Nonconvulsive Seizure Detection by Reduced-Lead Electroencephalography in Children with Altered Mental Status in the Emergency Department

Electroencephalography Quality and Application Times in a Pediatric Emergency Department Setting: A Feasibility Study

BACKGROUND

Status epilepticus is the most common neurological emergency presenting to pediatric emergency departments. Nonconvulsive status epilepticus can be extremely challenging to diagnose, however, requiring electroencephalographic (EEG) confirmation for definitive diagnosis. We aimed to determine the feasibility of achieving a good-quality pediatric EEG recording within 20 minutes of presentation to the emergency department.

METHODS

Single-center prospective feasibility study in Cork University Hospital, Ireland, between July 2021 and June 2022. Two-channel continuous EEG was recorded from children (1) aged <16 years and (2) with Glasgow Coma Scale <11 or a reduction in baseline Glasgow Coma Scale in the case of a child with a neurodisability.

RESULTS

Twenty patients were included. The median age at presentation was 65.8 months (interquartile range, 23.2 to 119.0); 50% had a background diagnosis of epilepsy. The most common reason for EEG monitoring was status epilepticus (85%) followed by suspected nonconvulsive status (10%) and reduced consciousness of unknown etiology (5%). The mean length of recording was 93.1 minutes (S.D. 47.4). The mean time to application was 41.3 minutes (S.D. 11.7). The mean percent of artifact in all recordings was 19.3% (S.D. 15.9). Thirteen (65%) EEGs had <25% artifact. Artifact was higher in cases in which active airway management was ongoing.

CONCLUSIONS

EEG monitoring can be achieved in a pediatric emergency department setting within one hour of presentation. Overall, artifact percentage was low outside of periods of airway manipulation. Future studies are required to determine its use in early seizure detection and its support role in clinical decision-making in these patients.

Comparison of neurological manifestation in children with and without coronavirus 2019 experiencing seizures with fever

Whether neurologic symptoms due to SARS-CoV-2 differ from those of non-SARS-CoV-2 viral infection is unclear. We aimed to describe these neurological manifestations and compare the clinical characteristics and treatments in children with seizures and fever with or without COVID-19. We retrospectively analyzed data from 105 hospitalized children (<18 years) with clinical seizures and fever between September 2021 and August 2022. We compared the clinical characteristics and treatments between the COVID-19 (n = 20) and non-COVID-19 (n = 85) groups. Patients with COVID-19 were older than those without (32.5 [20-86] months vs. 20 [16-32] months, p = 0.029). Seizure type and duration and impaired consciousness duration did not differ between groups. Six and 32 patients experienced status epilepticus lasting 30 min in the COVID-19 and non-COVID-19 groups, respectively. Most treatments did not differ between groups; however, electroencephalography was used less frequently for COVID-19. Neurological sequelae occurred in one and four patients in the COVID-19 and non-COVID-19 groups, respectively. In conclusion, seizures with fever due to SARS-CoV-2 were more common in older children. Seizure characteristics and neurologic sequelae did not differ in children with and those without COVID-19. In general, electroencephalography was used less during COVID-19 for infection control measures.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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 24 h 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.

CONCLUSIONS

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.

Integrating Neuromonitoring in Pediatric Emergency Medicine: Exploring Two Options for Point-of-Care Electroencephalogram (pocEEG) via Patient Monitors-A Technical Note

Central nervous system (CNS) disorders are among the most frequent presentations in critically ill children. Status epilepticus (SE) is a frequent scenario in the resuscitation bay. In patients with altered mental status, non-convulsive SE (NCSE) is often underrecognized and critically impacts the neurological outcome and duration of hospitalization. An electroencephalogram (EEG) is required to diagnose NCSE. However, standard EEG recordings are time- and staff-intensive, and their availability is limited, especially outside regular working hours. We aimed to improve patient care by developing a simplified EEG recording method, using a reduced lead montage (point-of-care EEG-pocEEG), that is suitable for use in pediatric emergency departments. The objective was to devise a cost-effective unit with low space requirements that fitted the existing technical infrastructure. We present two technical options for clinical pocEEG acquisition using patient monitors (GE Carescape, Philips IntelliVue) that enable data collection for educational and research purposes. A simplified, rapid response EEG like the pocEEG enables neuromonitoring of patients with CNS disorders in pediatric emergency settings, facilitating timely diagnosis and treatment initiation when standard EEG is not readily available.

