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In the case of suspicion of nonconvulsive status epilepticus (NCSE), reactivity on electroencephalograms (EEGs) can provide valuable diagnostic information. Reactivity refers to responses to auditory or somatosensory stimulation, with changes in amplitude and frequency of background activity. Because of self-perpetuating processes and the failure of self-terminating mechanisms, status epilepticus is unlikely to cease when patients spontaneously move, and it cannot typically be stopped by external stimulation (i.e., auditory and tactile stimuli). The defining EEG characteristic of absence status epilepticus is the presence of bilateral, synchronous, symmetric, rhythmic paroxysmal activity that shows little or no reactivity to sensory stimulation. On the other hand, in metabolic/toxic or multifactorial encephalopathies, triphasic waves (TWs) are influenced by the level of vigilance. TWs may be transiently abolished when patients increase their level of alertness from a drowsy/lethargic state to a state of wakefulness. This reactivity is only observed when patients can be aroused by a somatosensory or auditory stimulus. This reactivity tends to disappear with increasing severity of the disease and in comatose patients. In patients without preexisting developmental and epileptic encephalopathy, this pattern of stimulus-induced wakefulness with transient improvement of the EEG is a major criterion in determining that the EEG patterns are not ictal. This criterion of reactivity on EEGs, beyond the classical clinical/EEG criteria of NCSE (Salzburg criteria), should now be systematically added., (© 2024 The Authors. Epilepsia published by Wiley Periodicals LLC on behalf of International League Against Epilepsy.)

Electroencephalography (EEG) is a useful adjunct to clinical neurological examination, particularly as it may detect subtle or subclinical disturbance of cerebral function and it allows monitoring of cerebral activity over time. Continuous EEG combined with quantitative analysis and machine learning may help identify changes in real time, before the emergence of clinical signs and response to interventions. EEG is rarely pathognomonic in encephalopathy/encephalitis but when interpreted correctly and within the clinical context, certain phenotypes may indicate a specific pathophysiology (eg, lateralised periodic discharges in HSV-1, generalised periodic discharges in sporadic Creutzfeldt-Jakob disease, and extreme delta brushes in anti-n-methyl-D-aspartate receptor autoimmune encephalitis). EEG is included in some specialist guidelines for disease assessment, monitoring and prognostication (ie, hepatic, cancer immunotherapy, viral, prion, autoimmune encephalitis and hypoxic ischaemic encephalopathy). EEG is invaluable for confirming or excluding non-convulsive seizures or status epilepticus, particularly in critically ill patients, and in understanding new concepts such as epileptic encephalopathy and the ictal-interictal continuum., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Historically, periodic EEG patterns were described as any pattern with stereotyped paroxysmal complexes occurring at regular intervals, i.e., the period (T). T is the sum of the duration of the waveform (t1) and, eventually, the duration of the interval between two consecutive waves (t2). The American Clinical Neurophysiology Society introduced the concept of a clearly discernible inter-discharge interval between consecutive waveforms (i.e., t2). As this definition was not applied to what have previously been termed triphasic waves and in some cases of lateralized periodic discharges, we propose reconsideration of terminology that includes historical use of definitions. This will allow the development and usage of the concept for periodic EEG patterns as any runs of stereotyped paroxysmal waveforms separated by nearly identical intervals and prolonged repetitive complexes on the EEG. Prolonged expression means EEG is recorded for a sufficient period of time to prove that the pattern is repetitive, thus resulting in a monomorphic/monotonous pattern. More important than the inter-discharge interval (t2), periodic EEG patterns occur at time regular intervals (T). As a result, periodic EEG activity should be considered along a continuum and not the opposite of rhythmic EEG activity where no interval activity exists between consecutive waveforms., (© 2023. The Author(s).)

Objective: The Salzburg criteria for nonconvulsive status epilepticus (NCSE) and the American Clinical Neurophysiology Society (ACNS) Standardized Critical Care EEG Terminology 2021 include a diagnostic trial with intravenous (IV) antiseizure medications (ASMs) to assess electroencephalographic (EEG) and clinical response as a diagnostic criterion for definite NCSE and possible NCSE. However, how to perform this diagnostic test and assessing the EEG and clinical responses have not been operationally defined., Methods: We performed a Delphi process involving six experts to standardize the diagnostic administration of IV ASM and propose operational criteria for EEG and clinical response., Results: Either benzodiazepines (BZDs) or non-BZD ASMs can be used as first choice for a diagnostic IV ASM trial. However, non-BZDs should be considered in patients who already have impaired alertness or are at risk of respiratory depression. Levetiracetam, valproate, lacosamide, brivaracetam, or (if the only feasible drug) fosphenytoin or phenobarbital were deemed appropriate for a diagnostic IV trial. The starting dose should be approximately two thirds to three quarters of the full loading dose recommended for treatment of status epilepticus, with an additional smaller dose if needed. ASMs should be administered during EEG recording under supervision. A monitoring time of at least 15 min is recommended. If there is no response, a second trial with another non-BDZ or BDZs may be considered. A positive EEG response is defined as the resolution of the ictal-interictal continuum pattern for at least three times the longest previously observed spontaneous interval of resolution (if any), but minimum of one continuous minute. For a clinical response, physicians should use a standardized examination before and after IV ASM administration. We suggest a definite time-locked improvement in a focal deficit or at least one-step improvement on a new dedicated one-domain 10-level NCSE response scale., Significance: The proposed standardized approach of a diagnostic IV ASM trial further refines the ACNS and Salzburg diagnostic criteria for NCSE., (© 2023 The Authors. Epilepsia published by Wiley Periodicals LLC on behalf of International League Against Epilepsy.)

Aims: Seizures and status epilepticus (SE) are detected in almost a third of the comatose cardiac arrest survivors. As the literature is quite exhaustive regarding SE with motor symptoms in those patients, little is known about nonconvulsive SE (NCSE). Our aim was to compile the evidence from the literature of the frequency and outcome of NCSE in adult patients remaining in coma after resuscitation., Methods: The medical search PubMed was screened for most relevant articles reporting the emergence and outcome of NCSE in comatose post-resuscitated adult patients., Results: We identified 11 cohort studies (four prospective observational, seven retrospective) including 1092 patients with SE in 29-96% and NCSE reported in 1-20%. EEG evaluation started at a median of 9.5 h (range 7.5-14.8) after cardiac arrest, during sedation and targeted temperature management (TTM). Favorable outcome after NCSE occurred in 24.5%. We found no study reporting EEG to detect or exclude NCSE in patients remaining in coma prior to the initiation of TTM and without sedation withing the first hours after ROSC., Discussion: Studies on NCSE after ROSC are scarce and unsystematic, reporting favorable outcome in every fourth patient experiencing NCSE after ROSC. This suggests that NCSE is often overlooked and outcome after NCSE is not always poor. The low data quality does not allow firm conclusions regarding the effects of NCSE on outcome calling for further investigation. In the meantime, clinicians should avoid equating NCSE after ROSC with poor prognosis., (© 2022. The Author(s).)

Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Dr. Gelisse, Dr. Crespel, Dr. Thomas, Dr. Jallon, Dr. Genton report no conflicts of interest relevant to this article. Dr. Kaplan has consulted for Ceribell, testified in court on qEEG, and received honoraria from Wiley-Blackwell and Demos publications.

Summary: Triphasic waves are a fascinating and mysterious EEG feature. We now have to accept that, at times, epileptiform discharges may have a blunted "triphasic morphology," and that there may be great difficulty in distinguishing between these often similar forms. The aim of this review was to describe the evolution in our understanding of triphasic waves that has occurred regarding the pathophysiology of triphasic waves, their most frequent causes, and the diagnostic difficulties involved in interpretation and differentiation from nonconvulsive status epilepticus., Competing Interests: P. W. Kaplan has consulted with Ceribel, served on the boards of the ACNS and ABCN, and received royalties from Demos and Wiley-Blackwell. The remaining author has no funding or conflicts of interest to disclose., (Copyright © 2021 by the American Clinical Neurophysiology Society.)

Summary: The entity of triphasic waves (TWs) and TW encephalopathy has derived from the subjective art of EEG interpretation. Indeed, there are few if any guidelines regarding many different aspects of TWs. The authors seek to shed light on the nature and the diagnostic characteristics of various types of TWs, differentiating "typical" from "atypical" forms. The authors conclude that morphologies in the form of bursts of well-formed, smoothly contoured, negative-positive-negative, bilateral, symmetrical and synchronous, regular, reactive, periodic or rhythmic, 1.5 to 2.0 Hz, fronto-central, triphasic complexes with fronto-occipital lag meet the criteria for typical TWs and are highly suggestive of toxic-metabolic encephalopathies. These are most frequently hepatic, uremic, or sepsis-associated encephalopathies with multi-organ failure. In such cases, atypical TWs (frontopolar or parieto-occipital maximum, negative-positive or negative-positive-negative, asymmetric and asynchronous, unreactive, irregular, multifocal, continuous with spatiotemporal evolution, sharper and without fronto-occipital/occipito-frontal lag, or triphasic delta waves) are rarely seen. Atypical TWs are encountered in Angelman syndrome, toxic encephalopathies, hyperthyroidism/hypothyroidism, Hashimoto encephalopathy, nonconvulsive status epilepticus, dementia, sepsis-associated encephalopathy, cerebrovascular disorders, and certain boundary syndromes. Investigations describing TWs with uncommon etiologies revealed few with typical TWs, suggesting that the term "TWs" has been overused in the past. Triphasic waves arise from the interaction of multiple factors including toxic, metabolic, infectious, and structural disorders that affect circuits between thalamus and cortex. The patient's metabolic status, presence of potentially neurotoxic drugs, cerebral atrophy, white matter disease, dementia, or seizures help differentiate typical from typical TWs. Future studies will determine whether this dichotomy is heuristically and clinically helpful., Competing Interests: J. L. Fernández-Torre reports no conflicts of interest relevant to this article. P. W. Kaplan reports no conflicts of interest relevant to this article. He has consulted with Ceribel, served on the boards of the ACNS and ABCN and received royalties from Demos and Wiley-Blackwell. No funding was received. This article has not been presented anywhere., (Copyright © 2021 by the American Clinical Neurophysiology Society.)

There is an ongoing debate if Lateralized Periodic Discharges (LPDs) represent an interictal pattern reflecting non-specific but irritative brain injury, or conversely, is an ictal pattern. The challenge is: how to correctly manage these patients? Between this apparent dichotomous distinction, there is a pattern lying along the interictal-ictal continuum (IIC) that we may call "peri-ictal". Peri-ictal means that LPDs are temporally associated with epileptic seizures (although not necessarily in the same recording). Their recognition should lead to careful EEG monitoring and longer periods of video-EEG to detect seizure activity (clinical and/or subclinical seizures). In order to distinguish which kind of LPDs should be considered as representing interictal/irritative brain injury versus ictal/peri-ictal LPDs, a set of criteria, with both clinical/neuroimaging and EEG, is proposed. Among them, the dichotomy LPDs-proper versus LPDs-plus should be retained. Spiky or sharp LPDs followed by associated slow after-waves or periods of flattening giving rise to a triphasic morphology should be included in the definition of LPDs-plus. We propose defining a particular subtype of LPDs-plus that we call "LPDs-max". The LPDs-max pattern corresponds to an ictal pattern, and therefore, a focal non-convulsive status epilepticus, sometimes associated with subtle motor signs and epileptic seizures. LPDs-max include periodic polyspike-wave activity and/or focal burst-suppression-like patterns. LPDs-max have a posterior predominance over the temporo-parieto-occipital regions and are refractory to antiseizure drugs. Interpretations of EEGs in critically ill patients require a global clinical approach, not limited to the EEG patterns. The clinical context and results of neuroimaging play key roles., (Copyright © 2021 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Status epilepticus (SE) is the state of continuous or repetitive seizures, which can occur with or without convulsions. Evolving definitions of SE take into account the concept that neuronal injury may occur at different times in different types of SE.SE that does not respond to initial treatment may become refractory or even super-refractory. Nonconvulsive SE is increasingly recognized in comatose patients in critical care units, with the growing use of continuous electroencephalogram monitoring. SE is a neurologic emergency that carries a high risk of mortality and morbidity., Competing Interests: None declared., (Thieme. All rights reserved.)

