Critical Care EEG Terminology Research Articles

Cyclic Alternating EEG Patterns: From Sleep to Encephalopathy.

In the 2021 version of the Standardized Critical Care EEG Terminology, the American Clinical Neurophysiology Society introduced new definitions, including for the cyclic alternating pattern of encephalopathy (CAPE). CAPE refers to changes in background EEG activity, with two patterns alternating spontaneously in a regular manner. CAPE shares remarkable similarities with the cyclic alternating pattern, a natural EEG phenomenon occurring in normal non-rapid eye movement sleep, considered the main electrophysiological biomarker of sleep instability. This review explores similarities and differences between cyclic alternating pattern and CAPE and, leveraging the existing expertise on cyclic alternating pattern, aims to extend knowledge on CAPE. A standardized assessment of CAPE features is key to ascertain its prevalence and clinical significance among critically ill patients and to encompass the impact of confounding factors such as anesthetic and sedative agents. Although the preservation of non-rapid eye movement sleep-related elements has a well-known prognostic value in the critical care setting, the clinical importance of cyclic oscillating patterns and the prognostic significance of CAPE remain to be elucidated.

Ictal-Interictal Continuum in the Pediatric Intensive Care Unit.

The ictal-interictal continuum (IIC) consists of several electroencephalogram (EEG) patterns that are common in critically ill adults. Studies focused on the IIC are limited in critically ill children and have focused primarily on associations with electrographic seizures (ESs). We report the incidence of the IIC in the pediatric intensive care unit (PICU). We then compare IIC patterns to rhythmic and periodic patterns (RPP) not meeting IIC criteria looking for associations with acute cerebral abnormalities, ES, and in-hospital mortality. This was a retrospective review of prospectively collected data for patients admitted to the PICU at Children's National Hospital from July 2021 to January 2023 with continuous EEG. We excluded patients with known epilepsy and cerebral injury prior to presentation. All patients were screened for RPP. The American Clinical Neurophysiology Society standardized Critical Care EEG terminology for the IIC was applied to each RPP. Associations between IIC and RPP not meeting IIC criteria, with clinical and EEG variables, were calculated using odds ratios (ORs). Of 201 patients, 21% (42/201) had RPP and 12% (24/201) met IIC criteria. Among patients with an IIC pattern, the median age was 3.4years (interquartile range (IQR) 0.6-12years). Sixty-seven percent (16/24) of patients met a single IIC criterion, whereas the remainder met two criteria. ESs were identified in 83% (20/24) of patients and cerebral injury was identified in 96% (23/24) of patients with IIC patterns. When comparing patients with IIC patterns with those with RPP not qualifying as an IIC pattern, both patterns were associated with acute cerebral abnormalities (IIC OR 26 [95% confidence interval {CI} 3.4-197], p = 0.0016 vs. RPP OR 3.5 [95% CI 1.1-11], p = 0.03), however, only the IIC was associated with ES (OR 121 [95% CI 33-451], p < 0.0001) versus RPP (OR 1.3 [0.4-5], p = 0.7). Rhythmic and periodic patterns and subsequently the IIC are commonly seen in the PICU and carry a high association with cerebral injury. Additionally, the IIC, seen in more than 10% of critically ill children, is associated with ES. The independent impact of RPP and IIC patterns on secondary brain injury and need for treatment of these patterns independent of ES requires further study.

Periodic discharges plus fast activity on EEG predict worse outcomes in post-stroke epilepsy.

