Persistent nonconvulsive status epilepticus after the control of convulsive status epilepticus

Pharmacotherapy for Nonconvulsive Seizures and Nonconvulsive Status Epilepticus

Most seizures in critically ill patients are nonconvulsive. A significant number of neurological and medical conditions can be complicated by nonconvulsive seizures (NCSs) and nonconvulsive status epilepticus (NCSE), with brain infections, hemorrhages, global hypoxia, sepsis, and recent neurosurgery being the most prominent etiologies. Prolonged NCSs and NCSE can lead to adverse neurological outcomes. Early recognition requires a high degree of suspicion and rapid and appropriate duration of continuous electroencephalogram (cEEG) monitoring. Although high quality research evaluating treatment with antiseizure medications and long-term outcome is still lacking, it is probable that expeditious pharmacological management of NCSs and NCSE may prevent refractoriness and further neurological injury. There is limited evidence on pharmacotherapy for NCSs and NCSE, although a few clinical trials encompassing both convulsive and NCSE have demonstrated similar efficacy of different intravenous (IV) antiseizure medications (ASMs), including levetiracetam, valproate, lacosamide and fosphenytoin. The choice of specific ASMs lies on tolerability and safety since critically ill patients frequently have impaired renal and/or hepatic function as well as hematological/hemodynamic lability. Treatment frequently requires more than one ASM and occasionally escalation to IV anesthetic drugs. When multiple ASMs are required, combining different mechanisms of action should be considered. There are several enteral ASMs that could be used when IV ASM options have been exhausted. Refractory NCSE is not uncommon, and its treatment requires a very judicious selection of ASMs aiming at reducing seizure burden along with management of the underlying condition.

An Adult Case of Hemiplegia, Aphasia, and Hemispheric Atrophy Associated with Febrile Status Epilepticus

A 43-year-old man with a preceding infection was transferred to our hospital for febrile status epilepticus (SE). Although treatment for SE was immediately initiated, it failed. Therefore, continuous anesthetics treatment with mechanical ventilation was initiated. No epileptic discharge was found on an electroencephalogram. However, total aphasia and right hemiplegia due to left hemispheric swelling were noted on day 5. His aphasia and hemiplegia did not improve. The mechanism underlying the hemispheric involvement remains unclear. The initial diagnosis should be made with care in patients with febrile SE; furthermore, intensive treatment should be administered in the acute phase.

Not all patients with convulsive status epilepticus intubated in pre-hospital settings meet the criteria for refractory status epilepticus

INTRODUCTION

Mechanically ventilated patients admitted to the intensive care unit (ICU) for generalized convulsive status epilepticus (GCSE) are a heterogeneous population. Our objective was to evaluate the number of patients who fulfilled the diagnostic criteria for refractory GCSE and describe their initial management and prognosis.

METHODS

This multicenter retrospective study was conducted in four French ICUs in Pitié-Salpêtrière University Hospital in Paris and in the Hospital of Jossigny. Mechanically ventilated patients admitted to the ICU for GCSE between, January 1, 2014, and, December 31, 2016, were included. Patients with anoxia and traumatic brain injury were excluded. Their pre-hospital and ICU medical records were reviewed. The collected data included pre-hospital clinical status, pre-hospital antiepileptic treatment, reason for mechanical ventilation, duration of general anesthesia, and prognosis in the ICU. A retrospective initial diagnosis based on the findings of the analysis of the clinical records was attributed to each patient.

RESULTS

Among the 98 patients included, 88.8% (n = 87/98) fulfilled the diagnostic criteria for GCSE; of these cases, 16.1% (n = 14/87) were refractory. Eleven percent of the patients did not fulfill the criteria for GCSE at the time of initial management (retrospective diagnosis of single convulsive seizure, repetitive convulsive seizures, or psychogenic non-epileptic seizures). Most patients were intubated for coma (58.9%, n = 56/95, missing data: n = 3). In the ICU, the median [Q1-Q3] duration of general anesthesia before weaning was 12.3 h (5.0-18.0 h); 7% of the patients had a relapse of status epilepticus, and 2% died in the ICU.

CONCLUSION

Among the cases of confirmed GCSE in the mechanically ventilated patients admitted to the ICU, 16.1% were refractory, with an overall good prognosis. A significant proportion of patients did not fulfill the diagnostic criteria for refractory GCSE.

Carbogen inhalation during non-convulsive status epilepticus: A quantitative exploratory analysis of EEG recordings

Objective

To quantify the effect of inhaled 5% carbon-dioxide/95% oxygen on EEG recordings from patients in non-convulsive status epilepticus (NCSE).

Methods

Five children of mixed aetiology in NCSE were given high flow of inhaled carbogen (5% carbon dioxide/95% oxygen) using a face mask for maximum 120s. EEG was recorded concurrently in all patients. The effects of inhaled carbogen on patient EEG recordings were investigated using band-power, functional connectivity and graph theory measures. Carbogen effect was quantified by measuring effect size (Cohen’s d) between “before”, “during” and “after” carbogen delivery states.

Results

Carbogen’s apparent effect on EEG band-power and network metrics across all patients for “before-during” and “before-after” inhalation comparisons was inconsistent across the five patients.

Conclusion

The changes in different measures suggest a potentially non-homogeneous effect of carbogen on the patients’ EEG. Different aetiology and duration of the inhalation may underlie these non-homogeneous effects. Tuning the carbogen parameters (such as ratio between CO₂ and O₂, duration of inhalation) on a personalised basis may improve seizure suppression in future.

EEG Monitoring After Convulsive Status Epilepticus

After convulsive status epilepticus, patients of all ages may have ongoing EEG seizures identified by continuous EEG monitoring. Furthermore, high EEG seizure exposure has been associated with unfavorable neurobehavioral outcomes. Thus, recent guidelines and consensus statements recommend many patients with persisting altered mental status after convulsive status epilepticus undergo continuous EEG monitoring. This review summarizes the available epidemiologic data and related recommendations provided by recent guidelines and consensus statements.

A Theoretical Paradigm for Evaluating Risk-Benefit of Status Epilepticus Treatment

Aggressive treatment of status epilepticus with anesthetic drugs can provide rapid seizure control, but it might lead to serious medical complications and worse outcomes. Using a decision analysis approach, this concise review provides a framework for individualized decision making about aggressive and nonaggressive treatment in status epilepticus. The authors propose and review the most relevant parameters guiding the risk-benefit analysis of treatment aggressiveness in status epilepticus and present real-world-based case examples to illustrate how these tools could be used at the bedside and serve to guide future research in refractory status epilepticus treatment.

