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Introduction. Autoimmune encephalitis (AE) is a clinically challenging diagnosis with nonspecific neurological symptoms. Prompt diagnosis is important and often relies on neuroimaging. We present a case series of AE highlighting the importance of an early [18F]-fluoro-deoxy-glucose positron emission tomography (FDG-PET) scan. Methods. Retrospective review of seven consecutive cases of autoimmune encephalitis. Results. All patients had both magnetic resonance imaging (MRI) and FDG-PET scans. Initial clinical presentations included altered mental status and/or new onset seizures. Six cases had serum voltage-gated potassium channel (VGKC) antibody and one had serum N-methyl-D-aspartate (NMDA) antibody. MRI of brain showed mesial temporal lobe hyperintensity in five cases of VGKC. The other two patients with VGKC or NMDA AE had restiform body hyperintensity on MRI brain or a normal MRI, respectively. Mesial temporal lobe hypermetabolism was noted in three cases on FDG-PET, despite initial unremarkable MRI. Malignancy workup was negative in all patients. Conclusion. A high index of suspicion for AE should be maintained in patients presenting with cognitive symptoms, seizures, and limbic changes on neuroimaging. In cases with normal initial brain MRI, FDG-PET can be positive. Additionally, extralimbic hyperintensity on MRI may also be observed. [ABSTRACT FROM AUTHOR]

Purpose: Acute symptomatic seizures (ASyS) after stroke contribute the highest risk to poststroke epilepsy (PSE) development. We investigated the use of outpatient EEG (oEEG) among stroke patients with ASyS concerns., Methods: Adults with acute stroke, ASyS concerns (underwent cEEG), and outpatient clinical follow-up were included (study population). Patients with oEEG (oEEG cohort) were analyzed for electrographic findings. Univariable and multivariable analyses helped identify predictors of oEEG use in routine clinical care., Results: Among 507 patients, 83 (16.4%) underwent oEEG. The independent predictors of oEEG utilization included age (OR = 1.03 [1.01 to 1.05, P = 0.01]), electrographic ASyS on cEEG (OR 3.9 [1.77 to 8.9], P < 0.001), ASMs at discharge (OR 3.6 [1.9 to 6.6], P < 0.001), PSE development (OR 6.6 [3.5 to 12.6], P < 0.001), and follow-up duration (OR = 1.01 [1.002 to 1.02], P = 0.016). Almost 40% of oEEG cohort developed PSE, but only 12% had epileptiform abnormalities. Close to a quarter (23%) of oEEGs were within normal limits., Conclusions: One in six patients with ASyS concern after stroke undergoes oEEG. Electrographic ASyS, PSE development, and ASM at discharge are primary drivers of oEEG use. While PSE drives oEEG use, we need systematic, prospective investigation of outpatient EEG's role as prognostic tool for PSE development., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2023 by the American Clinical Neurophysiology Society.)

Objective: Acute symptomatic seizures (ASyS) after stroke are not uncommon. However, the impact of ASyS and its management with anti-seizure medications (ASMs) on patient-reported outcome measures (PROMs) remains poorly investigated. The objective of our study is to evaluate the association between PROMs and ASyS and ASMs following stroke., Methods: We performed a retrospective cohort study of all stroke patients who underwent inpatient continuous EEG (cEEG) monitoring performed due to suspected ASyS, including the ones with observed convulsive ASyS, from 04/01/2012 to 03/31/2018, who completed PROMs within 6 months of hospital discharge. Patient-reported outcome measures, including one Neuro-QoL and six PROMIS v1.0 domain scales, were completed by patients as the standard of care in ambulatory stroke clinics. Since ASMs are sometimes used without clearly diagnosed ASyS, we performed group comparisons based on ASM status at discharge, irrespective of their ASyS status. T-tests or Wilcoxon rank sum tests compared continuous variables across groups and chi-square tests or Fisher's exact tests were used for categorical variables., Results: A total of 508 patients were included in the study [mean age 62.0 ± 14.1 years, 51.6% female; 244 (48.0%) ischemic stroke, 165 (32.5%) intracerebral hemorrhage, and 99 (19.5%) subarachnoid hemorrhage]. A total of 190 (37.4%) patients were discharged on ASMs. At the time of the first PROM, conducted a median of 47 (IQR = 33-78) days after the suspected ASyS, and 162 (31.9%) were on ASMs. ASM use was significantly higher in patients diagnosed with ASyS. Physical Function and Satisfaction with Social Roles and Activities were the most affected health domains. Patient-reported outcome measures were not significantly different between groups based on ASyS (electrographic and/or convulsive), ASM use at hospital discharge, or ASM status on the day of PROM completion., Significance: There were no differences in multiple domain-specific PROMs in patients with recent stroke according to ASyS status or ASM use suggesting the possible lack of the former's sensitivity to detect their impact. Additional research is necessary to determine if there is a need for developing ASyS-specific PROMs., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Objective: While studies have explored clinical and EEG predictors of seizures on continuous EEG (cEEG), the role of cEEG indications as predictors of seizures has not been studied. Our study aims to fill this knowledge gap., Methods: We used the prospective cEEG database at Cleveland Clinic for the 2016 calendar year. Patients ≥ 18 years who underwent cEEG for the indication of altered mental status (AMS) and seizure-like events (SLE: motor or patient-reported events) were included. Baseline characteristics and EEG findings were compared between the two groups. Multivariable regression was used to compare the two groups and identify seizure detection risk factors., Results: Of 2227 patients (mean age 59.4 years) who met the inclusion criteria, 882 (50% females) underwent cEEG for AMS and 1345(51% females) for SLE. SLE patients were younger(OR: 0.988, CI: 0.98-0.99, p < 0.001), had longer monitoring(OR:1.04, CI:1.00-1.07, p = 0.033), were more likely to have epilepsy-related-breakthrough seizures(OR:25.9, CI:0.5.89-115, p < 0.001), psychogenic non-epileptic spells (OR:6.85, CI:1.60-29.3, p = 0.008), were more awake (p < 0.001) and more likely to be on anti-seizure medications(OR:1.60, CI:1.29-1.98, p < 0.001). On multivariable analysis, SLE was an independent predictor of seizure detection (OR: 2.60, CI: 1.77-3.88, p < 0.001)., Significance: Our findings highlight the differences in patients undergoing cEEG for AMS vs. SLE. SLE as a cEEG indication represents an independent predictor of seizures on cEEG and, therefore, deserves special attention. Future multicenter studies are needed to validate our findings., Competing Interests: Conflict of Interests All other authors declare no conflicts of interest relevant to this study. We confirm that we have read the Journal’s position on issues involved in ethical publications and affirm that this report is consistent with those guidelines., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background and Objective: Patients with acute symptomatic seizures (ASyS) after stroke are discharged on antiseizure medications (ASMs) and stay on them for an extended period. We analyzed the current ASM management practice, 6 months, and at the last follow-up after stroke-related ASyS concerns to identify chronic and long-term ASM use predictors., Methods: A single-center, retrospective cohort study of adults who underwent continuous EEG monitoring for ASyS concerns after stroke (April 1, 2012 to March 31, 2018) with at least 6 months of follow-up was performed. ASM use beyond 6 months after the initial ASyS concern was defined as "chronic" among patients discharged on them. "Long-term" ASM use at the last follow-up in all patients with ASyS concerns was analyzed. Logistic regression and Cox regression multivariable modeling to analyze predictors of "chronic" and "long-term" ASM use, respectively, was performed., Results: A total of 465 (mean age 61.7 ± 13.3 years and 52% female patients) patients (41.9% ischemic stroke, 36.1% intracerebral hemorrhage, and 21.9% subarachnoid hemorrhage) were included. Of the 179 (38.5%) patients discharged on ASMs, 132 (73.7%; 28.4% of study population) had chronic ASM use, despite 90% not experiencing any seizure (poststroke epilepsy [PSE]) during this time. The independent predictors of chronic ASM use were electrographic ASyS (odds ratio [OR] = 9.27, 95% CI = 2.53-60.4) and female sex (OR = 2.2, 95% CI = 1.02-4.83). After a median 61-month (5.1 years) follow-up, 101 (21.7%) patients in the study population were on long-term ASM use, including 67 (14.4%) who developed PSE. Long-term ASM use was associated with NIH Stroke Scale Score (OR = 1.5, 95% CI = 1.015-1.98), cortical involvement (OR = 1.28, 95% CI = 1.02-1.6), convulsive ASyS (OR = 1.46, 95% CI = 1.02-2.09), epileptiform findings on outpatient EEG (OR = 4.03, 95% CI = 1.28-12.76), and PSE development (OR = 7.06, 95% CI = 3.7-13.4)., Discussion: Chronic ASM use is highly associated with electrographic, rather than convulsive, ASyS. However, long-term ASM use is independently associated with PSE and its risk factors, including convulsive ASyS. With the ubiquity of stroke-related ASyS concerns in routine clinical practice, comparative effectiveness studies to guide ASM management are needed., (© 2022 American Academy of Neurology.)

