[Characteristic of children's EEG complexity at different ages and in different states].

OBJECTIVE

To study characteristics of children's EEG complexity at different ages and in different physiological states.

METHODS

The continuous 24-hour EEG recordings were obtained from 16 electrodes in 45 essential healthy children between the ages of 0 to 15 years. EEG complexity was analyzed by non-linear measure in 7 states: awake with eyes opened, awake with eyes closed, NREM (nonrapid eye movements) sleep including stages I and II (light sleep), III and IV (deep sleep) and REM (rapid eye movements) sleep. Meanwhile, the correlation was analyzed between complexity and ages.

RESULTS

(1) The global EEG complexity in state of being awake with eyes opened was greater than that with eyes closed; that in wakefulness state was greater than in sleep state. The EEG complexity gradually decreased with the increase of deep sleep in NREM sleep state. The complexity in REM sleep state was greater than that in deep sleep state, but lower than in wakefulness state. (2) The global EEG complexity was positively related to ages in state of being awake with eyes opened, state of being awake with eyes closed, light sleep, and not related to ages in deep-sleep state and REM sleep state. (3) In every brain area EEG complexity was positively related to ages in state of being awake with eyes closed. In paracentral region EEG complexity was positively related to ages in states of being awake with eyes opened and light sleep.

CONCLUSION

The EEG complexity was used to study the brain dynamical characteristics in different physiology states and the relationship between encephalic electric activity and brain development. It can be used as an objective index to evaluate the function and development of brain.