When is CT imaging indicated after a first unprovoked seizure?

• A. Only after if patient has a history of epilepsy.
• B. CT imaging is never indicated; MRI first.
• C. CT before MRI in unstable ED settings.
• D. If there are focal neurological deficits, head trauma, signs of increased ICP, or when rapid assessment is needed; and CT is often performed before MRI in unstable patients.

Answer: (D)

The main idea is to use imaging to quickly rule out any urgent intracranial problems after a first unprovoked seizure, with the choice of modality guided by the patient’s stability and clinical signs. CT is the fast, widely available option that’s preferred when rapid information is needed to assess for acute issues like hemorrhage, mass effect, edema, skull fractures, or signs of increased intracranial pressure. If there are focal neurological deficits, a history of head trauma, signs of increased ICP, or the patient is unstable and you need quick guidance for management, CT imaging is indicated. In stable patients, MRI provides better detail for identifying non-emergent etiologies (such as mesial temporal sclerosis or subtle cortical lesions) but takes longer and isn’t as readily available in an emergency. In unstable patients, CT is often done before MRI because it yields rapid results that inform urgent care.