[Case with difficulty in differentiating between transient neuroleptic malignant syndrome and catatonia after neuroleptic analgesia].

An 18-year-old woman was treated with neuroleptic analgesia using fentanyl, morphine, droperidol and haloperidol for general anesthesia and pain control for her knee operation. Postoperatively, she showed emotional unstableness, following dyspnea, tachycardia, fever, hyperhydrosis, muscle rigidity and myoclonus like involuntary movement. She received infusion of 140 mg dantrolene in total under suspicion of having neuroleptic malignant syndrome, but her symptoms improved slightly. After being transferred to our hospital, she exhibited immobility, mutism, rigidity, and catalepsy, and she was suspected of having lethal catatonia. Infusion of diazepam 10 mg resulted in dramatical improvement of her symptoms. Differential diagnosis between neuroleptic malignant syndrome and catatonia is difficult; however, a first line therapy is differential diagnosis. Thus, physician should consider catatonia when treating neuroleptic malignant like syndrome.