Characteristics and role in outcome prediction of continuous EEG after status epilepticus: A prospective observational cohort

Abstract

Summary Objective Continuous electroencephalography (cEEG) is important for treatment guidance in status epilepticus (SE) management, but its role in clinical outcome prediction is unclear. Our aim is to determine which cEEG features give independent outcome information after correction for clinical predictor. Methods cEEG data of 120 consecutive adult patients with SE were prospectively collected in three academic medical centers using the 2012 American Clinical Neurophysiology Society’s Standardized Critical Care EEG Terminology. Association between cEEG features and two clinical outcome measures (mortality and complete recovery) was assessed. Results In the first 24 h of EEG recording, 49 patients (40.8%) showed no periodic or rhythmic pattern, 45 (37.5%) had periodic discharges, 20 (16.7%) had rhythmic delta activity, and 6 (5%) had spike-and-wave discharges. Seizures were recorded in 68.3% of patients. After adjusting for known clinical predictive factors for mortality including the STatus Epilepticus Severity Score (STESS) and the presence of a potentially fatal etiology, the only EEG features (among rhythmic and periodic patterns, seizures, and background activity) that remained significantly associated with outcome were the absence of a posterior dominant rhythm (odds ratio [OR] 9.8; p = 0.033) for mortality and changes in stage II sleep pattern characteristics (OR 2.59 for each step up among these categories: absent, present and abnormal, present and normal; p = 0.002) for complete recovery. Significance After adjustment for relevant clinical findings, including SE severity and etiology, cEEG background information (posterior dominant rhythm and sleep patterns) is more predictive for clinical outcome after SE than are rhythmic and periodic patterns or seizures.

The role of cEEG as a predictor of patient outcome and survival in patients with intraparenchymal hemorrhages

“…Patients exhibiting EEGs with strong Stage II Sleep features had an increased likelihood of lower mRS scores and better functional recovery at discharge. This has been shown to be true in previous studies assessing functional outcome in other neurological conditions such as subarachnoid hemorrhage and status epilepticus [2,4]. It appears to hold significant value as an EEG feature associated with clinical outcome, even more so than PDR, poor EEG background, and continuity which lose their association value after adjusting for other known confounders.…”

“…Additionally, it was found that the presence of AP gradient, a background feature, in EEGs of IPH patients is independently associated with lower mortality after correcting for known confounders. A previous study in status epilepticus found that the presence of a posterior dominant rhythm, another background feature, was associated with lower mortality [2].…”

“…In comatose patients after cardiac arrest, EEG is the strongest predictor of poor outcome [1]. In status epilepticus, the absence of a strong posterior dominant rhythm (PDR) is associated with mortality, and presence of Stage II Sleep is associated with return to baseline after controlling for clinical predictive factors [2]. In intracerebral hemorrhages, periodic discharges have been shown to be independently correlated to poor outcome [3].…”

Pilot Observational Study to Detect Diurnal Variation and Misalignment in Heart Rate Among Critically Ill Patients

“…It is plausible that circadian misalignment contributes to poor recovery and contributes independently to death. Other studies have observed that disruptions of the sleep and circadian systems are associated with higher mortality in medical ICU patients (31)(32)(33) and other critical illness populations (34)(35)(36)(37). Conversely, we note that is a simple association rather than any implied causal effect, and this misalignment may be a marker of severity of illness.…”

Clinical and Electrophysiological Differentiation between Periodical and Epileptic Discharges

“…The authors reported that a lack of EEG reactivity was the single feature most closely related to mortality. 62 In our opinion, the reason for the discrepancies between these results and previous findings may be due to the finding that lack of EEG reactivity is a common symptom among patients with various types of brain damage. Furthermore, this symptom can be observed in patients with a relatively high level of consciousness.…”