Non-convulsive status epilepticus in adults: clinical forms and treatment

EEG and acute confusional state at the emergency department

OBJECTIVES

Acute confusional state (ACS) is a common cause of admission to the emergency department (ED). It can be related to numerous etiologies. Electroencephalography (EEG) can show specific abnormalities in cases of non-convulsive status epilepticus (NCSE), or metabolic or toxic encephalopathy. However, up to 80% of patients with a final diagnosis of NCSE have an ACS initially attributed to another cause. The exact place of EEG in the diagnostic work-up remains unclear.

METHODS

Data of consecutive patients admitted to the ED for an ACS in a two-year period and who were referred for an EEG were collected. The initial working diagnosis was based on medical history, clinical, biological and imaging investigations allowing classification into four diagnostic categories. Comparison to the final diagnosis was performed after EEG recordings (and sometimes additional tests) were performed, which allowed the reclassification of some patients from one category to another.

RESULTS

Seventy-five patients (mean age: 71.1 years) were included with the following suspected diagnoses: seizures for 8 (11%), encephalopathy for 14 (19%), other cause for 34 (45%) and unknown for 19 (25%). EEG was recorded after a mean of 1.5 days after symptom onset, and resulted in the reclassification of patients as follows: seizure for 15 (20%), encephalopathy for 15 (20%), other cause for 29 (39%) and unknown cause for 16 (21%). Moreover, ongoing epileptic activity (NCSE or seizure) and interictal epileptiform activity were found in eight (11%) patients initially diagnosed in another category.

DISCUSSION

In our cohort, EEG was a key examination in the management strategy of ACS in 11% of patients admitted to the ED. It resulted in a diagnosis of epilepsy in these patients admitted with unusual confounding presentations.

Rapid Electroencephalography and Artificial Intelligence in the Detection and Management of Nonconvulsive Seizures

STUDY OBJECTIVE

Nonconvulsive status epilepticus is a commonly overlooked cause of altered mental status. This study assessed nonconvulsive status epilepticus prevalence in emergency department (ED) patients with acute neurologic presentations using limited electroencephalogram (EEG) coupled with artificial intelligence (AI)-enhanced seizure detection technology. We then compared the accuracy of the AI EEG interpretations to those performed by an epileptologist.

METHODS

In a prospective observational cohort analysis, adult patients with unexplained mental status changes identified by emergency physicians received expedited placement of a limited EEG. Data collected encompassed patient demographics, clinical history, EEG interpretations by the AI algorithm and epileptologists, treatments, and disposition determinations.

RESULTS

There were 134 device applications on 132 patients (2 received the device twice) enrolled in the study, but 16 were missing data critical for identification or analysis and 9 did not meet the selection criteria. Of the 108 limited EEGs interpreted by an epileptologist, 69 were abnormal (diffuse slowing, highly epileptiform patterns, or spikes and sharps), 41 were normal, 5 were uninterpretable, and 3 captured episodes of seizure or status epilepticus. Limited EEG AI interpretation detected >90% seizure burden in 2 of 3 cases of seizure or status epilepticus as well as in 2 abnormal EEGs and 1 normal EEG, providing a sensitivity of 66.7% (95% confidence interval 9.4 to 99.2), a specificity of 97.0% (95% confidence interval 91.5 to 99.4), and a disease prevalence of 2.9%.

CONCLUSION

Limited AI-enhanced EEG can detect nonconvulsive status epilepticus in the ED; however, the technology tended to overestimate seizure burden in our cohort. This study found a lower nonconvulsive status epilepticus prevalence compared to prior literature reports.

Clinical Outcomes and Systemic Complications Related to the Severity and Etiology of Status Epilepticus Using a Common Data Model

BACKGROUND

Status epilepticus (SE) is a critical neurological emergency in patients with neurological and nonneurological diseases. Mortality rises with SE severity. However, whether brain injury or systemic organ dysfunction causes death after SE remains unclear. We studied clinical outcomes and systemic dysfunctions associated with SE using standardized data from the common data model. This model includes clinical evaluations and treatments that provide real-world evidence for standard practice.

METHODS

This retrospective cohort study used the common data model database of a single tertiary academic medical center. Patients diagnosed with SE (corresponding to G41 of the International Classification of Diseases 10 and administration of antiseizure medication) between January 1, 2001, and January 1, 2018, were enrolled. Demographics, classifications of SE severity, and outcomes were collected as operational definitions by using a common data model format. Systemic complications were defined based on the Sequential Organ Failure Assessment criteria.

RESULTS

The electronic medical records of 1,825,196 patients were transformed into a common data model, and 410 patients were enrolled. The proportion of patients classified as having nonrefractory SE was 65.4% (268/410), followed by refractory (28.5%, 117/410) and super-refractory SE (6.1%, 25/410). Patients with more severe SE had longer intensive care unit and hospital stays. Renal dysfunction and thrombocytopenia were higher in the in-hospital death group (P = 0.002 and 0.003, respectively). In multivariable analysis, the Acute Physiology and Chronic Health Evaluation II score and platelet count were significantly different in the in-hospital death group (odds ratio, 1.169, P = 0.004; and 0.989, P = 0.043).

CONCLUSIONS

Systemic complications after SE, especially low platelet counts, were linked to worse outcomes and increased mortality in a common data model. The common data model offers expandability and comprehensive analysis, making it a potentially valuable tool for SE research.

Clinical features of neuronal intranuclear inclusion disease with seizures: a systematic literature review

Background

Infant, junior, and adult patients with neuronal intranuclear inclusion disease (NIID) present with various types of seizures. We aimed to conduct a systematic literature review on the clinical characteristics of NIID with seizures to provide novel insight for early diagnosis and treatment and to improve prognosis of these patients.

Methods

We used keywords to screen articles related to NIID and seizures, and data concerning the clinical characteristics of patients, including demographic features, disease characteristics of the seizures, treatment responses, imaging examinations, and other auxiliary examination results were extracted.

Results

The included studies comprised 21 patients with NIID with seizures. The most common clinical phenotypes were cognitive impairment (76.20%) and impaired consciousness (57.14%), and generalized onset motor seizures (46.15%) represented the most common type. Compared with infantile and juvenile cases, the use of antiepileptic drugs in adults led to significant seizure control and symptom improvement, in addition to providing a better prognosis. The number of GGC sequence repeats in the NOTCH2NLC gene in six NIID patients with seizures who underwent genetic testing ranged 72-134.

Conclusion

The most common clinical phenotypes in patients with NIID with seizures were cognitive impairment and consciousness disorders. Patients with NIID presented with various types of seizures, with the most common being generalized onset motor seizures. Adult patients had a better prognosis and were relatively stable. The early diagnosis of NIID with seizures is of great significance for treatment and to improve prognosis.

Nonconvulsive Status Epilepticus: A Review for Emergency Clinicians

BACKGROUND

Status epilepticus is associated with significant morbidity and mortality and is divided into convulsive status epilepticus and nonconvulsive status epilepticus (NCSE).

OBJECTIVE

This review provides a focused evaluation of NCSE for emergency clinicians.