Post-seizure functional decline is a concern in post-stroke epilepsy (PSE). However, data on electroencephalogram (EEG) markers associated with functional decline are scarce. Thus, we investigated whether periodic discharges (PDs) and their specific characteristics are associated with functional decline in patients with PSE. In this observational study, patients admitted with seizures of PSE and who had scalp EEGs were included. The association between the presence or absence of PDs and post-seizure short-term functional decline lasting 7 days after admission was investigated. In patients with PD, EEG markers were explored for risk stratification of short-term functional decline, according to the American Clinical Neurophysiology Society's Standardized Critical Care EEG Terminology. The association between EEG markers and imaging findings and long-term functional decline at discharge and 6 months after discharge, defined as an increase in the modified Rankin Scale score compared with the baseline, was evaluated. In this study, 307 patients with PSE (median age, 75; range, 35-97 years; 64% males; hemorrhagic stroke, 47%) were enrolled. Compared with 247 patients without PDs, 60 patients with PDs were more likely to have short-term functional decline (12 (20%) vs. 8 (3.2%), p < 0.001), with an adjusted odds ratio (OR) of 4.26 (95% confidence interval (CI), 1.44-12.6; p = 0.009). Patients with superimposed fast-activity PDs (PDs+F) had significantly more localized (rather than widespread) lesions (87% vs. 58%, p = 0.003), prolonged hyperperfusion (100% vs. 62%, p = 0.023), and a significantly higher risk of short-term functional decline than those with PDs without fast activity (adjusted OR, 22.0; 95% CI, 1.87-259.4; p = 0.014). Six months after discharge, PDs+F were significantly associated with long-term functional decline (adjusted OR, 4.21; 95% CI, 1.27-13.88; p = 0.018). In PSE, PDs+F are associated with sustained neuronal excitation and hyperperfusion, which may be a predictor of post-seizure short- and long-term functional decline.

Diagnosing nonconvulsive status epilepticus: Defining electroencephalographic and clinical response to diagnostic intravenous antiseizure medication trials.

The Salzburg criteria for nonconvulsive status epilepticus (NCSE) and the American Clinical Neurophysiology Society (ACNS) Standardized Critical Care EEG Terminology 2021 include a diagnostic trial with intravenous (IV) antiseizure medications (ASMs) to assess electroencephalographic (EEG) and clinical response as a diagnostic criterion for definite NCSE and possible NCSE. However, how to perform this diagnostic test and assessing the EEG and clinical responses have not been operationally defined. We performed a Delphi process involving six experts to standardize the diagnostic administration of IV ASM and propose operational criteria for EEG and clinical response. Either benzodiazepines (BZDs) or non-BZD ASMs can be used as first choice for a diagnostic IV ASM trial. However, non-BZDs should be considered in patients who already have impaired alertness or are at risk of respiratory depression. Levetiracetam, valproate, lacosamide, brivaracetam, or (if the only feasible drug) fosphenytoin or phenobarbital were deemed appropriate for a diagnostic IV trial. The starting dose should be approximately two thirds to three quarters of the full loading dose recommended for treatment of status epilepticus, with an additional smaller dose if needed. ASMs should be administered during EEG recording under supervision. A monitoring time of at least 15 min is recommended. If there is no response, a second trial with another non-BDZ or BDZs may be considered. A positive EEG response is defined as the resolution of the ictal-interictal continuum pattern for at least three times the longest previously observed spontaneous interval of resolution (if any), but minimum of one continuous minute. For a clinical response, physicians should use a standardized examination before and after IV ASM administration. We suggest a definite time-locked improvement in a focal deficit or at least one-step improvement on a new dedicated one-domain 10-level NCSE response scale. The proposed standardized approach of a diagnostic IV ASM trial further refines the ACNS and Salzburg diagnostic criteria for NCSE.

Development of a structured process for the Spanish translation of the 2021 ACNS standardized critical care EEG terminology (P4-8.010)

