Electroencephalogram and Sensory Evoked Potentials

Abstract

The unusual finding of clinical unresponsiveness in association with an electroencephalogram resembling wakefulness has been related to lesions of the human neuraxis extending up to the photomesencephalic junction. In such a patient in whom an extensive infarct of the pons induced a state of clinical unresponsiveness, we were able to demonstrate the presence of a nearly normal EEG which included a driving response to intermittent photic stimulation, summated photic evoked responses within the range of normal variability, and slow wave sleep patterns. Evoked responses to clicks and the rapid eye movement phase of sleep were absent. Although alert behavior was never observed, it is felt that caution should be exercised in interpreting the significance of this finding in any mute paralyzed patient who exhibits an EEG pattern resembling wakefulness.