ELECTROENCEPHALOGRAPHIC ABNORMALITY IN "UNCOMPLICATED" CHILDHOOD DISEASES

Electroencephalograms were obtained from 1,298 children who had been admitted to a hospital with diagnoses of measles, mumps, chickenpox, rubella, or scarlet fever. The tracings were studied in relation to clinical evidence of encephalitic processes accompanying these diseases. The body temperature itself was not a factor, and normal EEG's were obtained in a number of patients whose rectal temperatures exceeded 40 C (104 F). Of 717 patients with measles, 37 had clinical evidence of encephalitis and all of the 37 had abnormal EEG's; of the 680 patients with measles without clinical evidence of encephalitis, 344 (51 %) had abnormally slow EEG's during the acute or immediate postacute phase of their illness. The probability of brain involvement was greatest at the age of 3 years for measles and chickenpox, and 2 years for mumps. Of the five diseases studied, rubella was the least likely and measles the most likely to be accompanied by clinical or electroencephalographic evidence of encephalitis. In three cases impairment of intellectual ability and general behavior was noted in spite of a return of the EEG to normal. The number of patients in whom the brain is affected by these diseases is far greater than the number with clinically obvious encephalitis.