Which imaging study is typically performed to identify structural brain causes after a first unprovoked seizure?

• A. Brain MRI is preferred for structural assessment; CT may be used in acute or unstable patients
• B. CT is preferred for structural assessment in all cases
• C. Ultrasound of the skull is preferred
• D. X-ray of skull is preferred

Answer: (A)

When assessing a first unprovoked seizure for structural brain causes, MRI of the brain is the imaging test of choice because it provides superior soft-tissue contrast and higher sensitivity to detect subtle structural abnormalities (such as tumors, cortical malformations, or mesial temporal sclerosis) that can underlie seizures.

In acute or unstable patients, CT is preferred because it can be performed quickly at the bedside and is excellent for rapidly ruling out acute problems like intracranial hemorrhage, mass effect, or edema, which are critical for immediate management.

Ultrasound of the skull and X-ray of the skull do not adequately visualize brain parenchyma and are not useful for identifying the structural causes of seizures in most adults.