<h3>Objective:</h3> To develop a Spanish translation of the 2021 critical care EEG terminology through a structured consensus of an interdisciplinary group with representation from Latin America and Spain. <h3>Background:</h3> Aiming for a common language for the classification of electroencephalogram (EEG) findings in critical care (ICU), the American Clinical Neurophysiology Society (ACNS) published the ICU-EEG terminology in 2013, which was updated in 2021. Since this nomenclature has not been published in Spanish, the potential use of the ICU-EEG terminology can be variable when translated into daily practice in Spanish-speaking countries. <h3>Design/Methods:</h3> The initial translation of the terminology was done in parallel by three subgroups of Spanish-speaking neurophysiologists and neurointensivists representing different regions of Latin America and Spain. Each subgroup worked iteratively on one section of the terminology. Scheduled meetings were carried out with the entire team to discuss translation differences and alternatives, which were recorded for discussion in future planned consensus groups. We have recruited 25 participants from Latin America and Spain to explore their impressions on the applicability, implementation, and regional differences of the translation in different Spanish-speaking countries. Using qualitative methodology, the consensus groups will follow nominal group technique methods. <h3>Results:</h3> The process, common discussion points, and consensus agreements and disagreements of the different terms chosen in the translation will be presented. <h3>Conclusions:</h3> The Spanish language is diverse, and the terms used to describe electroencephalographic findings vary in different countries. It is essential to consider these variations when translating guidelines into other languages. Translations need to be structured, iterative, and consensus-based with representations of different countries with the same language to encourage widespread use and a more homogeneous communication, which can in turn facilitate and encourage future research. <b>Disclosure:</b> Dr. Bruzzone has nothing to disclose. Dr. Rubinos has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Qualtrics Inc. Dr. Rubinos has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for American Epilepsy Society . The institution of Dr. Rubinos has received research support from University of North Carolina . Dr. Lowden has nothing to disclose. Dr. Appendino has nothing to disclose. Dr. Vidaurre has nothing to disclose. Daniel San Juan-Orta has nothing to disclose. Dr. Garcia Losarcos has nothing to disclose. Dr. Villamar has a non-compensated relationship as a Member of Editorial Board with Neurology: Clinical Practice that is relevant to AAN interests or activities. Dr. Villamar has a non-compensated relationship as a Member of Editorial Board with The Neurohospitalist that is relevant to AAN interests or activities. Dr. Burneo has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Elsevier, Clinical Neurology and Neurosurgery Journal. Dr. Burneo has received research support from The Jack Cowin Endowed Chair in Epilepsy Research. Dr. Burneo has received publishing royalties from a publication relating to health care. Dr. Mayor has nothing to disclose. Dr. Rodriguez-Ruiz has received personal compensation in the range of $0-$499 for serving as a Consultant for Atheneum. Dr. Rodriguez-Ruiz has stock in Lourbeth LLC. Dr. Gutierrez has nothing to disclose. Dr. Fernandez has nothing to disclose.

Evaluation of Automated Seizure Detection Measurements in Cardiac Arrest Patients Undergoing Ceribell Rapid-EEG (S30.009)

<h3>Objective:</h3> To retrospectively evaluate the performance of the Clarity™ automated seizure detection system (Ceribell, Inc) for the detection of seizures and status epilepticus in cardiac arrest patients. <h3>Background:</h3> In cardiac arrest patients who remain comatose after return of spontaneous circulation, seizures and EEG abnormalities are common. Thus, guidelines recommend urgent EEG initiation for evaluation of seizures in this population. Point-of-care EEG systems, such as Ceribell™ Rapid-EEG, allow for prompt initiation of EEG monitoring, albeit through a limited-channel montage. Rapid-EEG incorporates an automated seizure detection software (Clarity™) to measure seizure burden in real time and alert clinicians when a high seizure burden, consistent with possible status epilepticus, is identified. External validation of Clarity is still needed. <h3>Design/Methods:</h3> This study was a retrospective review of Ceribell Rapid-EEG recordings from all the patients who were admitted to the medical intensive care unit at Kent Hospital (Warwick, RI, USA) between 6/1/2021 and 3/18/2022 for management after cardiac arrest and who underwent Rapid-EEG monitoring as part of their routine clinical care (n=21). Board-certified epileptologists identified events that met criteria for seizures or status epilepticus, as per the 2021 American Clinical Neurophysiology Society’s Standardized Critical Care EEG Terminology, and evaluated any seizure burden detections generated by Clarity. <h3>Results:</h3> In this study, 4 of 21 cardiac arrest patients (19.0%) who underwent Rapid-EEG monitoring had multiple electrographic seizures, and 2 of those patients (9.5%) had electrographic status epilepticus within the first 24 hours of the study. None of these ictal abnormalities were detected by the Clarity seizure detection system. Clarity showed 0% seizure burden during all these events. <h3>Conclusions:</h3> The presence of frequent seizures and/or status epilepticus may go undetected by currently available automated seizure detection systems. Timely and careful review of all raw Rapid-EEG recordings by a qualified human EEG reader is necessary to guide clinical care. <b>Disclosure:</b> Dr. Villamar has a non-compensated relationship as a Member of Editorial Board with Neurology: Clinical Practice that is relevant to AAN interests or activities. Dr. Villamar has a non-compensated relationship as a Member of Editorial Board with The Neurohospitalist that is relevant to AAN interests or activities. The institution of Dr. Ayub has received research support from Brown Physicians Incorporated. Dr. Koenig has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Fuji SonoSite. Dr. Koenig has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Medscape.