Yield of Neurodiagnostic Testing in Children Presenting to a Pediatric Emergency Department With Altered Mental Status

BACKGROUND

Emergency department (ED) visits for altered mental status (AMS) in children are common. Neuroimaging is often performed to ascertain etiology, but its utility has not been well studied. Our objective is to describe the yield of neuroimaging studies in children who present to an ED with AMS.

METHODS

We performed a retrospective chart review of children 0-18 years of age, presenting to our PED between 2018 and 2021 with AMS. We abstracted patient demographics, physical examination, neuroimaging and EEG results, and final diagnosis. Neuroimaging and EEG studies were classified as normal or abnormal. Abnormal studies were categorized as clinically important and contributory: abnormalities that were clinically important and contributed to the etiology, clinically important but noncontributory: abnormalities that were clinically significant but did not explain the etiology, and incidental: abnormalities that were not clinically significant.

RESULTS

We analyzed 371 patients. The most common etiology of AMS was toxicologic (188, 51%) with neurologic causes (n = 50, 13.5%) accounting for a minority. Neuroimaging was performed in one-half (169, 45.5%) and abnormalities were noted in 44 (26%) studies. Abnormalities were clinically important and contributed to the etiologic diagnosis of AMS in 15/169 (8.9%), clinically important and noncontributory in 18/169 (10.7%), and incidental in 11/169 (6.5%). EEG was performed in 65 patients (17.5%), of which 17 (26%) were abnormal with only one being clinically important and contributory.

CONCLUSIONS

Though neuroimaging was performed in approximately one half of the cohort, it was contributory in a minority. Similarly, diagnostic utility of EEG in children with AMS was low.

Seizure detection with reduced electroencephalogram channels: research trends and outlook

Epilepsy is a prevalent condition characterized by recurrent, unpredictable seizures. Monitoring with surface electroencephalography (EEG) is the gold standard for diagnosing epilepsy, but a time-consuming, uncomfortable and sometimes ineffective process for patients. Further, using EEG over a brief monitoring period has variable success, dependent on patient tolerance and seizure frequency. The availability of hospital resources and hardware and software specifications inherently restrict the options for comfortable, long-term data collection, resulting in limited data for training machine-learning models. This mini-review examines the current patient journey, providing an overview of the current state of EEG monitoring with reduced electrodes and automated channel reduction methods. Opportunities for improving data reliability through multi-modal data fusion are suggested. We assert the need for further research in electrode reduction to advance brain monitoring solutions towards portable, reliable devices that simultaneously offer patient comfort, perform ultra-long-term monitoring and expedite the diagnosis process.

Benzodiazepine Use for Pediatric Patients With Suspected Nonconvulsive Status Epilepticus With or Without Simplified Electroencephalogram: A Retrospective Cohort Study

OBJECTIVES

In the present study, we aimed to determine the changes in the administration rate of benzodiazepines for pediatric patients with suspected nonconvulsive status epilepticus (NCSE) before and after the introduction of simplified electroencephalography (sEEG) in the emergency department.

METHODS

This retrospective cohort study included patients who were younger than 18 years and were admitted to the emergency department from August 1, 2009, to July 31, 2017, with altered level of consciousness and nonpurposeful movement of eyes or extremities after the cessation of convulsive status epilepticus. Patients with apparent persistent convulsions, those who were fully conscious on arrival, and those who were transferred from another hospital were excluded. The patients were categorized into pre and post groups based on the introduction of sEEG, and benzodiazepine administration was compared between the 2 groups.

