Osmotic Demyelination Syndrome in a Normonatremic Patient Under Treatment With Proton Pump Inhibitors

A 66-year-old woman was admitted to the emergency department with diarrhea, nausea, and vomiting as well as low-grade fever. She was initially treated with ciprofloxacin and metronidazole with symptomatic improvement and was discharged. One week later, she returned to the emergency department for gait instability, dizziness, and vomiting and had a witnessed generalized tonic-clonic seizure in the hospital. During both admissions, the presence of ionic alterations such as severe hypomagnesemia, hypophosphatemia, and hypokalemia stood out, while sodium levels remained normal. Among her antecedents, she had a hiatal hernia and had been receiving treatment with omeprazole for years.