A Case Report of Autoimmune Encephalitis: Could Post-COVID-19 Autoimmunity Become a Lethal Health Issue?

Autoimmune encephalitis in COVID-19 patients: a systematic review of case reports and case series

Background

There is mounting evidence suggesting that autoimmune encephalitis (AE) can be observed as a neurological complication in patients with COVID-19. This review aimed to summarize the clinical manifestations, types, and outcomes of COVID-19-associated AE.

Methods

A systematic search was conducted in the PubMed, Embase, and Web of Science databases to identify case reports and case series related to COVID-19-associated AE from 1 January 2020 to 31 March 2023. After a thorough screening and evaluation, irrelevant articles were excluded. Relevant information concerning types, clinical manifestations, and outcomes was extracted and synthesized.

Results

A total of 37 studies, comprising 34 case reports and 3 case series, were included in this review. Among the 42 COVID-19-associated AE patients, 21 (50%) cases were classified as an unknown antibodies (Ab) type of COVID-19-associated AE, 10 (23.80%) cases as anti-N-methyl-D-aspartate (NMDA) encephalitis, 4 (9.5%) cases as limbic encephalitis, and 3 (7.1%) cases as anti-myelin-oligodendrocyte-glycoprotein encephalitis, along with other rare types of AE. Disturbance of consciousness, seizures, and psychiatric symptoms were identified as the main clinical manifestations of COVID-19-associated AE. While the symptoms of AE displayed variation, most patients achieved full recovery although a few experienced residual symptoms of neurological damage.

Conclusion

This systematic review comprehensively describes the characteristics of COVID-19-associated AE. The main type of COVID-19-associated AE identified in this study is an unknown Ab type of COVID-19-associated AE. Despite the potentially life-threatening risks of COVID-19-associated AE, the majority of patients survived, with some patients reporting residual neurological symptoms.

Encephalitis in Patients with COVID-19: A Systematic Evidence-Based Analysis

Although severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) predominantly infects the respiratory system, several investigations have shown the involvement of the central nervous system (CNS) along the course of the illness, with encephalitis being one of the symptoms. The objective of this systematic review was to evaluate the characteristics (clinical, neuro-radiological aspects, and laboratory features) and outcomes of encephalitis in COVID-19 patients. PubMed, Scopus, and Google Scholar databases were searched from 1 December 2019 until 21 July 2022 to identify case reports and case series published on COVID-19 associated with encephalitis. The quality of the included studies was assessed by the Joanna Briggs Institute critical appraisal checklists. This systematic review included 79 studies, including 91 COVID-19 patients (52.7% male) experiencing encephalitis, where 85.6% were adults (49.3 ± 20.2 years), and 14.4% were children (11.2 ± 7.6 years). RT-PCR was used to confirm 92.2% of the COVID-19 patients. Encephalitis-related symptoms were present in 78.0% of COVID-19 patients at the time of diagnosis. In these encephalitis patients, seizure (29.5%), confusion (23.2%), headache (20.5%), disorientation (15.2%), and altered mental status (11.6%) were the most frequently reported neurologic manifestations. Looking at the MRI, EEG, and CSF findings, 77.6%, 75.5%, and 64.1% of the patients represented abnormal results. SARS-CoV-2-associated or -mediated encephalitis were the most common type observed (59.3%), followed by autoimmune encephalitis (18.7%). Among the included patients, 66.7% were discharged (37.8% improved and 28.9% fully recovered), whereas 20.0% of the reported COVID-19-positive encephalitis patients died. Based on the quality assessment, 87.4% of the studies were of high quality. Although in COVID-19, encephalitis is not a typical phenomenon, SARS-CoV-2 seems like a neuropathogen affecting the brain even when there are no signs of respiratory illness, causing a high rate of disability and fatality.