Background/objective: Early recognition of patients who may be at risk of developing acute symptomatic seizures would be useful. We aimed to determine whether continuous electroencephalography (cEEG) data using machine learning techniques such as neural networks and decision trees could predict seizure occurrence in hospitalized patients., Methods: This was a single center retrospective cohort analysis of cEEG data in patients aged 18-90 years who were admitted and underwent cEEG monitoring between 2010 and 2019 limited to 72 h excluding those who were seizing at the onset of recording. A total of 41,491 patients were reviewed; of these, 3874 were used to develop the static model and 1687 to develop the dynamic model (half with seizure and half without seizure in each cohort). Of these, 80% were randomly selected as derivation cohorts for each model and 20% were randomly selected as validation cohorts. Dynamic and static machine learning models (long short term memory (LSTM) and Extreme Gradient Boosting algorithm (XGBoost)) based on day-to-day dynamic EEG changes and binary static EEG features over the prior 72 h or until seizure, which ever was earlier, were used., Results: The static model was able to predict seizure occurrence based on cEEG data with sensitivity and specificity of 0.81 and 0.59, respectively, with an AUC of 0.70. The dynamic model was able to predict seizure occurrence with sensitivity and specificity of 0.72 and 0.80, respectively, and AUC of 0.81., Conclusions: Machine learning models could be applied to cEEG data to predict seizure occurrence based on available cEEG data. Dynamic day-to-day EEG data are more useful in predicting seizures than binary static EEG data. These models could potentially be used to determine the need for ongoing cEEG monitoring and to prioritize resources., Competing Interests: Conflicts of interest Authors have no relevant conflict of interests to declare., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Stroke patients who underwent continuous EEG (cEEG) monitoring within 7 days of presentation and developed post-stroke epilepsy (PSE; cases, n = 36) were matched (1:2 ratio) by age and follow-up duration with ones who did not (controls, n = 72). Variables significant on univariable analysis [hypertension, smoking, hemorrhagic conversion, pre-cEEG convulsive seizures, and epileptiform abnormalities (EAs)] were included in the multivariable logistic model and only the presence of EAs on EEG remained significant PSE predictor [OR = 11.9 (1.75-491.6)]. With acute EAs independently predicting PSE development, accounting for their presence may help to tailor post-acute symptomatic seizure management and aid anti-epileptogenesis therapy trials., (© 2022 The Authors. Annals of Clinical and Translational Neurology published by Wiley Periodicals LLC on behalf of American Neurological Association.)

Purpose: The use of continuous electroencephalographic (cEEG) monitoring has improved the understanding of the seizure risk during acute hospitalization. However, the immediate posthospitalization seizure risk in these patients remains unknown. Patients undergoing 30-day readmission after initial cEEG monitoring were analyzed to fill this knowledge gap., Methods: A prospectively maintained cEEG database (January 1, 2015-December 31, 2015) was used to identify adults who underwent a repeat cEEG during their 30-day readmission after cEEG during their index hospitalization (index cEEG). Various demographical, clinical, and cEEG variables were extracted including indication for cEEG: altered mental status and clinical seizure-like events., Results: A total of 57 of the 2,485 (2.3%) adults undergoing index cEEG during the study period had concerns for seizures and underwent repeat cEEG during a 30-day readmission. These patients were almost three times more likely to have suffered electrographic seizure on the index admission (odds ratio, 2.82; 95% confidence interval, 1.54-5.15; P < 0.001) compared with non-readmitted patients. Seizure-like events led to the readmission of 40.4% patients. Close to one in five (19.3%) readmitted patients were found to have an electrographic seizure. Only variable predictive of seizure on readmission was seizure-like events (odds ratio, 6.4; 95% confidence interval, 1.2-33.0; P = 0.02)., Conclusions: A small percentage of patients have clinical presentation concerning for seizures with in 30 days after index cEEG. The risk of electrographic seizures in this patient population is higher than patients who have cEEG monitoring but do not undergo a 30-day readmission requiring repeat cEEG. Future research on early identification of patients at risk of 30-day readmission because of concerns for seizure is needed., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2020 by the American Clinical Neurophysiology Society.)

