Which statement best differentiates meningitis from encephalitis?

Which statement best differentiates meningitis from encephalitis?

• A. Encephalitis often presents with altered mental status; meningitis with neck stiffness, fever, and headache.
• B. Meningitis usually includes limb weakness and seizures; encephalitis does not.
• C. Encephalitis does not involve brain tissue; meningitis does not involve meninges.
• D. Meningitis is primarily an autoimmune disease; encephalitis is caused by bacteria.

Answer: (A)

This question tests how to distinguish meningitis from encephalitis by where the inflammation occurs and the resulting symptoms. Encephalitis involves the brain itself, so it tends to produce altered mental status, confusion, personality or cognitive changes, and may cause seizures or focal neurological deficits. Meningitis, on the other hand, involves the meninges, so the classic signs are features of meningeal irritation such as fever, headache, and neck stiffness (and sometimes photophobia). Altered mental status can occur in meningitis too, but it is more defining for encephalitis. So, the statement that best differentiates them is that encephalitis is marked by altered mental status due to brain involvement, whereas meningitis is more likely to present with neck stiffness, fever, and headache due to meningeal irritation. Seizures can occur with encephalitis and are less typical as a primary feature of meningitis.

This question tests how to distinguish meningitis from encephalitis by where the inflammation occurs and the resulting symptoms. Encephalitis involves the brain itself, so it tends to produce altered mental status, confusion, personality or cognitive changes, and may cause seizures or focal neurological deficits. Meningitis, on the other hand, involves the meninges, so the classic signs are features of meningeal irritation such as fever, headache, and neck stiffness (and sometimes photophobia). Altered mental status can occur in meningitis too, but it is more defining for encephalitis.

So, the statement that best differentiates them is that encephalitis is marked by altered mental status due to brain involvement, whereas meningitis is more likely to present with neck stiffness, fever, and headache due to meningeal irritation. Seizures can occur with encephalitis and are less typical as a primary feature of meningitis.