Visually evoked bursts during isoflurane anaesthesia.

We studied EEG reactivity to visual stimuli during deep isoflurane (1.5-2.05 vol% end-tidal concentration) anaesthesia. Twelve patients were anaesthetized with isoflurane until burst suppression occurred in the EEG. Red LED goggles were used to give visual stimulation of 60 flashes, 4-ms duration each, at a frequency of 20 Hz. The stimuli, 3-strains of flashes, were given at random intervals. Both onset and offset of stimulation evoked bursts. The latency of visually evoked bursts was comparable with long latency evoked potentials, which are known to be related to cognitive processing. Our data showed that the central nervous system reacts strongly to photic stimulation during deep anaesthesia.

[1]  N. Birbaumer,et al.  Positive shifts of event-related potentials: a state of cortical disfacilitation as reflected by the startle reflex probe. , 1994, Electroencephalography and clinical neurophysiology.

[2]  J. Michenfelder,et al.  Canine Cerebral Oxygen Consumption during Enflurane Anesthesia and Its Modification during Induced Seizures , 1974, Anesthesiology.

[3]  R. J. Ellingson,et al.  Electroencephalograms of normal, full-term newborns immediately after birth with observations on arousal and visual evoked responses. , 1958, Electroencephalography and clinical neurophysiology.

[4]  D. Contreras,et al.  Cortical and thalamic cellular correlates of electroencephalographic burst-suppression. , 1994, Electroencephalography and clinical neurophysiology.

[5]  B. Rockstroh.  Regulation of Cortical Excitability in Patients with Epilepsy and its Measurement by Means of Slow Cortical Potentials , 1993 .

[6]  A. J. Derbyshire,et al.  THE EFFECTS OF ANESTHETICS ON ACTION POTENTIALS IN THE CEREBRAL CORTEX OF THE CAT , 1936 .

[7]  A. Yli-Hankala,et al.  Slow potentials of EEG burst suppression pattern during anaesthesia , 1993, Acta anaesthesiologica Scandinavica.

[8]  S. H. Curry,et al.  Slow Potential Changes in the Human Brain , 1993, NATO ASI Series.

[9]  A. Yli-Hankala,et al.  Vibration stimulus induced EEG bursts in isoflurane anaesthesia. , 1993, Electroencephalography and clinical neurophysiology.

[10]  E. Eger,et al.  ELECTROENCEPHALOGRAPHIC SEIZURE ACTIVITY IN DOGS DURING ANAESTHESIA Studies with Ethrane, fluroxene, halothane, chloroform, divinyl ether, diethyl ether, methoxyflurane, cyclopropane and Forane , 1971 .

[11]  V Jäntti,et al.  EEG burst‐suppression pattern correlates with the instantaneous heart rate under isoflurane anaesthesia , 1990, Acta anaesthesiologica Scandinavica.

[12]  A. Yli-Hankala,et al.  Propofol and isoflurane induced EEG burst suppression patterns in rabbits , 1995, Acta anaesthesiologica Scandinavica.

[13]  R. J. Ellingson.  Cortical electrical responses to visual stimulation in the human infant. , 1960, Electroencephalography and clinical neurophysiology.

[14]  P. Sebel,et al.  EVOKED POTENTIALS DURING ISOFLURANE ANAESTHESIA , 1986 .