Rapid identification of stroke mimics, such as seizures, is a critical part of the evaluation of patients presenting with acute focal neurological deficits. The primary role of CT perfusion is in identification of patients with acute ischemic stroke who may be candidates for reperfusion therapy, but also holds promise as a modality for identifying a seizure etiology. We review the literature on this topic and attempt to define characteristic CT perfusion findings at various points along the ictal-interictal (epileptic) continuum. We suggest an approach for using CT perfusion to differentiate stroke from seizure in patients with acute onset focal neurological deficits., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objectives: Low-voltage repetitive spikes are mainly described with invasive recordings and considered highly suggestive for focal cortical dysplasia (FCD). This EEG pattern has received less attention in routine scalp EEG., Methods: Prospective collection of EEGs with low-voltage (<50 µV) repetitive spikes (repetitive miniature spikes - RMS) between July 1982 and July 2017 at the EEG laboratory of the Medical University of Innsbruck. We analyzed patterns of RMS on routine scalp EEG recordings and examined the relationship to clinical and brain imaging data., Results: Overall, RMS were seen in 38 patients representing zero to four observations out of 5000 records per year. RMS occurred rhythmically in 14, periodically in 17 and irregularly in seven patients. The EEG pattern appeared with a frontal and central predominance. All but five patients had epilepsies; eleven patients had non-convulsive status epilepticus. Cerebral magnetic resonance imaging (cMRI) detected malformations of cortical development in eleven patients, including six patients with focal cortical dysplasias., Conclusions: RMS are rare EEG patterns indicating focal epilepsy. Their observation on routine scalp EEGs should prompt further clinic-radiologic investigation., Significance: RMS resemble a clearly recognizable pattern in routine EEG, which is highly associated with focal epilepsy. The term is descriptive and can be added to the red flags, which can be found on routine EEG indicating underlying structural brain pathology, often in form of focal cortical dysplasia., (Copyright © 2019 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Purpose: Continuous EEG (cEEG) monitoring is primarily used for diagnosing seizures and status epilepticus, and for prognostication after cardiorespiratory arrest. The purpose of this study was to investigate whether cEEG could predict survival and meaningful recovery., Methods: The authors reviewed inpatient cEEG reports obtained between January 2013 and November 2015 and recorded demographics, preadmission modified Rankin Scale, history of preexisting epilepsy, Glasgow Coma Scale for those admitted to the intensive care unit, and EEG data (posterior dominant rhythm, reactivity, epileptiform discharges, seizures, and status epilepticus). Associations between clinical outcomes (death vs. survival or clinically meaningful recovery [inpatient rehabilitation, home-based rehabilitation, or home] vs. other [death, skilled nursing facility]) and cEEG findings were assessed with logistic regression models. P < 0.05 was considered significant., Results: For 218 cEEG reports (197 intensive care unit admits), the presence of at least a unilateral posterior dominant rhythm was associated with survival (odds ratio for death, 0.38; 95% confidence interval, 0.19-0.77; P = 0.01) and with a clinically meaningful outcome (odds ratio, 3.26; 95% confidence interval, 1.79-5.93; P < 0.001); posterior dominant rhythm remained significant after adjusting for preadmission disability. Those with preexisting epilepsy had better odds of a meaningful recovery (odds ratio, 3.31; 95% CI, 1.34-8.17; P = 0.001). Treated seizures and status epilepticus were not associated with a worse mortality (P = 0.6) or disposition (P = 0.6). High Glasgow Coma Scale (≥12) at intensive care unit admission was associated with a clinically meaningful recovery (odds ratio, 16.40; 95% confidence interval, 1.58-170.19; P = 0.02)., Conclusions: Continuous EEG findings can be used to prognosticate survival and functional recovery, and provide guidance in establishing goals of care.

Objectives: Recommendations regarding nutrition during status epilepticus are lacking, and it is unclear whether restriction of calorie intake would result in beneficial effects or potential harm. We thus aimed to investigate associations between daily calorie intake and outcome in adult status epilepticus patients deriving from a 5-year cohort with a systematic and prospective collection of nutritional data., Design: Retrospective observational study., Setting: Medical ICUs at a tertiary academic medical care center., Patients: Consecutive patients with status epilepticus treated at the ICUs from 2012 to 2016 were included., Interventions: None., Measurements and Main Results: All patients with status epilepticus were monitored regarding nutrition support provided according to the guidelines. Relative risks of no return to baseline were estimated by Poisson regression with robust error variance and adjusted for potential confounders. Of 203 patients, 86 (42%) had return to baseline. Metabolic characteristics of patients with and without return to baseline did not differ. Patients without return to baseline received more calories and proteins per status epilepticus day, and increasing nutritional support was associated with ventilator-associated pneumonia (relative risk, 1.19; 95% CI, 1.09-1.28). Multivariable regression analysis revealed significant increases in relative risks for no return to baseline with every percent of days with nutrition (relative risk, 1.35; 95% CI, 1.05-1.74), with every 100 kcal (relative risk, 1.01; 95% CI, 1.002-1.01), and gram of protein intake (relative risk, 1.01; 95% CI, 1.001-1.01) per status epilepticus day, independent of potential confounders (including fatal etiology, duration and severity of status epilepticus, Charlson comorbidity index, and treatment with anesthetics)., Conclusions: Our results indicate that increased calorie intake during status epilepticus is independently associated with unfavorable outcome. These findings require further validation and investigations into potential mediators, such as induction of ketogenesis, immunomodulating effects, and/or reduction of ICU-associated complications, such as infections.

Objective: To uncover clinical characteristics leading to false outcome prediction of the Status Epilepticus Severity Score (STESS), a validated and broadly used clinical scoring system for outcome prediction in status epilepticus (SE)., Methods: From 2005 to 2016, adult patients with SE treated at the University Hospital Basel, Switzerland, were included. To assess independent associations of variables differing between patients with false and correct prediction of death (STESS ≥ 3), multivariable logistic regression models were computed using automated selection., Results: Among 467 patients, 12% died. The median STESS was 3 (interquartile range 2-4). Regarding prediction of death, the STESS was false-positive in 51% and false-negative in 1%. Patients surviving despite having a STESS ≥3 had less fatal etiologies, less nonconvulsive SE with coma, and lower Charlson Comorbidity Index, Simplified Acute Physiology Score II, and Acute Physiology and Chronic Health Evaluation II scores. In multivariable analyses, odds for survival were high with SE types other than nonconvulsive status with coma and low with an increasing Charlson Comorbidity Index in patients with a STESS ≥ 3 (odds ratio [OR] for survival 4.23, 95% confidence interval [CI] 2.33-9.60; and OR for survival 0.86, 95% CI 0.75-0.98). In patients with SE types other than nonconvulsive with coma, the STESS was mainly increased because they were frequently older than 65 years and had no seizure history., Conclusions: The STESS frequently and inadequately predicts death especially in patients with SE other than nonconvulsive with coma and few comorbidities. Clinicians are urged to interpret a STESS ≥3 with caution in such patients., (© 2019 American Academy of Neurology.)

