions in the longer term will be an important question to monitor in future studies.

Keywords: COVID-19; Guillain-Barre syndrome; SARS-CoV-2; autoimmune disease; neuromuscular disease (NMD); viral disease.

Figure 1

Viruses associated to their neuromuscular diseases and localisations. In this schematic diagram, viruses are represented according to the different diseases and neuromuscular localisations to which they are associated. Acute presentations are presented in the upper half of the figure and chronic disorders are presented in the lower half. Viruses are color-coded based on their family as follows: Coronaviridae (red), Orthomyxoviridae (yellow-green), Flaviviridae (cyan), Phenuiviridae (yellow), Picornaviridae (orange), Hantaviridae (blue), Hepeviridae (pink), Herpesviridae (green), and Retroviridae (purple). Note a general segregation of the viruses to the associated diseases/localisations. Note that SARS-CoV-2 is represented twice because of its association with GBS and variants, myasthenia gravis, and myopathic conditions. HIV is associated with a broad spectrum of neurological disorders and is therefore represented as a box spanning four disease categories. Abbreviations: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); Influenza A and B Virus (influenza); West Nile Virus (WNV); Zika Virus (ZIKV); Toscana virus (TOSV); Enterovirus (EV); Enterovirus D68 (EV-D68); Enterovirus A71 (EV-A71); Coxsackievirus B3 (CVB3); Echovirus-7 (E7); Hepatitis A Virus (HAV); Hepatitis E Virus (HEV); Hantavirus (Hanta); Hepatitis B virus (HBV); Varicella zoster virus (VZV); Epstein-Barr Virus (EBV); Cytomegalovirus (CMV); Human Immunodeficiency Virus (HIV), Human T-lymphotropic Virus (HTLV); Human Endogenous Retrovirus-W (HERV-W); Human Endogenous Retrovirus-K (HERV-K).

Figure 2

Localisations for neuromuscular consequences of SARS-CoV-2 infection. A highly schematic representation of the peripheral nervous system, showing major anatomic structures from the spinal cord through to muscle. Neuromuscular conditions associated with SARS-CoV-2 are listed below, with bidirectional arrows showing the approximate anatomic localisations of pathology.