Objective: Majority of seizures are detected within 24 hours on continuous EEG (cEEG). Some patients have delayed seizure detection after 24 hours. The purpose of this research was to identify risk factors that predict delayed seizure detection and to determine optimal cEEG duration for various patient subpopulations., Methods: We retrospectively identified all patients ≥18 years of age who underwent cEEG at Cleveland clinic during calendar year 2016. Clinical and EEG data for all patients and time to seizure detection for seizure patients were collected., Results: Twenty-four hundred and two patients met inclusion criteria. Of these, 316 (13.2%) had subclinical seizures. Sixty-five (20.6%) patients had delayed seizures detection after 24 hours. Seizure detection increased linearly till 36 hours of monitoring, and odds of seizure detection increased by 46% for every additional day of monitoring. Delayed seizure risk factors included stupor (13.2% after 48 hours, P = .031), lethargy (25.9%, P = .013), lateralized (LPDs) (27.7%, P = .029) or generalized periodic discharges (GPDs) (33.3%, P = .022), acute brain insults (25.5%, P = .036), brain bleeds (32.8%, P = .014), especially multiple concomitant bleeds (61.1%, P < .001), altered mental status (34.7%, P = .001) as primary cEEG indication, and use of antiseizure medications (27.8%, P < .001) at cEEG initiation., Significance: Given the linear seizure detection trend, 36 hours of standard monitoring appears more optimal than 24 hours especially for high-risk patients. For awake patients without epileptiform discharges, <24 hours of monitoring appears sufficient. Previous studies have shown that coma and LPDs predict delayed seizure detection. We found that stupor and lethargy were also associated with delayed seizure detection. LPDs and GPDs were associated with delayed seizures. Other delayed seizure risk factors included acute brain insults, brain bleeds especially multiple concomitant bleeds, altered mental status as primary cEEG indication, and use of ASMs at cEEG initiation. Longer cEEG (≥48 hours) is suggested for these high-risk patients., (© 2021 The Authors. Epilepsia Open published by Wiley Periodicals LLC on behalf of International League Against Epilepsy.)

Objective: Recent research has explored the use of continuous EEG (cEEG) monitoring for prognostication of spontaneous cardiac arrest (SCA). However, there is limited literature on the long-term (post-hospital discharge) electrographic findings among SCA survivors and their clinical correlates. Our study aims to fill this critical knowledge gap., Methods: We retrospectively used our EEG database to identify adults (≥18 years) with SCA history who underwent an outpatient laboratory-based EEG between 01/01/2011 and 12/31/2018. After electronic medical records (EMR) review, patients with epilepsy history and unclear/poorly documented SCA history were excluded. Outpatient EEGs were reviewed by authors. Acute EEG findings were extracted from the EEG database and EMR. In addition, we extracted data on acute and long-term neuroimaging findings (CT/MRI), post-SCA seizures, and anti-seizure medications (ASM) status. Descriptive analysis and Fisher's exact test were performed., Results: We included 32 SCA survivors (50% women; mean age = 52.1 ± 13.6 years) in the study. During a median clinical follow-up of 28.2 months, 3 patients suffered only clinical seizures, 3 only chronic post-hypoxic myoclonus, and 5 had both [11 (34.4%) in total]. Interictal epileptiform discharges (IEDs) were noted in one-third of the patients, which localized to vertex and frontocentral regions in all but one patient. Five (15.6%) of them did not suffer a clinical seizure despite the presence of EAs. Patients who developed epilepsy were significantly more likely to have abnormal neuroimaging findings [10/11 (90.9%)] during the follow-up compared to the rest of the patients [OR = 25 (95% CI 2.6->100, P = .002)]. Half of the study cohort was taking ASM at the last follow-up., Significance: Our small study reveals a signature location of IEDs in SCA survivors. Neuroimaging abnormalities seem to be a better indicator of epilepsy development, while EEG may reveal markers of potential epileptogenicity in the absence of clinical seizures. Future, larger studies are needed to confirm our findings., (© 2021 The Authors. Epilepsia Open published by Wiley Periodicals LLC on behalf of International League Against Epilepsy.)

Objective: To investigate the factors associated with the long-term continuation of anti-seizure medications (ASMs) in acute stroke patients., Methods: We performed a retrospective cohort study of stroke patients with concern for acute symptomatic seizures (ASySs) during hospitalization who subsequently visited the poststroke clinic. All patients had continuous EEG (cEEG) monitoring. We generated a multivariable logistic regression model to analyze the factors associated with the primary outcome of continued ASM use after the first poststroke clinic visit., Results: A total of 507 patients (43.4% ischemic stroke, 35.7% intracerebral hemorrhage, and 20.9% aneurysmal subarachnoid hemorrhage) were included. Among them, 99 (19.5%) suffered from ASySs, 110 (21.7%) had epileptiform abnormalities (EAs) on cEEG, and 339 (66.9%) had neither. Of the 294 (58%) patients started on ASMs, 171 (33.7%) were discharged on them, and 156 (30.3% of the study population; 53.1% of patients started on ASMs) continued ASMs beyond the first poststroke clinic visit [49.7 (±31.7) days after cEEG]. After adjusting for demographical, stroke- and hospitalization-related variables, the only independent factors associated with the primary outcome were admission to the NICU [Odds ratio (OR) 0.37 (95% CI 0.15-0.9)], the presence of ASySs [OR 20.31(95% CI 9.45-48.43)], and EAs on cEEG [OR 2.26 (95% CI 1.14-4.58)]., Interpretation: Almost a third of patients with poststroke ASySs concerns may continue ASMs for the long term, including more than half started on them acutely. Admission to the NICU may lower the odds, and ASySs (convulsive or electrographic) and EAs on cEEG significantly increase the odds of long-term ASM use., (© 2021 The Authors. Annals of Clinical and Translational Neurology published by Wiley Periodicals LLC on behalf of American Neurological Association.)

Background: Postanoxic myoclonus is a known poor prognostic sign, and other postanoxic spontaneous movements have been reported but poorly described. We aim to describe the electroclinical phenomenon of postanoxic eyelid openings in context of its possible prognostic value., Methods: We collected clinical data on postcardiac arrest patients with suspicious eyelid movements noted on continuous EEG monitoring. The eyelid movements captured on the video were correlated with the EEG findings and final clinical outcome. Neuroimaging data were reviewed when available. We also conducted a thorough literature review on this topic., Results: A total of 10 patients (5 females) with average age of 56.1 (±14.4) years were included. The mean cardiopulmonary resuscitation duration was 18.9 (±11.3) minutes. Postanoxic eyelid-opening movements occurred at variable intervals (0.5-570 seconds) in each individual. Close examination of eyelid opening (available in 6 patients) revealed them to be tonic movements, lasting an average of 3 (±0.8) seconds and always succeeded the onset of burst of EEG activity in a burst-suppression background. This is a transient phenomenon, lasting a median duration of 30 (interquartile range 7.75-36) hours. MRI findings in 3 patients demonstrated diffuse cortical ischemic injury with relative sparing of the brainstem. All patients died within 2-7 days following cardiac arrest., Conclusions: Contrary to previous descriptions, the postanoxic tonic eyelid openings (PATEO) are repetitive but nonperiodic, nonmyoclonic movements. Their close and specific temporal correlation with the burst of EEG activity suggests that this could be considered an ictal phenomenon requiring an intact midbrain based on MRI findings., (© 2021 American Academy of Neurology.)

