Novel Coronavirus and its Neuro-Invasive Structure

Yeni Koronavirüs ve Nöro-invaziv Yapısı

The novel Coronavirus (COVID-19 / SARS-CoV-2) appeared in the city of Wuhan in China in December 2019 and rapidly spread around the world. The coronavirus known as SARS-CoV, which previously appeared, seemingly have the same structure and effects as COVID-19 known as the novel coronavirus that appeared in China.

Respiratory problems seem to be the most characteristic symptom of the patients diagnosed with COVID-19, and the majority of the patients who apply to intensive care cannot breathe by
themselves.  Additionally, headaches, nausea, vomiting and neurological symptoms have been observed in some patients. Evidences increasing in numbers show that the coronaviruses (SARS-CoV and COVID-19) are not always limited to affecting the respiratory tract and that they can also invade the central nervous system, causing neurological diseases.

Under the light of genomic analyses, it is possible to see that a high homological sequence is shared between SARS-CoV and COVID-19. Furthermore, it has been determined that COVID-19 uses the same receptor as SARS-CoV to enter human cells.

Many coronaviruses (CoV) have a similar viral structure and infectious pathway. Therefore, the infection mechanisms, which were previously determined for other CoVs, can also be implemented for COVID-19. Growing numbers of evidences show that neurotropism is a common trait of the CoVs. (Neurotropism: Viruses that are capable of infecting nerve cells.)

In a study, it can be seen that Covid-19 is not only a virus affecting the respiratory tract but also a neurotropic virus. Having a neuro-invasive potential, COVID-19 can also affect the central nervous system. It has been said that COVID-19 holding on to the respiratory center in the brain stem can be one of the reasons why the symptom of a sudden respiratory failure occurs. In the postmortem examinations made, it can be seen that the virus can reach the respiratory center located in the central nervous system by spreading in a synaptic manner through the retention in brain stem and respiratory center and via receptor cells in the lungs. Coronavirus can cause neural damage through systemic inflammation, blood-brain barrier and olfactory nerve pathways. (Li, Bai, & Hashikawa, 2020)

REFERENCES:
– Li, Y. C., Bai, W. Z., & Hashikawa, T. (2020). The neuroinvasive potential of SARS-CoV2 may be at least partially responsible for the respiratory failure of COVID-19 patients. Journal of Medical Virology, 2, 0–2. https://doi.org/10.1002/jmv.25728

Prof. Dr. Kemal Arıkan
Psychiatrist