RESULTS

During the study period, 464 patients with status epilepticus visited our emergency department and 69 and 93 patients fulfilling the study criteria were categorized into the pre and post groups, respectively. There were no significant differences in patient background characteristics between the 2 groups. Simplified electroencephalography was recorded in 52 patients in the post group. Benzodiazepines were administered in 44 of 69 patients (63.8%) in the pre group and 44 of 93 (47.3%) in the post group, and the benzodiazepine administration rate was significantly decreased after the introduction of sEEG ( P = 0.04). The hospitalization rate was significantly lower in the post group, but there were no significant differences in the rates of intensive care unit admission, reconvulsion after discharge, and final diagnoses between the 2 groups.

CONCLUSIONS

Simplified electroencephalography might aid in determining the need for anticonvulsant treatment for suspected NCSE in pediatric patients. Albeit not a definitive diagnostic tool, sEEG might be a reliable choice in the evaluation of pediatric patients with suspected NCSE.

Growth and differentiation factor-15 as a potential prognostic biomarker for status-epilepticus-associated-with-fever: A pilot study

OBJECTIVE

Biomarkers predicting poor outcomes of status-epilepticus-associated-with-fever (SEF) at an early stage may contribute to treatment guidance. However, none have been reported thus far. We investigated the dynamics of serum growth and differentiation factor (GDF)-15 after seizure onset in patients with SEF and determined whether GDF-15 can predict poor outcomes, particularly in the first 6 h after seizure onset.

METHODS

We enrolled 37 pediatric patients with SEF and eight patients with simple febrile seizures (SFS) and collected their blood samples within 24 h of seizure onset and eight febrile control patients between March 1, 2017 and September 30, 2020. All patients were aged ≤15 years.

RESULTS

In the SEF group, the median post-seizure serum GDF-15 values were 1,065 (<6h), 2,720 (6-12 h), and 2,411 (12-24 h) pg/mL. The median serum GDF-15 in the first 6 h was measured in patients with SEF without a significant past medical history (n = 21) and was found to be statistically significantly higher (1,587 pg/mL) than in the febrile control (551 pg/mL) and SFS (411 pg/mL) groups. The median serum GDF-15 was statistically significantly higher in patients with SEF with sequelae (n = 5) and patients with acute encephalopathy with biphasic seizures/reduced diffusion/hemorrhagic shock and encephalopathy syndrome (n = 6) than in patients with SEF without sequelae (n = 16) (15,898 vs 756 pg/mL) and patients with prolonged FS (n = 15) (9,448 vs 796 pg/mL).

CONCLUSIONS

This study demonstrates the dynamics of serum GDF-15 in patients with SEF and indicates the potential of GDF-15 as an early predictor of poor outcomes.

Prediction of AESD and neurological sequelae in febrile status epilepticus

OBJECTIVE

The clinical prediction rule (CPR) for acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) was developed with an area under the receiver operating characteristic curve (AUC) of 0.95 - 0.96. Our objective was to verify the AESD CPR in a new cohort and compare the utilities of three CPRs of acute encephalopathy: the Tada, Yokochi, and Nagase criteria.

METHODS

We reviewed the clinical data and medical charts of 580 consecutive patients (aged < 18 years) with febrile convulsive status epilepticus lasting for ≥ 30 min in 2002 - 2017 and measured the performance of the CPRs in predicting AESD and sequelae.

RESULTS

The CPRs predicted AESD with an AUC of 0.84 - 0.88. The Tada criteria predicted AESD with a positive predictive value (PPV) of 0.25 and a negative predictive value (NPV) of 0.99. The Yokochi criteria predicted AESD with a PPV and NPV of 0.20 and 0.95, respectively, after 12 h. The Nagase criteria predicted AESD with a PPV and NPV of 0.14 and 1.00, respectively, after 6 h. The PPVs of the Tada, Yokochi, and Nagase criteria for sequelae were 0.28, 0.28, and 0.17, respectively; the corresponding NPVs were 0.97, 0.95, and 0.98, respectively.

