[The malignant neuroleptic syndrome and malignant hyperthermia]

We report on a patient with neuroleptic malignant syndrome (NMS) caused by a therapy for endogenous depression. The symptoms were hyperpyrexia (39.2 degrees C), rigidity, elevated creatine kinase (CK: 594 U/l) and coma. After transfer from an outside hospital, he was treated, at first without effect with dantrolene p.o. (80 mg q.i.d.) and i.v. (1 mg/kg-1/h-1). Clinical improvement and temperature reduction were noted when the levels of neuroleptic drugs fell during unspecific intensive care with mechanical ventilation, sedation (flunitrazepam, barbiturates), relaxation (pancuronium), and hydration. After uncomplicated weaning from the ventilator the patient became more cooperative and was returned to the psychiatric ward. Further treatment took the form of combined drug therapy with biperiden and flunitrazepam and in addition a series of 12 electroconvulsive therapies (ECT). The elevated CK levels initially decreased, serum potassium levels were found to be within normal limits, and myoglobinuria was not detected during the further course. Trigger agents for NMS are antipsychotic drugs such as thioxanthenes, phenothiazines and butyrophenones. Because the signs and symptoms are so similar to those of malignant hyperthermia (MH), it has been suggested that NMS and MH are related diseases. The postulated mechanisms of NMS become apparent in the CNS, whereas those of MH affect the muscle cell itself. An abnormal in vitro contraction test after NMS should suggest to triggering of MH crisis after succinylcholine administration in anaesthesia for ECT.(ABSTRACT TRUNCATED AT 250 WORDS)