DISCUSSION

NCSE is a form of status epilepticus presenting with prolonged seizure activity. This disease is underdiagnosed, as it presents with nonspecific signs and symptoms, most commonly change in mental status without overt convulsive motor activity. Causes include epilepsy, cerebral pathology or injury, any systemic insult such as infection, and drugs or toxins. Mortality is primarily related to the underlying condition. Patients most commonly present with altered mental status, but other signs and symptoms include abnormal ocular movements and automatisms such as lip smacking or subtle motor twitches in the face or extremities. The diagnosis is divided into electrographic and electroclinical, and although electroencephalogram (EEG) is recommended for definitive diagnosis, emergency clinicians should consider this disease in patients with prolonged postictal state after a seizure with no improvement in mental status, altered mental status with acute cerebral pathology (e.g., stroke, hypoxic brain injury), and unexplained altered mental status. Assessment includes laboratory evaluation and neuroimaging with EEG. Management includes treating life-threatening conditions, including compromise of the airway, hypoglycemia, hyponatremia, and hypo- or hyperthermia, followed by rapid cessation of the seizure activity with benzodiazepines and other antiseizure medications.

CONCLUSIONS

An understanding of the presentation and management of NCSE can assist emergency clinicians in the care of these patients.

Point-of-care electroencephalography enables rapid evaluation and management of non-convulsive seizures and status epilepticus in the emergency department

Objectives

To describe our institutional experience with point-of-care electroencephalography (pocEEG) and its impact on the evaluation/management of suspected non-convulsive seizures in the emergency department (ED).

Methods

We retrospectively identified 157 adults who underwent pocEEG monitoring in our community hospital ED in 1 year. We calculated the time to obtain pocEEG in the ED (door-to-EEG time) and examined the impact of pocEEG findings (categorized as seizure, highly epileptiform patterns, slowing, or normal activity) on antiseizure medication treatment.

Results

PocEEG revealed seizures (14%, n = 22), highly epileptiform patterns (22%, n = 34), slowing (44%, n = 69), and normal activity (20%, n = 32). The median door-to-EEG time (from initial ED evaluation to pocEEG monitoring) was only 1.2 hours (interquartile range 0.1-2.1) even though 55% of studies were performed after-hours (5 pm-9 am). Most patients were admitted (54% to the intensive care unit, 41% to floor). Antiseizure medication treatment occurred pre-pocEEG in 93 patients (59%) and post-pocEEG in 88 patients (56%). By reviewing the relationship between pocEEG monitoring and antiseizure medication management, we found a significant association between pocEEG findings and changes in management (P < 0.001). Treatment escalation occurred more frequently in patients with epileptiform activity (seizures or highly epileptiform patterns, 52%) than patients with non-epileptiform activity (normal or slow, 25%, P < 0.001), and avoidance of treatment escalation occurred more frequently in patients with normal or slow activity (27%) than patients with seizures or highly epileptiform patterns (2%, P < 0.001).

Conclusion

Our study, the largest to date describing the real-world use of pocEEG in emergency medicine, found that rapid EEG acquisition in the ED was feasible in a community hospital and significantly affected the management of suspected non-convulsive seizures.

Status epilepticus: review on diagnosis, monitoring and treatment

Status epilepticus (SE) is a frequent neurological emergency associated with high morbidity and mortality. According to the new ILAE 2015 definition, SE results either from the failure of the mechanisms responsible for seizure termination or initiation, leading to abnormally prolonged seizures. The definition has different time points for convulsive, focal and absence SE. Time is brain. There are changes in synaptic receptors leading to a more proconvulsant state and increased risk of brain lesion and sequelae with long duration. Management of SE must include three pillars: stop seizures, stabilize patients to avoid secondary lesions and treat underlying causes. Convulsive SE is defined after 5 minutes and is a major emergency. Benzodiazepines are the initial treatment, and should be given fast and an adequate dose. Phenytoin/fosphenytoin, levetiracetam and valproic acid are evidence choices for second line treatment. If SE persists, anesthetic drugs are probably the best option for third line treatment, despite lack of evidence. Midazolam is usually the best initial choice and barbiturates should be considered for refractory cases. Nonconvulsive status epilepticus has a similar initial approach, with benzodiazepines and second line intravenous (IV) agents, but after that, aggressiveness should be balanced considering risk of lesion due to seizures and medical complications caused by aggressive treatment. Usually, the best approach is the use of sequential IV antiepileptic drugs (oral/tube are options if IV options are not available). EEG monitoring is crucial for diagnosis of nonconvulsive SE, after initial control of convulsive SE and treatment control. Institutional protocols are advised to improve care.

Analysis of electroclinical features of nonconvulsive status epilepticus: a study of four cases

Background

The nonconvulsive status epilepticus (NCSE) is an epileptic condition characterized by little or no obvious symptoms, thus is often easily to be underrecognized, underdiagnosed or even undetected by clinicians. This article is written to advance the recognition and diagnosis of NCSE.

Case presentation

Four cases of NCSE were reported and their semiology, electroencephalogram (EEG) features, etiology, treatment and prognosis were retrospectively analyzed. Most of the 4 cases presented with impaired consciousness (confused, slow reaction and lags in response) and some strange behaviors (being upset and restless or washing hands repeatedly). None of them had any obvious motor symptoms like tonic or clonic movements. EEG of the 4 cases initially manifested with either a focal or a generalized onset, then evolved into spike-and-wave pattern gradually. With a favorable response to antiepileptic drugs, they all had a good outcome without any sequela.

Conclusions

NCSE is much more common than was considered in the past, which is featured by little or no evidence of movement or other symptoms. NCSE can lead to a favorable outcome in most patients.

Postictal psychosis, a cause of secondary affective psychosis: A clinical description study of 77 patients

OBJECTIVE

Postictal psychosis (PIP) is a severe complication occurring at least in 2% of patients with epilepsy. Since the 19th century, psychiatrists have reported the specificity of PIP presentation, but descriptions did not clearly distinguish PIP from after-seizure delirium. This study aimed to provide a precise description of psychiatric signs occurring during PIP, and improve recognition of PIP.

METHODS

We performed a review of clinical descriptions available in literature (48 patients), that we gathered with a retrospective multicentric case series of patients from three French epilepsy units (29 patients). For each patient, we collected retrospectively the psychiatric signs, and epilepsy features.

RESULTS

We found a high prevalence of persecutory (67.5%) and religious (55.8%) delusions, with almost systematic hallucinations (83.1%) and frequent mood disturbances (76.6%), especially euphoria. Severe consequences were not negligible (other-directed assault in 20.8%, self-directed in 13.0%). The type of delusion was associated with mood symptoms (p = 0.017). Episode onset was mainly sudden/rapid (90.9%), its duration was mostly between one and 14 days (64.9%) and the response to antipsychotic medication was good. Disorder was recurrent in more than a half of the sample (57.1% of patients with at least 2 episodes).

CONCLUSION

Considering our findings, PIP resembles more an affective psychosis, than a purely psychotic disorder. The presence of affective signs differentiates PIP from other psychotic comorbidities in epilepsy. Additionally, resemblance between PIP and psychotic manic episode might help to discuss links between epilepsy and bipolar disorder.

COVID-19 masquerading as a non-convulsive status epilepticus

Since the outbreak of the coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), more and more atypical presentations of COVID-19 are being reported. Here, we present and discuss non-convulsive status epilepticus (NCSE) as presenting symptom of SARS-CoV-2 infection at the Emergency Department.

Functional neuroimaging in nonepileptiform electroencephalographic patterns in status epilepticus

BACKGROUND

The diagnosis of nonconvulsive status epilepticus (NCSE) in patients with nonepileptiform EEG patterns remains a challenge.

