Spontaneous electrical activity (EEG) and event-related computer averaged brain electrical potentials (EPs) are becoming an integral part of CNS function monitoring in neurological intensive care patients. EEG monitoring using the compressed spectral array (CSA) computer analysis offers continuous information about cerebral electrical activity, permitting an accurate definition of the severity of brain injury, forecasting patient's course, and early detection of secondary intracranial changes. It offers more precise indications for treatment and prognosis. Combining EEG with multimodality EPs permits a finer diagnosis of the location and extent of CNS damage and contributes information, not otherwise obtainable, on the integrity of CNS pathways. Changes is electrophysiological patterns are often related to changes in other physiological parameters or events affecting the patient. Consequently, it appears advantageous to monitor simultaneously other CNS and body functions and record, process and display the data obtained in the patient care area. To make this comprehensive monitoring system reliable and useful, a wise application of advanced computer technology and a high degree of understanding of intracranial dynamics are required.