The aim of this study was to estimate spectral properties and propagation of the EEG signals registered during sevoflurane anaesthesia between individual EEG recording channels. The intensities of activity flows were calculated for delta, theta, alpha and beta waves using the Directed Transfer Function integration procedure. It was found that delta waves played the dominant role in the EEG signal propagation during anesthesia and it was suggested that theta and alpha waves propagation could be related to the processes participating in the wakefulness control. Data obtained with DTF method were compared with data received from the analysis of cerebral blood flow with the use of PET in other laboratory. This study showed that analysis of the EEG signal propagation is useful for better understanding and thus safer induction of anaesthesia procedure.
Alkire MT, Haier RJ, Fallon JH. Towards a unified theory of narcosis: brain imaging evidence for a thalamocortical switch as the neurophysiologic basis of anestheticinduced unconsciousness. Conscious Cogn. 2000;9:370-386.
Kaminski MJ, Blinowska KJ, Szelenberger W. Topographic analysis of coherence and propagation of EEG activity during sleep and wakefulness. Electroenceph Clin Neurophysiol. 1997;102:216-227.
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