Quantitative Electroencephalography (EEG) Predicting Acute Neurologic Deterioration in the Pediatric Intensive Care Unit: A Case Series

Abstract

Introduction: Continuous neurologic assessment in the pediatric intensive care unit is challenging. Current electroencephalography (EEG) guidelines support monitoring status epilepticus, vasospasm detection, and cardiac arrest prognostication, but the scope of brain dysfunction in critically ill patients is larger. We explore quantitative EEG in pediatric intensive care unit patients with neurologic emergencies to identify quantitative EEG changes preceding clinical detection. Methods: From 2017 to 2020, we identified pediatric intensive care unit patients at a single quaternary children's hospital with EEG recording near or during acute neurologic deterioration. Quantitative EEG analysis was performed using Persyst P14 (Persyst Development Corporation). Included features were fast Fourier transform, asymmetry, and rhythmicity spectrograms, “from-baseline” patient-specific versions of the above features, and quantitative suppression ratio. Timing of quantitative EEG changes was determined by expert review and prespecified quantitative EEG alert thresholds. Clinical detection of neurologic deterioration was defined pre hoc and determined through electronic medical record documentation of examination change or intervention. Results: Ten patients were identified, age 23 months to 27 years, and 50% were female. Of 10 patients, 6 died, 1 had new morbidity, and 3 had good recovery; the most common cause of death was cerebral edema and herniation. The fastest changes were on “from-baseline” fast Fourier transform spectrograms, whereas persistent changes on asymmetry spectrograms and suppression ratio were most associated with morbidity and mortality. Median time from first quantitative EEG change to clinical detection was 332 minutes (interquartile range: 201-456 minutes). Conclusion: Quantitative EEG is potentially useful in earlier detection of neurologic deterioration in critically ill pediatric intensive care unit patients. Further work is required to quantify the predictive value, measure improvement in outcome, and automate the process.

Review of Noninvasive Neuromonitoring Modalities in Children II: EEG, qEEG

“…qEEG is also used to detect life-threatening neurologic decompensation before becoming irreversible (e.g., cerebral herniation). Two recent publications evaluated qEEG trends for identifying intracranial emergencies prior to clinical deterioration in children [ 145 , 146 ]. One study used qualitative review of the qEEG by neurophysiologists and the Persyst Z-score trend to create alerts for 10 patients.…”

“…Asymmetry spectrograms are particularly helpful for rapidly identifying differences between hemispheres. Persistent changes in asymmetry spectrograms have been associated with unfavorable outcome (morbidity and mortality) in a small pediatric study aimed at predicting neurologic deterioration [ 145 ]. Differences in the asymmetry spectrogram appear related to cerebral perfusion, either increased (seizure) or decreased (stroke, post-ictal state), or extracerebral pathology (subdural hemorrhage or superficial scalp swelling).…”

“…A running average is calculated with percentage suppression on the y-axis. This qEEG tool is particularly useful for neurologic conditions that result in background suppression, such as severe hypoxic-ischemic encephalopathy [144], refractory intracranial hypertension, or pharmacologically induced burst suppression [145][146][147][148].…”

The Past, Present, and Future of Tele-EEG

“…In many ways, tele-EEG has followed the trajectory of cardiac monitoring in intensive care unit (ICU) patients in the early 1960s, when telemetry first became available. Tele-EEG growth has been fueled by the evolution of brain monitoring technology, 3 4 which has in turn been driven by the personnel shortages from professionalizing technologists involved in monitoring studies as well as physicians responsible for reading them. 5 6 7 The emerging evidence for improving patient outcomes with cEEG 4 8 9 10 11 12 and attendant expansion of critical care as well as growing interest in aEEG as an adjunct or alternative to specialized epilepsy centers has propelled widespread dissemination of professional society guidelines that standardize tele-EEG.…”

“…Tele-EEG growth has been fueled by the evolution of brain monitoring technology, 3 4 which has in turn been driven by the personnel shortages from professionalizing technologists involved in monitoring studies as well as physicians responsible for reading them. 5 6 7 The emerging evidence for improving patient outcomes with cEEG 4 8 9 10 11 12 and attendant expansion of critical care as well as growing interest in aEEG as an adjunct or alternative to specialized epilepsy centers has propelled widespread dissemination of professional society guidelines that standardize tele-EEG. 13 14 15 16 17 18 19 20 These factors, buttressed by investment in broadband infrastructure and the Current Procedural Terminology (CPT) billing code revisions, particularly post-COVID-19, have facilitated the use and expansion of tele-EEG.…”