For workup of new-onset seizures in older adults, which imaging modality is commonly obtained?

• A. MRI brain without contrast
• B. CT with contrast
• C. X-ray skull
• D. Ultrasound

Answer: (A)

In workups for new-onset seizures in older adults, the aim is to identify structural brain abnormalities that could be driving the seizures. Magnetic resonance imaging provides the most sensitive and detailed view of brain tissue, making it the best tool to detect the range of potential causes in this age group. MRI brain without contrast offers excellent soft-tissue contrast, allowing detection of subtle findings such as mesial temporal sclerosis, small tumors, vascular lesions, post-stroke changes, and early inflammatory or demyelinating processes that can lower the seizure threshold.

Choosing MRI without contrast minimizes risks associated with contrast agents—such as kidney issues or rare gadolinium-related complications—while still delivering comprehensive information about brain structure. In many cases, a contrast-enhanced study is added later if a specific lesion is suspected or if the non-contrast scan is nondiagnostic.

X-ray skull and ultrasound lack the resolution and detail to identify most causes of seizures, and CT with contrast, while useful in certain acute scenarios (for rapid assessment of bleeding or mass effect), is generally less sensitive than MRI for many nonhemorrhagic etiologies in older adults. Hence, MRI brain without contrast is commonly obtained to guide diagnosis and management.