Acute hypernatremia and neuroleptic malignant syndrome in Parkinson disease.

Neuroleptic malignant syndrome is a clinical syndrome characterized by fever, muscle rigidity, and mutism. Some patients with neuroleptic syndrome may have elevated creatine phosphokinase values and abnormal liver aminotransferase values. Precipitating factors are important clues for prompt diagnosis. Typical precipitating factors include antipsychotic agents and major tranquilizers. In Parkinson disease, drug withdrawal, menstruation, and hyponatremia are precipitating factors. We report a case of neuroleptic malignant syndrome in a patient with Parkinson disease and hypernatremia. In addition, we hypothesized that sudden change of sodium concentrations in the central nervous system could trigger neuroleptic malignant syndrome in patients with Parkinson disease. According to our experience, neuroleptic malignant syndrome is a clinical diagnosis and prompt diagnosis avoids unnecessary, expensive work-ups.