American Board of Internal Medicine (ABIM) Certification Practice Exam

Once dementia is confirmed, what type of imaging study should be ordered?

1. X-ray of the skull

2. Structural neuroimaging study (MRI or CT)

3. Functional MRI

4. Electroencephalography (EEG)

The correct answer is: Structural neuroimaging study (MRI or CT)

When dementia is confirmed, the appropriate imaging study to order is a structural neuroimaging study, such as MRI (Magnetic Resonance Imaging) or CT (Computed Tomography). This is essential for several reasons. First, structural neuroimaging helps identify any underlying causes of dementia, such as brain atrophy, tumors, or vascular changes that may contribute to cognitive decline. In particular, MRI is more sensitive than CT in detecting subtle changes in brain structure, especially in cases of Alzheimer's disease or frontotemporal dementia. Second, these imaging studies can exclude other potential causes of cognitive impairment, such as strokes, hematomas, or normal pressure hydrocephalus, which may require different management strategies. Third, understanding the type and extent of structural brain changes can guide treatment decisions and help in prognostication. For example, significant medial temporal lobe atrophy is often associated with Alzheimer's disease, influencing management options. While functional MRI and EEG also have their roles in neurology, they are not first-line studies for evaluating dementia. Functional MRI is typically used in research settings to measure brain activity rather than structural integrity, and EEG is primarily used to assess electrical activity in the brain, which may help in cases of seizure disorders or other neurological