Diagnosing and Monitoring Seizures in the ICU: The Role of Continuous EEG for Detection and Management of Seizures in Critically Ill Patients, Including the Ictal-Interictal Continuum

Abstract

Advances in computer technology have made it possible to perform prolonged digital continuous video EEG monitoring of many critically ill patients simultaneously. Studies using continuous EEG monitoring (cEEG) have found that these patients often have nonconvulsive seizures (NCSzs) that may contribute to secondary brain injury. Improving quantitative EEG (qEEG) software speeds data review to allow screening of multiple prolonged recordings to detect NCSz and provides continuous information about changes in brain function in real time at the bedside and remotely. Optimal sensitivity and specificity of qEEG tools is obtained with full electrode montages and careful maintenance of scalp electrodes. Standardized nomenclature for EEG patterns seen in critically ill patients has been tested, published, and utilized for multicenter research on these patterns. Guidelines on when and how to perform cEEG have been published. New electrode technologies, such as MRI-compatible electrodes, help reduce the burden on EEG technologists while limiting interruptions in recordings. In addition to detecting NCSz, cEEG can also be used for dynamic detection of other changes in brain function such as ischemia and can be coupled with other modalities of monitoring brain physiology such as microdialysis, tissue oximetry, and intracranial electrophysiology. Together, these tools can allow for early detection of brain at risk for injury and alert the physician to intervene before the damage becomes irreversible.