Background: The coronavirus disease of 2019 (COVID-19) emerged as a global pandemic. Historically, the group of human coronaviruses can also affect the central nervous system leading to neurological symptoms; however, the causative mechanisms of the neurological manifestations of COVID-19 disease are not well known. Seizures have not been directly reported as a part of COVID-19 outside of patients with previously known brain injury or epilepsy. We report two cases of acute symptomatic seizures, in non-epileptic patients, associated with severe COVID-19 disease., Case Presentations: Two advanced-age, non-epileptic, male patients presented to our northeast Ohio-based health system with concern for infection in Mid-March 2020. Both had a history of lung disease and during their hospitalization tested positive for SARS-CoV-2. They developed acute encephalopathy days into their hospitalization with clinical and electrographic seizures. Resolution of seizures was achieved with levetiracetam., Discussion: Patients with COVID-19 disease are at an elevated risk for seizures, and the mechanism of these seizures is likely multifactorial. Clinical (motor) seizures may not be readily detected in this population due to the expansive utilization of sedatives and paralytics for respiratory optimization strategies. Many of these patients are also not electrographically monitored for seizures due to limited resources, multifactorial risk for acute encephalopathy, and the risk of cross-contamination. Previously, several neurological symptoms were seen in patients with more advanced COVID-19 disease, and these were thought to be secondary to multi-system organ failure and/or disseminated intravascular coagulopathy-related brain injury. However, these patients may also have an advanced breakdown of the blood-brain barrier precipitated by pro-inflammatory cytokine reactions. The neurotropic effect and neuroinvasiveness of SARS-Coronavirus-2 have not been directly established., Conclusions: Acute symptomatic seizures are possible in patients with COVID-19 disease. These seizures are likely multifactorial in origin, including cortical irritation due to blood-brain barrier breakdown, precipitated by the cytokine reaction as a part of the viral infection. Patients with clinical signs of seizures or otherwise unexplained encephalopathy may benefit from electroencephalography monitoring and/or empiric anti-epileptic therapy. Further studies are needed to elucidate the risk of seizures and benefit of monitoring in this population.

Objective: As concerns regarding neurological manifestations in COVID-19 (coronavirus disease 2019) patients increase, limited data exists on continuous electroencephalography (cEEG) findings in these patients. We present a retrospective cohort study of cEEG monitoring in COVID-19 patients to better explore this knowledge gap., Methods: Among 22 COVID-19 patients, 19 underwent cEEGs, and 3 underwent routine EEGs (<1 h). Demographic and clinical variables, including comorbid conditions, discharge disposition, survival and cEEG findings, were collected., Results: cEEG was performed for evaluation of altered mental status (n = 17) or seizure-like events (n = 5). Five patients, including 2 with epilepsy, had epileptiform abnormalities on cEEG. Two patients had electrographic seizures without a prior epilepsy history. There were no acute neuroimaging findings. Periodic discharges were noted in one-third of patients and encephalopathic EEG findings were not associated with IV anesthetic use., Conclusions: Interictal epileptiform abnormalities in the absence of prior epilepsy history were rare. However, the discovery of asymptomatic seizures in two of twenty-two patients was higher than previously reported and is therefore of concern., Significance: cEEG monitoring in COVID-19 patients may aid in better understanding an epileptogenic potential of SARS-CoV2 infection. Nevertheless, larger studies utilizing cEEG are required to better examine acute epileptic risk in COVID-19 patients., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Objective: Postencephalitic epilepsy is often resistant to antiseizure medications, leading to evaluation for epilepsy surgery. Characterizing its localization carries implications for optimal surgical approach. We aimed to determine whether a prior history of encephalitis is associated with specific epileptogenic networks among patients with drug resistant epilepsy undergoing stereotactic EEG (SEEG)., Methods: We conducted a retrospective cohort study of drug resistant epilepsy, with and without a prior history of encephalitis. We analyzed SEEG recordings to identify patterns of seizure onset and organization. Seventeen patients with a history of encephalitis (of infectious etiology in two subjects) were identified from a database of patients undergoing SEEG and were compared to seventeen drug-resistant epilepsy controls without a history of encephalitis matched for confounding variables including pre-implantation hypotheses, epilepsy duration, age, and sex., Results: Independent bilateral seizures were noted in 65% of the postencephalitic epilepsy cohort. We identified four SEEG-ictal patterns in patients with a prior history of encephalitis: (1) anteromesial temporal onset (24%), (2) anteromesial temporal onset with early spread to the perisylvian region (29%), (3) perisylvian (59%) and (4) synchronized anteromesial temporal and perisylvian (29%) onsets. Patterns 3 and 4, with perisylvian involvement at onset, were unique to the encephalitis group (p = 0.0003 and 0.04 respectively) and exhibited a "patchwork" organization. None of the encephalitis patients vs 5/7 matched controls had Engel I outcome (p = 0.0048)., Conclusions: Postencephalitic epilepsies involve anteromesial temporal and perisylvian networks, often in a bilateral independent manner. Unique ictal patterns involving the perisylvian regions was identified in the encephalitis group, but not in the matched control group., Significance: These findings may reflect a selective vulnerability of the perisylvian regions to epilepsy resulting from encephalitis, significantly mitigating the chances of success with SEEG-guided temporal resections., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Purpose: Acute symptomatic seizures (ASyS) are common in critically ill patients. It is unknown how ASyS affect posthospitalization self-reported health compared to patients with established epilepsy., Methods: This is a retrospective cohort study from 2010 to 2018. Patients were identified by an institutional epilepsy database (Ebase). Patient-reported outcome measures (PROMs) were completed as part of standard of care and included the number of seizures in the prior 4 weeks, Liverpool Seizure Severity Scale (LSSS) ictal score, quality of life in epilepsy (QOLIE)-10, Patient Health Questionnaire-9 scales, and the PROM Information System Global Health (PROMIS-GH) scale. Mixed-effects models were created to adjust for age, sex, and race and to examine score trajectory over the 1 year after baseline., Results: A total of 15 311 established epilepsy patients and 317 patients with ASyS were identified. When compared to patients with epilepsy, patients with ASyS were older, mostly male, more often black, and had worse baseline scores on the QOLIE-10 ( P < .001), PROMIS-GH Physical Health ( P = .037), and LSSS Ictal ( P = .006) scales. Patient-Reported Outcomes Measurement Information System Mental and Physical Health T-scores were worse than the general population (T-score = 50) for patients with both ASyS (44 and 42.5, respectively) and epilepsy (44.2 and 44.6, respectively). After adjusting for age, sex, and race, patients with ASyS reported 38% fewer seizures ( P = .006) yet worse QOLIE-10 score ( P = .034). We found that scores improved over time for all PROMs except for PROMIS-GH Mental Health., Conclusion: Compared to patients with epilepsy, patients with ASyS had fewer seizures but worse epilepsy-specific quality of life. Independent of group status, scores generally improved over time., Competing Interests: Declaration of Conflicting Interests: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2020.)

