Which symptom is most characteristic of encephalitis compared with meningitis?

• A. Fever and neck stiffness
• B. Photophobia
• C. Seizures without alteration of consciousness
• D. Altered mental status and confusion

Answer: (D)

Encephalitis affects the brain itself, so it often disrupts overall brain function and produces altered mental status, confusion, and sometimes personality changes or coma. Meningitis, on the other hand, is inflammation of the meninges and typically presents with fever, headache, and meningeal signs like neck stiffness and sensitivity to light, with mental status usually preserved early on. Because altered mental status reflects brain parenchymal involvement rather than meningeal irritation, it is the most characteristic feature that distinguishes encephalitis from meningitis. The other symptoms—fever with neck stiffness, photophobia, and seizures—can occur with meningitis or may be seen in encephalitis, but they do not specifically indicate brain dysfunction the way altered mental status does. Seizures can occur in encephalitis, but they often accompany impaired consciousness rather than presenting with seizures alone.