Nonconvulsive status epilepticus in adults: Electroclinical differences between proper and comatose forms

Subacute encephalopathy with seizures in alcoholics (SESA) syndrome

PURPOSE

To describe four patients with subacute encephalopathy with seizures in alcoholics (SESA) syndrome and to review its clinical, electroencephalogram (EEG), neuroimaging and diagnostic criteria.

METHODS

We conducted a retrospective analysis of a series of prospectively collected patients who met the previously established criteria for SESA syndrome. Subsequently, we reviewed all cases published in the English language from the initial description to the present.

RESULTS

We found 34 patients diagnosed with SESA syndrome to date, including the four cases of SESA in this report. Fourteen out of 34 (41.1 %) patients were over 60 years of age. Twelve (35.2 %) were abstinent from alcohol and in 4 (11.7 %) there was excessive alcohol consumption. Triggering causes were unknown in 18 cases (53.0 %). All cases (100 %) presented with an altered mental status. Fourteen (41.1 %) subjects had a history of epileptic seizures in the context of acute withdrawal syndrome (AWS). Twenty (58.8 %) patients had focal motor seizures (FMSs), 24 (70.5 %) bilateral tonic-clonic seizures (BTCSs), and 15 (44.1 %) focal impaired awareness seizures (FIASs). In 8 (23.5 %), criteria for focal nonconvulsive status epilepticus (NCSE) were met. Twenty-eight (82.3 %) subjects had transient neurological deficits. In 29 (85.2 %) subjects, lateralized periodic discharges (LPDs) were observed in the EEG. Areas of increased T2/FLAIR signal and restricted diffusion were mentioned in 22 subjects (64.7 %). Transfer to the intensive care unit (ICU) was necessary in 8 (23.5 %) subjects. Thirteen (38.2 %) had recurrent episodes. Enduring cerebral sequelae had been mentioned in 9 (26.4 %) cases. The most used anti-seizure medication (ASM) was levetiracetam, followed by phenytoin and lacosamide.

CONCLUSION

SESA syndrome represents a well-defined subtype of focal NCSE in patients with chronic alcoholism. Its prompt recognition can facilitate the initiation of early ASM therapy and help implement a video-EEG evaluation and neuroimaging strategy.

Nonconvulsive Status Epilepticus: Clinical Findings, EEG Features, and Prognosis in a Developing Country, Mexico

PURPOSE

There is a lack of clinical and epidemiological knowledge about nonconvulsive status epilepticus (NCSE) in developing countries including Mexico, which has the highest prevalence of epilepsy in the Americas. Our aim was to describe the clinical findings, EEG features, and outcomes of NCSE in a tertiary center in Mexico.

METHODS

We conducted a retrospective case series study (2010-2020) including patients (≥15 years old) with NCSE according to the modified Salzburg NCSE criteria 2015 with at least 6 months of follow-up. We extracted the clinical data (age, sex, history of epilepsy, antiseizure medications, clinical manifestations, triggers, and etiology), EEG patterns of NCSE, and outcome. Descriptive statistics and multinomial logistic regression were used.

RESULTS

One hundred thirty-four patients were analyzed; 74 (54.8%) women, the total mean age was 39.5 (15-85) years, and 71% had a history of epilepsy. Altered state of consciousness was found in 82% (including 27.7% in coma). A generalized NCSE pattern was the most common (32.1%). The NCSE etiology was mainly idiopathic (56%), and previous uncontrolled epilepsy was the trigger in 48% of patients. The clinical outcome was remission with clinical improvement in 54.5%. Multinomial logistic regression showed that the patient's age (P = 0.04), absence of comorbidities (P = 0.04), history of perinatal hypoxia (P = 0.04), absence of clinical manifestations (P = 0.01), and coma (P = 0.03) were negatively correlated with the outcome and only the absence of generalized slowing in the EEG (P = 0.001) had a significant positive effect on the prognosis.

CONCLUSIONS

Age, history of perinatal hypoxia, coma, and focal ictal EEG pattern influence negatively the prognosis of NCSE.

Nonconvulsive status epilepticus in neurocritical care: A critical reappraisal of outcome prediction scores

OBJECTIVE

Nonconvulsive status epilepticus (NCSE) is a frequent condition in the neurocritical care unit (NCCU) patient population, with high morbidity and mortality. We aimed to assess the validity of available outcome prediction scores for prognostication in an NCCU patient population in relation to their admission reason (NCSE vs. non-NCSE related).

METHODS

All 196 consecutive patients diagnosed with NCSE during the NCCU stay between January 2010 and December 2020 were included. Demographics, Simplified Acute Physiology Score II (SAPS II), NCSE characteristics, and in-hospital and 3-month outcome were extracted from the electronic charts. Status Epilepticus Severity Score (STESS), Epidemiology-Based Mortality Score in Status Epilepticus (EMSE), and encephalitis, NCSE, diazepam resistance, imaging features, and tracheal intubation score (END-IT) were evaluated as previously described. Univariable and multivariable analysis and comparison of sensitivity/specificity/positive and negative predictive values/accuracy were performed.

RESULTS

A total of 30.1% died during the hospital stay, and 63.5% of survivors did not achieve favorable outcome at 3 months after onset of NCSE. Patients admitted primarily due to NCSE had longer NCSE duration and were more likely to be intubated at diagnosis. The receiver operating characteristic (ROC) for SAPS II, EMSE, and STESS when predicting mortality was between .683 and .762. The ROC for SAPS II, EMSE, STESS, and END-IT when predicting 3-month outcome was between .649 and .710. The accuracy in predicting mortality/outcome was low, when considering both proposed cutoffs and optimized cutoffs (estimated using the Youden Index) as well as when adjusting for admission reason.