Editorial introductions.

Current Opinion in Neurology was launched in 1988. It is one of a successful series of review journals whose unique format is designed to provide a systematic and critical assessment of the literature as presented in the many primary journals. The field of neurology is divided into 14 sections that are reviewed once a year. Each section is assigned a Section Editor, a leading authority in the area, who identifies the most important topics at that time. Here we are pleased to introduce the Journal's Section Editors for this issue. SECTION EDITORS Lawrence J. HirschLawrence J. HirschLawrence J. Hirsch, MD is Professor of Neurology, Chief of the Division of Epilepsy and EEG, and Co-Director of the Comprehensive Epilepsy Center, all at Yale University, USA. He has held leadership positions in the American Clinical Neurophysiology Society (ACNS), American Epilepsy Society, American Academy of Neurology, and the Epilepsy Foundation, and is lead author of the 2012 and 2021 ACNS guidelines on critical care EEG terminology. He is founder and former chair of the Critical Care EEG Monitoring Research Consortium, which now includes more than 50 centers, and co-chair of the medical advisory board of the NORSE Institute. He has been an active researcher throughout his career, having published more than 200 peer-reviewed manuscripts and more than 100 reviews, editorials or book chapters on topics including status epilepticus, all aspects of EEG including intracranial recordings and brain monitoring in the critically ill, brain stimulation, epilepsy surgery, seizure clusters, rescue medications, sudden death in epilepsy (SUDEP), and anti-seizure medication use. He has won multiple teaching awards and is co-author of the first-ever atlas on EEG in critical care, now in its 2nd edition. He continues to see patients in the inpatient and outpatient setting, direct fellowship programs, teach, mentor, and manage a large epilepsy division at a level IV Comprehensive Epilepsy Center. Michael F. WatersMichael F. WatersMichael F. Waters, MD, PhD, is a neurologist, director of both the Neurovascular Division and the Petznick Stroke Center, and a professor in the Department of Neurology at Barrow Neurological Institute, USA. He is board certified in neurology by the American Board of Psychiatry and Neurology with subspecialty board certification in vascular neurology. Dr Waters’ expertise is stroke and neurovascular disease, including signs, symptoms, diagnostics, and treatments. He is a fellow of both the American Academy of Neurology and American Heart Association and a member of the American Neurological Association, American Society of Human Genetics, and the Society of Vascular and Interventional Neurology. Dr Waters received his Masters in genetics from Penn State University in State College, Pennsylvania, USA, and his doctorate in biochemistry and molecular biology from The University of Florida College of Medicine in Gainesville, USA, where he also completed his MD. He completed his residency training at the University of California – Los Angeles Department of Neurology and completed his fellowship in clinical and molecular neurogenetics at Cedars Sinai Medical Center in Los Angeles, USA. Dr Waters’ research studies include genetic mechanisms of stroke, neuroprotection in stroke, stroke treatment, multiple clinical trials investigating stroke treatments, and neurogenetic mechanisms of neuroplasticity.

Automated Seizure Detection in Patients with Cardiac Arrest: A Retrospective Review of Ceribell™ Rapid-EEG Recordings.

