Novel coronavirus and the central nervous system
Tong Sun, Junwen Guan
Abstract
An outbreak of a novel coronavirus (2019-nCoV) that emerged in Wuhan has rapidly spread throughout China and has now become a global public health concern. As of early March, a total of 100 000 cases have been confirmed in multiple countries. Clinical characteristics of 2019-nCoV that respiratory symptoms, such as cough, are the most common [1] This is consistent with the finding that the majority of patients are virus-positive in nasopharyngeal and oropharyngeal swabs, suggesting that it mainly invades and infects the respiratory system, a hypothesis supported by pathological data [2] In addition, it has been reported that patients’ stool has tested positive for 2019-nCoV, indicating that the virus could spread from the respiratory tract to the digestive tract, or that individuals could be infected via the faecal–oral route. However, the neuroinvasive potential is poorly understood. In general, the blood–brain barrier serves as a natural defence against exogenously pathogenic microorganisms, attenuating the risk of intracranial infection. It is already known that human coronaviruses can spread from the respiratory tract to the central nervous system (CNS) through transneuronal and hematogenous routes, resulting in encephalitis and neurological diseases [3] On 4 March 2020, researchers from Beijing Ditan Hospital, China, first described a confirmed patient with 2019-nCoV whose cerebrospinal fluid (CSF) tested positive for 2019-nCoV by gene sequencing [4] suggesting a need to consider direct infection when patients with 2019-nCoV present with neurological disorders. Even though most patients with 2019-nCoV infection do not test positive for the virus in CSF, this first reported case of 2019-nCoV infection with positive findings in CSF raises concerns regarding virus-associated neuroinvasion. Considering that encephalitis is associated with high mortality and morbidity, early diagnosis and management might contribute to improved outcomes [5] For the severely affected and comatose patients and those who are vulnerable to intracranial infection, regular brain imaging and CSF examination are essential if neurological symptoms occur. This reported case raises the question of the possible increased susceptibility of patients with a history of neurological illnesses including stroke to neuroinvasion, which needs to be addressed in future studies. The current work has no funding. The authors declare no financial or other conflicts of interest.