[Malignant syndrome in multiple system atrophy].

Five of fourteen patients with multiple system atrophy (MSA) experienced a total of eight episodes of malignant syndrome, three episodes in 1, two episodes in 1 patient, and a single episode in each of the other patients. Four patients had extrapyramidal symptoms and required antiparkinson therapy, including dopaminergic agonists. Five episodes occurred in the summer season. Two were caused by decreased or irregular doses of antiparkinson drugs, one by administration of an antidepressant drug, three by complications, and two by elevation of body temperature of environmental origin. A patient without parkinsonism became febrile after administration of droxidopa, which may be a central pyrogenic substance that acts via the noradrenergic system. Administration of dopaminergic drugs and dantrolene sodium was followed by recovery in four episodes in three patients. One patient manifested dysautonomia after recovery from the malignant syndrome. Another patient with high serum creatine kinase levels and myoglobinuria developed renal failure requiring hemodialysis. Another patient died of DIC. Besides withdrawal of dopaminergic agents, which alter monoaminergic neuron activity, stress to the body and heating by a variety of factors tend to trigger the malignant syndrome in MSA.