Objective: To characterize a critically ill cohort with status epilepticus (SE) by the illness severity scoring systems SAPS II (Simplified Acute Physiology Score II), APACHE II (Acute Physiology and Chronic Health Evaluation II), and SOFA (Sequential Organ Failure Assessment), and to compare their performance with the STESS (Status Epilepticus Severity Score) for outcome prediction., Methods: The prospective cohort study was carried out at the University Hospital Basel, a Swiss tertiary academic medical care center. Consecutive adult SE patients hospitalized in the intensive care units from 2011 to 2016 were included. Illness severity scores and additional clinical data were recorded. Logistic regression models using automated variable selection were applied to identify scores associated with no return to functional and neurological baseline and death. Measures of discrimination and calibration were assessed., Results: Among 184 patients, 33% returned to baseline. Median scores of the illness severity scores were within the lowest third of the possible scoring ranges, and all differed significantly between patients with and without return to baseline. The areas under the receiver operating curves for the prediction of no return to baseline and death ranged from 0.64 to 0.73, with the highest value for the STESS predicting no return to baseline. Measures of calibration revealed adequate model fit for all analyses. Among integral components of the scoring systems, only the Glasgow Coma Scale (GCS) differed significantly between patients with and without return to baseline. In multivariable analyses, decreasing GCS and increasing STESS had the strongest associations (odds ratio [OR] = 0.84, 95% confidence interval [CI] = 0.77-0.93 and OR = 1.34, 95% CI = 1.05-1.68, respectively) with no return to baseline independent of all other scoring systems, whereas the APACHE II revealed the strongest association with death (OR = 1.15, 95% CI = 1.06-1.25)., Significance: Although complex illness severity scoring systems in SE patients facilitate benchmarking and comparisons with other severely ill patient cohorts, they offer no advantages over the STESS and GCS regarding prediction of no return to baseline., (Wiley Periodicals, Inc. © 2018 International League Against Epilepsy.)

Objectives: Early identification of patients who are at risk of prolonged status epilepticus (SE) and patients with high chances of full recovery despite prolonged SE may urge clinicians to intensify treatment rather than to withdraw care. We aimed to develop prediction models based on readily available clinical parameters to predict prolonged SE at seizure onset and to identify patients with high chances for full recovery., Methods: From 2005 to 2016, all adult SE patients treated at the University Hospital Basel, a Swiss medical care center, were included. Multivariable Poisson regression was performed to identify predictors of prolonged SE (defined as SE for >12, >24, and >48 hours) and return to baseline from prolonged SE. The area under the receiver-operating characteristic curves (AUROC) for prediction models was calculated., Results: Of 467 patients, the median age was 66.7 years and mortality was 12%. Relative risk (RR) for death was 1.06 (P < 0.0001) with every SE day. In multivariable analysis, nonconvulsive SE with coma, SE severity score ≥3, and acute brain lesions at SE onset independently predicted prolonged SE with an AUROC of 0.68 for >12, 0.67 for >24, and 0.72 for >48 hours of SE. Absence of nonconvulsive SE with coma and a decreasing Charlson comorbidity index were independent predictors for return to baseline in prolonged SE with an AUROC of 0.82 and 0.76 following cross-validation. Both associations remained significant despite adjustments for determinants of adverse outcome, such as anesthetics and vasopressors (nonconvulsive SE with coma RR = 0.24, 95% confidence interval [CI] 0.07-0.86; comorbidity index RR = 0.87, 95% CI 0.76-0.99)., Significance: Although our data indicate that identification of prolonged SE at seizure onset is unreliable, timely recognition of patients with high chances of good outcome despite prolonged SE is promising on the basis of comorbidities, type of SE, and level of consciousness. Further external validation of this prediction model is needed., (Wiley Periodicals, Inc. © 2018 International League Against Epilepsy.)

Purpose: To acquaint readers with the underrecognized subacute encephalopathy with seizures in chronic alcoholics (SESA) that has more recently been associated with different types of status epilepticus., Methods: Case reports and review of the literature on SESA and nonconvulsive status epilepticus (NCSE)., Results: Two cases: one with alternating bifrontoparietal NCSE, and one with focal, confusional NCSE, with imaging and EEG correlates., Conclusion: Underrecognized SESA may present as NCSE with focal clinical, EEG and reversible diffusion-weighted MRI abnormalities, warranting expedited diagnosis and antiseizure treatment to minimize morbidity.

Objectives: Status epilepticus is a neurologic emergency with high morbidity and mortality requiring neurointensive care and treatment of systemic complications. This systematic review compiles the current literature on acute systemic complications of generalized convulsive status epilepticus in adults and their immediate clinical impact along with recommendations for optimal neurointensive care., Data Sources: We searched PubMed, Medline, Embase, and the Cochrane library for articles published between 1960 and 2016 and reporting on systemic complications of convulsive status epilepticus., Study Selection: All identified studies were screened for eligibility by two independent reviewers., Data Extraction: Key data were extracted using standardized data collection forms., Data Synthesis: Thirty-two of 3,046 screened articles were included. Acute manifestations and complications reported in association with generalized convulsive status epilepticus can affect all organ systems fueling complex cascades and multiple organ interactions. Most reported complications result from generalized excessive muscle contractions that increase body temperature and serum potassium levels and may interfere with proper and coordinated function of respiratory muscles followed by hypoxia and respiratory acidosis. Increased plasma catecholamines can cause a decay of skeletal muscle cells and cardiac function, including stress cardiomyopathy. Systemic complications are often underestimated or misinterpreted as they may mimic underlying causes of generalized convulsive status epilepticus or treatment-related adverse events., Conclusions: Management of generalized convulsive status epilepticus should center on the administration of antiseizure drugs, treatment of the underlying causes, and the attendant systemic consequences to prevent secondary seizure-related injuries. Heightened awareness, systematic clinical assessment, and diagnostic workup and management based on the proposed algorithm are advocated as they are keys to optimal outcome.

Introduction: Non-convulsive status epilepticus (NCSE) is a complex and diverse condition which is often an under-recognised entity in the intensive care unit. When NCSE is identified the optimal treatment strategy is not always clear. Areas covered: This review is based on a literature review of the key literature in the field over the last 5-10 years. The articles were selected based on their importance to the field by the authors. Expert commentary: This review discusses the complex situations when a neurological consultation may occur in a critical care setting and provides an update on the latest evidence regarding the recognition of NCSE and the decision making around determining the aggressiveness of treatment. It also considers the ictal-interictal continuum of conditions which may be met with, particularly in the era of continuous EEG, and provides an approach for dealing with these. Suggestions for how the field will develop are discussed.