Electroencephalogram Monitoring in Critical Care

Seizures are common in critically ill patients. Electroencephalogram (EEG) is a tool that enables clinicians to provide continuous brain monitoring and to guide treatment decisions-brain telemetry. EEG monitoring has particular utility in the intensive care unit as most seizures in this setting are nonconvulsive. Despite the increased use of EEG monitoring in the critical care unit, it remains underutilized. In this review, we summarize the utility of EEG and different EEG modalities to monitor patients in the critical care setting.

The Crashing Toxicology Patient

This article examines, using an organ-systems based approach, rapid diagnosis, resuscitation, and critical care management of the crashing poisoned patient in the emergency department. The topics discussed in this article include seizures and status epilepticus, respiratory failure, cardiovascular collapse and mechanical circulatory support, antidotes and drug-specific therapies, acute liver failure, and extracorporeal toxin removal.

High-Frequency Oscillations in the Scalp EEG of Intensive Care Unit Patients With Altered Level of Consciousness

PURPOSE

In comatose patients, distinguishing between nonconvulsive status epilepticus and diffuse structural or metabolic encephalopathies is often challenging. Both conditions can generate periodic discharges on EEG with similar morphology and periodicity. We investigated the occurrence of high-frequency oscillations-potential biomarkers of epileptogenesis-on scalp EEG of comatose patients with periodic discharges in the EEG.

METHODS

Fifteen patients were included. Patients were divided into three groups, according to underlying etiology: Group 1, seizure related; group 2, structural; group 3, nonstructural. EEG recordings were compared with respect to the presence and rates of gamma (30-80 Hz) and ripples (80-250 Hz).

RESULTS

Patients were 23 to 106 years old (median, 68 years); 60% were female. 206 channels were eligible for analysis (median, 15 channels/patient). Overall, 43% of channels showed gamma, and 24% had ripples. Group 2 showed the highest proportion of channels with gamma (47%), followed by group 1 (38%) and group 3 (36%). Mean gamma rates were higher in group 2 (4.65 gamma/min/channel) than in group 1 (1.52) and group 3 (1.44) (P < 0.001). Group 2 showed the highest proportion of channels with ripples (29.2%), followed by group 1 (15%) and group 3 (24.2%). Mean ripple rates were higher in group 2 (5.09 ripple/min/channel) than in group 1 (0.96) and group 3 (0.83) (P < 0.001).

CONCLUSIONS

Fast oscillations, including high-frequency oscillations, can be detected in scalp EEG of patients with altered consciousness. High rates of fast activity may suggest an underlying structural brain lesion. Future studies are needed to determine whether fast oscillations in the setting of acute/subacute brain lesions are a biomarker of subsequent development of human epilepsy.

Clinical and advanced neurophysiology in the prognostic and diagnostic evaluation of disorders of consciousness: review of an IFCN-endorsed expert group

The analysis of spontaneous EEG activity and evoked potentialsis a cornerstone of the instrumental evaluation of patients with disorders of consciousness (DoC). Thepast few years have witnessed an unprecedented surge in EEG-related research applied to the prediction and detection of recovery of consciousness after severe brain injury,opening up the prospect that new concepts and tools may be available at the bedside. This paper provides a comprehensive, critical overview of bothconsolidated and investigational electrophysiological techniquesfor the prognostic and diagnostic assessment of DoC.We describe conventional clinical EEG approaches, then focus on evoked and event-related potentials, and finally we analyze the potential of novel research findings. In doing so, we (i) draw a distinction between acute, prolonged and chronic phases of DoC, (ii) attempt to relate both clinical and research findings to the underlying neuronal processes and (iii) discuss technical and conceptual caveats.The primary aim of this narrative review is to bridge the gap between standard and emerging electrophysiological measures for the detection and prediction of recovery of consciousness. The ultimate scope is to provide a reference and common ground for academic researchers active in the field of neurophysiology and clinicians engaged in intensive care unit and rehabilitation.

Seizure Risk in Patients Undergoing 30-Day Readmission After Continuous EEG Monitoring

PURPOSE

The use of continuous electroencephalographic (cEEG) monitoring has improved the understanding of the seizure risk during acute hospitalization. However, the immediate posthospitalization seizure risk in these patients remains unknown. Patients undergoing 30-day readmission after initial cEEG monitoring were analyzed to fill this knowledge gap.

METHODS

A prospectively maintained cEEG database (January 1, 2015-December 31, 2015) was used to identify adults who underwent a repeat cEEG during their 30-day readmission after cEEG during their index hospitalization (index cEEG). Various demographical, clinical, and cEEG variables were extracted including indication for cEEG: altered mental status and clinical seizure-like events.

RESULTS

A total of 57 of the 2,485 (2.3%) adults undergoing index cEEG during the study period had concerns for seizures and underwent repeat cEEG during a 30-day readmission. These patients were almost three times more likely to have suffered electrographic seizure on the index admission (odds ratio, 2.82; 95% confidence interval, 1.54-5.15; P < 0.001) compared with non-readmitted patients. Seizure-like events led to the readmission of 40.4% patients. Close to one in five (19.3%) readmitted patients were found to have an electrographic seizure. Only variable predictive of seizure on readmission was seizure-like events (odds ratio, 6.4; 95% confidence interval, 1.2-33.0; P = 0.02).

CONCLUSIONS

A small percentage of patients have clinical presentation concerning for seizures with in 30 days after index cEEG. The risk of electrographic seizures in this patient population is higher than patients who have cEEG monitoring but do not undergo a 30-day readmission requiring repeat cEEG. Future research on early identification of patients at risk of 30-day readmission because of concerns for seizure is needed.

A Trial of Real-Time Electrographic Seizure Detection by Neuro-ICU Nurses Using a Panel of Quantitative EEG Trends

BACKGROUND

Non-convulsive seizures (NCS) are a common occurrence in the neurologic intensive care unit (Neuro-ICU) and are associated with worse outcomes. Continuous electroencephalogram (cEEG) monitoring is necessary for the detection of NCS; however, delays in interpretation are a barrier to early treatment. Quantitative EEG (qEEG) calculates a time-compressed simplified visual display from raw EEG data. This study aims to evaluate the performance of Neuro-ICU nurses utilizing bedside, real-time qEEG interpretation for detecting recurrent NCS.

METHODS

This is a prospective, single-institution study of patients admitted to the Duke Neuro-ICU between 2016 and 2018 who had NCS identified on traditional cEEG review. The accuracy of recurrent seizure detection on hourly qEEG review by bedside Neuro-ICU nurses was compared to the gold standard of cEEG interpretation by two board-certified neurophysiologists. The nurses first received brief qEEG training, individualized for their specific patient. The bedside qEEG display consisted of rhythmicity spectrogram (left and right hemispheres) and amplitude-integrated EEG (left and right hemispheres) in 1-h epochs.

