Severe fever with thrombocytopenia syndrome–associated encephalitis and intracranial hypotension: A case report

Severe fever with thrombocytopenia syndrome (SFTS) is a natural infectious disease caused by severe fever with thrombocytopenia syndrome virus (SFTSV). Central nervous system (CNS) involvement is not rare in SFTS. In this work, we report a case of SFTS with CNS symptom onset and the metagenomic next-generation sequencing of cerebrospinal fluid (CSF), confirming invasion of SFTSV into the CNS. The case’s lumbar puncture indicated an exceptionally low CSF opening pressure—an uncommon finding in other CNS infections and in case reports of SFTS. A spontaneous subdural effusion was observed on the fourth day of hospitalization. Moreover, a flow cytometry analysis of bone marrow revealed a restricted expression of the lambda light chain in monoclonal B cells and plasma cells. The patient succumbed to their severe illness. The early recognition of the disease may be crucial for prognosis despite the disease’s current lack of specific treatments.