Objective: We present a model for the outpatient care of patients undergoing continuous electroencephalography (cEEG) monitoring during a hospitalization, named the post-acute symptomatic seizure (PASS) clinic. We investigated whether establishing this clinic led to improved access to epileptologist care., Methods: As part of the PASS clinic initiative, electronic health record (EHR) provides an automated alert to the inpatient care team discharging adults on first time antiepileptic drug (AED) after undergoing cEEG monitoring. The alert explains the rationale and facilitates scheduling for a PASS clinic appointment, three-month after discharge, along with a same-day extended (75 minutes) EEG. We compared the initial epilepsy clinic visits by patients undergoing cEEG in 2017, before ("Pre-PASS" period and cohort) and after ("PASS" period and cohort) the alert went live in the EHR., Results: Of the 170 patients included, 68 (40%) suffered a seizure during the mean follow-up of 20.9 ± 10 months. AEDs were stopped or reduced in 66 out of 148 (44.6%) patients discharged on AEDs. Pre-PASS cohort included 45 patients compared to 145 patients in the PASS cohort, accounting for 5.8% and 9.9% of patients, respectively, who underwent cEEG during the corresponding periods (odds ratio [OR] = 1.8, 95% CI = 1.26-2.54, P  = .001). The two cohorts did not differ in terms of electrographic or clinical seizures. The PASS cohort was significantly more likely to be followed up within 1-6 months of discharge (OR = 4.6, 95% CI = 2.1-10.1, P  < .001) and have a pre-clinic EEG (51.2% vs 11.1%; OR = 8.39, 95% CI = 3.1-22.67, P  < .001)., Significance: PASS clinic, a unique outpatient transition of care model for managing patients at risk of acute symptomatic seizure led to an almost twofold increase in access to an epileptologist. Future research should address the wide knowledge gap about the best post-hospital discharge management practices for these patients., Competing Interests: None of the authors has any conflict of interest to disclose. We confirm that we have read the Journal's position on issues involved in ethical publication and affirm that this report is consistent with those guidelines., (© 2020 The Authors. Epilepsia Open published by Wiley Periodicals LLC on behalf of International League Against Epilepsy.)

Objective: This study was designed to investigate if highly epileptic electroencephalogram (EEG) findings in patients with acute brain injury increase the long-term risk of epilepsy development., Methods: Adults patients, lacking epilepsy history, with electrographic seizures or lateralized periodic discharges (LPDs) (cases) were identified and matched based on age, mental status, and etiology with the ones lacking any epileptiform activity (controls) on continuous EEG (cEEG) during hospitalization. The primary outcome of clinical seizures after hospital discharge and their antiepileptic drug (AED) status was determined using a telephonic interview. Logistic regression models using generalized estimating equations to account for the matched nature of the data were performed., Results: A total of 70 cases [16 (22.9%) "LPDs only," 34 (48.6%) "electrographic seizure only," and 20 (28.6%) "both"] and controls were enrolled. A total of 22 (31.4%) cases developed epilepsy after a mean follow-up duration of 20.6 ± 5.0 months compared to three (4.3%) controls. After adjusting for cEEG indication and follow-up duration, the odds of cases developing epilepsy were almost 15 times higher compared to the controls (OR = 14.8, 95% CI = 2.4-92.3, P = 0.004). This elevated risk was despite a 10 times higher likelihood of cases to be taking AEDs at the last follow-up (OR = 10.34, 95% CI = 3.7-29, P < 0.001)., Interpretation: Highly epileptic EEG findings in patients with acute brain injury may serve as prognostic biomarkers of epilepsy development. Although prospective studies are required to confirm our findings, it seems that with epilepsy developing in almost one-third cases in less than 2-year follow-up period, such patients may potentially be ideal candidates for epilepsy prevention clinical trials., (© 2019 The Authors. Annals of Clinical and Translational Neurology published by Wiley Periodicals, Inc on behalf of American Neurological Association.)

Purpose: Seizure is a well-recognized complication of both remote and acute ischemic strokes. Predictors of seizure recurrence and epilepsy in patients with ischemic stroke who develop acute symptomatic seizures (ASyS) on continuous electroencephalography (cEEG) have not been well studied., Methods: We present a five-year retrospective study of acute and remote ischemic stroke patients who developed ASyS on cEEG. We then identified risk factors for the development of seizure recurrence., Results: Sixty-five patients with ischemic stroke and ASyS were identified and reviewed. All ASyS were noted to be nonconvulsive seizures. Clinical recurrence of seizures was identified in 19 of these patients (29.2%) at follow-up. Rate of seizure recurrence was higher in remote ischemic stroke patients (84.2%), compared to acute ischemic stroke patients (15.8%, p = 0.0116, OR 0.17, 95% CI 0.049-0.65). Sharp waves/spikes on follow-up EEG significantly correlated with seizure recurrence ( p = 0.006, OR 0, 95% CI 0-0.3926). Patients discharged on ≥3 antiepileptic drugs (AEDs) were at a higher risk of having seizure recurrence ( p = 0.0015, OR 0.05, 95% CI 0.0089-0.37)., Conclusion: We identified risk factors of seizure recurrence in patients with ASyS as remote ischemic stroke, requiring multiple AEDs, and the presence of sharp waves on follow-up EEG. This study highlights the usefulness of cEEG in evaluating patients with acute or remote strokes., Competing Interests: None of the authors have any conflict of interest or financial interests to disclose related to this research project., (Copyright © 2019 Pravin George et al.)

Objective: A retrospective, single-center study to analyze the determinants of a repeat continuous EEG (cEEG) monitoring during hospitalization and its outcomes using a matched case-control study design., Methods: Adults with a repeat cEEG session (cases) were matched by age (±3 years), gender, and mental status to patients with a single cEEG (controls) during hospitalization. Several clinical and EEG characteristics were analyzed to identify predictors of repeat cEEG. Repeat cEEG outcomes were analyzed based on its yield of electrographic seizure. We investigated the predictors of finding increased epileptic potential (degree of association with electrographic seizures) on the repeat cEEG, a marker for possible anti-epileptic drugs (AEDs) management change., Results: A total of 213 (8.6% of all unique cEEG patients) cases were included. A multivariable conditional logistic regression model comparing cases and controls showed that the presence of acute brain insult [odds ratio (OR) = 3.36, 95% CI = 1.26-8.94, P  = .015], longer hospital admission (OR = 1.11, 95% CI = 1.07-1.15, P  < .001) and being on AEDs at the end of index cEEG (OR = 4.0, 95% CI = 1.8-8.87, P  < .001) was determinants of a repeat cEEG. Among cases, 17 (8%) had electrographic seizures on repeat cEEG. Increased epileptic potential on repeat cEEG was noted in 34 (16%) cases. The latter is associated with change in etiology after the index cEEG ( P  = .03) and duration of repeat cEEG ( P  = .003) based on multivariable logistic regression model. AEDs were changed in 46 (21.6%) patients based on repeat cEEG findings., Significance: Repeat cEEG is not an uncommon practice. It leads to the diagnosis of electrographic seizures in a significant percentage of patients. With the potential of impacting AED management in 16%-21% patients, it should be considered in high-risk patients suffering acute brain insults undergoing prolonged hospitalization., Competing Interests: None of the authors has any conflict of interest to disclose. We confirm that we have read the Journal's position on issues involved in ethical publication and affirm that this report is consistent with those guidelines., (© 2019 The Authors. Epilepsia Open published by Wiley Periodicals Inc. on behalf of International League Against Epilepsy.)