RESULTS

Twenty patients were included and 174 1-h qEEG blocks were analyzed. Forty-seven blocks contained seizures (27%). The sensitivity was 85.1% (95% CI 71.1-93.1%), and the specificity was 89.8% (82.8-94.2%) for the detection of seizures for each 1-h block when compared to interpretation of conventional cEEG by two neurophysiologists. The false positive rate was 0.1/h. Hemispheric seizures (> 4 unilateral EEG electrodes) were more likely to be correctly identified by nurses on qEEG than focal seizures (≤ 4 unilateral electrodes) (p = 0.03).

CONCLUSIONS

After tailored training sessions, Neuro-ICU nurses demonstrated a good sensitivity for the interpretation of bedside real-time qEEG for the detection of recurrent NCS with a low false positive rate. qEEG is a promising tool that may be used by non-neurophysiologists and may lead to earlier detection of NCS.

Prevalence of electrographic seizure in dogs and cats undergoing electroencephalography and clinical characteristics and outcome for dogs and cats with and without electrographic seizure: 104 cases (2009-2015)

OBJECTIVE

To determine the prevalence of electrographic seizure (ES) and electrographic status epilepticus (ESE) in dogs and cats that underwent electroencephalography (EEG) because of suspected seizure activity and to characterize the clinical characteristics, risk factors, and in-hospital mortality rates for dogs and cats with ES or ESE.

DESIGN

Retrospective case series.

ANIMALS

89 dogs and 15 cats.

PROCEDURES

Medical records of dogs and cats that underwent EEG at a veterinary neurology service between May 2009 and April 2015 were reviewed. Electrographic seizure was defined as ictal discharges that evolved in frequency, duration, or morphology and lasted at least 10 seconds, and ESE was defined as ES that lasted ≥ 10 minutes. Patient signalment and history, physical and neurologic examination findings, diagnostic test results, and outcome were compared between patients with and without ES or ESE.

RESULTS

Among the 104 patients, ES and ESE were diagnosed in 21 (20%) and 12 (12%), respectively. Seventeen (81%) patients with ES had no or only subtle signs of seizure activity. The in-hospital mortality rate was 48% and 50% for patients with ES and ESE, respectively, compared with 19% for patients without ES or ESE. Risk factors for ES and ESE included young age, overt seizure activity within 8 hours before EEG, and history of cluster seizures.

CONCLUSIONS AND CLINICAL REVELANCE

Results indicated that ES and ESE were fairly common in dogs and cats with suspected seizure activity and affected patients often had only subtle clinical signs. Therefore, EEG is necessary to detect patients with ES and ESE.

Electrographic seizures and ictal-interictal continuum (IIC) patterns in critically ill patients

Critical care long-term continuous electroencephalogram (cEEG) monitoring has expanded dramatically in the last several decades spurned by technological advances in EEG digitalization and several key clinical findings: 1-Seizures are relatively common in the critically ill-large recent observational studies suggest that around 20% of critically ill patients placed on cEEG have seizures. 2-The majority (~75%) of patients who have seizures have exclusively "electrographic seizures", that is, they have no overt ictal clinical signs. Along with the discovery of the unexpectedly high incidence of seizures was the high prevalence of EEG patterns that share some common features with archetypical electrographic seizures but are not uniformly considered to be "ictal". These EEG patterns include lateralized periodic discharges (LPDs) and generalized periodic discharges (GPDs)-patterns that at times exhibit ictal-like behavior and at other times behave more like an interictal finding. Dr. Hirsch and colleagues proposed a conceptual framework to describe this spectrum of patterns called the ictal-interictal continuum (IIC). In the following years, investigators began to answer some of the key pragmatic clinical concerns such as which patients are at risk of seizures and what is the optimal duration of cEEG use. At the same time, investigators have begun probing the core questions for critical care EEG-what is the underlying pathophysiology of these patterns, at what point do these patterns cause secondary brain injury, what are the optimal treatment strategies, and how do these patterns affect clinical outcomes such as neurological disability and the development of epilepsy. In this review, we cover recent advancements in both practical concerns regarding cEEG use, current treatment strategies, and review the evidence associating IIC/seizures with poor clinical outcomes.

A reappraisal of the value of video-EEG recording in the emergency department

Introduction: Some neurologic conditions that can quickly and with low costs be recognized, classified and treated thanks to the availability of an EEG recording in an emergency setting. However, although considered a cheap, not invasive, highly accurate diagnostic investigation, still today, an EEG recording in emergency, in real time during the event paroxysmal ictal phase, is not yet been become a routine.Areas covered: This review will cover the role and utility of EEG recording in the emergency setting, both in emergency department and intensive care unit, in adult and pediatric age, in people admitted for status epilepticus (convulsive or non-convulsive), paroxysmal non-epileptic events, or other conditions/diseases presenting with mental status changes.Expert opinion: The prompt recognition of some specific EEG-patterns can permit an immediate and appropriate therapeutic choice with the resolution of dramatic clinical pictures, which, if not recognized, sometimes could result in severe prognostic events with high mortality or neuropsychiatric disability. It is important in the next future, to improve the availability of these EEG digital continuous monitoring, which should be widely used in emergency settings, developing moreover tools and techniques permitting also review, analysis and EEG-reporting by experts who can work away from the hospital.

Diagnostic Reliability of Headset-Type Continuous Video EEG Monitoring for Detection of ICU Patterns and NCSE in Patients with Altered Mental Status with Unknown Etiology

BACKGROUND/OBJECTIVE

Simplified continuous electroencephalogram (cEEG) monitoring has shown improvement in detecting seizures; however, it is insufficient in detecting abnormal EEG patterns, such as periodic discharges (PDs), rhythmic delta activity (RDA), spikes and waves (SW), and continuous slow wave (CS), as well as nonconvulsive status epilepticus (NCSE). Headset-type continuous video EEG monitoring (HS-cv EEG monitoring; AE-120A EEG Headset™, Nihon Kohden, Tokyo, Japan) is a recently developed easy-to-use technology with eight channels. However, its ability to detect abnormal EEG patterns with raw EEG data has not been comprehensively evaluated. We aimed to examine the diagnostic accuracy of HS-cv EEG monitoring in detecting abnormal EEG patterns and NCSE in patients with altered mental status (AMS) with unknown etiology. We also evaluated the time required to initiate HS-cv EEG monitoring in these patients.