Objective: To investigate the feasibility, safety, and efficacy of a ketogenic diet (KD) for superrefractory status epilepticus (SRSE) in adults., Methods: We performed a prospective multicenter study of patients 18 to 80 years of age with SRSE treated with a KD treatment algorithm. The primary outcome measure was significant urine and serum ketone body production as a biomarker of feasibility. Secondary measures included resolution of SRSE, disposition at discharge, KD-related side effects, and long-term outcomes., Results: Twenty-four adults were screened for participation at 5 medical centers, and 15 were enrolled and treated with a classic KD via gastrostomy tube for SRSE. Median age was 47 years (interquartile range [IQR] 30 years), and 5 (33%) were male. Median number of antiseizure drugs used before KD was 8 (IQR 7), and median duration of SRSE before KD initiation was 10 days (IQR 7 days). KD treatment delays resulted from intravenous propofol use, ileus, and initial care received at a nonparticipating center. All patients achieved ketosis in a median of 2 days (IQR 1 day) on KD. Fourteen patients completed KD treatment, and SRSE resolved in 11 (79%; 73% of all patients enrolled). Side effects included metabolic acidosis, hyperlipidemia, constipation, hypoglycemia, hyponatremia, and weight loss. Five patients (33%) ultimately died., Conclusions: KD is feasible in adults with SRSE and may be safe and effective. Comparative safety and efficacy must be established with randomized placebo-controlled trials., Classification of Evidence: This study provides Class IV evidence that in adults with SRSE, a KD is effective in inducing ketosis., (© 2017 American Academy of Neurology.)

Background: The use of anesthetics has been linked to poor outcome in patients with status epilepticus (SE). This association, however, may be confounded, as anesthetics are mostly administered in patients with more severe SE and critical illnesses., Objective: To minimize treatment-selection bias, we assessed the association between continuously administered intravenous anesthetic drugs (IVADs) and outcome in SE patients by a matched two-center study design., Methods: This cohort study was performed at the Johns Hopkins Bayview Medical Center, Baltimore, MD, USA and the University Hospital Basel, Basel, Switzerland. All consecutive adult SE patients from 2005 to 2013 were included. Odds ratios (ORs) for death and unfavorable outcome (Glasgow Outcome Score [GOS] 1-3) associated with administration of IVADs were calculated. To account for confounding by known outcome determinants (age, level of consciousness, worst seizure type, acute/fatal etiology, mechanical ventilation, and SE duration), propensity score matching and coarsened exact matching were performed in addition to multivariable regression models., Results: Among 406 consecutive patients, 139 (34.2%) were treated with IVADs. Logistic regression analyses of the unmatched and matched cohorts revealed increased odds for death and unfavorable outcome in survivors who had received IVADs (unmatched: OR death  = 3.13, 95% confidence interval [CI] 1.47-6.60 and OR GOS1-3  = 2.51, 95% CI 1.37-4.60; propensity score matched: OR death  = 3.29, 95% CI 1.35-8.05 and OR GOS1-3  = 2.27, 95% CI 1.02-5.06; coarsened exact matched: OR death  = 2.19, 95% CI 1.27-3.78 and OR GOS1-3  = 3.94, 95% CI 2.12-7.32)., Conclusion: The use of IVADs in SE is associated with death and unfavorable outcome in survivors independent of known confounders and using different statistical approaches. Randomized trials are needed to determine if these associations are biased by outcome predictors not yet identified and hence not accounted for in this study.

Subclinical rhythmic electrographic discharges in adults (SREDA) is a well-known benign EEG phenomenon. However, the occurrence of SREDA is rare, and atypical forms are even more elusive, with only few cases reported in the literature. Herein, we describe a case of a 77-year-old woman with a left middle cerebral artery stroke and paroxysms of rhythmic, sharply contoured activity over the right central head region, mimicking focal seizures on EEG, that were determined to represent atypical SREDA. To our knowledge, no case of SREDA with a contralateral structural cerebral abnormality has been described, and its occurrence offers some limited insight as to the mechanisms underlying this mysterious entity., (© EEG and Clinical Neuroscience Society (ECNS) 2016.)

Nonconvulsive status epilepticus (NCSE) is a state of continuous or repetitive seizures without convulsions. Owing to the nonspecific symptoms and considerable morbidity and mortality associated with NCSE, clinical research has focused on early diagnosis, risk stratification and seizure termination. The subtle symptoms and the necessity for electroencephalographic confirmation of seizures result in under-diagnosis with deleterious consequences. The introduction of continuous EEG to clinical practice, and the characterization of electrographic criteria have delineated a number of NCSE types that are associated with different prognoses in several clinical settings. Epidemiological studies have uncovered risk factors for NCSE; knowledge of these factors, together with particular clinical characteristics and EEG observations, enables tailored treatment. Despite these advances, NCSE can be refractory to antiepileptic drugs, necessitating further escalation of treatment. The presumptive escalation to anaesthetics, however, has recently been questioned owing to an association with increased mortality. This Review compiles epidemiological, clinical and diagnostic aspects of NCSE, and considers current treatment options and prognosis.

Objectives: The aims of this study were to determine the etiology, clinical features, and predictors of outcome of new-onset refractory status epilepticus., Methods: Retrospective review of patients with refractory status epilepticus without etiology identified within 48 hours of admission between January 1, 2008, and December 31, 2013, in 13 academic medical centers. The primary outcome measure was poor functional outcome at discharge (defined as a score >3 on the modified Rankin Scale)., Results: Of 130 cases, 67 (52%) remained cryptogenic. The most common identified etiologies were autoimmune (19%) and paraneoplastic (18%) encephalitis. Full data were available in 125 cases (62 cryptogenic). Poor outcome occurred in 77 of 125 cases (62%), and 28 (22%) died. Predictors of poor outcome included duration of status epilepticus, use of anesthetics, and medical complications. Among the 63 patients with available follow-up data (median 9 months), functional status improved in 36 (57%); 79% had good or fair outcome at last follow-up, but epilepsy developed in 37% with most survivors (92%) remaining on antiseizure medications. Immune therapies were used less frequently in cryptogenic cases, despite a comparable prevalence of inflammatory CSF changes., Conclusions: Autoimmune encephalitis is the most commonly identified cause of new-onset refractory status epilepticus, but half remain cryptogenic. Outcome at discharge is poor but improves during follow-up. Epilepsy develops in most cases. The role of anesthetics and immune therapies warrants further investigation., (© 2015 American Academy of Neurology.)