In patients with cardiac arrest who remain comatose after return of spontaneous circulation, seizures and other abnormalities on electroencephalogram (EEG) are common. Thus, guidelines recommend urgent initiation of EEG for the evaluation of seizures in this population. Point-of-care EEG systems, such as Ceribell™ Rapid Response EEG (Rapid-EEG), allow for prompt initiation of EEG monitoring, albeit through a reduced-channel montage. Rapid-EEG incorporates an automated seizure detection software (Clarity™) to measure seizure burden in real time and alert clinicians at the bedside when a high seizure burden, consistent with possible status epilepticus, is identified. External validation of Clarity is still needed. Our goal was to evaluate the real-world performance of Clarity for the detection of seizures and status epilepticus in a sample of patients with cardiac arrest. This study was a retrospective review of Rapid-EEG recordings from all the patients who were admitted to the medical intensive care unit at Kent Hospital (Warwick, RI) between 6/1/2021 and 3/18/2022 for management after cardiac arrest and who underwent Rapid-EEG monitoring as part of their routine clinical care (n = 21). Board-certified epileptologists identified events that met criteria for seizures or status epilepticus, as per the 2021 American Clinical Neurophysiology Society's Standardized Critical Care EEG Terminology, and evaluated any seizure burden detections generated by Clarity. In this study, 4 of 21 patients with cardiac arrest (19.0%) who underwent Rapid-EEG monitoring had multiple electrographic seizures, and 2 of those patients (9.5%) had electrographic status epilepticus within the first 24h of the study. None of these ictal abnormalities were detected by the Clarity seizure detection system. Clarity showed 0% seizure burden throughout the entirety of all four Rapid-EEG recordings, including the EEG pages that showed definite seizures or status epilepticus. The presence of frequent electrographic seizures and/or status epilepticus can go undetected by Clarity. Timely and careful review of all raw Rapid-EEG recordings by a qualified human EEG reader is necessary to guide clinical care, regardless of Clarity seizure burden measurements.

Balancing the risks and benefits of anesthetics in status epilepticus

PurposeAccording to international guidelines, status epilepticus refractory to first- and second-line antiseizure medication should be treated with anesthetics. Therefore, continuously delivered intravenous midazolam, propofol, or barbiturates are recommended as third-line therapy. While electroencephalographically (EEG)-controlled titration of anesthetics to seizure termination or to the emergence of an EEG burst-suppression pattern makes sense, evidence of the efficacy and tolerability of such third-line treatment is limited and concerns regarding the risks of anesthesia remain. The lack of treatment alternatives and persistent international discord reflecting contradictory results from some studies leave clinicians on their own when deciding to escalate treatment.In this conference-accompanying narrative review, we highlight the challenges of EEG-monitored third-line treatment and discuss recent studies that examined earlier administration of anesthetics. ResultsBased on the literature, maintaining continuous burst suppression is difficult despite the constant administration of anesthetics, and the evidence for burst suppression as an adequate surrogate target is limited by methodological shortcomings as acknowledged by international guidelines. In our Swiss cohort including 102 patients with refractory status epilepticus, burst suppression as defined by the American Clinical Neurophysiology Society's Critical Care EEG Terminology 2021 was established in only 21%. Besides case reports suggesting that rapid but short-termed anesthesia can be sufficient to permanently stop seizures, a study including 205 patients revealed that anesthesia as second-line treatment was associated with a shorter median duration of status epilepticus (0.5 versus 12.5 days, p < 0.001), median ICU (2 versus 5.5 days, p < 0.001) and hospital stay (8 versus 17 days, p < 0.001) with equal rates of complications when compared to anesthesia as third-line treatment. ConclusionsRecent investigations have led to important findings and new insights regarding the use of anesthetics in refractory status epilepticus. However, numerous methodological limitations and remaining questions need to be considered when it comes to the translation into clinical practice, and, in consequence, call for prospective randomized studies.This paper was presented at the 8th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures held in September 2022.

WE-128. Utility of American clinical neurophysiology society’s standardized critical care EEG terminology 2021 for diagnosis of anti-glutamic acid decarboxylase antibody-associated-disorders

WE-128. Utility of American clinical neurophysiology society’s standardized critical care EEG terminology 2021 for diagnosis of anti-glutamic acid decarboxylase antibody-associated-disorders

BIRDs (Brief Potentially Ictal Rhythmic Discharges) watching during EEG monitoring.