OBJECTIVE

To evaluate the usefulness of single photon emission computerized tomography (SPECT) and its quantification (QtSPECT) in the diagnosis of NCSE.

METHODS

We retrospectively reviewed patients admitted with clinical suspicion of NCSE who underwent an HMPAO-SPECT simultaneously with scalp EEG showing nonepileptiform patterns, in a 5-year period. After a complete diagnostic workup, treatment, and clinical evolution, disregarding the SPECT results, patients were classified into confirmed NCSE (n = 11) and non-NCSE (n = 8). Then, we compared the EEG and SPECT results in both groups.

RESULTS

Lateralized rhythmic delta activity (LRDA) was predominant in the NCSE group (45.4%, p = .045), while lateralized irregular slowing was observed equally in both groups. Patients with NCSE showed significant hyperperfusion compared with non-NCSE patients (p = .026). QtSPECT correctly classified 91% of patients in NCSE and 75% patients with non-NCSE (p = .006).

CONCLUSIONS

Regional cerebral blood flow measured with SPECT could be useful in the diagnosis of NCSE in cases of an EEG pattern with lateralized slow activity and high clinical suspicion.

Hippocampal injury and learning deficits following non-convulsive status epilepticus in periadolescent rats

The effects of non-convulsive status epilepticus (NCSE) on the developing brain remain largely elusive. Here we investigated potential hippocampal injury and learning deficits following one or two episodes of NCSE in periadolescent rats. Non-convulsive status epilepticus was induced with subconvulsive doses of intrahippocampal kainic acid (KA) under continuous EEG monitoring in postnatal day 43 (P43) rats. The RKA group (repeated KA) received intrahippocampal KA at P43 and P44, the SKA group (single KA injection) received KA at P43 and an intrahippocampal saline injection at P44. Controls were sham-treated with saline. The modified two-way active avoidance (MAAV) test was conducted between P45 and P52 to assess learning of context-cued and tone-signaled electrical foot-shock avoidance. Histological analyses were performed at P52 to assess hippocampal neuronal densities, as well as potential reactive astrocytosis and synaptic dysfunction with GFAP (glial fibrillary acidic protein) and synaptophysin (Syp) staining, respectively. Kainic acid injections resulted in electroclinical seizures characterized by behavioral arrest, oromotor automatisms and salivation, without tonic-clonic activity. Compared to controls, both the SKA and RKA groups had lower rates of tone-signaled shock avoidance (p < 0.05). In contextual testing, SKA rats were comparable to controls (p > 0.05), but the RKA group had learning deficits (p < 0.05). Hippocampal neuronal densities were comparable in all groups. Compared to controls, both the SKA and RKA groups had higher hippocampal GFAP levels (p < 0.05). The RKA group also had lower hippocampal Syp levels compared to the SKA and control groups (p < 0.05), which were comparable (p > 0.05). We show that hippocampal NCSE in periadolescent rats results in a seizure burden-dependent hippocampal injury accompanied by cognitive deficits. Our data suggest that the diagnosis and treatment of NCSE should be prompt.

Status Epilepticus Mortality Risk Factors and a Correlation Survey with the Newly Modified STESS

BACKGROUND

Status epilepticus (SE) is a neurological emergency and is usually associated with significant morbidity and mortality rates. Several clinical scales have been proposed to predict the clinical outcome of such incidents, including the Status Epilepticus Severity Score (STESS), the modified STESS (mSTESS), and the Encephalitis-Nonconvulsive Status Epilepticus-Diazepam Resistance-Image Abnormalities-Tracheal intubation (END-IT). Nevertheless, there is still a need for a more practical and precise predictive scale.

METHODS

This is a retrospective cohort study which examines data from patients with SE in our Department of Neurology between 2009 and 2020. Based on the outcome of each case, the patients were divided into survivor and non-survivor groups. We analyzed the independent factors and adjusted the STESS to achieve a better prediction of prognosis. The predictive accuracy of our new STESS scale was then compared with that of the mSTESS and the END-IT.

RESULTS

Data on a total of 59 patients were collected, with 6 of them classified as non-survivors. The effects of the variables of age, sex, underlying disease(s), and type(s) of antiepileptic drug (AED) use showed no significant differences between the survivor and non-survivor groups. Importantly, the number of AEDs used in the first week and the use of thiobarbiturates predicted non-survival. We adjusted the STESS to create the newly modified STESS (nSTESS), which showed a better predictive capacity than the STESS, the mSTESS, and the END-IT.

CONCLUSIONS

Our adjustment of the STESS with the addition of the factors "number of AEDs within the first week" and "use of thiobarbiturates", could have a positive impact on the prediction of mortality rates compared with currently used scales. This nSTESS could potentially be useful in clinical practices, for the early prediction of outcomes for patients with SE.

De-novo non-convulsive status epilepticus in adult medical inpatients without known epilepsy: Analysis of mortality related factors and literature review

Background

Non-convulsive status epilepticus (NCSE) often goes unnoticed and is not easily detected in patients with a decreased level of consciousness, especially in older patients. In this sense, lack of data in this population is available.

Aims

The aim of the present study was to examine daily clinical practice and evaluate factors that may influence the prognosis of NCSE in non-epileptic medical inpatients.

Methods

We conducted a retrospective analysis including patients admitted by any cause in an Internal Medicine ward. All patients with compatible symptoms, exclusion of other causes, clinical suspicion or diagnosis of NCSE, and compatible EEG were included. Patients with a previous diagnosis of epilepsy were excluded. We also conducted a literature review by searching the PubMed/Medline database with the terms: Nonconvulsive Status OR Non-Convulsive Status.

Results

We included 54 patients, mortality rate reached 37% and the main factors linked to it were hypernatremia (OR = 16.2; 95% CI, 1.6–165.6; P = 0.019) and atrial fibrillation (OR = 6.7; 95% CI, 1.7–26; P = 0.006). There were no differences regarding mortality when comparing different diagnosis approach or treatment regimens. Our literature review showed that the main etiology of NCSE were neurovascular causes (17.8%), followed by antibiotic treatment (17.2%) and metabolic causes (17%). Global mortality in the literature review, excluding our series, reached 20%.

Discussion

We present the largest series of NCSE cases in medical patients, which showed that this entity is probably misdiagnosed in older patients and is linked to a high mortality.

Conclusion

The presence of atrial fibrillation and hypernatremia in patients diagnosed with NCSE should advise physicians of a high mortality risk.

Automated Pupillometry for Assessment of Treatment Success in Nonconvulsive Status Epilepticus

BACKGROUND

Altered pupillary function may reflect nonconvulsive status epilepticus (NCSE). Neurological pupil index (NPi) assessed by automated pupillometry is a surrogate marker of global pupillary function. We aimed to assess NPi changes in relation to NCSE treatment response.

METHODS

In this prospective observational study, serial automated pupillometry was performed in 68 NCSE episodes. In accordance with local standards, patients were treated with clonazepam (1-2 mg), levetiracetam (40 mg/kg), and lacosamide (5 mg/kg) in a stepwise approach under continuous electroencephalography monitoring until NCSE was terminated. Patients with refractory NCSE received individualized regimens. NPi was assessed bilaterally before and after each treatment step. For statistical analysis, the lower NPi of both sides (minNPi) was used. Nonparametric testing for matched samples and Cohen's d to estimate effect size were performed. Principal component analysis was applied to assess the contribution of baseline minNPi, age, sex, and NCSE duration to treatment outcome.

