Clinical risk factors for neuroleptic malignant syndrome

Pharmacological risk factors for neuroleptic malignant syndrome (NMS) are better defined than clinical risk factors. We examined the psychopathological status preceding the onset of NMS in 20 patients. We evaluated four key psychiatric symptoms (psychomotor agitation, catatonia, disorganization and confusion) and grouped them into definite clinical syndromes. Six patients presented with an acute and severe catatonic syndrome, with all the four key psychiatric symptoms. Twelve patients presented with an acute and severe disorganized psychotic episode, with two or three key psychiatric symptoms, but not catatonia. Our study suggests that a clinical syndrome of acute disorganization, in addition to acute catatonia, is a potential clinical risk factor for NMS. The two syndromes, which can occur in the context of different mental disorders, are related to each other as both implicate alteration in behavioural monitoring, and were, in our experience, unresponsive to neuroleptics. In conclusion, we hypothesize that the recognition of these two syndromes should reduce NMS occurrence. We recommend a judicious use of neuroleptics not only in patients with acute catatonia, but also in patients with acute disorganization.