CSF pattern in encephalitis typically includes which of the following?

• A. Normal glucose with increased protein and lymphocytic pleocytosis
• B. Low glucose with neutrophilic predominance
• C. Elevated opening pressure with neutrophilia
• D. Decreased protein with lymphocytosis and normal glucose

Answer: (A)

Encephalitis is typically a viral process, and the CSF reflects that inflammatory pattern: lymphocytic predominance (increased lymphocytes), with elevated protein, while glucose remains normal. This combination—normal glucose with increased protein and lymphocytic pleocytosis—is the classic CSF signature for viral encephalitis. In contrast, bacterial meningitis usually shows neutrophilic predominance and low glucose due to consumption by bacteria and leukocytes, which is not typical of encephalitis. Opening pressure can be higher in various CNS infections but isn’t the defining feature here; the key clue is the lymphocytic response with preserved glucose.