Background and Purpose: New-onset refractory status epilepticus is a clinical condition characterized by acute and prolonged pharmacoresistant seizures without a pre-existing relevant neurologic disorder, prior epilepsy, or clear structural, toxic, or metabolic cause. New-onset refractory status epilepticus is often associated with antineuronal antibodies and may respond to early immunosuppressive therapy, reflecting an inflammatory element of the condition. FDG-PET is a useful diagnostic tool in inflammatory and noninflammatory encephalitis. We report here FDG-PET findings in new-onset refractory status epilepticus and their correlation to disease activity, other imaging findings, and outcomes., Materials and Methods: Twelve patients who met the criteria for new-onset refractory status epilepticus and who had FDG-PET and MR imaging scans and electroencephalography at a single academic medical center between 2008 and 2017 were retrospectively identified. Images were independently reviewed by 2 radiologists specialized in nuclear imaging. Clinical characteristics and outcome measures were collected through chart review., Results: Twelve patients underwent 21 FDG-PET scans and 50 MR imaging scans. Nine (75%) patients were positive for autoantibodies. All patients had identifiable abnormalities on the initial FDG-PET in the form of hypermetabolism (83%) and/or hypometabolism (42%). Eight (67%) had medial temporal involvement. All patients ( n = 3) with N -methyl-D-aspartic acid receptor antibodies had profound bilateral occipital hypometabolism. Initial MR imaging findings were normal in 6 (50%) patients. Most patients had some degree of persistent hyper- (73%) or hypometabolism (45%) after immunosuppressive therapy. FDG-PET hypometabolism was predictive of poor outcome (mRS 4-6) at hospital discharge ( P = .028)., Conclusions: Both FDG-PET hypometabolism and hypermetabolism are seen in the setting of new-onset refractory status epilepticus and may represent markers of disease activity., (© 2019 by American Journal of Neuroradiology.)

Acute symptomatic seizures have been known to occur in critically ill patients for many years. It was not until the widespread use of continuous EEG (cEEG) in the critically ill did we appreciate the incidence of electrographic seizures and status epilepticus in the ICU (Newey and Kinzy, 2018). Many of the seizures that occur are without any apparent clinical signs at the time of the recording. The patients often have convulsive seizures at onset then over the next few hours they lose the ability to have a generalized tonic clonic convulsion. They may then have subtle clinical signs (ictal nystagmus, facial twitching, etc.) or lose any apparent motor response. The end result is that many of the patients lose any clinical signs for their seizures by the time they are in the ICU and their seizures are termed "nonconvulsive." The recognition of seizures in the ICU is important for the effects the seizures have on outcome, particularly in morbidity and mortality and the risk of developing epilepsy after the acute symptomatic event. The use of cEEG in the ICU population has not only highlighted the high incidence of seizure activity but has also been used to assess overall cerebral function with applications in ischemia monitoring and prognostication, and to assess the degree of encephalopathy. This chapter will illustrate the core principles of cEEG monitoring in the critical care population including the incidence of seizures, determining who is at highest risk for seizures, how long patients should be monitored and ICU EEG seizure., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objective: To determine the clinical correlates bilateral independent periodic discharges (BIPDs) and their association with electrographic seizures and outcome., Methods: Retrospective case-control study of patients with BIPDs compared to patients without periodic discharges ("No PDs") and patients with lateralized periodic discharges ("LPDs"), matched for age, etiology and level of alertness., Results: We included 85 cases and 85 controls in each group. The most frequent etiologies of BIPDs were stroke, CNS infections, and anoxic brain injury. Acute bilateral cerebral injury was more common in the BIPDs group than in the No PDs and LPDs groups (70% vs. 37% vs. 35%). Electrographic seizures were more common with BIPDs than in the absence of PDs (45% vs. 8%), but not than with LPDs (52%). Mortality was higher in the BIPDs group (36%) than in the No PDs group (18%), with fewer patients with BIPDs achieving good outcome (moderate disability or better; 18% vs. 36%), but not than in the LPDs group (24% mortality, 26% good outcome). In multivariate analyses, BIPDs remained associated with mortality (OR: 3.0 [1.4-6.4]) and poor outcome (OR: 2.9 [1.4-6.2])., Conclusion: BIPDs are caused by bilateral acute brain injury and are associated with a high risk of electrographic seizures and of poor outcome., Significance: BIPDs are uncommon but their identification in critically ill patients has potential important implications, both in terms of clinical management and prognostication., (Copyright © 2018. Published by Elsevier B.V.)

Objective: Anti-NMDA receptor encephalitis (NMDARE) may not respond to first line immunotherapy. Biomarkers to track disease course and guide escalation of immunotherapy are needed. We describe the evolution of EEG in four patients with NMDARE requiring prolonged intensive care., Methods: Within a database of 121 patients with immune-mediated neurological disorders, ten with NMDARE were retrospectively identified. Four patients did not respond to first line immunotherapy. Continuous EEG was reviewed and correlated with clinical status and treatment., Results: Intermittent polymorphic delta slowing was present in all patients. Generalized rhythmic delta occupied increasing proportion of the EEG as disease progressed, at times with superimposed beta. The institution of second line immunotherapy was followed by progressive decrease in rhythmic delta, predating clinical improvement. In one patient who did not respond to second line immunotherapy, rhythmic delta continued to occupy a majority of the recording. The extreme delta pattern was not seen in a comparison cohort of patients with autoimmune encephalitis without anti-NMDA-R antibodies., Conclusions: Extreme delta, with or without brushes, increases with progression of NMDARE, responds to escalation of immunotherapy, predating clinical improvement, and is likely specific to NMDA-R antibodies., Significance: Extreme delta may be a surrogate marker of disease activity in NMDARE refractory to first line immunotherapy., (Copyright © 2018 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Purpose: We sought to characterize the electroclinical features of seizures associated with autoimmune encephalitis and their relevance to outcome., Methods: 19 patients with seizures and autoimmune encephalitis were identified from a database of 100 patients (2008-2017) with autoimmune neurological disorders. Clinical and electroclinical characteristics were collected. Persistent seizures at last follow-up were then correlated with electroclinical features., Results: Status epilepticus (53%) and early intractability to AEDs (median time to second AED 9.5 days) marked the onset of refractory seizures (median number of AEDs 3). Seizure semiology (abdominal (16%), psychic (42%), olfactory (6%) auras), interictal temporal epileptiform discharges (42%), and ictal onset in the temporal region (63%) mirrored radiologic involvement of the medial temporal regions (on MRI in 74% and/or FDG-PET in 75%). In addition, multimodal auras, with somatosensory (26%), autonomic (26%), gustatory (11%), and visual (16%), features were seen in 82% of patients with focal aware seizures, invoking broader involvement of the perisylvian regions. A change in seizure semiology and EEG findings was often seen. Electroclinical features were similar regardless of antibody type, with the exception of the association of faciobrachial dystonic seizures with LGI1 antibodies. Eight patients had medically intractable seizures at last follow-up and were more likely than patients with seizure remission to have generalized tonic-clonic seizures and temporal lobe involvement on the basis of semiological features, interictal EEG and MRI changes., Conclusions: Seizures associated with autoimmune encephalitis exhibit common electroclinical features which show dynamic evolution over time. We propose a role for the temporo-perisylvian regions in their generation., (Copyright © 2018 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.)