CONCLUSIONS

The effectiveness of the AESD CPR in a new cohort was lower than that in the derivation study. CPRs are not sufficient as diagnostic tests, but they are useful as screening tests. The Nagase criteria are the most effective for screening among the three CPRs due to their high NPV and swiftness.

Early non-convulsive seizures are associated with the development of acute encephalopathy with biphasic seizures and late reduced diffusion

INTRODUCTION

Children with either febrile seizure or acute encephalopathy exhibit seizures and/or impaired consciousness accompanied by fever of unknown etiology (SICF). Among children with SICF, we previously reported those who have refractory status epilepticus or prolonged neurological abnormalities with normal AST levels are at a high risk for the development of acute encephalopathy with biphasic seizures and late reduced diffusion (AESD), considered to be caused by excitotoxicity. Non-convulsive seizures (NCS) are common in critically ill children and cause excitotoxic neuronal injury. The aim of this study was to elucidate the prevalence of NCS in the acute phase of children at a high risk for developing AESD and the relationship between NCS in the acute phase and neurological outcomes.

METHODS

We studied 137 children with SICF at a high risk for developing AESD and who underwent continuous electroencephalogram monitoring (cEEG) upon admission to a tertiary pediatric care center at Hyogo Prefectural Kobe Children's Hospital between October 2007 and August 2018. Patient characteristics and outcomes were compared between patients with NCS and without NCS.

RESULTS

Of the 137 children, NCS occurred in 30 children; the first NCS were detected in cEEG at the beginning in 63.3%, during the first hour in 90%, and within 12 h in 96.7%. Neurological sequelae were more common in NCS patients (20.0%) than in non-NCS patients (1.9%; p = 0.001). Five in 30 NCS patients (16.7%) and 3 in 107 non-NCS patients (2.8%) developed AESD (p = 0.013).

CONCLUSION

The occurrence of NCS is associated with subsequent neurological sequelae, especially the development of AESD.

Feasibility and usefulness of rapid 2-channel-EEG-monitoring (point-of-care EEG) for acute CNS disorders in the paediatric emergency department: an observational study

INTRODUCTION

The aim of this study was to determine the feasibility and clinical utility of point-of-care electroencephalogram (pocEEG) in the paediatric emergency department (ED) for children presenting with acute non-traumatic central nervous system (CNS) disorders.

METHODS

Retrospective observational study of prospectively collected data in paediatric patients (0-16 years) with acute non-traumatic CNS-disorders presenting between April 2014 and February 2017 to a single paediatric ED in Switzerland.The 2-channel EEG was applied to all patients presenting with acute seizures or impaired consciousness to the ED. For a pocEEG, scalp surface electrodes are applied in five locations, thus allowing registration of fronto-temporal bilateral cortical activity. Neurology consultants assisted with interpretation of readings. EEG findings and clinical characteristics were collected. Feasibility and usefulness were rated via Likert scale.

RESULTS

36 patients with acute seizures or altered mental status were analysed. Age range was 9 months to 15 years, median age of 34 months. 21 of 36 (58%) patients arrived out of hours. Application of electrodes was rated as 'easy' in 28 (77.8%) patients and rated as 'difficult' in 8 (22.2%). The utility of the EEG was rated by physicians as 'very useful/diagnostic' in 13 cases (36%), 'useful' in 21 cases (58%), 'not useful' in two cases (8%). None were rated 'negative.'

CONCLUSION

Uptake of pocEEG introduction has been very encouraging. Provider ratings were overwhelmingly positive. Recognition of non-convulsive status epilepticus was improved and pocEEG facilitated more targeted interventions.

