Posterior Reversible Encephalopathy Syndrome Mimicking Brainstem Infarction: A Dilemma

We had recently reported one case at American Journal of Emergency Medicine about centralvariant posterior reversible encephalopathy syndrome (PRES) in an 84-year-old woman with an initial misdiagnosis as central pontine myelinolysis (CPM). Here, we introduce another case of centralvariant PRES in a 49-year-old man mimicking as acute brainstem infarction in the cranial computed tomography (CT) findings. A 49-year-old man was admitted to the emergency department with a 5-day history of vertigo, cognitive decline, and difficulty in walking. Neurologic examination revealed drowsiness with a Glasgow Coma Scale score of 12 (eye opening: 3, best verbal response: 4, and best motor response: 5), slow movement in pursuit and saccades, and gait instability with a Medical Research Council scale of grade 4-5. Non-contrast cranial CT showed hypodense lesions in the pons, and antiplatelet agent was initiated for presumed pons infarction. However, the brain magnetic resonance imaging (MRI) demonstrated vasogenic edema in the corresponding area, consistent with the diagnosis of central-variant PRES. This case report raises the awareness that when hypodense brainstem lesions on brain CT in patients with progressive neurological dysfunction, the rare condition of central-variant PRES should be considered in the differential diagnosis to avoid inadequate management. Cranial magnetic resonance imaging (MRI) may help in diagnosis and dealing with of these patients with similar radiological and clinical abnormalities.