A Review of Neurological Involvement in Patients with SARS-CoV-2 Infection

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative pathogen of the recent pandemic of coronavirus disease 19 (COVID-19). As the infection spreads, there is increasing evidence of neurological and psychiatric involvement in COVID-19. Headache, impaired consciousness, and olfactory and gustatory dysfunctions are common neurological manifestations described in the literature. Studies demonstrating more specific and more severe neurological involvement such as cerebrovascular insults, encephalitis and Guillain-Barré syndrome are also emerging. Respiratory failure, a significant condition that leads to mortality in COVID-19, is hypothesized to be partly due to brainstem impairment. Notably, some of these neurological complications seem to persist long after infection. This review aims to provide an update on what is currently known about neurological involvement in patients with COVID-19 due to SARS-CoV-2 infection. In this review, we demonstrate invasion routes of SARS-CoV-2, provide evidence to support the neurotropism hypothesis of the virus, and investigate the pathological mechanisms that underlie neurological complications associated with SARS-CoV-2.

Olfactory dysfunction in COVID‐19, new insights from a cohort of 353 patients: The ANOSVID study

“…In addition, Cocco et al 38 found a significant relationship between OD and altered trigeminal sensation. Moreover, Xu et al 39 have suggested trigeminal nerve as putative neuroanatomical route for SARS‐CoV‐2 dissemination. More precise studies on this subject are needed but these data could be interesting to understand the pathway of SARS‐CoV‐2 to the nervous system.…”

“… 27 on post‐mortem samples demonstrated the presence of RNA and viral protein of SARS‐CoV‐2 in the brain. Two paths to the central nervous system have been proposed, 39 the first by axonal transport through the olfactory bulb after infection of basal cells expressing ACE2. The second one by hematogenous transport by destruction of the endothelial cells of the blood‐brain barrier or via immune cells expressing ACE2 (dendritic cells, macrophages) in the manner of a Trojan horse.…”

Genomic surveillance of SARS-CoV-2 in patients presenting neurological manifestations

“…Among those, neurological manifestations, ranging from olfactory dysfunction to any neurologic manifestation, with the most common being encephalopathy, have been of great concern since the beginning of the pandemic [ 11 , 38 ]. The mechanisms accounting for the onset of neurological symptoms/complications in certain COVID-19 patients is still matter of study, especially in terms of the role directly played by the virus [ 11 , 28 , 38 , 39 ].…”

“…In this cohort of patients, four were between 25 and 35 years old, one around 55 and two above 70 years old. Neurological symptoms and complications displayed by the selected subjects are reported in the literature among the most frequent COVID19-related neurological manifestations [ 13 , 39 ]. All patients in the most severe neurological conditions presented important respiratory symptoms, such as interstitial pneumonia, and were intubated.…”

The relationship between the serotonergic system and COVID-19 disease: A review

“…In addition, a number of severe neurological disorders such as encephalitis have been also observed in patients with COVID-19 disease 13 , 14 , 15 , 16 . In this regard, clinical studies have shown that some patients infected with COVID-19 have symptoms similar to those of intracranial infections such as headache, epilepsy, and impaired consciousness 17 , 18 , 19 , 20 , 21 .…”