METHODS

We prospectively observed and retrospectively examined patients who were admitted with AMS between January and December 2017 at the neurointensive care unit at Asakadai Central General Hospital, Saitama, Japan. We excluded patients whose data were missing for various reasons, such as difficulties in recording, and those whose consciousness had recovered between HS-cv EEG and conventional cEEG (C-cEEG) monitoring. For the included patients, we performed HS-cv EEG monitoring followed by C-cEEG monitoring. Definitive diagnosis was confirmed by C-cEEG monitoring with the international 10-20 system. As the primary outcome, we verified the sensitivity and specificity of HS-cv EEG monitoring in detecting abnormal EEG patterns including PDs, RDA, SW, and CS, in detecting the presence of PDs, and in detecting NCSE. As the secondary outcome, we calculated the time to initiate HS-cv EEG monitoring after making the decision.

RESULTS

Fifty patients (76.9%) were included in the final analyses. The median age was 72 years, and 66% of the patients were male. The sensitivity and specificity of HS-cv EEG monitoring for detecting abnormal EEG patterns were 0.974 (0.865-0.999) and 0.909 (0.587-0.998), respectively, and for detecting PDs were 0.824 (0.566-0.926) and 0.970 (0.842-0.999), respectively. We diagnosed 13 (26%) patients with NCSE using HS-cv EEG monitoring and could detect NCSE with a sensitivity and specificity of 0.706 (0.440-0.897) and 0.970 (0.842-0.999), respectively. The median time needed to initiate HS-cv EEG was 57 min (5-142).

CONCLUSIONS

HS-cv EEG monitoring is highly reliable in detecting abnormal EEG patterns, with moderate reliability for PDs and NCSE, and rapidly initiates cEEG monitoring in patients with AMS with unknown etiology.

How and Whom to Monitor for Seizures in an ICU: A Systematic Review and Meta-Analysis

OBJECTIVES

To pool prevalence of nonconvulsive seizure, nonconvulsive status epilepticus, and epileptiform activity detected by different electroencephalography types in critically ills and to compare detection rates among them.

DATA SOURCES

MEDLINE (via PubMed) and SCOPUS (via Scopus) STUDY SELECTION:: Any type of study was eligible if studies were done in adult critically ill, applied any type of electroencephalography, and reported seizure rates. Case reports and case series were excluded.

DATA EXTRACTION

Data were extracted independently by two investigators. Separated pooling of prevalence of nonconvulsive seizure/nonconvulsive status epilepticus/epileptiform activity and odds ratio of detecting outcomes among different types of electroencephalography was performed using random-effect models. This meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and also adhered to the Meta-analyses Of Observational Studies in Epidemiology guidelines. Quality of evidence was assessed with the Newcastle-Ottawa Quality Assessment Scale for observational studies and Cochrane methods for randomized controlled trial studies.

DATA SYNTHESIS

A total of 78 (16,707 patients) and eight studies (4,894 patients) were eligible for pooling prevalence and odds ratios. For patients with mixed cause of admission, the pooled prevalence of nonconvulsive seizure, nonconvulsive status epilepticus, either nonconvulsive seizure or nonconvulsive status epilepticus detected by routine electroencephalography was 3.1%, 6.2%, and 6.3%, respectively. The corresponding prevalence detected by continuous electroencephalography monitoring was 17.9%, 9.1%, and 15.6%, respectively. In addition, the corresponding prevalence was high in post convulsive status epilepticus (33.5%, 20.2%, and 32.9%), CNS infection (23.9%, 18.1%, and 23.9%), and post cardiac arrest (20.0%, 17.3%, and 22.6%). The pooled conditional log odds ratios of nonconvulsive seizure/nonconvulsive status epilepticus detected by continuous electroencephalography versus routine electroencephalography from studies with paired data 2.57 (95% CI, 1.11-5.96) and pooled odds ratios from studies with independent data was 1.57 (95% CI, 1.00-2.47).

CONCLUSIONS

Prevalence of seizures detected by continuous electroencephalography was significantly higher than with routine electroencephalography. Prevalence was particularly high in post convulsive status epilepticus, CNS infection, and post cardiac arrest.

Current Status and Recommendations in Multimodal Neuromonitoring

Every patient in neurocritical care evolves through two phases. Acute pathologies are addressed first. These include trauma, hemorrhagic or ischemic stroke, or neuroinfection. Soon after, the concentration shifts to identifying secondary pathologies like fever, seizures, and ischemia, which may exacerbate the brain injury. Frequent bedside examinations are not sufficient for timely detection and prevention of secondary brain injury (SBI) as per the International Multidisciplinary Consensus Conference on Multimodality Monitoring in Neurocritical Care. Multimodality monitoring (MMM) can help in tailoring treatment decisions to prevent such a brain injury. Multimodal neuromonitoring involves data-guided therapeutic interventions by employing various tools and data integration to understand brain physiology. Monitors provide real-time information on cerebral hemodynamics, oxygenation, metabolism, and electrophysiology. The monitors may be invasive/noninvasive and global/regional. We have reviewed such technologies in this write-up. Novel themes like bioinformatics, clinical research, and device development will also be discussed.

Rapid Bedside Evaluation of Seizures in the ICU by Listening to the Sound of Brainwaves: A Prospective Observational Clinical Trial of Ceribell's Brain Stethoscope Function

BACKGROUND

Patients suffering from non-convulsive seizures experience delays in diagnosis and treatment due to limitations in acquiring and interpreting electroencephalography (EEG) data. The Ceribell EEG System offers rapid EEG acquisition and conversion of EEG signals to sound (sonification) using a proprietary algorithm. This study was designed to test the performance of this EEG system in an intensive care unit (ICU) setting and measure its impact on clinician treatment decision.

METHODS

Encephalopathic ICU patients at Stanford University Hospital were enrolled if clinical suspicion for seizures warranted EEG monitoring. Treating physicians rated suspicion for seizure and decided if the patient needed antiepileptic drug (AED) treatment at the time of bedside evaluation. After listening to 30 s of EEG from each hemisphere in each patient, they reevaluated their suspicion for seizure and decision for additional treatment. The EEG waveforms recorded with Ceribell EEG were subsequently analyzed by three blinded epileptologists to assess the presence or absence of seizures within and outside the sonification window. Study outcomes were EEG set up time, ease of use of the device, change in clinician seizure suspicion, and change in decision to treat with AED before and after sonification.

RESULTS

Thirty-five cases of EEG sonification were performed. Mean EEG setup time was 6 ± 3 min, and time to obtain sonified EEG was significantly faster than conventional EEG (p < 0.001). One patient had non-convulsive seizure during sonification and another had rhythmic activity that was followed by seizure shortly after sonification. Change in treatment decision after sonification occurred in approximately 40% of patients and resulted in a significant net reduction in unnecessary additional treatments (p = 0.01). Ceribell EEG System was consistently rated easy to use.