Brief Potentially Ictal Rhythmic Discharges (BIRDs), initially described in neonates, have been shown to correlate with increased risk of seizures in both critically ill and non-critically ill adults. In critically ill patients, BIRDs are associated with acute brain injury and worse functional outcomes. In non-critically ill adults, BIRDs are seen in patients with epilepsy with a greater likelihood of having drug resistance. The location of BIRDs seems to better predict the seizure onset zone compared to other interictal epileptiform discharges. The definition of BIRDs includes Paroxysmal Fast Activity (PFA), and they have similar clinical significance regardless of the exact cut-off frequencies. Their potential as a biomarker for seizure activity and seizure onset zone has been suggested. In patients with status epilepticus, BIRDs also resolve or decrease when seizures resolve. Thus, if BIRDs are observed on scalp EEG, more extended EEG monitoring is recommended to estimate their seizure burden and to guide treatment. With the recent addition of BIRDs in the critical care EEG terminology, with future investigations, we may soon be able to reach a consensus about the definition of electrographic seizures and better understand their neurophysiology and clinical significance.

Programming of Electronic Medical Record for ACNS Standardized Critical Care EEG Terminology (P1-1.Virtual)

Programming of Electronic Medical Record for ACNS Standardized Critical Care EEG Terminology (P1-1.Virtual)

Revised Electroencephalography Terminology and Clinical Consideration

Electroencephalography (EEG) has been used for decades to evaluate and assess brain function. It is a useful method to diagnose brain disorders. However, confirmed interpretation of EEG is quite challenging because there is no standardized method for EEG reading and this may lead to interrater variability even among expert electroencephalographers. In this background, uniformly accepted nomenclature for EEG pattern were required to improve interrater agreement and to support communication for EEG research. American Clinical Neurophysiology Society (ACNS) established the standardized critical care EEG terminology since 2012 and has recently published the revised 2021 version of EEG terminology. This review covers new concepts of 2021 ACNS EEG terminology and clinical considerations of various EEG patterns.

Lateralized Periodic Discharges Detected and Described via Intraoperative Neuromonitoring

ABSTRACT This case report details lateralized periodic discharges (LPDs) detected and described via intraoperative neuromonitoring during tumor resection. Descriptions and quantifications were made according to the American Clinical Neurophysiology Society’s Standardized Critical Care EEG Terminology: 2021 Version. Further, this case illustrates quantitative changes to the LPDs observed in real time as the tumor was removed.

Management of Status Epilepticus, Refractory Status Epilepticus, and Super-refractory Status Epilepticus.

Status epilepticus is a serious condition caused by disorders and diseases that affect the central nervous system. In status epilepticus, hypersynchronous epileptic activity lasts longer than the usual duration of isolated self-limited seizures (time t1), which causes neuronal damage or alteration of neuronal networks at a certain time point (time t2), depending on the type of and duration of status epilepticus. The successful management of status epilepticus includes both the early termination of seizure activity and the earliest possible identification of a causative etiology, which may require independent acute treatment. In nonconvulsive status epilepticus, patients present only with subtle clinical signs or even without any visible clinical manifestations. In these cases, EEG allows for the assessment of cerebral function and identification of patterns in need of urgent treatment. In 2015, the International League Against Epilepsy proposed a new definition and classification of status epilepticus, encompassing four axes: symptomatology, etiology, EEG, and age. Various validation studies determined the practical usefulness of EEG criteria to identify nonconvulsive status epilepticus. The American Clinical Neurophysiology Society has incorporated these criteria into their most recent critical care EEG terminology in 2021. Etiology, age, symptomatology, and the metabolic demand associated with an increasing duration of status epilepticus are the most important determinants of prognosis. The consequences of status epilepticus can be visualized in vivo by MRI studies. The current knowledge about status epilepticus allows for a more reliable diagnosis, earlier treatment, and improved cerebral imaging of its consequences. Outcome prediction is a soft tool for estimating the need for intensive care resources.

