The Electroencephalogram and Delirium

The electroencephalogram (EEG) reflects the activity of thousands or even millions of cortical neurons with important input from subcortical structures. As changes in milliseconds may be visible in EEG, temporal resolution is excellent. However, spatial resolution of regular, low-density EEG is poor, hampering anatomical inferences. During delirium, EEG shows distinct features, of which an increase of slow activity (oscillations in the theta and delta frequency range) seems to be shared among all delirious patients. EEG is a relatively cheap method that can be applied at the bedside. EEG can aid in resolving unanswered research questions about the pathophysiology of delirium and be used for delirium detection and monitoring.