General anesthesia after neuroleptic malignant syndrome

The neuroleptic malignant syndrome (NMS) is an uncommon and potentially lethal complication of therapy with neuroleptics characterized by pallor, hyperthermia, and extrapyramidal signs (Delay and Deniker, 1968). Malignant hyperthermia (MH) is a rare but often fatal complication of general anesthesia characterized by hyperpyrexia and muscle rigidity, but not related to neuroleptic therapy. For both syndromes, NMS and MH, a common pathophysiology has been considered (Meltzer, 1973; Itoh, 1977; Caroff, 1980). These two syndromes may also be clinically indistinguishable from "acute lethal catatonia" characterized by fever, muscular hypertonicity, and stupor, first described by Stauder in 1934. We now report a case in whom NMS appeared following neuroleptic treatment for a psychotic depressive syndrome. After remission from the NMS, the patient underwent general anesthesia nine times for electroconvulsive therapy (ECT) without ill effect. This case supports the theory of distinct pathogenic mechanisms for both NMS and MH.