Malignant neuroleptic syndrome--its present status in Japan and clinical problems.

Fourteen cases in which hyperpyrexia, akinesia, mutism, extrapyramidal symptoms and severe, diverse autonomic symptoms developed in the course of neuroleptic drug therapy are reported as the malignant neuroleptic syndrome, with analysis and discussion of the clinical features and pathogenic factors. Possible factors contributing to the danger of evoking this syndrome are: 1. Physical exhaustion associated with dehydration, and 2. Parenteral administration of neuroleptic agents, especially of the incisive type. Symptomatologic similarity of the syndrome to the condition known as malignant hyperthermia during anesthesia is also discussed.