Acute Disseminated Encephalomyelitis in Setting of COVID-19 Infection and HSV-2 Reactivation: A Case Report

Case Diagnosis: Post-infectious acute disseminated encephalomyelitis with cerebellar peduncle and thoracic spinal cord involvement

Case Description or Program Description: A 63-year-old male presented with acute bilateral lower extremity numbness, weakness, and urinary retention following recent COVID-19 infection. Thoracic magnetic resonance imaging (MRI) showed T3-T9 bilateral anterior horn T2 hyperintensities. Cerebral spinal fluid (CSF) showed elevated protein and negative viral panel. Aquaporin-4 antibody and Myelin oligodendrocyte glycoprotein antibody were negative. He received Nirmatrelvir/Ritonavir, intravenous methylprednisolone, and plasma exchange, but symptoms progressed. MRI Brain was suggestive of acute disseminated encephalomyelitis (ADEM). Repeat lumbar puncture showed newly positive CSF herpes simplex virus 2 (HSV-2).

Setting: Acute Inpatient Rehabilitation

Assessment/Results: In conjunction with neurology and infectious diseases consultations, the patient was presumed to have post-infectious myelitis. It was suspected that COVID-19 infection contributed to reactivation of latent HSV-2 infection, resulting in delayed positive HSV-2 in CSF on repeat lumbar puncture. Functionally, he required two-person dependent assistance on inpatient rehabilitation admission and progressed to independent ambulation but with persistent neurogenic bladder requiring intermittent catheterization by six months.

Discussion (relevance): ADEM is an immune-mediated inflammatory disorder characterized by demyelination of the central nervous system. Generally, there is an antecedent viral infection, including HSV-2 infection. While there are some reported cases of COVID-19 associated transverse myelitis and HSV-2 associated myelitis, there are no documented cases of COVID-19 myelitis with reactivation of latent viral infection. Furthermore, reported functional outcomes after COVID-19 myelitis are variable and it is unknown how much of an impact concomitant latent virus reactivation has on prognosis.

Conclusions: This case highlights a unique presentation of COVID-associated myelitis, which was associated with reactivation of latent HSV-2. It is possible that some cases of COVID-associated myelitis have an underlying reactivation of another virus. It may be prudent to test patients for reactivation of viral infection as this may impact functional outcomes.