RESULTS

In 97.1% of 68 episodes, NCSE could be terminated; in 16.2%, NCSE was refractory. In 85.3% of episodes, an abnormal baseline minNPi ≤ 4.0 was obtained. After NCSE termination, minNPi increased significantly (p < 0.001). Cohen's d showed a strong effect size of 1.24 (95% confidence interval 0.88-1.61). Baseline minNPi was higher in clonazepam nonresponders vs. responders (p = 0.008), minNPi increased in responders (p < 0.001) but not in nonresponders. NCSE refractivity was associated with normal baseline minNPi (principal component analysis, component 1, 32.6% of variance, r = 0.78), male sex, and longer NCSE duration (component 2, 27.1% of variance, r = 0.62 and r = 0.78, respectively).

CONCLUSIONS

Automated pupillometry may be a helpful noninvasive neuromonitoring tool for the assessment of patients with NCSE and response to treatment.

Status epilepticus without impairment of consciousness: Long-term outcomes according to duration

OBJECTIVE

The point after which non-convulsive status epilepticus (NCSE) can cause permanent damage remains to be elucidated. The aim of this study was to analyze the association between time to resolution and long-term outcomes in NCSE.

METHODS

We performed a retrospective study of all patients with focal NCSE without consciousness impairment at two tertiary care hospitals in Spain. All the data were registered prospectively and the study period was December 2014-May 2018. We collected information on demographics, SE etiology, time to administration of different lines of treatment, time to NCSE resolution, and outcomes at discharge, 1 year, and 4 years. Clinical outcome was prospectively categorized as good (return to baseline function) or poor (new disability and death).

RESULTS

Seventy-four patients with a mean (±SD) age of 63.4 ± 17.5 years and a mean follow-up time of 2.4 ± 2.2 years were studied. A poor outcome at discharge was associated with a potentially fatal etiology (p < 0.001), EMSE score (Epidemiology-based Mortality Score in Status Epilepticus) (p = 0.012), lateral periodic discharges on EEG (p = 0.034), and occurrence of major complications during hospitalization (p = 0.007). An SE duration of >100 h was clearly associated with a worse outcome (p < 0.001). In the multiple regression analysis, the only independent predictors of a poor outcome at discharge were an SE duration of >+100 hours (p = 0.001), a potentially fatal etiology (p = 0.001), and complications during hospitalization (p = 0.010). An SE duration of >100 hours retained its value as the optimal cutoff point for predicting poor outcomes at both 1 year (p = 0.037) and 4 years (p = 0.05). Other predictors of poor long-term outcomes were a potentially fatal etiology (p < 0.001) and EMSE score (p = 0.034) at 1 year, and progressive symptomatic etiology at 4 years (p = 0.025).

SIGNIFICANCE

In patients with focal NCSE without consciousness impairment, a potentially fatal etiology and an SE duration of >100 h were associated with poor short-term and long-term outcomes.

Nonconvulsive Status Epilepticus in Metabolic Encephalopathy in Indonesia Referral Hospital

Background

Nonconvulsive status epilepticus (NCSE) is often underdiagnosed in patients with metabolic encephalopathy (ME). The diagnosis of ME should be made specifically to recognize the underlying etiology. Delay in seizure identification and making a diagnosis of NCSE contributed to the poor outcome.

Objective

This study aimed to find the incidence and outcome of NCSE in patients with ME.

Methods and Material

This was an observational prospective cross-sectional study in patients with ME in emergency and critical care units in Cipto Mangunkusumo General Hospital. The diagnosis of NCSE was based on EEG using Salzburg Criteria for Nonconvulsive Status Epilepticus (SCNC). The outcome was assessed within 30 days after the NCSE diagnosis has been made.

Results

A total of 50 patients with ME were involved in this study. NCSE was confirmed in 32 subjects (64%). The most common etiology of ME was sepsis (58%). The mortality rate in the NCSE and non-NCSE group was 40.6% vs 44.4%. Multiple aetiologies were risk factors to poor outcome in the NCSE group.

Conclusions

The incidence of NCSE among patients with ME at our hospital was high. Despite the anti-epileptic treatment of the NCSE group, the underlying cause of ME is still the main factor that affected the outcome. Therefore, aggressive treatment of anti-epileptic drug (AED) should be very carefully considered knowing the possible side-effect that might worsen the outcome of patients with ME.

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.

Non-convulsive status epilepticus in the immediate postoperative period following spine surgery

Background

Non-convulsive status epilepticus (NCSE), in which continuous epileptiform discharges occur without seizure-like movement, is rare and unfamiliar to anesthesiologists, both of which make this condition overlooked in patients with decreased levels of consciousness following general anesthesia.

Case

We report on an elderly female patient who developed NCSE in the immediate postoperative period after the spine surgery. Initially, delayed emergence from anesthesia was suspected, but the electroencephalogram confirmed NCSE, and anticonvulsant therapy was initiated.

Conclusions

Delayed emergence is commonly attributed to cerebrovascular events or residual anesthetic effects, but NCSE must be included in the differential diagnosis, especially in elderly patients. Anticonvulsant therapy should be initiated as soon as possible for a better prognosis.

Non-Convulsive Status Epilepticus in the Presence of Catatonia: A Clinically Focused Review

INTRODUCTION

Catatonia is classically associated with psychiatric conditions but may occur in medical and neurologic disorders. Status epilepticus (SE) is a seizure lasting more than five minutes or two or more seizures within a five-minute period without interictal recovery of consciousness. Non-convulsive status epilepticus (NCSE) is SE without prominent motor activity that may present with catatonic symptoms. The relevance of NCSE as a potential etiology for catatonia is not clear in the literature.

METHODS

A systematic review was completed to evaluate the literature on NCSE presenting with catatonia. PubMed and PsycInfo databases were searched and articles were reviewed for the presence of catatonia and NCSE.

RESULTS

15 articles describing 27 cases meeting inclusion criteria were identified. The authors add 1 case to the literature. The most common catatonic symptoms identified in NCSE were mutism and stupor. Clinical features frequent in NCSE presenting with catatonia included new catatonic symptoms, age over 50 years, comorbid neurological conditions, or a change in medications that affect seizure threshold. A documented psychiatric history was also common and may contribute to delayed diagnosis.

DISCUSSION/CONCLUSION

It is important to consider NCSE in the differential diagnosis of new catatonic symptoms. A suggested approach to diagnostic evaluation is provided.

Quantitative Infrared Pupillometry in Nonconvulsive Status Epilepticus

BACKGROUND

Nonconvulsive status epilepticus (NCSE) is a frequent disorder in neurocritical care and diagnosing it can be challenging. NCSE patients often show altered pupil function, but nature and extent may vary. Infrared pupillometry allows detection of subtle changes of pupil function. The neurological pupil index (NPi) is considered a surrogate marker of global pupil function which is supposed to be independent of absolute parameters such as the pupil diameter.

OBJECTIVE

Cross-sectional observational study to assess whether NPi is altered in NCSE.

