Central pontine myelinolysis due to rapid correction of hyponatremia induced by excessive water intake.

We report a 25-year-old female with a recent diagnosis of gastric B-cell lymphoma based on imaging and pathological findings. She was discharged against medical advice after it was recommended to her, by an "alternative medicine practitioner," to restrict her diet to excessive ingestion of the "Holy water Zamzam" (natural well water in Makkah). She presented back with altered level of awareness and severe, new-onset hyponatremia. The hyponatremia was corrected rapidly and her condition improved. Six days later, she developed the classical pyramidal and extrapyramidal features of central pontine myelinolysis, documented by MRI. The patient succumbed to her original disease 3 months later.