Status epilepticus refractory to first-line and second-line antiepileptic treatments challenges neurologists and intensivists as mortality increases with treatment refractoriness and seizure duration. International guidelines advocate anesthetic drugs, such as continuously administered high-dose midazolam, propofol, and barbiturates, for the induction of therapeutic coma in patients with treatment-refractory status epilepticus. The seizure-suppressing effect of anesthetic drugs is believed to be so strong that some experts recommend using them after benzodiazepines have failed. Although the rationale for the use of anesthetic drugs in patients with treatment-refractory status epilepticus seems clear, the recommendation of their use in treating status epilepticus is based on expert opinions rather than on strong evidence. Randomized trials in this context are lacking, and recent studies provide disturbing results, as the administration of anesthetics was associated with poor outcome independent of possible confounders. This calls for caution in the straightforward use of anesthetics in treating status epilepticus. However, there are still more questions than answers, and current evidence for the adverse effects of anesthetic drugs in patients with status epilepticus remains too limited to advocate a change of treatment algorithms. In this overview, the rationale and the conflicting clinical implications of anesthetic drugs in patients with treatment-refractory status epilepticus are discussed, and remaining questions are elaborated. This article is part of a Special Issue entitled "Status Epilepticus"., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Nonconvulsive status epilepticus (NCSE) in adults represents a constellation of conditions producing ongoing ictal impairment with myriad clinical presentations. These may vary from minimal obtundation, to psychosis to coma for which electroencephalography is essential to diagnosis. Treatment is highly variable and is tailored to the level of consciousness, probable outcome and underlying etiology. There is a new and emerging understanding of the nature of NCSE, its classification and the challenges in treatment. The aim of this article is to review the classic and most recent literature on NCSE in adults focusing attention on the clinical settings in which NCSE frequently occurs, in order to improve awareness of the issues involved in electroclinical diagnosis, treatment and prognostication.

Purpose: The aim of this paper is to describe two additional cases of subacute encephalopathy with seizures in alcoholics (SESA syndrome), and to propose that this entity now should be considered as a subtype of nonconvulsive status epilepticus (NCSE)., Methods: We retrospectively analyzed the clinical characteristics, electroencephalography (EEG), neuroimaging data, and prognosis of these two further cases of SESA syndrome. In addition, we compare our findings with the cases previously described in the English literature in order to propose new diagnostic criteria., Results: Two adults with history of chronic alcohol abuse were admitted because of confusion and seizures. A routine EEG showed frequent periodic lateralized epileptiform discharges (PLEDs) localized over the right temporal regions. In one case, we captured two complex partial seizures (CPSs) arising from the right hemisphere. Neuroimaging studies revealed subjacent chronic vascular pathology. Following transfer to the intensive care unit (ICU), both improved to antiepileptic treatment and were discharged with full recovery., Conclusion: On the basis of our findings and a review of the literature, we suggest that SESA syndrome represents a subtype of partial or localization-related NCSE given its particular clinical, electroencephalographic, neuroimaging and prognostic characteristics., (Copyright © 2014 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.)

Objective: To evaluate the risks of continuously administered IV anesthetic drugs (IVADs) on the outcome of adult patients with status epilepticus (SE)., Methods: All intensive care unit patients with SE from 2005 to 2011 at a tertiary academic medical care center were included. Relative risks were calculated for the primary outcome measures of seizure control, Glasgow Outcome Scale score at discharge, and death. Poisson regression models were used to control for possible confounders and to assess effect modification., Results: Of 171 patients, 37% were treated with IVADs. Mortality was 18%. Patients with anesthetic drugs had more infections during SE (43% vs 11%; p < 0.0001) and a 2.9-fold relative risk for death (2.88; 95% confidence interval 1.45-5.73), independent of possible confounders (i.e., duration and severity of SE, nonanesthetic third-line antiepileptic drugs, and critical medical conditions) and without significant effect modification by different grades of SE severity and etiologies. As IVADs were used after first- and second-line drugs failed, there was a correlation between treatment-refractory SE and the use of IVADs, leading to insignificant results regarding the risk of IVADs and outcome after additional adjustment for refractory SE., Conclusion: Our findings heighten awareness regarding adverse effects of IVADs. Randomized controlled trials are needed to further clarify the association of IVADs with outcome in patients with SE., Classification of Evidence: This study provides Class III evidence that patients with SE receiving IVADs have a higher proportion of infection and an increased risk of death as compared to patients not receiving IVADs.

Objective: To describe a case series of adult patients in the intensive care unit in super-refractory status epilepticus (SRSE; refractory status lasting 24 hours or more despite appropriate anesthetic treatment) who received treatment with the ketogenic diet (KD)., Methods: We performed a retrospective case review at 4 medical centers of adult patients with SRSE treated with the KD. Data collected included demographic features, clinical presentation, diagnosis, EEG data, anticonvulsant treatment, and timing and duration of the KD. Primary outcome measures were resolution of status epilepticus (SE) after initiation of KD and ability to wean from anesthetic agents., Results: Ten adult patients at 4 medical centers were started on the KD for SRSE. The median age was 33 years (interquartile range [IQR] 21), 4 patients (40%) were male, and 7 (70%) had encephalitis. The median duration of SE before initiation of KD was 21.5 days (IQR 28) and the median number of antiepileptic medications used before initiation of KD was 7 (IQR 7). Ninety percent of patients achieved ketosis, and SE ceased in all patients achieving ketosis in a median of 3 days (IQR 8). Three patients had minor complications of the KD including transient acidosis and hypertriglyceridemia and 2 patients ultimately died of causes unrelated to the KD., Conclusion: We describe treatment of critically ill adult patients with SRSE with the KD, with 90% of patients achieving resolution of SE. Prospective trials are warranted to examine the efficacy of the KD in adults with refractory SE., Classification of Evidence: This study provides Class IV evidence that for intensive care unit patients with refractory SE, a KD leads to resolution of the SE.

Objectives: A clinical scoring system for patients with status epilepticus was developed for predicting outcome, planning the level of monitoring needed, and guiding treatment. The aim was to confirm the external validity and transportability of the Status Epilepticus Severity Score prediction functions for outcome in adult patients with status epilepticus., Design: Observational cohort study., Setting: Tertiary academic medical care center., Patients: Consecutive adult ICU patients with status epilepticus., Interventions: None., Measurements and Main Results: History of seizures, age, seizure type, and level of consciousness were determined at status epilepticus onset, in order to calculate the Status Epilepticus Severity Score. The main outcome measure was the ability to accurately predict the outcome of status epilepticus by measures of discrimination and calibration. Among 171 status epilepticus patients with a mean age of 64.1 years (± 16.3), mortality was 18%. The receiver operating characteristic curve for prediction of death by the Status Epilepticus Severity Score had an area under the curve of 0.744 with an optimal cutoff point greater than or equal to 4. Hosmer-Lemeshow statistics revealed good calibration of the Status Epilepticus Severity Score (chi-square goodness-of-fit test = 1.39; p = 0.845)., Conclusions: This study is the first independent external validation of the predictive accuracy of the Status Epilepticus Severity Score and its transportability to ICU patients with status epilepticus. Measures of discrimination and calibration indicated that Status Epilepticus Severity Score performed reasonably well on our cohort of ICU patients with status epilepticus. However, the specific optimal cutoff point for survival versus death in our cohort was different than proposed.