Objective: To evaluate the incidence of new onset epilepsy and associated risk factors in patients with periodic patterns on continuous electroencephalography (cEEG) during critical illness., Methods: The local cEEG database and then medical records were reviewed from January 1, 2013 to June 30, 2013 to find adult patients with no history of epilepsy who had periodic discharges-either lateralized (LPDs) or generalized (GPDs)-or nonperiodic/nonepileptogenic (NP/NE) findings on cEEG and ≥3 months of clinical follow-up. Clinical seizure after discharge was the primary outcome. Chi-square test, Kruskal-Wallis test, and Cox proportional hazards models were used for statistical analysis., Results: A total of 195 patients (median age = 67.8 years) were included. There were 53 (27%), 73 (37%), and 69 (35%) patients with LPDs, GPDs, and NP/NE findings on cEEG, respectively. These three groups did not differ by demographic or clinical variables. A total of 29 (15%) patients (LPDs = 20 [38%], GPDs = 4 [6%], and NP/NE = 5 [7%]) developed epilepsy during a median follow-up of 32.1 (95% confidence interval [CI] = 13.2-42.8) months. The hazard ratio for epilepsy development among LPD patients was 7.7 (95% CI = 2.9-20.7) times compared to the NP/NE group, and the risk further increased to 11.4 (95% CI = 4-31.4) times if they also had electrographic seizures. This association remained significant despite adjusting for each covariate at a time., Significance: Patients with LPDs on cEEG during critical illness are at least seven times more likely to develop epilepsy compared to patients with NP/NE findings. This risk is further increased if patients with LPDs have electrographic seizures. In comparison, the presence of GPDs does not seem to impact the risk for developing epilepsy. cEEG findings at the time of acute insult have potential to serve as prognostic biomarkers for epilepsy development., (Wiley Periodicals, Inc. © 2018 International League Against Epilepsy.)

Purpose: Electrographic seizures detected by continuous electroencephalography (CEEG) in critically ill patients with altered mental status is becoming increasingly recognized. Data guiding the appropriate selection of patients to be monitored on CEEG are lacking. The aims of this article were to study the incidence of seizures in the critical care setting and to evaluate for clinical predictors to improve the efficiency of CEEG monitoring., Methods: Retrospective review of the CEEG and clinical data on 1,123 consecutive patients who had continuous video EEG over a 24-month period., Results: Seizures were recorded in 215 patients on CEEG monitoring (19.1%). In total, 89.3% of these seizures occurred without clinical signs. Patients who were in a coma were more likely to have EEG seizures (odds ratio, 3.64; 95% confidence interval, 2.23-5.95) compared with those awake. The incidence of seizures was overrepresented in patients with extra-axial tumors (41.9%), multiple sclerosis (35.7%), and intra-axial tumors (33.0%). Lateralized periodic discharges were predictive (odds ratio, 8.27; 95% confidence interval, 5.52-12.46) of seizure occurrence compared with those with no epileptiform patterns. Only generalized periodic discharges with triphasic morphology had no increased odds of seizure (odds ratio, 1.02; 95% confidence interval, 0.24-3.03). When present, electroencephalography seizures were detected within 24 hours in 92% of monitored patients., Conclusions: Continuous electroencephalography monitoring in the critical care setting demonstrates a linear increase in seizure incidence with declining mental status. Recognizing clinical conditions and electroencephalography markings may help in the appropriate selection of critically ill patients for CEEG monitoring.

Background: Neurological complications in liver failure are common. Often under-recognized neurological complications are seizures and status epilepticus. These may go unrecognized without continuous electroencephalography (CEEG). We highlight the observed electro-radiological changes in patients with grade III/IV hepatic encephalopathy (HE) found to have seizures and/or status epilepticus on CEEG and the associated neuroimaging., Methods: This study was a retrospective review of patients with West Haven grade III/IV HE and seizures/status epilepticus on CEEG., Results: Eleven patients were included. Alcohol was the most common cause of HE (54.5%). All patients were either stuporous/comatose. The most common CEEG pattern was diffuse slowing (100%) followed by generalized periodic discharges (GPDs; 36.4%) and lateralized periodic discharges (LPDs, 36.4%). The subtype of GPDs with triphasic morphology was only seen in 27.3%. All seizures and/or status epilepticus were without clinical signs. Magnetic resonance imaging (MRI) was available in six patients. Cortical hyperintensities on diffusion weighted imaging sequence were seen in all six patients. One patient had CEEG seizure concomitantly with the MRI. Seven patients died prior to discharge., Conclusion: Seizures or status epilepticus in the setting of HE were without clinical findings and could go unrecognized without CEEG. The finding of cortical hyperintensity on MRI should lead to further evaluation for unrecognized seizure or status epilepticus.

Purpose: The long-term electrographic features of lateralized periodic discharges (LPD) and their impact on clinical management are unclear. The authors investigated routine EEGs (rEEG) to analyze the delayed natural history of LPDs, and studied the clinical care of these patients., Methods: After IRB approval, the prospectively maintained continuous EEG (cEEG) database was searched to identify patients fulfilling the following criteria: LPDs on cEEG, age ≥18 years, no epilepsy history, and rEEG completed within 1 to 12 months of hospital discharge. Their rEEGs were reviewed followed by clinical data extraction. Appropriate statistical tools were used for data analysis., Results: Thirty-nine patients (20 females) with a mean age of 63.3 ± 16.8 years at the time of cEEG fulfilled the study criteria. Thirty-three (85%) had associated electrographic seizures. rEEG was performed 4.7 ± 3.5 months after cEEG. Seven (18%) patients had interictal epileptiform discharges (IEDs) on the rEEG. The LPDs on cEEG of these patients were more often continuous, with an amplitude >2 times their background compared with 10 (26%) patients with normal rEEGs findings. After a mean follow-up of 19.8 ± 9.9 months, 11 (31%) patients developed epilepsy, but only 3 had IEDs on their rEEG. Majority (86%) of patients were on AEDs at the time of last follow-up., Conclusions: LPDs lead to markers of epileptogenicity in around 18% of patients. One-third of the study population developed epilepsy. rEEG findings were not found to be good indicators of epilepsy development in our small, retrospective study limited by its sampling bias. Indiscriminate, long-term use of AEDs in these patients is a concerning finding.

