American Board of Internal Medicine (ABIM) Certification Practice Exam

What is a key symptom of Posterior Reversible Encephalopathy Syndrome (PRES)?

1. Severe chest pain

2. Bilateral lower limb weakness

3. Nausea and vomiting

4. Blurry vision only

The correct answer is: Nausea and vomiting

Nausea and vomiting are indeed key symptoms of Posterior Reversible Encephalopathy Syndrome (PRES). This condition is primarily characterized by a range of neurological symptoms that arise due to edema in the brain's posterior regions. The pathology often associates with conditions like hypertension, renal failure, and autoimmune disorders. Patients suffering from PRES typically present with acute neurological changes, which can include headaches, altered mental status, visual disturbances, and seizures, in addition to nausea and vomiting. The presence of nausea and vomiting in these patients is linked to increased intracranial pressure and central nervous system disturbances arising from the edema. In contrast, while other symptoms such as visual disturbances can occur in PRES, those symptoms alone do not encapsulate the syndrome effectively since PRES typically presents with a broader range of neurological symptoms. Therefore, nausea and vomiting serve as significant indicators of this syndrome, particularly when presented with the background of relevant precipitating medical conditions.