In the context of cerebral meningitis, what finding would suggest a viral rather than a bacterial cause?

In the context of cerebral meningitis, a lymphocytic predominance in the cerebrospinal fluid (CSF) analysis is a key finding that suggests a viral cause. Viral meningitis typically elicits a response characterized by an increase in lymphocytes, which are a type of white blood cell. This contrasts with bacterial meningitis, which usually presents with a predominance of neutrophils, indicating a different immune response to bacterial pathogens.

The presence of lymphocytes is an important marker, as viral infections tend to stimulate the immune system differently than bacterial infections. In viral meningitis, other CSF characteristics may include normal glucose levels and moderate protein elevation, further supporting the viral diagnosis. Consequently, when lymphocytes are the predominant cells found in the CSF, it strongly indicates that the cause of meningitis is viral rather than bacterial.