METHODS

128 consecutive adult emergency patients who had experienced a suspected seizure, have not reached their prior functional level regarding level of consciousness, mental status or focal deficits, had no obvious clinical signs of status epilepticus and had an EEG indication as determined by the treating clinician for exclusion of NCSE were examined by routine EEG and pupillometry. Exclusion criteria were ocular comorbidity (n = 21) and poor EEG quality (n = 4). Pupillometry was performed once directly before the beginning of EEG recording. NCSE diagnosis (no NCSE, possible NCSE and confirmed NCSE) was established according to Salzburg consensus criteria blinded to pupillometry results. Group comparison was performed for right NPi, left NPi, lowest NPi of both sides (minNPi) and the absolute difference of both sides (diffNPi) applying non-parametric testing. In post-hoc analysis, receiver operating characteristics (ROC) of NCSE diagnosis (combined confirmed NCSE and possible NCSE) were performed for minNPi and diffNPi.

RESULTS

From 103 patients included in the final analysis, 5 (4.9%) had confirmed NCSE, 7 (6.8%) had possible NCSE. Right NPi (p = 0.002), left NPi (p < 0.001) and minNPi (p < 0.001) were significantly lower in "confirmed NCSE" and "possible NCSE" compared to "no NCSE"; diffNPi was significantly higher in "confirmed NCSE" and "possible NCSE" compared to "no NCSE" (p < 0.001). There was no significant difference of minNPi and diffNPi between "confirmed NCSE" and "possible NCSE". ROC analysis showed an optimal cut-off of minNPi for NCSE diagnosis of 4.0 (AUC = 0.93, 95% CI 0.86-0.99). Optimal ROC analysis cut-off of diffNPi for NCSE diagnosis was 0.2 (AUC = 0.89, 95% CI 0.80-0.99).

CONCLUSIONS

NPi was significantly reduced and the difference between left and right NPi was significantly higher in confirmed NCSE. An NPi < 4.0 on either side as well as an NPi difference of both sides > 0.2 may be potential indicators of NCSE. Infrared pupillometry may be a helpful diagnostic tool in the assessment of NCSE and should be studied further in larger populations.

Non-convulsive seizure clustering misdiagnosed as vertebrobasilar insufficiency

Diagnosing non-convulsive seizures (NCSs) is a great challenge for most clinicians due to a wide spectrum of clinical presentations. The complexity of the disease course usually results in a delayed diagnosis or misdiagnosis so that timely and appropriate treatment is not given. Herein, we report a case with NCSs misdiagnosed as vertebrobasilar insufficiency (VBI), in which the patient suffered from episodes of prominent dizziness, vertigo, becoming transfixed, and worsening response within a day. Brain magnetic resonance image findings were unremarkable, however electroencephalography (EEG) showed rhythmic epileptiform discharges that appeared to originate from the right frontal area with ipsilateral hemispheric involvement. We prescribed intravenous valproate and the seizures ceased. Few studies have reported a patient with NCS misdiagnosed with VBI, a very different entity. It is thus important that clinicians should be aware of the trivial symptoms of NCSs, and to consider implementing early EEG studies and anti-epileptic drug therapy.

Nonconvulsive status epilepticus after surgery for ruptured intracranial aneurysms: Incidence, associated factors, and impact on the outcome

OBJECTIVE

To evaluate the incidence of nonconvulsive status epilepticus (NCSE) after surgery for ruptured intracranial aneurysms, to define factors associated with this complication, and to determine its impact on the outcome.

PATIENTS AND METHODS

Clinical and neurophysiological data of 66 patients with aneurysmal subarachnoid hemorrhage (aSAH) who underwent continuous EEG (cEEG) monitoring after microsurgical clipping (53 cases) or endovascular coiling (13 cases) of the ruptured aneurysm were analyzed retrospectively. The diagnosis of NCSE was based on the American Clinical Neurophysiology Society and Salzburg Consensus criteria.

RESULTS

NCSE was revealed in 10 patients (15 %), all of whom underwent craniotomy and aneurysm clipping. In comparison to the subgroup without NCSE, among those who were diagnosed with this complication there was a significantly greater proportion of men (70 % vs. 34 %; P = 0.041), cases with the Glasgow Coma Scale score at admission < 13 (90 % vs. 36 %; P = 0.004), the Hunt and Hess aSAH grades 3-5 (90 % vs. 45 %; P = 0.013), and hydrocephalus (70 % vs. 29 %; P = 0.044). In addition, they required a significantly longer hospital stay (medians, 62.5 vs. 39.5 days; P = 0.015) and showed trend for the lower rate of favorable disability outcomes (20 % vs. 54 %; P = 0.084).

CONCLUSIONS

NCSE is encountered rather often after the microsurgical clipping of ruptured intracranial aneurysms, especially in severely disabled patients with high-grade aSAH and/or associated hydrocpephalus, and may significantly affect the clinical course and prolong recovery. cEEG monitoring may be helpful for timely diagnosis and treatment of this complication.

[Electroencephalography in acute stroke]

OBJECTIVE

To determine the incidence of non-convulsive status epilepticus, epileptiform activity, rhythmic and periodic patterns in patients with acute stroke.

MATERIAL AND METHOD

An analysis of electroencephalography (EEG) in 86 stroke patients in the neurointensive care unit of the tertiary medical center was performed. Criteria for starting EEG recording were epileptic seizures or clinical suspicion of uncontrolled epileptic status. The ictal-interictal continuum biomarkers and the diagnostic value of EEG for prediction of survival and recovery were assessed.

RESULTS

Pathological changes on EEG were recorded in 84% of patients. These patients showed the absence of the dominant occipital rhythm (66%) and hemispheric slowing (42%). Diffuse slowing below the theta range was observed in 41% of patients. EEG reactivity was absent in 20%. Sporadic epileptiform discharges were recorded in 36% of patients and rhythmic and periodic patterns in 26%. Reliable predictors of the unfavorable outcome were the absence of dominant occipital rhythm, lack of reactivity, and low amplitude of the background EEG. No association between the recording of epileptiform activity and the probability of death was shown.

CONCLUSION

The most useful EEG biomarkers for predicting survival are amplitude, dominant frequency of background EEG activity and reactivity to external stimulus. Sporadic epileptiform discharges, rhythmic, and periodic patterns are not mandatory associated with a negative prognosis in stroke patients.

Recommandations Formalisées d’Experts SRLF/SFMU : Prise en charge des états de mal épileptiques en préhospitalier, en structure d’urgence et en réanimation dans les 48 premières heures (A l’exclusion du nouveau-né et du nourrisson)

La Société de réanimation de langue française et la Société française de médecine d’urgence ont décidé d’élaborer de nouvelles recommandations sur la prise en charge de l’état mal épileptique (EME) avec l’ambition de répondre le plus possible aux nombreuses questions pratiques que soulèvent les EME : diagnostic, enquête étiologique, traitement non spécifique et spécifique. Vingt-cinq experts ont analysé la littérature scientifique et formulé des recommandations selon la méthodologie GRADE. Les experts se sont accordés sur 96 recommandations. Les recommandations avec le niveau de preuve le plus fort ne concernent que l’EME tonico-clonique généralisé (EMTCG) : l’usage des benzodiazépines en première ligne (clonazépam en intraveineux direct ou midazolam en intramusculaire) est recommandé, répété 5 min après la première injection (à l’exception du midazolam) en cas de persistance clinique. En cas de persistance 5 min après cette seconde injection, il est proposé d’administrer la seconde ligne thérapeutique : valproate de sodium, (fos-)phénytoïne, phénobarbital ou lévétiracétam. La persistance avérée de convulsions 30 min après le début de l’administration du traitement de deuxième ligne signe l’EMETCG réfractaire. Il est alors proposé de recourir à un coma thérapeutique au moyen d’un agent anesthésique intraveineux de type midazolam ou propofol. Des recommandations spécifiques à l’enfant et aux autres EME sont aussi énoncées.

