Using EEG to Study Coma in the Neurocritical Care Unit

Despite its clinical significance, the pathophysiology of coma is still under investigation and the physiology of emergence from coma remains a mystery. Furthermore, predictors of emergence from coma, despite their obvious clinical value, remain un-established. Because of its low arousal state and hypothesized parallel neurophysiological mechanisms, sleep has been studied as both an animal and human model of coma, and awakening from sleep has likewise been studied as a surrogate of coma emergence. In this study, we will determine whether certain electrographic patterns, known as spectral shifts, which have correlates in normal sleep, are predictive of eventual awakening from coma and the time course of this emergence. To detect spectral shifts in comatose patients, EEG monitoring must be performed for several days. Quick, simple, and reliable EEG recording in the ICU will be enhanced by a small device that can be easily and properly positioned on the head by hospital personnel and which lacks cumbersome cables or receivers. Traditional EEG monitoring requires placement of up to 25 wires, which can impede efficient intensive patient care. Our hypothesis is that we can detect a difference in spectral shifts in comatose patients who will eventually emerge from coma as compared to comatose patients who do not wake up and that a wireless EEG patch-type device can effectively make this distinction.