Purpose: To risk-stratify electrographic features of lateralized periodic discharges (LPDs) in acute structural brain lesions for predictors of electrographic seizures., Methods: This is a retrospective review of 100 consecutive patients with LPDs. Epileptiform features of LPDs were described based on electrographic features: blunt delta morphology, sharply contoured, overlying fast frequencies, and/or rhythmicity (loss of interdischarge interval lasting ≥1 second). EEG seizures were defined as evolving in frequency, distribution, or morphology at ≥2 Hz for ≥10 seconds., Results: Overall, electrographic seizures occurred in 55% of patients with LPDs. Lateralized periodic discharges with rhythmicity (odds ratio 13.91) were most significant for predicting status epilepticus and/or seizures. This was followed by LPDs with overlying faster frequencies (odds ratio 5.16) and then sharply contoured morphology (odds ratio 4.09). Blunt delta morphology (0.24) had the lowest risk for seizures., Conclusions: Electrographic features of LPDs may help determine seizure risk in patients with acute structural lesions. Sharply contoured morphology, overlying fast frequencies, or rhythmicity, showed progressively higher risk of seizures on continuous electroencephalography, whereas blunt delta morphology had the lowest risk of seizures.

Purpose: Pharmacologic sedation is often used to induce burst suppression in cases of refractory status epilepticus, but there is little evidence to guide the weaning of sedation. Similarly, the morphologic feature of bursts is of unknown clinical relevance. Recently, the standardized American Clinical Neurophysiology Society terminology of critical care EEG introduced the term highly epileptiform bursts (HEBs). Knowing the association of HEBs with seizure may direct the therapy for refractory status epilepticus., Methods: Consecutive adult patients classified as having burst suppression were identified in our EEG database. Those of an anoxic etiology were excluded. Available EEG records were reviewed, both visually and quantitatively, for the presence of burst suppression. Using the American Clinical Neurophysiology Society terminology, burst suppression was dichotomized into HEBs or nonepileptiform bursts. Periods of transition out of burst suppression were identified, and whether burst suppression was followed by seizure or a continuous slow EEG within 24 hours was determined., Results: Twenty-four patients were identified with a burst suppression pattern followed by either seizure or a continuous slow EEG within 24 hours, with some patients having multiple (maximal 5) transitions out of burst suppression, for a total of 33 examples of burst suppression. HEBs were associated with subsequent seizure (P = 0.0001), independent of medication exposure., Conclusions: Whether or not HEBs are indeed predictive of recurrent seizure or may be used to direct the therapy for status epilepticus, specifically the weaning of anesthetic medications, requires further prospective study in a larger cohort of patients.

Purpose of Review: Epilepsy emergencies include acute repetitive seizures and status epilepticus. Their prognosis depends on the etiology of the seizures and the time spent in status epilepticus. This review discusses the current perspective on the diagnosis and treatment of status epilepticus and acute repetitive seizures in the intensive care unit., Recent Findings: Current data on the treatment of status epilepticus emphasize early treatment over the choice of antiepileptic drug. The Rapid Anticonvulsant Medication Prior to Arrival Trial (RAMPART) data support the efficacy of prehospital treatment using faster routes of benzodiazepine administration. As additional antiepileptic drugs have become available in an IV formulation, their use in status epilepticus has increased, with little data to guide their administration. Recent publications have also stressed the changing epidemiology of status epilepticus in the United States, with a rise in incidence without much change in overall mortality. This rise is likely related to improved diagnostic capabilities with better availability and usage of continuous EEG in the intensive care unit and to the aging of the patient population., Summary: Acute repetitive seizures and status epilepticus are neurologic emergencies that are being increasingly diagnosed and treated in the modern era. Rapid treatment may influence patient prognosis, future cognitive outcomes, and the long-term potential for developing epilepsy. However, little is known about the mechanisms that perpetuate seizure activity, and our ability to intervene and prevent this condition remains limited. Preventing complications during the treatment of status epilepticus plays a large role in prognosis and the chance of treatment success.

Purpose: Continuous EEG (cEEG) has helped to identify nonconvulsive seizures (NCS) and nonconvulsive status epilepticus (NCSE) along with lateralized periodic patterns (LPDs or PLEDs) in ICU patients with much higher frequency than previously appreciated, but understanding their implications may be more complex. The aim of this study was to investigate the incidence of recurrent seizures after hospital discharge and their associated factors in patients with PLEDs and NCS in the critical care setting., Methods: After IRB approval, we used our EEG reporting database to find 200 consecutive patients who had PLEDs and/or NCSs on cEEG. Patients with less than 3 months of follow-up were excluded. Remaining patients were divided into three groups: PLEDs+Seizure (NCS/NCSE), PLEDs only, and Seizures (NCS/NCSE) only. Medical records were reviewed to gather demographical and clinical details. Univariate data analysis was done using JMP 9.0 (Marlow, Buckinghamshire, UK)., Results: There were 51 patients in 'PLEDs+Seizure' group, 45 in 'PLEDs only' group, and 22 in 'Seizure only' group. Ischemic stroke, hemorrhage, and tumors were the top three etiologies. Nearly 47% of our study population had postdischarge seizures during a mean follow-up period of 11.9 (+/-6) months. We found that 24.4% of patients in the PLEDs only group had seizures after discharge, which increased to 60.7% if they had seizures as well during their ICU stay. Slightly more than 52% of patients had a postdischarge EEG, of which, 59% was in the form of inpatient cEEG during a rehospitalization, accounting for 30.5% of the total study population. It was an indicator of high readmission rates in this population., Conclusion: Almost every other patient with PLEDs and/or NCS on cEEG had seizures after ICU discharge. A quarter of patients on cEEG in the ICU with PLEDs alone had seizures after discharge, and after excluding prior epilepsy, 17% of patients with PLEDs had seizures on follow-up. This was dramatically increased with the recording of PLEDs with NCS, with 60% of patients having seizures after discharge from the ICU and 48% of patients after excluding prior epilepsy. Patients with NCS on cEEG alone had 63% chance of seizure recurrence that dropped to 38% with exclusion of prior epilepsy. Future studies are needed to define the postdischarge outcomes including seizure recurrence in this patient population. This article is part of a Special Issue entitled "Status Epilepticus"., (Copyright © 2015 Elsevier Inc. All rights reserved.)