Detection and management of the neuroleptic malignant syndrome.

Two patients who developed the neuroleptic malignant syndrome (NMS) are described, and pertinent literature is reviewed. A 30-year-old man developed NMS, apparently as a result of haloperidol treatment of chronic undifferentiated schizophrenia. Treatment with cooling blankets, acetaminophen, dantrolene sodium, and bromocriptine mesylate decreased abnormal vital signs, but catatonia continued. After 30 treatments with electroconvulsive therapy over a one-month period, the patient's catatonia was resolved, and he was discharged on no medication with the schizophrenia in remission. The second patient was a 22-year-old woman who developed NMS after five weeks of therapy with haloperidol and thiothixene for an acute episode of abnormal behavior. She did not respond to therapy with cooling blankets, acetaminophen, antibiotics, and amobarbital sodium. Dantrolene sodium therapy produced no improvement except for some relief of muscular rigidity. Electroconvulsive therapy (22 treatments over one month) successfully decreased the patient's elevated liver enzymes and leukocyte count, but periodic temperature elevations and catatonia continued. Prompt diagnosis and treatment of NMS are essential, as the mortality rate is 20%. Acute lethal catatonia and malignant hyperthermia are considered in differential diagnosis. Both central and peripheral pathophysiologic mechanisms are probably involved in NMS, and most cases are seen in patients with psychiatric illness. Onset of NMS does not seem related to duration of neuroleptic therapy and, in susceptible persons, additional factors may be required to trigger onset of NMS. Symptoms, including diffuse muscular rigidity, akinesia, and fever, develop within 24-72 hours. Neurologic symptoms may develop or worsen, and leukocytosis and elevated levels of liver enzymes occur. Death can result from respiratory or cardiovascular failure, and rhabdomyolysis can lead to acute renal failure.(ABSTRACT TRUNCATED AT 250 WORDS)