CONCLUSION

The Ceribell EEG System enabled rapid acquisition of EEG in patients at risk for non-convulsive seizures and aided clinicians in their evaluation of encephalopathic ICU patients. The ease of use and speed of EEG acquisition and interpretation by EEG-untrained individuals has the potential to improve emergent clinical decision making by quickly detecting non-convulsive seizures in the ICU.

Nonconvulsive seizures and nonconvulsive status epilepticus in the neuro ICU should or should not be treated aggressively: A debate

This article presents a "debate" about the appropriate level of aggressiveness of treatment for nonconvulsive status epilepticus (NCSE), held at the International Congress of Clinical Neurophysiology in Washington D.C. on 4 May 2018. The proposition for discussion was "Nonconvulsive seizures and status epilepticus in the intensive care unit should be treated aggressively." Dr. Andrea O. Rossetti from Lausanne, Switzerland, spoke in support of the proposition and Dr. Lawrence J. Hirsch from New Haven, Connecticut, discussed reasons for rejecting the proposal. Dr. Frank W. Drislane from Boston, Massachusetts, was asked by the conference organizers to add comments and perspective.

Clinico-Etiological Profile of Pediatric Refractory Status Epilepticus at a Public Hospital in India

BACKGROUND AND PURPOSE

Refractory status epilepticus (RSE) has been infrequently studied in Indian children. This research was conducted to study the clinico-etiological profiles and short-term outcomes of children aged 1 month to 12 years with convulsive RSE, at a public hospital.

METHODS

The study was conducted between 1st April 2016 and 28th February 2017 after receiving clearance from an Institutional Ethics Committee. All children (aged 1 month to 12 years) who presented to the pediatrics department of a tertiary-care public hospital with convulsive status epilepticus (SE), or who developed SE during their hospital stay, were enrolled. All patients were investigated and managed according to a standard protocol. Outcomes were assessed based on the Glasgow Outcome Scale. Details of children who progressed to RSE were compared to those without RSE.

RESULTS

Fifty children (28 males) with CSE were enrolled, of which 20 (40%) progressed to RSE. Central nervous system (CNS) infection was the most common etiology (53% in SE and 55% in RSE, p > 0.05). Non-compliance with anti-epileptic drugs was the second most common etiology. The overall mortality rate was 38%, and although the odds of death in RSE (50%) were higher than in SE (30%), this difference was not statistically significant (p = 0.15). The odds of having a poor outcome was six times higher in children with RSE as compared to those with SE (odds ratio, 6.0; 95% confidence interval, 1.6-22.3; p = 0.005).

CONCLUSIONS

When managing CNS infections, pediatricians need to be aware of the high risk of developing RSE. In addition, the possibility of RSE should be considered and managed promptly in an intensive-care setting, to reduce the mortality and morbidity of this severe neurological condition.

Electroencephalographic monitoring in the critically ill patient: What useful information can it contribute?

Monitoring is a crucial part of the care of the critically ill patient. It detects organ dysfunction and provides guidance on the therapeutic approach. Intensivists closely monitor the function of various organ systems, and the brain is no exception. Continuous EEG monitoring is a noninvasive and uninterrupted way of assessing cerebral cortical activity with good spatial and excellent temporal resolution. The diagnostic effectiveness of non-convulsive status epilepticus as a cause of unexplained consciousness disorder has increased the use of continuous EEG monitoring in the neurocritical care setting. However, non-convulsive status epilepticus is not the only indication for the assessment of cerebral cortical activity. This study summarizes the indications, usage and methodology of continuous EEG monitoring in the intensive care unit, with the aim of allowing practitioners to become familiarized the technique.

Postictal syndrome: The forgotten continent. An overview of the clinical, biochemical and imaging features

Postictal syndrome (PIS) encompasses the clinical, biological, electroencephalographic (EEG) and magnetic resonance imaging (MRI) signs that follow the termination of a seizure. These signs occur as soon as the epileptic discharge ends, but might remain for a substantially long period of time, making them amenable to clinical observation. As a direct consequence, neurologists and intensivists are more frequently attending patients with PIS than during their seizure. Moreover, careful PIS documentation may help physicians to diagnose epileptic seizure from other non-epileptic disorders. Careful analysis of PIS could also be helpful to better characterize the seizure (seizure subtypes, and to some extent, the localization and/or lateralization of the seizure). This article aims to review the main clinical, biological, EEG and MRI components of PIS, discuss differential diagnoses and propose a general clinical attitude, based on the acronym "WAITTT": W for "Watch", to monitor and investigate PIS in order to provide relevant information on seizure, AIT for "Avoid Inappropriate Treatment", to underscore the risk carrying out unnecessary drug injections and intensive care procedures in the setting of a self-limited symptomatology, and TT for "Take Time", to keep in mind that time remains the clinician's best ally for treating patients with PIS.

A Comparison of Parenteral Phenobarbital vs. Parenteral Phenytoin as Second-Line Management for Pediatric Convulsive Status Epilepticus in a Resource-Limited Setting

Introduction: Pediatric convulsive status epilepticus (CSE) which is refractory to first-line benzodiazepines is a significant clinical challenge, especially within resource-limited countries. Parenteral phenobarbital is widely used in Africa as second-line agent for pediatric CSE, however evidence to support its use is limited. Purpose: This study aimed to compare the use of parenteral phenobarbital against parenteral phenytoin as a second-line agent in the management of pediatric CSE. Methodology: An open-labeled single-center randomized parallel clinical trial was undertaken which included all children (between ages of 1 month and 15 years) who presented with CSE. Children were allocated to receive either parenteral phenobarbital or parenteral phenytoin if they did not respond to first-line benzodiazepines. An intention-to-treat analysis was performed with the investigators blinded to the treatment arms. The primary outcome measure was the success of terminating CSE. Secondary outcomes included the need for admission to the pediatric intensive care unit (PICU) and breakthrough seizures during the admission. In addition, local epidemiological data was collected on the burden of pediatric CSE. Results: Between 2015 and 2018, 193 episodes of CSE from 111 children were enrolled in the study of which 144 met the study requirements. Forty-two percent had a prior history of epilepsy mostly from structural brain pathology (53%). The most common presentation was generalized CSE (65%) caused by acute injuries or infections of the central nervous system (59%), with 19% of children having febrile status epilepticus. Thirty-five percent of children required second-line management. More patients who received parenteral phenobarbital were at a significantly reduced risk of failing second-line treatment compared to those who received parenteral phenytoin (RR = 0.3, p = 0.0003). Phenobarbital also terminated refractory CSE faster (p < 0.0001). Furthermore, patients who received parenteral phenobarbital were less likely to need admission to the PICU. There was no difference between the two groups in the number of breakthrough seizures that occurred during admission. Conclusion: Overall this study supports anecdotal evidence that phenobarbital is a safe and effective second-line treatment for the management of pediatric CSE. These results advocate for parenteral phenobarbital to remain available to health care providers managing pediatric CSE in resource-limited settings. Attachments: CONSORT 2010 checklist Trial registration: NCT03650270 Full trial protocol available: https://clinicaltrials.gov/ct2/show/NCT03650270?recrs=e&type=Intr&cond=Status+Epilepticus&age=0&rank=1.

