Coronaviruses and the central nervous system.

Area of Science:

• Neuroscience
• Virology
• Infectious Diseases

Background:

• Seven human coronavirus (CoV) species are known pathogens, including SARS-CoV, SARS-CoV-2, MERS-CoV, HCoV-OC43, HCoV-229E, HCoV-HKU1, and HCoV-NL63.
• All human CoVs are associated with central nervous system (CNS) dysfunction, manifesting differently in infants, children, and adults.

Purpose of the Study:

• To review the basic biology of coronaviruses relevant to CNS disease.
• To outline the spectrum of clinical abnormalities associated with CoV infection in the human CNS.
• To examine the evidence for CoV infection of the human brain and discuss relevant animal models of neuropathogenesis.

Main Methods:

• Literature review of existing studies on coronavirus biology and CNS manifestations.
• Analysis of clinical data on CoV-associated neurological symptoms in different age groups.
• Examination of evidence for viral entry, neurotropism, and neuropathology in humans and animal models.

Main Results:

• CoV CNS dysfunction ranges from febrile seizures in young children to non-focal neurological or constitutional abnormalities in adults.
• Neurotropism and neurovirulence depend on CNS receptor expression and host immune response, with variations based on viral species.
• While direct neuronal infection and rare meningoencephalitis occur, significant human neuropathologies like cerebrovascular accidents are infrequent but documented for epidemic CoVs.

Conclusions:

• Coronaviruses exhibit diverse impacts on the human CNS, influenced by viral characteristics and host factors.
• Understanding CoV neuropathogenesis, supported by animal models, is crucial for managing neurological complications.
• Further research is needed to fully elucidate the mechanisms of CoV entry into the CNS and subsequent pathologies.