Neuroimaging in Zoonotic Outbreaks Affecting the Central Nervous System: Are We Fighting the Last War?

G.X Goh,L.-F Wang,K Tan,B.S.P Ang,C.C Tchoyoson Lim

doi:10.3174/ajnr.a6727

G.X Goh, L.-F Wang + Show 3 more

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https://doi.org/10.3174/ajnr.a6727

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Abstract

When preparing for the coronavirus disease 2019 pandemic and its effects on the CNS, radiologists should be familiar with neuroimaging appearances in past zoonotic infectious disease outbreaks. Organisms that have crossed the species barrier from animals to humans include viruses such as Hendra, Nipah, Severe Acute Respiratory Syndrome, and influenza, as well as bacteria and others. Brain CT and MR imaging findings have included cortical abnormalities, microinfarction in the white matter, large-vessel occlusion, and features of meningitis. In particular, the high sensitivity of diffusion-weighted MR imaging in detecting intracranial abnormalities has been helpful in outbreaks. Although the coronaviruses causing the previous Severe Acute Respiratory Syndrome outbreak and the current coronavirus disease 19 pandemic are related, it is important to be aware of their similarities as well as potential differences. This review describes the neuroimaging appearances of selected zoonotic outbreaks so that neuroradiologists can better understand the current pandemic and potential future outbreaks.

Highlights

Other important examples of novel zoonotic virus emergence linked to bats include the 1998 Nipah virus (NiV) disease in pigs in Malaysia, Severe Acute Respiratory Syndrome coronavirus 1 (SARS-CoV) in China in 2002, Middle East respiratory syndrome coronavirus (MERS-CoV) in Saudi Arabia starting in 2012, and devastating outbreaks of filoviruses from 1967 through 2018 (Fig 1).[15,16]
The causative bacterium or virus is usually isolated from the CSF, as has been described in Hendra virus (HeV) and NiV outbreaks; in many case reports for SARS-CoV/SARS-CoV-2, MERS-CoV, and the Ebola virus, the causative viruses were not successfully isolated.[45,47]
An immune-mediated response may be responsible for some MR imaging findings, including an early excessive innate immune response such as “cytokine storm”[67] and a late immune response, typically taking place some days or weeks after an acute infection.[68]

Summary

Introduction

Increasing recognition of bats as animal reservoirs of zoonotic pathogens began with the Hendra virus (HeV) outbreak in 1994 and has only since accelerated up to the current COVID-19 pandemic.[13,14] Other important examples of novel zoonotic virus emergence linked to bats include the 1998 Nipah virus (NiV) disease in pigs in Malaysia, Severe Acute Respiratory Syndrome coronavirus 1 (SARS-CoV) in China in 2002, Middle East respiratory syndrome coronavirus (MERS-CoV) in Saudi Arabia starting in 2012, and devastating outbreaks of filoviruses from 1967 through 2018 (Fig 1).[15,16]

Results

Conclusion