COVID-19-associated encephalitis successfully treated with combination therapy.

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

Encephalitis associated with human herpesvirus-7 infection in an immunocompetent adult.

BACKGROUND: Primary Human herpesvirus-7 (HHV-7) infection usually occurs during childhood and causes several clinical manifestations: mainly exanthem subitum (roseola infantum), followed by a lifelong latent state with possible reactivation in case of immunodeficiency. Nevertheless, some considerably different approaches exist regarding the natural history of HHV-7 and the possible consequences of HHV-7 infection in immunocompetent adults. In particular, little is known about its pathogenic role in central nervous system (CNS) disease in nonimmunosuppressed adults. Specifically, in case of encephalitis, it is important to distinguish between infectious encephalitis and postinfectious encephalomyelitis for the management of patients CASE PRESENTATION: We describe here a case of encephalitis associated to human herpesvirus-7 with associated polymyeloradiculopathy in an immunocompetent patient which may contribute to the delineation of the approach to a patient profile with a similar clinical presentation and evolution to those presented in the literature. CONCLUSIONS: This case may alert clinicians to consider this specific etiology in the differential diagnosis of encephalopathy in patients with suspected infectious encephalitis who do not respond to acyclovir or in patients who develop acute polymyeloradiculopathy, considering that HHV-7 may be a pathological factor and that a timely diagnosis is crucial for the early administration of specific treatment.