Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Encephalitis With Cerebrospinal Fluid Polymerase Chain Reaction (PCR) Positivity and Normal Neuroimaging: A Case Report.

Neurological manifestations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are common, yet direct neuroinvasion remains a rare finding. We report the case of a 46-year-old male presenting with acute delirium and behavioral changes in the total absence of respiratory symptoms. While initial neuroimaging and infectious workups were unremarkable, a repeat lumbar puncture detected SARS-CoV-2 RNA in the cerebrospinal fluid (CSF), supporting the diagnosis of SARS-CoV-2-associated encephalitis. The patient experienced a spontaneous recovery, highlighting the importance of cerebrospinal fluid polymerase chain reaction (CSF PCR) testing even when systemic viral loads are undetectable.