Associations between Electroencephalographic Variables, Early Post-Traumatic Seizure Risk, and Outcomes following Pediatric Severe Traumatic Brain Injury

AbstractEarly post-traumatic seizures (PTS) are associated with worse outcomes in children with traumatic brain injury (TBI). Our aim was to identify the association between continuous electroencephalogram (cEEG) characteristics and early PTS risk following pediatric severe TBI. We also evaluated the relationship between cEEG background features and outcomes. A single-center retrospective cohort study was performed on children between 0 and 18 years of age admitted to the pediatric intensive care unit from 2016 to 2019 with severe TBI and cEEG monitoring within 7 days of injury. Raw cEEG tracings were reviewed by an epileptologist in accordance with American Clinical Neurophysiology Society (ACNS) Critical Care EEG terminology. Univariate comparisons were made between children with and without early PTS, as well as between those with and without varying cEEG background features. Eighteen children (31%) of the 59 included had early PTS. Interictal abnormalities, inclusive of sporadic spikes and sharp waves, rhythmic delta activity, or lateralized periodic discharges (LPDs) were more common among children with seizures (100 vs. 22%; p &lt; 0.01). LPDs were also more common in the seizure group (44 vs. 2%; p &lt; 0.01). Background discontinuity was associated with worse Glasgow Outcome Scale—Extended Pediatric Version (GOS-E Peds) scores at discharge and 3-, 6-, and 12-month post-discharge (p &lt; 0.01). Lack of reactivity was also associated with worse GOS-E Peds scores at 3-, 6-, and 12-month post-discharge (p &lt; 0.01). Interictal abnormalities and LPDs were each associated with early PTS following pediatric severe TBI. Larger studies should evaluate if high-risk patients would benefit from prolonged cEEG monitoring and/or more aggressive anti-seizure prophylaxis. Discontinuity and lack of variability were associated with worse outcomes. Future studies should attempt to clarify their role as potential early markers of prognosis.

HP34: Usefulness of EEG for patients in ICU with agitation and delirium

For patients admitted in Intensive Care Unit [ICU] the genesis of agitation is multifactorial [Thiago Lopes de Almeida, 2016]. In one study on patients with altered mental status, electroencephalography showed that 5% of patients had non- convulsive seizure, 75% of these were in status [Zeller, 2017]. We retrospectively analyzed 63 patients admitted in ICU with different neurological diseases that have had an episode of agitation or confirmed delirium. They were examined with EEG to rule out non-convulsive status epilepticus. The patients were at least 18 years old, with a Richmond Agitation Sedation Scale more than 2. The American Clinical Neurophysiology Society's Standardized Critical Care EEG Terminology and modified Salzburg EEG criteria were applied. Results: 2 [3%] of 63 patients presented non convulsive seizure and in 4 cases [6.3%] non-convulsive status epilepticus was confirmed with the following patterns: 25% - with rhythmic delta activity exceeding 0.5/s and clinical and EEG improvements from antiepileptic drugs; 50%- epileptiform discharges ≤2.5 Hz, with fluctuation in morphology, frequency and location. Periodic discharges [PDs] were recorded in 9.5% of 63 patients; in 24 cases [38%] diffuse delta or theta slowing were recorded, in other 16% - sporadic epileptiform discharges and in 27% - no changes. Conclusion: EEG is useful in agitated and confused patients to exclude an ictal phenomenon. It is very important to consider that the results may be influenced by the heterogeneity of the group, patients with various neurological pathologies, the presence of ICU-related artifacts, sedation that might influence the EEG patterns.

Outcomes of seizures, status epilepticus, and EEG findings in critically ill patient with COVID-19

ObjectiveSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has a myriad of neurological manifestations and its effects on the nervous system are increasingly recognized. Seizures and status epilepticus (SE) are reported in the novel coronavirus disease (COVID-19), both new onset and worsening of existing epilepsy; however, the exact prevalence is still unknown. The primary aim of this study was to correlate the presence of seizures, status epilepticus, and specific critical care EEG patterns with patient functional outcomes in those with COVID-19. MethodsThis is a retrospective, multicenter cohort of COVID-19-positive patients in Southeast Michigan who underwent electroencephalography (EEG) from March 12th through May 15th, 2020. All patients had confirmed nasopharyngeal PCR for COVID-19. EEG patterns were characterized per 2012 ACNS critical care EEG terminology. Clinical and demographic variables were collected by medical chart review. Outcomes were divided into recovered, recovered with disability, or deceased. ResultsOut of the total of 4100 patients hospitalized with COVID-19, 110 patients (2.68%) had EEG during their hospitalization; 64% were male, 67% were African American with mean age of 63 years (range 20–87). The majority (70%) had severe COVID-19, were intubated, or had multi-organ failure. The median length of hospitalization was 26.5 days (IQR = 15 to 44 days). During hospitalization, of the patients who had EEG, 21.8% had new-onset seizure including 7% with status epilepticus, majority (87.5%) with no prior epilepsy. Forty-nine (45%) patients died in the hospital, 46 (42%) recovered but maintained a disability and 15 (14%) recovered without a disability. The EEG findings associated with outcomes were background slowing/attenuation (recovered 60% vs recovered/disabled 96% vs died 96%, p < 0.001) and normal (recovered 27% vs recovered/disabled 0% vs died 1%, p < 0.001). However, these findings were no longer significant after adjusting for severity of COVID-19. ConclusionIn this large multicenter study from Southeast Michigan, one of the early COVID-19 epicenters in the US, none of the EEG findings were significantly correlated with outcomes in critically ill COVID-19 patients. Although seizures and status epilepticus could be encountered in COVID-19, the occurrence did not correlate with the patients’ functional outcome.

Triphasic waves on electroencephalogram in patients with encephalopathy and their diagnosis significance. A review

Triphasic waves are high-amplitude (&gt;70 µV) positive sharp transients preceded and followed by relatively low-amplitude negative waves. The distribution is generalized and tends to have a repetition rate of approximately 1 to 2 Hz. This EEG-pattern is traditionally associated with hepatic encephalopathy, although they have been observed in a wide array of neurological disorders including subcortical white-matter disease, infections, metabolic disturbances and nonconvulsive status epilepticus.American Clinical Neurophysiology Society suggested Standardized Critical Care EEG Terminology (2012). One of the goals was to eliminate terms with clinical connotations, such as ‘triphasic waves’, a term that implies a metabolic encephalopathy with no relationship to seizures for many clinicians. The term ‘triphasic waves’ was replaced by ‘Generalized periodic discharges (GPDs) with triphasic morphology’. The clinical significance ofthese waveforms and their relationship with seizures and prognosis has been debated, and differentiation between interictal patterns, patternsassociated with seizures, and the patterns representing nonconvulsive status epilepticus have been concluded to be a challenge. In cases of uncertainty, the decision to treat should follow on a thorough evaluation with a continuous EEG monitoring and using a short-acting benzodiazepine or non-sedating antiepileptic drugs in order to discern the effects of the pattern on the patient’s clinical exam and EEG.

The effectiveness of neurology resident EEG training for seizure recognition in critically ill patients.

EEG monitoring in the ICU is essential for diagnosing seizures in critically ill patients. Neurology residents are the frontline for rapid diagnosis of seizures. Residents received EEG training through didactic lectures and their epilepsy rotations. We hypothesized that seizure recognition was dependent on epilepsy rotation, not the seniority of the residency. Residents were taught ACNS Standardized Critical Care EEG Terminology, unified EEG terminology and criteria for non-convulsive status epilepticus. EEG segments were given to residents for seizure recognition, and explanations provided to residents after each test. Anonymous results with the postgraduate training year (PGY) and time spent in epilepsy rotation were collected. These tests were conducted 3 times, with total of 48 EEG segments, between October, 2017 and May, 2019. There were 43 participates, including 4 PGY-1 (9.3%), 20 PGY-2 (46.5%), 12 PGY-3 (27.9%), and 7 PGY-4 (16.3%) residents. The mean rate of seizure recognition was 57.1% in PGY-1, 63.8% in PGY-2, 58.4% in PGY-3, and 70.1% in PGY-4. Comparing the duration of epilepsy rotations, the mean correct scores of seizure recognition were 58.6%, 64.6%, 64.4%, and 67.3% for duration at 0, 0.5, 1, and 2 months respectively. There was no significant difference regarding the PGY or the time of epilepsy rotation statistically by ANOVA (p = 0.37). Seizure recognition in the EEG of a critically ill patient is not solely dependent time spent in epilepsy rotation or stage of residency training. EEG interpretation skill may require an alternate approach, and continuous training.