Electroencephalography and evoked potentials: Technical background

Abstract

Information provided by neurophysiological investigations is of outstanding importance for clinical practice and research dealing with patients with disorders of consciousness. However, because most of these patients are treated in the intensive care unit (ICU), some related problems must be known. The ICU is an environment full of electrical devices prone to produce artifacts, and patients with disorders of consciousness are exposed to many different treatments that may interfere with electrical signals and their interpretation. It is therefore highly important that the electroencephalogram (EEG) and the different sorts of evoked potentials (EP) are acquired under good conditions and according to current recommendations. This chapter reviews the technical background necessary to illustrate how to acquire good EEG/EP signals in the ICU, and will also focus on some practical pitfalls.