Intravenously Administered Ganaxolone Blocks Diazepam-Resistant Lithium-Pilocarpine-Induced Status Epilepticus in Rats: Comparison with Allopregnanolone

Ganaxolone (GNX) is the 3β-methylated synthetic analog of the naturally occurring neurosteroid, allopregnanolone (ALLO). GNX is effective in a broad range of epilepsy and behavioral animal models and is currently in clinical trials designed to assess its anticonvulsant and antidepressant activities. The current studies were designed to broaden the anticonvulsant profile of GNX by evaluating its potential anticonvulsant activities following i.v. administration in treatment-resistant models of status epilepticus (SE), to establish a pharmacokinetic (PK)/pharmacodynamic (PD) relationship, and to compare its PK and anticonvulsant activities to ALLO. In PK studies, GNX had higher exposure levels, a longer half-life, slower clearance, and higher brain penetrance than ALLO. Both GNX and ALLO produced a sedating response as characterized by loss of righting reflex, but neither compound produced a full anesthetic response as animals still responded to painful stimuli. Consistent with their respective PK properties, the sedative effect of GNX was longer than that of ALLO. Unlike other nonanesthetizing anticonvulsant agents indicated for SE, both GNX and ALLO produced anticonvulsant activity in models of pharmacoresistant SE with administration delay times of up to 1 hour after seizure onset. Again, consistent with their respective PK properties, GNX produced a significantly longer anticonvulsant response. These studies show that GNX exhibited improved pharmacological characteristics versus other agents used as treatments for SE and position GNX as a uniquely acting treatment of this indication.

Evaluation of cerebral blood flow in older patients with status epilepticus using arterial spin labeling

Introduction

Although older patients with status epilepticus (SE) have a high mortality rate and poor outcome, it is difficult to perform emergent electroencephalography (EEG) to diagnose SE in community hospitals. Arterial spin labeling (ASL) is a non-invasive magnetic resonance imaging (MRI) technique that can rapidly assess cerebral blood flow (CBF). Further, ASL can detect increased CBF in the ictal period. Therefore, ASL may be a useful tool for diagnosing SE in older patients. However, its effectiveness in this population is unknown.

Methods

We retrospectively investigated differences in CBF abnormalities between older patients (≥70 years) and non-older patients (<70 years) with SE using ASL. Participants were diagnosed with convulsive status epilepticus (CSE) or non-convulsive status epilepticus (NCSE) based on symptoms, brain MRI, and EEG.

Results

ASL detected CBF abnormalities in 40% of older patients with CSE or NCSE. Rates of CBF abnormalities in older patients were not significantly different compared with that in non-older patients.

Conclusions

ASL did not detect a higher rate of CBF abnormalities in older patients, but may help physicians diagnose SE in older patients in a community hospital setting if emergent EEG cannot be immediately performed.

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ASL is a non-invasive MRI technique.

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ASL can assess CBF in a short time.

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ASL showed abnormality in CBF in 40% of older patients with SE.

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ASL detected CBF abnormality more often in older patients with NCSE than with CSE.

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ASL may be an aid to diagnosing SE in older patients.

Preliminary experience with point-of-care EEG in post-cardiac arrest patients

OBJECTIVE

Abnormal electroencephalography (EEG) patterns are common after resuscitation from cardiac arrest and have clinical and prognostic importance. Bedside continuous EEGs are not available in many institutions. We tested the feasibility of using a point-of-care system for EEG acquisition.

METHODS

We prospectively enrolled a convenience sample of post-cardiac arrest patients between 9/2015-1/2017. Upon hospital arrival, a limited EEG montage was applied. We tested both continuous EEG (cEEG) and this point-of-care EEG (eEEG). A board-certified epileptologist and a board-certified neurointensivist jointly reviewed all EEGs. Cohen's kappa coefficient evaluated agreement between eEEG and cEEG and Fisher's exact test evaluated their associations with survival to hospital discharge and proximate cause of death.

RESULTS

We studied 95 comatose post-cardiac arrest patients. Mean age was 59 (SD17) years. Most (61%) were male, few (N = 22; 23%) demonstrated shockable rhythms, and PCAC IV illness severity was present in 58 (61%). eEEG was interpretable in 57 (60%) subjects. The most common eEEG interpretations were: continuous (21%), generalized suppression (14%), burst-suppression (12%) and burst-suppression with identical bursts (10%). Seizures were detected in 2 eEEG subjects (2%). No patient with seizure or burst-suppression with identical bursts survived. cEEG demonstrated generalized suppression (31%), burst-suppression with identical bursts (27%), continuous (18%) and seizure (4%). The eEEG and cEEG demonstrated fair agreement (kappa = 0.27). Neither eEEG nor cEEG was associated with survival (p = 0.19; p = 0.11) or proximate cause of death (p = 0.14; p = 0.8) CONCLUSIONS: eEEG is feasible, although artifact often precludes interpretation. eEEG is fairly associated with cEEG and may facilitate post-cardiac arrest care.

Critical Care in the Pediatric Emergency Department

In caring for critically ill children, recognition and management often begins in the pediatric emergency department. A seamless transition in care is needed to ensure appropriate care to the sickest of children. This review covers the management of critically ill children in the pediatric emergency department beyond the initial stabilization for conditions such as acute respiratory failure and pediatric acute respiratory distress syndrome, traumatic brain injury, status epilepticus, congenital heart disease, and metabolic emergencies.

