HYPERVENTILATION ACTIVATION ON EEG RECORDING IN CHILDREN WITH EPILEPSY

In 20 patients with epilepsy, electroencephalography (EEG) slowing was quantitatively characterized during standardized hyperventilation act ivation (respiratory rate: 30/min, threefold elevation of total expira tory volume, duration: 4 min) and changes in cerebral blood flow and v elocity in the right common carotid artery were monitored with the Dop pler ultrasonic method, Thirteen age-matched normal children served as controls, The results were as follows: (1) EEG slowing in the epileps y group was greater compared with controls, (2) There was a significan t decrease in mean frequency (decrease in alpha power and increase in delta power) during hyperventilation in the epilepsy group, but no sig nificant change in the controls, (3) The decrease in cerebral blood no w (CBF) was greater in the epilepsy group at the beginning of hyperven tilation, possibly related to the greater EEG slowing. (4) The percent age of CBF at the end of hyperventilation was similar in the epilepsy and control groups, The difference in EEG response to hyperventilation between the 2 groups may be due to differences in the decrease in CBF volume and the sensitivity of the change in CBF.