American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the primary reason for performing an EEG in cases of encephalitis?

1. To assess for pneumonia

2. To confirm the diagnosis and identify the causative organism

3. To monitor blood pressure stability

4. To check for blood clots

The correct answer is: To confirm the diagnosis and identify the causative organism

Performing an EEG (electroencephalogram) in cases of encephalitis is primarily aimed at confirming the diagnosis and identifying the causative organism. Encephalitis, which is an inflammation of the brain, can lead to significant changes in electrical activity in the brain, which can be detected through an EEG. The EEG may show abnormalities such as diffuse slowing, periodic lateralized epileptiform discharges, or other specific patterns that can guide diagnosis by suggesting a particular type of encephalitis or neurological involvement. Furthermore, while an EEG does not directly confirm a specific infectious organism, it can help distinguish between encephalitis of infectious origin and other potential causes, thus aiding in the overall clinical assessment. In contrast, assessing for pneumonia, monitoring blood pressure stability, or checking for blood clots are not primary indications for performing an EEG in the context of encephalitis. These evaluations would involve different diagnostic methods like imaging studies, blood tests, or clinical evaluations, and do not provide insight into the neurological complications that arise from encephalitis.