EEG efficiency of detecting sub-clinical seizures in critical ill patients: Retrospective study

Abstract

Introduction Continuous electroencephalography (cEEG) monitoring in the critical care setting demonstrates a linear increase in seizure incidence with declining mental status. Delayed diagnosis and treatment of non-convulsive status epilepticus (NCSE) may lead to increased mortality. No clinical or paraclinical parameter can reliably distinguish elderly patients with delirium with or without patterns compatible with NCSE in the absence of cEEG monitoring. EEG may be over-utilized in our hospital ICUs & usually ordered for most of the patient with altered mental status. We aimed to evaluate the efficiency of EEG to detect subclinical seizures in patients with altered level of consciousness. Methods Single-center retrospective study comprised 24 patients who were hospitalized in King Fahad Specialist Hospital in Dammam between January2017-December2018 due to change of their level of consciousness. Descriptive analysis was used to study the factors involved in the patient findings. Findings/prognosis Only 1 of the 4 patients with subclinical seizures had periodic lateralizing epileptogenic discharges. Only one of the patients with the subclinical seizures was known to have seizure. Last 2 patients were post cardiac arrest & one had brain metastasis. 2 of the patients with the subclinical seizure died few days later because of the seizure or drug side effects. Conclusion Patient with decrease level of consciousness after clinical seizure increase suspicion of subclinical seizure, therefore, early diagnosis of the subclinical seizure allows early management and most likely better outcome. However, there was an over utilization of EEG found in through the study.