The diagnosis of nonconvulsive status epilepticus (NCSE) relies largely on electroencephalography (EEG) findings. The lack of a unified EEG terminology, and of evidence-based EEG criteria, leads to varying criteria for and ability to diagnose NCSE. We propose a unified terminology and classification system for NCSE, using, as a template, the Standardised Computer-based Organised Reporting of EEG (SCORE). This approach integrates the terminology recently proposed for the rhythmic and periodic patterns in critically ill patients, the electroclinical classification of NCSE (type of NCSE) and the context for the pathologic conditions and age-related epilepsy syndromes. We propose flexible EEG criteria that employ the SCORE system to assemble a database for determining evidence-based EEG criteria for NCSE., (Wiley Periodicals, Inc. © 2013 International League Against Epilepsy.)

Proceeding from the proposed classification of status epilepticus syndromes by Shorvon in 1994, we performed a systematic search for reports presenting electroencephalography (EEG) patterns of nonconvulsive status epilepticus (NCSE) on all syndromes in the classification, where possible. Using the online medical search engine PubMed for 22 different search strategies, EEG patterns supporting a diagnosis of NCSE were sought. From a total of 4,328 search results, 123 cases with corresponding EEG patterns could be allocated to underlying epilepsy syndromes. Based on the characteristic EEG patterns found for the different NCSE syndromes, we present a synthesis of the significant EEG morphologies and evolutions in the individual NCSE syndromes., (Wiley Periodicals, Inc. © 2013 International League Against Epilepsy.)

Objective: To address the question: does non-convulsive status epilepticus warrant the same aggressive treatment as convulsive status epilepticus?, Methods: We used a decision model to evaluate the risks and benefits of treating non-convulsive status epilepticus with intravenous anesthetics and ICU-level aggressive care. We investigated how the decision to use aggressive versus non-aggressive management for non-convulsive status epilepticus impacts expected patient outcome for four etiologies: absence epilepsy, discontinued antiepileptic drugs, intraparenchymal hemorrhage, and hypoxic ischemic encephalopathy. Each etiology was defined by distinct values for five key parameters: baseline mortality rate of the inciting etiology; efficacy of non-aggressive treatment in gaining control of seizures; the relative contribution of seizures to overall mortality; the degree of excess disability expected in the case of delayed seizure control; and the mortality risk of aggressive treatment., Results: Non-aggressive treatment was favored for etiologies with low morbidity and mortality such as absence epilepsy and discontinued antiepileptic drugs. The risk of aggressive treatment was only warranted in etiologies where there was significant risk of seizure-induced neurologic damage. In the case of post-anoxic status epilepticus, expected outcomes were poor regardless of the treatment chosen. The favored strategy in each case was determined by strong interactions of all five model parameters., Conclusions: Determination of the optimal management approach to non-convulsive status epilepticus is complex and is ultimately determined by the inciting etiology.

Genetic epilepsies with generalized spike-wave complexes (GSWCs) and encephalopathy triphasic waves (TWs) may resemble each other and have three phases per complex. Electroencephalographic (EEG) interpretation is subjective, and EEGers have noted "TWs" in cases labeled nonconvulsive status epilepticus (NCSE). Direct comparison of both wave forms under the same conditions is rarely possible. In a single patient with generalized spike waves who developed hepatic TWs, morphologic characteristics of both were compared, and it was found that GSWCs have higher frequency first, second, and third phases; steeper phase 2 slope; and briefer after-going slow waves maximal at F3 to F4. Total complex duration was approximately 0.12 seconds. The TWs had dominant high-voltage phases 2 and 3 located more posteriorly, in the frontocentral region, lasting an average of approximately 0.32 seconds. These morphologic distinctions may help differentiate TWs from GSWCs.

There have been many attempts at defining the electroencephalography (EEG) characteristics of nonconvulsive status epilepticus (NCSE) without a universally accepted definition. This lack of consensus arises because the EEG expression of NCSE does not exist in isolation, but reflects status epilepticus under the variety of pathologic conditions that occur with age, cerebral development, encephalopathy, and epilepsy syndrome. Current NCSE definitions include "boundary conditions," in which electroencephalographic seizure activity occurs without apparent clinical seizures. Furthermore, what appears to one interpreter as status epilepticus, is not to another reader, reflecting the "art" of EEG interpretation. Seizures and epilepsy syndromes have undergone an evolution that has moved beyond a classification of focal or generalized conditions into a syndromic approach. It seems appropriate to make similar changes in the EEG analysis of the syndromes of NCSE. In effect, the literature on epilepsy classification has progressed to incorporate the different NCSE types with clinical descriptions, but the specific EEG evidence for these types is found largely in individual reports, and often by description only. NCSE classification of EEG patterns should derive from the aggregate of published EEG patterns in the respective clinical subtype, supported by an analysis of these EEG studies. The analysis that follows presents clinical descriptions and EEG patterns of NCSE in the neonatal period, infancy, childhood, adulthood, and late adulthood from a syndromic perspective based on age, encephalopathy, cerebral development, etiology, and syndrome. Proceeding from the proposed classification of status epilepticus syndromes in "Status epilepticus: its clinical features and treatment in children and adults" (published in 1994 by Cambridge University Press, New York), we have performed a systematic search for reports presenting EEG patterns of NCSE using the online medical search engine PubMed for 22 different search strategies. EEG patterns were reviewed by two board-certified epileptologists who reached consensus regarding presence of NCSE. From a total of 4,328 search results, 123 cases with corresponding EEG patterns could be allocated to underlying epilepsy syndromes. Typical characteristic, prominent electrographic patterns, and sequential arrangements are elucidated for the different NCSE syndromes. This compendium of patterns by NCSE syndrome classification with illustration of EEGs, and delineation of electroencephalographic features helps define the characteristics and semiologic borderlines among the types of NCSE., (Wiley Periodicals, Inc. © 2012 International League Against Epilepsy.)

