State of consciousness and ERP (event-related potential) measures. Diagnostic and prognostic value of electrophysiology for disorders of consciousness

Abstract

Disorders of consciousness were amply studied in the recent years. At this regards new methodologies and technologies were applied to explore the diagnostic and prognostic criteria that may be applied to the patients. Specifically electrophysiological measures were used to verify the degree of awareness and responsiveness in coma, vegetative states (VS), minimal consciousness state (MC), and locked-in syndrome (LI). Recently, ERPs (event-related potentials) were adopted to integrate the classical neuroimaging measures. Between the others, MMN (mismatch negativity) and P300 deflections were found to represent a consistent index of the present state of consciousness and to be predictive of successive modifications of this state. Also frequency-based EEG measures, such as brain oscillations, were revealed to be relevant marker of consciousness and awareness, able to predict the future evolution of pathology.