Coexistence of neuroleptic malignant syndrome and a hyperosmolar hyperglycemic state

Neuroleptic malignant syndrome (NMS) is a rare idiosyncratic disorder characterized by muscle rigidity, hyperthermia, autonomic dysfunction, and altered consciousness. Although the incidence of NMS is low, it may be fatal if early recognition is delayed. There are a variety of precipitating factors for NMS including systemic illness and dehydration. The combination of NMS with systemic illness can be difficult to diagnose because the systemic illness may mask the coexistence of NMS. We report a patient with hyperosmolar hyperglycemic state with coexistent NMS to remind physicians that hyperosmolar hyperglycemic state may precipitate the development of NMS in patients receiving neuroleptics.