Limbic encephalitis (LE) with waxing and waning neuropsychiatric manifestations including behavioral, personality, psychiatric, and memory changes can evolve over days to months. Many features of LE show remarkable overlap with the characteristics of mesial-temporal (limbic) status epilepticus (MTLSE or LSE). With LE, these prolonged impaired states are assumed not to be due to ongoing epileptic activity or MTLSE, because scalp EEGs usually show no epileptiform spike-wave activity; cycling behavioral and motor changes are attributed to LE; there may be little immediate improvement with antiepileptic drugs (AEDs); and of course, implanted electrodes are rarely used. Conversely, it is known that in pre-surgical patients with refractory limbic epilepsy, implanted electrodes have revealed limbic seizures that cannot be seen at the scalp. This paper assembles a chain of inferences to advance the proposition that refractory LE might represent LSE more often than is thought, and that implanted electrodes should be considered in some cases. We present two cases that suggest that LE was also LSE, one of which warranted implanted electrodes (case 1)., (Copyright © 2011 Elsevier Inc. All rights reserved.)

We retrospectively analysed the clinical characteristics, electroencephalogram (EEG) records, brain magnetic resonance imaging (MRI) scans, antiepileptic therapy and prognosis of a case series with ambulatory non-convulsive status epilepticus (NCSE) which evolved into a malignant form (mNCSE). mNCSE was defined as NCSE that continues or recurs five days or more after the onset of general anaesthesia, including those cases where NCSE recurs upon reduction or withdrawal of anaesthetic therapy. Four women and two men were studied. The mean age was 42.8 years (range: 19-63 years). Two of six patients had a previous diagnosis of epilepsy. Four patients died. Two patients had a good outcome with return to consciousness and activities of daily life, and one of these subjects developed temporal lobe epilepsy. In four patients, the cause of mNCSE was encephalitis. Clinical presentation was complex partial status epilepticus (CPSE) in three patients and generalised NCSE (GNCSE) in the other three. Two of the latter had encephalitis and one was diagnosed with progressive myoclonus epilepsy (PME) of Lafora type. The mean duration of the NCSE episode was 47.5 days (range: 9-139 days; SD: 53.1). In three patients, continuous or rhythmic focal epileptiform discharges were the EEG pattern at onset. In the other three, continuous rhythmic generalised spike-wave, polyspike-wave or sharp slow-wave complexes were observed. Antiepileptic treatment was heterogeneous and patients were treated with an average of 6.0 AEDs (range: 3-10; SD: 3.0). In summary, mNCSE is a severe epileptic condition that occurs often in the context of encephalitis or pre-existing epilepsy. Both CPSE and GNCSE may occur. Although high mortality is associated with mNCSE, some patients may survive with normal or good recovery.

Stuttering is a repetitive, iterative disfluency of speech, and is usually seen as a developmental problem in childhood. Acquired causes in adults include strokes and medications. When stuttering occurs with seizure-like events, it is usually attributed to psychogenic nonepileptic seizures. We describe an elderly man who experienced personality change and bouts of stuttering, followed by anarthria with preserved writing and then aphasia affecting written and uttered language, and ending with confusion. EEG recordings showed nonconvulsive status epilepticus (NCSE) with focality in the left frontal region followed by bifrontal NCSE. This case enlarges our understanding of the behavioral correlates of focal frontal seizures to include simple partial seizures with speech and then language output disturbances (aphemia, then aphasia), progressing to complex partial phenomenology in the setting of frontal NCSE., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Electrodecremental status epilepticus is classically described in infants and children with severe refractory epilepsy, mental retardation, and structural brain abnormalities. We describe a 24-year-old woman who presented to the emergency department with prolonged tonic status epilepticus which evolved into stimulus-induced diffuse voltage attenuation (SIDVA) pattern in the setting of aseptic meningoencephalitis. There was no history of seizures or further events after recovery. This is the first report of a SIDVA pattern in an adult without a history of epilepsy.

Background: Postanoxic status epilepticus (PSE) is considered a predictor of fatal outcome and therefore not intensively treated; however, some patients have had favorable outcomes. The aim of this study was to identify favorable predictors for awakening beyond vegetative state in PSE., Methods: We studied six subjects treated with hypothermia improving beyond vegetative state after cerebral anoxia, despite PSE. They were among a cohort of patients treated for anoxic encephalopathy with therapeutic hypothermia in our institution between October 1999 and May 2006 (retrospectively, 3/107 patients) and June 2006 and May 2008 (prospectively, 3/74 patients). PSE was defined by clinical and EEG criteria. Outcome was assessed according to the Glasgow-Pittsburgh Cerebral Performance Categories (CPC)., Results: All improving patients had preserved brainstem reflexes, cortical somatosensory evoked potentials, and reactive EEG background during PSE. Half of them had myoclonic PSE, while three had nonconvulsive PSE. In the prospective arm, 3/28 patients with PSE showed this clinical-electrophysiologic profile; all awoke. Treatments consisted of benzodiazepines, various antiepileptic drugs, and propofol. One subject died of pneumonia in a minimally conscious state, one patient returned to baseline (CPC1), three had moderate impairment (CPC2), and one remained dependent (CPC3). Patients with nonconvulsive PSE showed a better prognosis than subjects with myoclonic PSE (p = 0.042)., Conclusion: Patients with postanoxic status epilepticus and preserved brainstem reactions, somatosensory evoked potentials, and EEG reactivity may have a favorable outcome if their condition is treated as status epilepticus.

Persistent seizures and failure to regain consciousness following witnessed seizure activity require emergency neurological consultation. Although outcome is largely dependent on underlying cause, early maximal anticonvulsant therapy is critical to reducing morbidity. This review covers important concepts in the clinical and EEG diagnosis of status epilepticus, and discusses treatment algorithms for single and recurrent seizures, emphasizing the need to rationalize therapy depending on the presumed duration of seizure activity. The review takes the perspective of the neurological consultant in the intensive care unit, and considers all pharmacological approaches available to the intensivist as described in the current literature and from clinical experience.

Lithium therapy can cause a confusional state by direct toxicity, precipitation of nonconvulsive status epilepticus, or by interplay with other neuroleptic medications to produce neuroleptic malignant syndrome or serotonin syndrome. These conditions resemble each other clinically, but EEG may help differentiate among them. We reviewed the EEG patterns with triphasic waves or rhythmic delta activity in lithium toxic patients and discuss clinical and EEG differentiation among syndromes. Lithium toxicity poses significant diagnostic challenges from EEG and clinical perspectives.