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Meta-Analysis
. 2021 Oct;28(10):3491-3502.
doi: 10.1111/ene.14913. Epub 2021 Jun 2.

Encephalitis as a neurological complication of COVID-19: A systematic review and meta-analysis of incidence, outcomes, and predictors

Isabel Siow  1 , Keng Siang Lee  2 , John J Y Zhang  1 , Seyed Ehsan Saffari  3 , Adeline Ng  4   5
Affiliations
Meta-Analysis

Encephalitis as a neurological complication of COVID-19: A systematic review and meta-analysis of incidence, outcomes, and predictors

Isabel Siow et al. Eur J Neurol. 2021 Oct.

Abstract

Background and purpose: Although COVID-19 predominantly affects the respiratory system, recent studies have reported the occurrence of neurological disorders such as stroke in relation to COVID-19 infection. Encephalitis is an inflammatory condition of the brain that has been described as a severe neurological complication of COVID-19. Despite a growing number of reported cases, encephalitis related to COVID-19 infection has not been adequately characterised. To address this gap, this systematic review and meta-analysis aims to describe the incidence, clinical course, and outcomes of patients who suffer from encephalitis as a complication of COVID-19.

Methods: All studies published between 1 November 2019 and 24 October 2020 that reported on patients who developed encephalitis as a complication of COVID-19 were included. Only cases with radiological and/or biochemical evidence of encephalitis were included.

Results: In this study, 610 studies were screened and 23 studies reporting findings from 129,008 patients, including 138 with encephalitis, were included. The average time from diagnosis of COVID-19 to onset of encephalitis was 14.5 days (range = 10.8-18.2 days). The average incidence of encephalitis as a complication of COVID-19 was 0.215% (95% confidence interval [CI] = 0.056%-0.441%). The average mortality rate of encephalitis in COVID-19 patients was 13.4% (95% CI = 3.8%-25.9%). These patients also had deranged clinical parameters, including raised serum inflammatory markers and cerebrospinal fluid pleocytosis.

Conclusions: Although encephalitis is an uncommon complication of COVID-19, when present, it results in significant morbidity and mortality. Severely ill COVID-19 patients are at higher risk of suffering from encephalitis as a complication of the infection.

Keywords: COVID-19; complication; coronavirus; encephalitis.

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Conflict of interest statement

The authors declare no financial or other conflicts of interest.

Figures

FIGURE 1
FIGURE 1
Preferred Reporting Items for Systematic Reviews and Meta‐Analyses study design
FIGURE 2
FIGURE 2
Incidence of encephalitis in COVID‐19. Inverse Variance (IV)
FIGURE 3
FIGURE 3
Mortality of patients with encephalitis as a complication of COVID‐19. Inverse Variance (IV)
See this image and copyright information in PMC

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