Detection of seizure patterns with multichannel amplitude-integrated EEG and the color density spectral array in the adult neurology intensive care unit

This study's purpose was to determine the sensitivity, false-positive and false-negative of seizure detection in adult intensive care by amplitude-integrated electroencephalography (aEEG) and color density spectral array (CDSA).30 continuous electroencephalogram (EEG) recordings were randomly performed in 3 digital EEG-recording machines, 3 specialized neurophysiologists participated in this study, underwent 4 hours of training of CDSA and aEEG, marked any epochs suspected to be seizures without access to the raw EEG. The results will be compared and analyzed with continuous EEG reading to consider sensitivity, positive or negative rate.The recordings in this study, comprised 720 hours of EEG containing a total of 435 seizures. The median sensitivity for seizure identification was 80% of CDSA and 81.3% of aEEG, Median false-positive was 4 per 24 hours of CDSA, and 2 per 24 hours of aEEG display, Median false-negative was 4 per 24 hours of CDSA, and 4 per 24 hours of aEEG display. The time spent in identification of seizures by CDSA and aEEG was much time-saving than continuous EEG-reading.In this study, both CDSA and aEEG have a higher sensitivity but lower false-positive or missed rate in the interpretation of seizure identification in adult NICU.

Emergency Neurological Life Support: Status Epilepticus

Patients with prolonged or rapidly recurring convulsions lasting more than 5 min should be considered to be in status epilepticus (SE) and receive immediate resuscitation. Although there are few randomized clinical trials, available evidence and experience suggest that early and aggressive treatment of SE improves patient outcomes, for which reason this was chosen as an Emergency Neurological Life Support protocol. The current approach to the emergency treatment of SE emphasizes rapid initiation of adequate doses of first line therapy, as well as accelerated second line anticonvulsant drugs and induced coma when these fail, coupled with admission to a unit capable of neurological critical care and electroencephalography monitoring. This protocol will focus on the initial treatment of SE but also review subsequent steps in the protocol once the patient is hospitalized.

Treatment of Refractory and Super-refractory Status Epilepticus

Refractory and super-refractory status epilepticus (SE) are serious illnesses with a high risk of morbidity and even fatality. In the setting of refractory generalized convulsive SE (GCSE), there is ample justification to use continuous infusions of highly sedating medications-usually midazolam, pentobarbital, or propofol. Each of these medications has advantages and disadvantages, and the particulars of their use remain controversial. Continuous EEG monitoring is crucial in guiding the management of these critically ill patients: in diagnosis, in detecting relapse, and in adjusting medications. Forms of SE other than GCSE (and its continuation in a "subtle" or nonconvulsive form) should usually be treated far less aggressively, often with nonsedating anti-seizure drugs (ASDs). Management of "non-classic" NCSE in ICUs is very complicated and controversial, and some cases may require aggressive treatment. One of the largest problems in refractory SE (RSE) treatment is withdrawing coma-inducing drugs, as the prolonged ICU courses they prompt often lead to additional complications. In drug withdrawal after control of convulsive SE, nonsedating ASDs can assist; medical management is crucial; and some brief seizures may have to be tolerated. For the most refractory of cases, immunotherapy, ketamine, ketogenic diet, and focal surgery are among several newer or less standard treatments that can be considered. The morbidity and mortality of RSE is substantial, but many patients survive and even return to normal function, so RSE should be treated promptly and as aggressively as the individual patient and type of SE indicate.

Antiepileptic drugs in critically ill patients

BACKGROUND

The incidence of seizures in intensive care units ranges from 3.3% to 34%. It is therefore often necessary to initiate or continue anticonvulsant drugs in this setting. When a new anticonvulsant is initiated, drug factors, such as onset of action and side effects, and patient factors, such as age, renal, and hepatic function, should be taken into account. It is important to note that the altered physiology of critically ill patients as well as pharmacological and nonpharmacological interventions such as renal replacement therapy, extracorporeal membrane oxygenation, and target temperature management may lead to therapeutic failure or toxicity. This may be even more challenging with the availability of newer antiepileptics where the evidence for their use in critically ill patients is limited.

MAIN BODY

This article reviews the pharmacokinetics and pharmacodynamics of antiepileptics as well as application of these principles when dosing antiepileptics and monitoring serum levels in critically ill patients. The selection of the most appropriate anticonvulsant to treat seizure and status epileptics as well as the prophylactic use of these agents in this setting are also discussed. Drug-drug interactions and the effect of nonpharmacological interventions such as renal replacement therapy, plasma exchange, and extracorporeal membrane oxygenation on anticonvulsant removal are also included.

CONCLUSION

Optimal management of antiepileptic drugs in the intensive care unit is challenging given altered physiology, polypharmacy, and nonpharmacological interventions, and requires a multidisciplinary approach where appropriate and timely assessment, diagnosis, treatment, and monitoring plans are in place.

Does semiology of status epilepticus have an impact on treatment response and outcome?

OBJECTIVE

This study investigated whether there is an association between semiology of status epilepticus (SE) and response to treatment and outcome.

METHOD

Two hundred ninety-eight consecutive adult patients (160 females, 138 males) with SE at the University of Munich Hospital were prospectively enrolled. Mean age was 63.2±17.5 (18-97) years. Patient demographics, SE semiology and electroencephalography (EEG) findings, etiology, duration of SE, treatment, and outcome measures were investigated. Status epilepticus semiology was classified according to a semiological status classification. Patient's short-term outcome was determined by Glasgow Outcome Scale (GOS).

RESULTS

The most frequent SE type was nonconvulsive SE (NCSE) (39.2%), mostly associated with cerebrovascular etiology (46.6%). A potentially fatal etiology was found in 34.8% of the patients. More than half (60.7%) of the patients had poor short-term outcome (GOS≤3) with an overall mortality of 12.4%. SE was refractory to treatment in 21.5% of the patients. Older age, potentially fatal etiology, systemic infections, NCSE in coma, refractory SE, treatment with anesthetics, long SE duration (>24h), low Glasgow Coma Scale (GCS) (≤8) at onset, and high Status Epilepticus Severity Score (STESS-3) (≥3) were associated with poor short-term outcome and death (p<0.05). Potentially fatal etiology and low GCS were the strongest predictors of poor outcome (Exp [b]: 4.74 and 4.10 respectively, p<0.05).

CONCLUSION

Status epilepticus semiology has no independent association with outcome, but potentially fatal etiology and low GCS were strong predictive factors for poor short-term outcome of SE.

Updates in Refractory Status Epilepticus

Refractory status epilepticus is defined as persistent seizures despite appropriate use of two intravenous medications, one of which is a benzodiazepine. It can be seen in up to 40% of cases of status epilepticus with an acute symptomatic etiology as the most likely cause. New-onset refractory status epilepticus (NORSE) is a recently coined term for refractory status epilepticus where no apparent cause is found after initial testing. A large proportion of NORSE cases are eventually found to have an autoimmune etiology needing immunomodulatory treatment. Management of refractory status epilepticus involves treatment of an underlying etiology in addition to intravenous anesthetics and antiepileptic drugs. Alternative treatment options including diet therapies, electroconvulsive therapy, and surgical resection in case of a focal lesion should be considered. Short-term and long-term outcomes tend to be poor with significant morbidity and mortality with only one-third of patients reaching baseline neurological status.

