[Recurrent fever related to dantrolene sodium in a girl with sequelae of acute encephalopathy].

A fever of unknown origin developed in a patient with sequelae of acute encephalopathy who had received dantrolene for severe spasticity. A chronic subdural hematoma was found on MRI, and initially it was suspected that the patient had an intracranial infection. However, close investigation ruled out the chronic subdural hematoma as the source of infection. The patient's fever continued in spite of administration of antibiotics and antimycotics. We suspected that the fever was drug-induced and discontinued the use of dantrolene. As a result, the patient's fever promptly went down. After discontinuation of dantrolene the patient experienced increased muscle tone, vomiting and sleep disturbances. Dantrolene was readministered with the consent of the patient's family, but the fever returned. When dantrolene was once again discontinued, the fever immediately went down. We concluded that the fever of the patient was induced by dantrolene.