Acute hemorrhagic leukoencephalitis in a COVID-19 patient-a case report with literature review

Acute hemorrhagic leukoencephalitis (AHLE) is a rare and severe form of acute disseminated encephalomyelitis (ADEM). Only a few reports of AHLE in coronavirus disease 2019 (COVID-19) patients have been described to date. We report a case of COVID-19-related AHLE along with a literature review describing salient clinical and imaging characteristics.

A literature search was performed on Medline (2020-present), PubMed, Cochrane Library, CINAHL, and Google scholar on 28 January 2021 for all articles published using MeSH terms "COVID-19" or "SARS-CoV-2" with "Acute hemorrhagic leukoencephalitis" or "Acute hemorrhagic encephalitis." Relevant case reports and case series describing clinical and imaging features of AHLE associated with SARS-CoV-2 infection were included, data compiled, and critically reviewed.

Acute onset encephalopathy and rapidly deteriorating neurological status is the common clinical presentation in AHLE. CSF analysis reveals elevated proteins and lymphocytic pleocytosis. Typical neuroimaging features include multifocal, variable-sized, poorly defined cerebral white matter lesions with cortical sparing. Involvement of the brainstem, cerebellar peduncles, and deep grey matter can also occur, although rarely. Lesions are hyperintense on T2-weighted (T2W) and fluid-attenuated inversion recovery (FLAIR) images, hypointense on T1W images, and show microhemorrhages, variable diffusion restriction, and post-contrast enhancement. Extensive microhemorrhages, brainstem involvement, and gross hemorrhage often portend a poor prognosis.

Heightened awareness about the clinical and imaging presentation of COVID-19-related AHLE can positively alter the outcome in a select few by enabling early diagnosis and aggressive management.