Nonconvulsive status epilepticus after cessation of convulsive status epilepticus in pediatric intensive care unit patients

Little is known about pediatric patients suffering from nonconvulsive status epilepticus (NCSE) after convulsive status epilepticus (CSE) cessation. The aim of this study was to identify in pediatric patients the clinical characteristics of NCSE after CSE cessation and the factors that contribute to patient outcomes. Data from clinical features, electroencephalography (EEG) characteristics, neuroimaging findings, treatments, and prognosis were systematically summarized, and the associations between clinical characteristics and prognosis were quantified. Thirty-eight children aged 51days-14years, 2months were identified in the Chongqing Medical University pediatric intensive care unit as having experienced NCSE after CSE cessation between October 1, 2014 and April 1, 2017. All patients were comatose, 15 of whom presented subtle motor signs. The most common underlying etiology was acute central nervous system (CNS) infection. Electroencephalography (EEG) data showed that, during the NCSE period, all patients had several discrete episodes (lasting from 30s to 6h long), and the most common duration was 1-5min. The ictal onset locations were classified as focal (16 patients, 42.1%), multiregional independent (10 patients, 26.3%), and generalized (12 patients, 31.6%). Wave morphologies varied during the ictal and interictal periods. Neuroimaging detected signal abnormalities in the cerebral cortex or subcortex of 33 patients with NCSE (87%), which were classified as either multifocal and consistent with extensive cortical edema (21 patients, 55.3%) or focal (12 patients, 31.6%). Twelve patients were on continuous intravenous phenobarbital, and 31 were on continuous infusion of either midazolam (27 patients) or propofol (4 patients). At least one other antiepileptic drug was prescribed for 32 patients. Three patients were on mild hypothermia therapy. The duration of NCSE lasted <24h for 20 patients and >24h for 18 patients. The mortality rate was 21.1%, and half of the surviving patients had severe neurological morbidity. Our results indicated that EEG monitoring after treatment of CSE was essential to the recognition of persistent seizures. The clinical features, EEG characteristics, and neuroimaging findings varied during the NCSE period. The morbidity is high in pediatric patients who had NCSE after CSE. Convulsive status epilepticus (CSE) duration and neuroimaging results may be related to the prognosis.

Cardiopulmonary Resuscitation in Infants and Children With Cardiac Disease: A Scientific Statement From the American Heart Association

Cardiac arrest occurs at a higher rate in children with heart disease than in healthy children. Pediatric basic life support and advanced life support guidelines focus on delivering high-quality resuscitation in children with normal hearts. The complexity and variability in pediatric heart disease pose unique challenges during resuscitation. A writing group appointed by the American Heart Association reviewed the literature addressing resuscitation in children with heart disease. MEDLINE and Google Scholar databases were searched from 1966 to 2015, cross-referencing pediatric heart disease with pertinent resuscitation search terms. The American College of Cardiology/American Heart Association classification of recommendations and levels of evidence for practice guidelines were used. The recommendations in this statement concur with the critical components of the 2015 American Heart Association pediatric basic life support and pediatric advanced life support guidelines and are meant to serve as a resuscitation supplement. This statement is meant for caregivers of children with heart disease in the prehospital and in-hospital settings. Understanding the anatomy and physiology of the high-risk pediatric cardiac population will promote early recognition and treatment of decompensation to prevent cardiac arrest, increase survival from cardiac arrest by providing high-quality resuscitations, and improve outcomes with postresuscitation care.

Non-convulsive status epilepticus: mimics and chameleons

Non-convulsive status epilepticus (NCSE) is an enigmatic condition with protean manifestations. It often goes unrecognised, leading to delays in its diagnosis and treatment. The principal reason for such delay is the failure to consider and request an electroencephalogram (EEG), although occasional presentations have no scalp or surface electroencephalographic correlate. In certain settings with limited EEG availability, particularly out-of-hours, clinicians should consider treating without an EEG. Patients need a careful risk–benefit analysis to assess the risks of neuronal damage and harm versus the risks of adverse effects from various intensities of therapeutic intervention. Specialists in EEG, intensive care or epilepsy are invaluable in the management of patients with possible NCSE.

Diagnostic utility of eight-channel EEG for detecting generalized or hemispheric seizures and rhythmic periodic patterns

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Current practice lacks rapid detection tools to screen for seizures.

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High agreement exists between neurologists’ diagnoses using full and reduced montage EEG.

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Reduced channel EEG can be used to screen for generalized or hemispheric or rhythmic and periodic abnormalities.

Objectives

To compare the diagnostic utility of electroencephalography (EEG) using reduced, 8-channel montage (rm-EEG) to full, 18-channel montage (fm-EEG) for detection of generalized or hemispheric seizures and rhythmic periodic patterns (RPPs) by neurologists with extensive EEG training, neurology residents with minimal EEG exposure, and medical students without EEG experience.

Methods

We presented EEG samples in both fm-EEG (bipolar montage) and rm-EEG (lateral leads of bipolar montage) to 20 neurologists, 20 residents, and 42 medical students. Unanimous agreement of three senior epileptologists defined samples as seizures (n = 7), RPPs (n = 10), and normal or slowing (n = 20). Differences in median accuracy, sensitivity, and specificity were assessed using Wilcoxon signed-rank tests.

Results

Full and reduced EEG demonstrated similar accuracy when read by neurologists (fm-EEG: 95%, rm-EEG: 95%, p = 0.29), residents (fm-EEG: 80%, rm-EEG: 80%, p = 0.05), and students (fm-EEG: 60%, rm-EEG: 51%, p = 0.68). Moreover, neurologists’ sensitivity for detecting seizure activity was comparable between fm-EEG (100%) and rm-EEG (98%) (p = 0.17). Furthermore, the specificity of rm-EEG for seizures and RPP (neurologists: 100%, residents: 90%, students: 86%) was significantly greater than that of fm-EEG (neurologists: 93%, p = 0.03; residents: 80%, p = 0.01; students: 69%, p < 0.001).

Conclusions

The reduction of the number of EEG channels from 18 to 8 does not compromise neurologists’ sensitivity for detecting seizures that are often a core reason for performing urgent EEG. It may also increase their specificity for detecting rhythmic and periodic patterns, and thereby providing important diagnostic information to guide patient’s management.

Significance

Our study is the first to document the utility of a reduced channel EEG above the hairline compared to full montage EEG in aiding medical staff with varying degrees of EEG training to detect generalized or hemispheric seizures.

Continuous Electroencephalography Monitoring in Adults in the Intensive Care Unit

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2018. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2018. Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901.