Immunological and Neurological Manifestations of COVID-19: An Intimate Relationship

Abstract

Background: COVID-19 has superseded all medical scientific challenges in 2020. It presented with a range of respiratory involvement from the mild upper respiratory tract to severe pneumonia with ARDS. A percentage of these patients manifested variable neurological presentations expanding the challenges of patients’ assessment, care, and management.
Objective: To discuss the neurological manifestations and the possible immunopathology of COVID-19.
Methods: A literature search was performed in the PubMed database for the relevant articles published in English language between April 9th ,  2020 and June 1, 2020. Few papers were extracted from Google Scholar and pre-print material as well. The keywords used to perform search  included “COVID-19,” “SARS Cov2,” “neurological manifestations,” and “immunology and pathology of COVID-19”. However, animal studies were excluded in the neurological manifestations, and the final number of literature search outcome was 27 articles.
Results: The immunopathology involves angiotensin-converting enzyme (ACE) receptor 2 and spike protein S1. COVID-19 has a tremendous affinity to the ACE2 receptor. The status of secondary hemophagocytic lymphohistiocytosis (sHLH) and the cytokine storm lead to different organ damage and the corresponding clinical manifestations. The documented neurological manifestations mainly include acute ischemic stroke, hemorrhagic stroke, temporal lobe, thalamic encephalitis, and one case of Guillain-Barre Syndrome, in addition to agitation, headache, and seizures.
Conclusion: Although the intimate relationship between the neurons and the immune activation is the basic concept of COVID-19   immunopathology, the definite routes of entry to the neuronal cells are yet to be disclosed. Acute stroke, myositis, headache, and  meningoencephalitis are the most common types of complications of COVID-19 so far.

Keywords: COVID-19, neurological manifestations, ACE2