The adenosine A1 receptor agonist WAG 994 suppresses acute kainic acid-induced status epilepticus in vivo

Status epilepticus (SE) is a neurological emergency characterized by continuous seizure activity lasting longer than 5 min, often with no recovery between seizures (Trinka et al., 2015). SE is refractory to benzodiazepine and second-line treatments in about 30% cases. Novel treatment approaches are urgently needed as refractory SE is associated with mortality rates of up to 70%. Robust adenosinergic anticonvulsant effects have been known for decades, but translation into seizure treatments was hampered by cardiovascular side effects. However, the selective adenosine A1 receptor agonist SDZ WAG 994 (WAG) displays diminished cardiovascular side effects compared to classic A1R agonists and was safely administered systemically in human clinical trials. Here, we investigate the anticonvulsant efficacy of WAG in vitro and in vivo. WAG robustly inhibited high-K⁺-induced continuous epileptiform activity in rat hippocampal slices (IC₅₀ = 52.5 nM). Importantly, WAG acutely suppressed SE in vivo induced by kainic acid (20 mg/kg i.p.) in mice. After SE was established, mice received three i.p. injections of WAG or diazepam (DIA, 5 mg/kg). Interestingly, DIA did not attenuate SE while the majority of WAG-treated mice (1 mg/kg) were seizure-free after three injections. Anticonvulsant effects were retained when a lower dose of WAG (0.3 mg/kg) was used. Importantly, all WAG-treated mice survived kainic acid induced SE. In summary, we report for the first time that an A1R agonist with an acceptable human side-effect profile can acutely suppress established SE in vivo. Our results suggest that WAG stops or vastly attenuates SE while DIA fails to mitigate SE in this model.

Autoimmune encephalitis as an increasingly recognised cause of non-convulsive status epilepticus: A retrospective, multicentre evaluation of patient characteristics and electroencephalography (EEG) results

PURPOSE

Status epilepticus (SE) is a severe condition of unrelenting seizures requiring urgent identification and treatment. SE may be unprovoked, occurring in someone with epilepsy, or may be provoked by acute intracranial disease or metabolic derangement. Increasingly encephalitis, particularly autoimmune types, is reported to cause refractory seizures. Whilst convulsive SE is readily identified, non-convulsive SE (NCSE) can be difficult to identify clinically, and electroencephalography (EEG) is required. Therefore, it is critical to identify the key clinical features associated with NCSE on EEG to inform future use of EEG.

METHODS

We conducted a multicentre, retrospective analysis of EEG requests from four general and one specialist neurology hospital in the Northwest of England (2015-2018). Cases were identified from EEG requests for patients with suspected NCSE or other indications such as encephalopathy. We compared demographic and clinical characteristics between EEG-confirmed cases of NCSE and a randomly selected sample of negative controls.

RESULTS

358 EEGs were reviewed, and 8 positive cases of NCSE were identified. Epilepsy was identified as the aetiology in 2 of these cases, and autoimmune encephalitis another 2 cases (one patient with N-methyl-d-aspartate receptor antibodies and another with voltage gated potassium channel antibodies). Previous alcohol excess (p = 0.005) and subtle motor signs (p = 0.047) on examination were observed more frequently in patients with NCSE compared to controls.

CONCLUSION

Physicians should have a low threshold for urgent EEG in patients with suspected or previous encephalitis, especially if autoimmunity is suspected or subtle motor signs are present.

False alarms reduction in non-convulsive status epilepticus detection via continuous EEG analysis

OBJECTIVE

Frequent false alarms from computer-assisted monitoring systems may harm the safety of patients with non-convulsive status epilepticus (NCSE). In this study, we aimed at reducing false alarms in the NCSE detection based on preventing from three common errors: over-interpretation of abnormal background activity, dense short ictal discharges and continuous interictal discharges as ictal discharges.

APPROACH

We analyzed 10 participants' hospital-archived 127-hour electroencephalography (EEG) recordings with 310 ictal discharges. To reduce the false alarms caused by abnormal background activity, we used morphological features extracted by visibility graph methods in addition to time-frequency features. To reduce the false alarms caused by over-interpreting short ictal discharges and interictal discharges, we created two synthetic classes-'Suspected Non-ictal' and 'Suspected Ictal'-based on the misclassified categories and constructed a synthetic 4-class dataset combining the standard two classes-'Non-ictal' and 'Ictal'-to train a 4-class classifier. Precision-recall curves were used to compare our proposed 4-class classification model and the standard 2-class classification model with or without the morphological features in the leave-one-out cross validation stage. The sensitivity and precision were primarily used as performance metrics for the detection of a seizure event.

MAIN RESULTS

The 4-class classification model improved the performance of the standard 2-class model, in particular increasing the precision by 15% at an 80% sensitivity level when only time-frequency features were used. Using the morphological features, the 4-class classification model achieved the best performances: a sensitivity of 93% ± 12% and a precision of 55% ± 30% in the group level. 100% accuracy was reached in a participant's 4.3-hour recording with 5 ictal discharges.

SIGNIFICANCE

False alarms in the NCSE detection were remarkably reduced using the morphological features and the proposed 4-class classification model.

A case of paroxysmal homonymous hemianopsia: Uncommon presentation of nonconvulsive status epilepticus

Paroxysmal homonymous hemianopsia (HH) is uncommon presentation of epilepsy. We demonstrate a rare case of paroxysmal HH that was diagnosed by magnetic resonance (MR) arterial spin-labeling (ASL). A 82-year-old woman presented with abrupt onset of isolated visual field abnormality without convulsive epilepsy at 16 days after a traumatic head injury. Diffusion weighted and MR-ASL obtained on admission revealed hyperintensity and hyperperfusion in the right temporo-occipital cortex. Nonconvulsive status epilepticus was suspected. The patient was treated with oral levetiracetam and the symptoms resolved in 3 days. Paroxysmal HH should be considered in patients who present with simple partial epilepsy, and MR-ASL imaging may assist in the differential diagnosis of these patients.

Aphasic status epilepticus of frontal origin treated by resective surgery

Aphasic status epilepticus (SE) is a clinical entity of SE, but it has not been well recognized. We report a 43-year-old female with a chronic drug-resistant epilepsy with aphasic SE, treated by resective surgery. The patient showed long-lasting weekly episodes of hypokinesia, slow verbal response, and dysphasia, which were diagnosed as symptoms of aphasic SE. Magnetic resonance imaging showed encephalomalacia in the left frontal lobe with a hemosiderin rim. Intracranial electroencephalography revealed continuous spikes, predominantly on the left superior frontal gyrus with hemosiderin deposit. The aphasic symptoms were seen when ictal discharges gradually spread to the wide area of the left anterior frontal lobe, including the language area. The episodes of recurrent aphasic SE had disappeared by one year after the left anterior frontal resection. We should consider aphasic SE when language impairment is episodic, and consider surgical intervention in cases where it repeatedly occurs despite appropriate medical therapy.

