A patient presents with acute headache, neck stiffness, and fever. What is the most appropriate initial test to evaluate for meningitis?

In the context of a patient presenting with acute headache, neck stiffness, and fever, the most appropriate initial test to evaluate for meningitis is a CT scan of the head. A CT scan is typically performed prior to a lumbar puncture in certain clinical scenarios to rule out any contraindications for performing the lumbar puncture, particularly the risk of herniation due to increased intracranial pressure or the presence of a mass lesion.

While lumbar puncture is essential for confirming the diagnosis of meningitis by analyzing cerebrospinal fluid (CSF), a CT scan serves as a critical initial step to ensure the safety of proceeding with the lumbar puncture. Furthermore, CT scans are helpful in identifying any structural abnormalities in the brain that could lead to complications during the lumbar puncture procedure.

Other choices such as blood cultures, although important in managing a suspected infection, do not directly evaluate for meningitis and are considered adjunctive tests. An MRI of the brain, while useful in certain situations, is not usually the first-line imaging modality for suspected meningitis compared to a CT scan. Therefore, the initial assessment focuses on ruling out serious complications with a CT scan before definitive diagnostic testing with a lumbar puncture is performed.