COVID-19-associated encephalitis successfully treated with combination therapy

Acute encephalitis can occur in different viral diseases due to infection of the brain or by an immune mechanism. Severe novel coronavirus disease 2019 (COVID-19) is associated with a major immune inflammatory response with cytokine upregulation including interleukin 6 (IL-6). We report a case presenting with acute encephalitis that was diagnosed as having severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection with hyperinflammatory systemic response and recovered after therapy with immunoglobulins and cytokine blockade.

A 39-year-old-man was brought to the Emergency Department with drowsiness, mental disorientation, intermittent fever and headache. A brain magnetic resonance imaging showed extensive involvement of the brain including cortical and subcortical right frontal regions, right thalamus, bilateral temporal lobes and cerebral peduncles, with no leptomeningeal enhancement. Cerebrospinal fluid (CSF) showed a leukocyte count of 20/µL (90% lymphocytes), protein level of 198 mg/dL, and glucose of 48 mg/dL. SARS-CoV-2 was detected in nasopharyngeal swabs by reverse-transcriptase-PCR (RT-PCR) but it was negative in the CSF. Remarkable laboratory findings in blood tests included low lymphocyte count and elevated ferritin, IL-6 and D-dimer. He had a complicated clinical course requiring mechanical ventilation. Intravenous immunoglobulins and cytokine blockade with tocilizumab, an IL-6 receptor antagonist, were added considering acute demyelinating encephalomyelitis. The patient made a full recovery, suggesting that it could have been related to host inflammatory response.

This case report indicates that COVID-19 may present as an encephalitis syndrome mimicking acute demyelinating encephalomyelitis that could be amenable to therapeutic modulation.