Thiazide-induced hyponatremia: an unusual neurologic course.

We have presented a case of thiazide-induced hyponatremia that followed an unusual course after the patient, suffering from extreme lethargy, was admitted with a serum sodium concentration of 104 mEq/L. Although the electrolyte imbalance was essentially corrected within 20 hours and there was clinical improvement, three days later the patient suddenly lost consciousness. She was comatose for more than a month, apparently from extrapontine myelinolysis. After a dramatic improvement, the patient was discharged with almost no neurologic deficit.