Which of the following indicates a high risk patient requiring a CT scan before performing a lumbar puncture?

A CT scan is often indicated before performing a lumbar puncture in patients who present with specific risk factors that could suggest increased intracranial pressure or the possibility of a mass lesion. In this case, a patient who is over 60 years old and exhibits focal neurological findings presents a high risk for serious conditions such as a brain tumor, stroke, or hemorrhage. The combination of advanced age and focal neurological deficits raises concern for an underlying structural issue that could complicate the lumbar puncture procedure, potentially leading to herniation or other complications.

By performing a CT scan in this scenario, clinicians can assess for any abnormalities that may warrant caution before proceeding with the lumbar puncture. This step is essential to ensure patient safety and prevent any adverse outcomes. Other factors, such as age under 20, a history of migraines, or immunocompetence, do not carry the same level of risk for complications associated with lumbar puncture in the absence of other significant clinical indications.