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Long-lasting slow verbal response and dysphasia could be manifestations of aphasic status epilepticus of frontal origin

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Epilepsy surgery should be considered for repeat aphasic SE under appropriate medical treatment after definite diagnosis

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Precise time correlations between aphasic symptoms and ictal discharges could be unclear even by intracranial electroencephalography.

Etiological assessment of status epilepticus

Status epilepticus (SE) is a potentially serious condition that can affect vital and functional prognosis and requires urgent treatment. Etiology is a determining factor in the patient's functional outcome and in almost half of all cases justifies specific treatment to stop progression. Therefore, identifying and addressing the cause of SE is a key priority in SE management. However, the etiology can be difficult to identify among acute and remote causes, which can also be multiple and interrelated. The most common etiologies are the discontinuation of antiepileptic medication in patients with a prior history of epilepsy, and acute brain aggression in cases of new onset SE (cerebrovascular pathologies are the most common). The list of remaining possible etiologies includes heterogeneous pathological contexts. Refractory SE and especially New-Onset Refractory Status Epilepticus (NORSE) lead to an extension of the etiological assessment in the search for encephalitis of autoimmune or infectious origin in adults and in children, as well as a genetic pathology in children in particular. This is an overview of current knowledge of SE etiologies and a pragmatic approach for carrying out an etiological assessment based on the following steps: - Which etiological orientation is identified according to the field and clinical presentation?; - Which etiologies to look for in an inaugural SE?; - Which first-line assessment should be carried out? The place of the biological, EEG and imaging assessment is discussed; - Which etiologies to look for in case of refractory SE?

Time Is Brain: The Use of EEG Electrode Caps to Rapidly Diagnose Nonconvulsive Status Epilepticus

OBJECTIVE

To perform a feasibility pilot study comparing the usefulness of EEG electrode cap versus standard scalp EEG for acquiring emergent EEGs in emergency department, inpatient, and intensive care unit patients.

BACKGROUND

Nonconvulsive status epilepticus (NCSE) is a neurological emergency diagnosed exclusively by EEG. Nonconvulsive status epilepticus becomes more resistant to treatment 1 hour after continued seizure activity. EEG technologists are alerted "stat" when there is immediate need for an EEG during oncall hours, yet delays are inevitable. Alternatively, EEG caps can be quickly placed by in-house residents at bedside for assessment.

DESIGN/METHODS

EEG caps were compared with standard-of-care "stat" EEGs for 20 patients with suspected NCSE. After the order for a stat EEG was placed, neurology residents were simultaneously alerted and placed an EEG cap prior to the arrival of the on-call out-of-hospital technologist. Both EEG cap recordings and standard EEG recordings were visually reviewed at 10 and 20 minutes in a blinded manner by two electroencephalographers. The timing, accuracy of interpretation, and diagnosis between the two techniques were then compared.

RESULTS

Of the 20 adult patients, 70% (14 of 20) of EEG cap recordings were interpretable, whereas 95% (19 of 20) standard EEGs were interpretable; three had findings consistent with NCSE on both the EEG cap and standard EEG recordings. In the time analysis, 16 patients were included. EEG cap placement was significantly more time efficient than an EEG performed by technologist using the usual "stat" EEG protocol, with the median EEG cap electrode placement occurring 86 minutes faster than standard EEG (22.5 minutes vs. 104.5 minutes; P < 0.0001; n = 16).

CONCLUSIONS

New rapid EEG recording using improved EEG caps may allow for rapid diagnosis and clinical decision making in suspected NCSE.

Prevalence and clinical correlates of non-convulsive status epilepticus in elderly patients with acute confusional state: A systematic literature review

Non-convulsive status epilepticus (NCSE) is a potentially treatable condition that poses considerable diagnostic challenges. NCSE is thought to be more common in the elderly than in the general population, however additional diagnostic challenges complicate its recognition in older patients, because of the wide differential diagnosis with common underlying causes of acute confusional state in this age group. We set out to review the existing evidence on the clinical correlates of NCSE in the elderly population. A systematic literature review was conducted according to the methodological standards outlined in the PRISMA statement to assess the clinical correlates of NCSE in patients aged 60 or older. Our literature search identified 11 relevant studies, which confirmed that the incidence of NCSE increases with age, in particular with regard to focal forms with impairment of consciousness. Female gender, history of epilepsy (or a recently witnessed seizure with motor features), and abnormal ocular movements appeared to correlate with the diagnosis of NCSE in the elderly, prompting prioritization of electroencephalography tests for diagnostic confirmation. Epidemiological data in the elderly vary widely because of the heterogeneity of definitions and diagnostic criteria applied across different studies. Based on our findings, it is recommended to keep a low threshold for requesting electroencephalography tests to confirm the diagnosis of NCSE in elderly patients with acute confusional state, even in the presence of a presumed symptomatic cause.

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.

Pharmacotherapy for Refractory and Super-Refractory Status Epilepticus in Adults

Patients with prolonged seizures that do not respond to intravenous benzodiazepines and a second-line anticonvulsant suffer from refractory status epilepticus and those with seizures that do not respond to continuous intravenous anesthetic anticonvulsants suffer from super-refractory status epilepticus. Both conditions are associated with significant morbidity and mortality. A strict pharmacological treatment regimen is urgently required, but the level of evidence for the available drugs is very low. Refractory complex focal status epilepticus generally does not require anesthetics, but all intravenous non-anesthetizing anticonvulsants may be used. Most descriptive data are available for levetiracetam, phenytoin and valproate. Refractory generalized convulsive status epilepticus is a life-threatening emergency, and long-term clinical consequences are eminent. Administration of intravenous anesthetics is mandatory, and drugs acting at the inhibitory gamma-aminobutyric acid (GABA)_A receptor such as midazolam, propofol and thiopental/pentobarbital are recommended without preference for one of those. One in five patients with anesthetic treatment does not respond and has super-refractory status epilepticus. With sustained seizure activity, excitatory N-methyl-d-aspartate (NMDA) receptors are increasingly expressed post-synaptically. Ketamine is an antagonist at this receptor and may prove efficient in some patients at later stages. Neurosteroids such as allopregnanolone increase sensitivity at GABA_A receptors; a Phase 1/2 trial demonstrated safety and tolerability, but randomized controlled data failed to demonstrate efficacy. Adjunct ketogenic diet may contribute to termination of difficult-to-treat status epilepticus. Randomized controlled trials are needed to increase evidence for treatment of refractory and super-refractory status epilepticus, but there are multiple obstacles for realization. Hitherto, prospective multicenter registries for pharmacological treatment may help to improve our knowledge.

Non-convulsive status epilepticus associated with neuronal intranuclear inclusion disease: A case report and literature review

We report a case of neuronal intranuclear inclusion disease (NIID) confirmed by detection of intranuclear inclusions in a skin biopsy specimen. Brain magnetic resonance imaging showed mild cerebral atrophy and linear hyperintensities at the corticomedullary junction on diffusion-weighted images. This patient developed nonconvulsive status epilepticus with generalized periodic discharges on electroencephalography after recurrent symptoms of paroxysmal nausea and slowly progressive cognitive decline. There have been no previous reports of NIID with nonconvulsive status epilepticus to our knowledge. Since adult patients with NIID display a wide variety of clinical manifestations, skin biopsy should be considered in patients who have leukoencephalopathy of unknown origin.

