Spectrum concept of neuroleptic malignant syndrome.

Although neuroleptic malignant syndrome (NMS) was initially thought to be a rare, idiosyncratic complication, the incidence estimates have been rising over the years. A part of this increase can be explained on the basis of an over-inclusive definition of NMS. The unitary concept of NMS has been challenged recently and a spectrum concept has been enunciated on the basis of findings of retrospective chart-reviews which have used too broad a definition of NMS. The authors describe three cases of neuroleptic-related toxicity with different clinical presentations which appeared in a manner apparently supporting the spectrum concept. They discuss this controversial concept critically, however, and caution against its overzealous use in routine clinical practice owing to its far-reaching clinical implications.