CSF findings in herpes simplex encephalitis typically include which of the following?

CSF findings in herpes simplex encephalitis typically include which of the following?

• A. Increased white blood cells
• B. Decreased protein
• C. Decreased glucose
• D. Normal CSF

Answer: (A)

Herpes simplex encephalitis triggers an inflammatory response in the CSF, so you see pleocytosis—an increased white blood cell count. This inflammation is usually accompanied by elevated CSF protein, while glucose remains typically normal. Early in the illness neutrophils may be seen, but later the cells are mainly lymphocytes. Because of this inflammatory pattern, a CSF with increased white blood cells best fits HSV encephalitis. Decreased protein and especially decreased glucose are less consistent with viral infections (glucose tends to be normal in viral meningitis), and normal CSF would miss the inflammatory changes. PCR for HSV DNA in CSF is used to confirm the diagnosis.

Herpes simplex encephalitis triggers an inflammatory response in the CSF, so you see pleocytosis—an increased white blood cell count. This inflammation is usually accompanied by elevated CSF protein, while glucose remains typically normal. Early in the illness neutrophils may be seen, but later the cells are mainly lymphocytes. Because of this inflammatory pattern, a CSF with increased white blood cells best fits HSV encephalitis. Decreased protein and especially decreased glucose are less consistent with viral infections (glucose tends to be normal in viral meningitis), and normal CSF would miss the inflammatory changes. PCR for HSV DNA in CSF is used to confirm the diagnosis.