Ketamine for Refractory Status Epilepticus: A Systematic Review

BACKGROUND

Ketamine is an emerging third-line medication for refractory status epilepticus, a medical and neurological emergency requiring prompt and appropriate treatment. Owing to its pharmacological properties, ketamine represents a practical alternative to conventional anaesthetics.

OBJECTIVE

The objective of this study was to assess the efficacy and safety of ketamine to treat refractory status epilepticus in paediatric and adult populations.

METHODS

We conducted a literature search using the PubMed database, Cochrane Database of Systematic Reviews and ClinicalTrials.gov website.

RESULTS

We found no results from randomised controlled trials. The literature included 27 case reports accounting for 30 individuals and 14 case series, six of which included children. Overall, 248 individuals (29 children) with a median age of 43.5 years (range 2 months to 67 years) were treated in 12 case series whose sample size ranged from 5 to 67 patients (median 11). Regardless of the status epilepticus type, ketamine was twice as effective if administered early, with an efficacy rate as high as 64% in refractory status epilepticus lasting 3 days and dropping to 32% when the mean refractory status epilepticus duration was 26.5 days. Ketamine doses were extremely heterogeneous and did not appear to be an independent prognostic factor. Endotracheal intubation, a negative prognostic factor for status epilepticus, was unnecessary in 12 individuals (10 children), seven of whom were treated with oral ketamine for non-convulsive status epilepticus.

CONCLUSIONS

Although ketamine has proven to be effective in treating refractory status epilepticus, available studies are hampered by methodological limitations that prevent any firm conclusion. Results from two ongoing studies (ClinicalTrials.gov identification number: NCT02431663 and NCT03115489) and further clinical trials will hopefully confirm the better efficacy and safety profile of ketamine compared with conventional anaesthetics as third-line therapy in refractory status epilepticus, both in paediatric and adult populations.

Multimodal Predictions of Super-Refractory Status Epilepticus and Outcome in Status Epilepticus Due to Acute Encephalitis

Objective: Status epilepticus (SE) is one of the most critical symptoms of encephalitis. Studies on early predictions of progression to super-refractory status epilepticus (SRSE) and poor outcome in SE due to acute encephalitis are scarce. We aimed to investigate the values of neuroimaging and continuous electroencephalogram (EEG) in the multimodal prediction. Methods: Consecutive patients with convulsive SE due to acute encephalitis were included in this study. Demographics, clinical features, neuro-imaging characteristics, medical interventions, and anti-epileptic treatment responses were collected. All the patients had EEG monitoring for at least 24 h. We determined the early predictors of SRSE and prognostic factors of 3-month outcome using multivariate logistic regression analyses. Results: From March 2008 to February 2018, 570 patients with acute encephalitis were admitted to neurological intensive care unit (N-ICU) of Xijing hospital. Among them, a total of 94 patients with SE were included in this study. The percentage of non-SRSE and SRSE were 76.6 and 23.4%. Cortical or hippocampal abnormality on neuroimaging (p = 0.002, OR 20.55, 95% CI 3.16-133.46) and END-IT score (p < 0.001, OR 4.07, 95% CI 1.91-8.67) were independent predictors of the progression to SRSE. At 3 months after N-ICU discharge, 56 (59.6%) patients attained good outcomes, and 38 (40.4%) patients had poor outcomes. The recurrence of clinical or EEG seizures within 2 h after the infusion rate of a single anesthetic drug >50% proposed maximal dose (p = 0.044, OR 4.52, 95% CI 1.04-19.68), tracheal intubation (p = 0.011, OR 4.99, 95% CI 1.37-11.69) and emergency resuscitation (p = 0.040, OR 9.80, 95% 1.11-86.47) predicted poor functional outcome. Interpretation: Initial neuro-imaging findings assist early identification of the progression to SRSE. Continuous EEG monitoring contributes to outcome prediction in SE due to acute encephalitis.

External validation of the epidemiology-based mortality score in status epilepticus in an American intensive care population

INTRODUCTION

Although overall mortality of status epilepticus is high, baseline patient characteristics and co-morbidities may be helpful to predict outcomes and shape treatment decisions. Two previously published scoring systems exist to predict outcomes: the Status Epilepticus Severity Score (STESS) and the Epidemiology-based Mortality Score in Status Epilepticus (EMSE). However, a comparison of the two scores has not previously been completed in an American intensive care unit. We hypothesize that both scores will adequately predict the primary outcome of in-hospital death, but that the EMSE may more accurately predict functional outcomes, and significantly impact treatment decisions for both clinicians and families.

METHODS

We performed a retrospective analysis of all cases of status epilepticus admitted to the Neuro-Critical Care Unit (NCCU) at the Ohio State University Wexner Medical Center from 6/1/2014 - 8/31/2015. We collected data on age, comorbidities, EEG findings, and seizure history. The primary outcome measured was in-hospital death; secondary outcomes included length of stay in the NCCU, placement of a tracheostomy and/or a percutaneous endoscopic gastrostomy upon discharge, and discharge location were used as surrogate markers for outcome severity. A sensitivity and specificity analysis was carried out, in addition to a student's t-test for a comparison of the two scores. ANOVA was completed to compare secondary outcomes RESULTS: Forty-six patients were admitted to the NCCU for management of status epilepticus during June 2014 and January 2016, thirteen of which experienced in-hospital death. The median age of the sample was 60, with approximately half of the sample (52.63%) having 3 or more comorbidities. The sensitivity of both EMSE and STESS were very high (100% and 90% respectively); however, the specificities were very low (28.6% and 42.9% respectively). A student's t-test between those who experienced in-hospital death and those who did not was only significant for EMSE at the p < 0.1 level (p = 0.055). Additionally, mean EMSE scores but not STESS scores, were significantly higher (p < 0.001) for those patients who were discharged to skilled nursing facilities or with hospice than compared to those who were discharged to home or to acute inpatient rehabilitation.

CONCLUSIONS

The EMSE and STESS may be useful to predict outcomes of status epilepticus in populations with few comorbid conditions, but are less helpful when patients have multiple medical problems. Secondly, while neither score may be specific enough to differentiate for the primary outcome of death, their utility may be helpful to predict secondary outcomes that strongly affect clinical decisions. Based on these results, we believe a prospective trial of EMSE and STESS should be carried out to obtain more information on their utility, especially in American patients who may have more relevant comorbidities than in other countries.

Prognostic scores in status epilepticus-a critical appraisal

Currently, there are 4 published scales evaluating status epilepticus (SE) prognosis: the Status Epilepticus Severity Score (STESS), the Epidemiology-based Mortality score in Status Epilepticus (EMSE), the modified STESS (mSTESS), and the Encephalitis Nonconvulsive Status Epilepticus Diazepam Resistence Imaging Tracheal Intubation (END-IT) score. The first prognostic score published for SE, the STESS, is a simple and practical scale that evaluates patient prognosis upon admission and is used widely to predict the outcome and stratify patients. Another scale, which was developed based on large epidemiologic studies, the EMSE, is more easily adapted to different regions around the world when assessing individual risk and stratifying patients in interventional studies. The mSTESS was created by adding the modified Rankin Scale (mRS) to the STESS, which decreases the ceiling effect and increases the mortality prediction capabilities of the STESS. The END-IT is the only prognostic scale assessing functional outcome and is comprehensively simple and satisfyingly accurate. Evaluating the limitations of each of these scales aids in the exploration and advancement of SE prognostic scales, thereby facilitating better clinical interventions and scientific research.