Delirious behavior in children with influenza: its clinical features and EEG findings.

The clinical characteristics and electroencephalogram (EEG) findings in delirious behavior in children with influenza were studied in order to differentiate it from influenza-associated encephalitis/encephalopathy. Fifteen consecutive children with delirious behavior associated with influenza were investigated. Their clinical courses were investigated using medical records. EEG was obtained during the delirious behavior, when possible. The body temperature during the delirious behavior was 39.0 degrees C or higher in 13 children. A subtle reduction of consciousness was observed in 10 children. Seizures were observed in five children. EEG revealed some mildly abnormal findings in 13 children, including mild slowing of the background activity, insertion of semirhythmic high voltage slow waves, and appearance of relatively high voltage semirhythmic theta waves. The EEG findings normalized after the delirious behavior had disappeared. EEG revealed transient and mild abnormalities in children with delirious behavior but without encephalitis/encephalopathy, and thus might be useful for diagnostic evaluation in such condition.