2026 American Academy of Neurology Abstract Website

Objective:

Background:

Posterior Reversible Encephalopathy Syndrome (PRES) is characterized by neurologic symptoms, evidence of vasogenic edema on imaging, and reversible clinical or radiographic findings. It is theorized to occur in the setting of severe hypertension or toxin-mediated endothelial dysfunction. Hypertension and seizures are common presenting symptoms.

Design/Methods:

Results:

A 46-year-old gentleman with a past medical history of GERD presented in myoclonic status epilepticus. Initial evaluation showed hypertensive emergency (250/170), leukocytosis, severe hypercalcemia (20.9 mg/dL), hypokalemia, and acute kidney injury (Cr 5.84 mg/dL). The patient’s wife revealed that, on a naturopathic provider’s recommendation, the patient recently replaced famotidine with licorice root extract for GERD treatment, in addition to already taking excessive amounts of calcium carbonate for his GERD. MRI T2 FLAIR demonstrated confluent posterior predominant hyperintensities, suggestive of PRES. His treatment course consisted of anti-epileptic medications, anti-hypertensives, and restoration of electrolytes. He was weaned off sedation with improvement of neurologic function. Repeat MRI showed resolution of posterior FLAIR hyperintensities. At his four-month follow-up, he had no focal neurologic deficits or seizures.

Conclusions:

This patient was diagnosed with PRES caused by secondary hyperaldosteronism and milk-alkali syndrome with hypercalcemic crisis. Licorice contains glycyrrhizic acid which inhibits 11-hydroxysteroid dehydrogenase, responsible for converting cortisol to cortisone. Elevated cortisol levels produce a pseudo-hyperaldosteronism state, causing secondary hypertension. Calcium carbonate, in excess, can precipitate milk-alkali syndrome. The associated hypercalcemia can induce elevations in blood pressure through various mechanisms. Licorice and hypercalcemia have each been suggested in the literature as a rare precipitant of PRES. This case highlights a patient presenting with two rare etiologies of PRES, likely exacerbating his risk for development. The importance of a thorough history including supplements and non-prescription medications is brought to light in this case. Early recognition and treatment of PRES is crucial to symptom resolution and minimizing long term complications.