Which CSF finding is typical of viral meningitis?

Which CSF finding is typical of viral meningitis?

• A. Elevated opening pressure
• B. Neutrophilic pleocytosis
• C. Lymphocytic pleocytosis
• D. Very low protein

Answer: (C)

Viral meningitis typically triggers a lymphocyte-dominated inflammatory response in the CSF, so the hallmark finding is a lymphocytic pleocytosis. This reflects how the body fights viruses in the meninges, producing more lymphocytes in the CSF than other immune cells. In this setting, opening pressure is usually normal or only mildly elevated, protein is normal to mildly elevated, and glucose tends to be normal. By contrast, neutrophilic pleocytosis would point toward bacterial meningitis, and very low protein is not characteristic of viral infection.

Viral meningitis typically triggers a lymphocyte-dominated inflammatory response in the CSF, so the hallmark finding is a lymphocytic pleocytosis. This reflects how the body fights viruses in the meninges, producing more lymphocytes in the CSF than other immune cells. In this setting, opening pressure is usually normal or only mildly elevated, protein is normal to mildly elevated, and glucose tends to be normal. By contrast, neutrophilic pleocytosis would point toward bacterial meningitis, and very low protein is not characteristic of viral infection.