Diagnosis in the Neuroleptic Malignant Syndrome

Neuroleptic ma lignant syndrome (NMS) is an uncommon, potentiall y le thal complication of treatment with antipsychotic medication. First described in America n journals by De lay and Deniker in 1968 (1), this syndrome has been reported for many years in th e European and Japanese literature. Neuroleptic malignant syndrome is characterized by fever, altered men tal status, autonomic dysfunction, and generalized skeletal muscle ri gidity. Its appearance usually fo llows use of high potency neuroleptics in th erapeu tic doses . In the American literature, most reported cases have re sulted fr om use of haloperidol, fluphenazine, thiothixene or piperazine deri vatives (2,3). Longacting depot fluphenazine has been particularly implicated (4,5). One reported case has been attributed to thioridazine therapy (6), and another to tetrab enazine and alphamethyltyrosine therapy (3). Features of NMS are also described following use o f neuroleptics in conj unct ion with lithium salts and tricyclic antidepressants, and in sedat ive withdrawal syndromes (7,8). While persons of all ages may be affect ed , nearly 75 % are under age 40 , male-to-female ratio being 2: 1 (5).