Elevated cytokine, chemokine, and growth and differentiation factor-15 levels in hemorrhagic shock and encephalopathy syndrome: A retrospective observational study

Patients with hemorrhagic shock and encephalopathy syndrome (HSES) have a high early mortality rate, which may be caused by a 'cytokine storm'. However, there is little information on how cytokines and chemokines change over time in these patients. We aimed to describe the characteristics of HSES by examining changes in serum biomarker levels over time. Six patients with HSES were included. We retrospectively evaluated their clinical course and imaging/laboratory data. We measured serum levels of multiple cytokines [interleukin 1β (IL-1β), IL-2, IL-4, IL-6, IL-10, IL-17, interferon-gamma, and tumor necrosis factor alpha], chemokines (IL-8, monocyte chemoattractant protein-1, interferon-inducible protein-10), and growth and differentiation factor (GDF)-15. The highest cytokine and chemokine levels were noted in the first 24 h, and decreased thereafter. The GDF-15 level was markedly high. Cytokine, chemokine, and GDF-15 levels were significantly higher in patients with HSES than in controls in the first 24 h, except for IL-2 and IL-4. Patients with HSES have high inflammatory cytokine and chemokine levels, a high GDF-15 level in the first 24 h, and high lactate levels. Our study provides new insights on the pathophysiology of HSES, a detailed clinical picture of patients with HSES, and potential biomarkers.

Thiamylal anaesthetic therapy for febrile refractory status epilepticus in children

PURPOSE

To evaluate barbiturate anaesthetic therapy using thiamylal for febrile refractory status epilepticus (fRSE) in children.

METHODS

This was a review of a prospectively-collected database between April 2012-March 2016 for fRSE cases treated with thiamylal anaesthetic therapy in a single paediatric hospital in Japan. The sample comprised 23 children (median age, 23 months) with fRSE that underwent thiamylal anaesthetic therapy for convulsive seizures lasting longer than 60 min, sustained after intravenous administration of benzodiazepine and non-benzodiazepine anticonvulsants. The intervention comprised protocol-based thiamylal anaesthetic therapy with bolus administration. We measured the dose and time required to achieve the burst suppression pattern (BSP) on electroencephalography, seizure recurrence, death, neurological sequelae, and complications.

RESULTS

All patients except one reached the BSP. The thiamylal median dose until reaching the BSP was 27.5 mg/kg, and the median time from thiamylal administration to reaching the BSP was 109.5 min. There was one case of immediate treatment failure and one of withdrawal seizure, but no breakthrough seizure. No deaths occurred during treatment, and neurological sequelae occurred in four cases (17%). Vasopressors were administered in all cases. Other complications included 11 cases of pneumonia and one of enterocolitis.

CONCLUSION

We revealed the time and dose required to reach the BSP with thiamylal anaesthetic therapy using bolus administration in children. Our results suggested that reaching the BSP with bolus administration requires markedly less time than without bolus administration, rarely causes seizure recurrence in paediatric fRSE, and causes haemodynamic dysfunction and infections as often as observed without bolus administration.

Detailed characteristics of acute encephalopathy with biphasic seizures and late reduced diffusion: 18-year data of a single-center consecutive cohort

OBJECTIVE

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is a syndrome characterized by biphasic seizures with impaired consciousness. AESD is rare outside Asia, and consecutive cohort studies are therefore scarce. Herein, we aimed to describe the detailed characteristics of AESD, including clinical course, electroencephalogram data, laboratory data, imaging findings, treatment, and outcomes.

METHODS

We reviewed the clinical database and medical charts of 43 consecutive pediatric patients (<18 years old) who developed AESD between October 1, 2002, and September 30, 2019.

RESULTS

We found that AESD occurred even though patients did not develop prolonged seizures. A comparison between the two groups (first seizure duration <30 min and first seizure duration ≥30 min) revealed three main findings: first, patients with AESD who had shorter seizures had better prognosis than those with prolonged seizures; second, patients with AESD who had shorter seizures tended to have earlier occurrence of a second seizure; and third, high signal intensity on diffusion-weighted magnetic resonance imaging was observed mainly in frontal areas, not diffusely, in patients with shorter seizures, and in a broader area in patients with prolonged seizures.

CONCLUSIONS

Our description of the detailed clinical picture of AESD may add new insight into its pathophysiology.