The prognostic implications of suppression-burst activity in the EEG in infancy.

Thirty-nine children, seen between 1960 and 1973, showed suppression-burst activity in their original EEG recordings. Follow-up information was available for 19 girls and 10 boys. Suppression-burst activity was seen at a mean age of 4 months. Most of the children (86 per cent) had infantile spasms, and 96 per cent were severely retarded on presentation. Fifteen died (52 per cent), 9 of them before the age of 2, and all had severe retardation and neurological abnormalities. Of the 14 survivors, only 1 attends a normal school (she was only mildly retarded on presentation), 71 per cent are severely retarded, 71 per cent have neurological abnormalities, and 60 per cent continue to have fits. Although hypsarrhythmia itself is not necessarily associated with a bad prognosis, the finding of suppression-burst activity certainly implies a grave outlook.