SIGNIFICANCE

The scores EMSE, STESS, and END-IT perform poorly when predicting outcome of patients with NCSE in an NCCU environment. They should be interpreted cautiously and only in conjunction with other clinical data in this particular patient group.

Prevalence, electroclinical spectrum and effect on the outcome of non-convulsive status epilepticus in critically ill patients; the utility of routine electroencephalogram

OBJECTIVES

To highlight the importance of routine electroencephalogram (rEEG) in detecting non-convulsive status epilepticus (NCSE), describing the electroclinical spectrum and effect on outcome in critically ill patients with altered mental status (CIPAMS).

METHODS

This retrospective study was conducted at King Fahd University Hospital. Clinical data and EEG recordings of CIPAMS to rule out NCSE were reviewed. All patients had at least 30 minutes of EEG recording. The Salzburg Consensus criteria (SCC) were applied to diagnose NCSE. The data analysis was performed using SPSS version 22.0. The chi-squared test was used to compare categorical variables such as etiologies, EEG findings, and functional outcomes. Multivariable analysis was performed to identify the predictors of unfavorable outcomes.

RESULTS

A total of 323 CIPAMS referred to rule out NCSE were enrolled (mean age 57.8 ± 20 years). Nonconvulsive status epilepticus was diagnosed in 54 (16.7%) patients. A significant association was found between subtle clinical features and NCSE (P =< 0.01). Acute ischemic stroke (18.5%), sepsis (18.5%), and hypoxic brain injury (22.2%) were the main etiologies. The previous history of epilepsy was significantly associated with NCSE (P = 0.01). Acute stroke, cardiac arrest, mechanical ventilation, and NCSE were statistically associated with unfavorable outcomes. Nonconvulsive status epilepticus was an independent predictor of unfavorable outcomes (P = 0.02, OR = 2.75, CI = 1.16-6.48) during multivariable analysis. Sepsis was associated with higher mortality (P =< 0.01, OR = 2.4, CI = 1.4-4.0).

SIGNIFICANCE

Our study findings suggest that the utility of rEEG in detecting NCSE in CIPAMS should not be underestimated. Important observations further indicate that repeating rEEG is advisable, as this would increase the likelihood of identifying NCSE. Thus, physicians should consider and repeat rEEG when evaluating CIPAMS in order to detect NCSE, which is an independent predictor of unfavorable outcomes. Nonetheless, further studies comparing rEEG and cEEG yields are required to augment the current understanding of the electroclinical spectrum and better describe NCSE in CIPAMS.

Typical absence status epilepticus in older people: syndromic delineation

Objective We describe the clinical, electroencephalograph^ and neuroimaging findings of older patients with typical absence status epilepticus (ASE). Methods This investigation was a retrospective analysis of prospectively collected consecutive patients between January 2011 and October 2021. All patients ≥60 years with impairment of awareness and continuous generalized, rhythmic, synchronous and symmetric epileptiform discharges and normal background on video-electroencephalogram (vEEG) were included. Results Six patients were identified with a diagnosis of typical ASE. The mean age was 67 years. Five could be classified as idiopathic generalized epilepsy (IGE) though two had been erroneously categorized as cryptogenic focal epilepsy (FE). In one, the episode of ASE was thought to represent the beginning of late-onset IGE (de novo late-onset typical ASE). In all cases, ASE was controlled within the first 24 hours. Significance Typical ASE is a rare cause of confusion in the elderly population requiring urgent vEEG evaluation. It most frequently represents reactivation of a previous IGE, in effect related to patients with epilepsy with onset in childhood or adolescence, not previously diagnosed or treated, representing rather the debut of (de novo) late-onset IGE.

Focal nonconvulsive status epilepticus in children: clinical and electroencephalographic features in 38 patients

PURPOSE

The aim of this study was to characterize clinically, etiologically, and electroencephalographically focal Nonconvulsive Status Epilepticus (NCSE) in children. Moreover, we tried to identify focal NCSE features distinguishing between different ages, NCSE etiologies, and cases of de novo onset.

METHODS

We retrospectively identified patients (aged 1 month to 18 years) who had EEG-documented focal NCSE between January 2001 and December 2019. We analyzed the clinical features, etiology, and EEG features of each event.

RESULTS

Thirty-eight patients were included in this study. NCSE had a de novo onset in 26 patients and was the first manifestation of previously undiagnosed epilepsy in 12 patients. NCSE etiology was acute symptomatic in 13 patients. Acute symptomatic NCSE events were mainly observed in hospitalized children, were usually longer, and had a significantly higher frequency of repetitive EEG patterns than other etiologies. In patients with epilepsy, the etiology of NCSE was remote symptomatic in 14, progressive in 6, and cryptogenic in 5; a definite or suspected genetic disorder was observed in 11. EEG localization was frequent in posterior regions (18 children). Eleven patients had refractory NCSE and 4 required admission to the intensive care unit.

CONCLUSION

Focal NCSE in children is more frequent in the first years of life, mainly involves posterior regions, and often has de novo onset. In the case of de novo focal NCSE both acute symptomatic NCSE and new-onset epilepsy must be considered and investigated. A higher frequency of repetitive EEG patterns and an inpatient setting are significantly associated with acute symptomatic NCSE.

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

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

Diazepam for outpatient treatment of nonconvulsive status epilepticus in pediatric patients with Angelman syndrome

Nonconvulsive status epilepticus (NCSE) is present in multiple pediatric neurogenetic syndromes with epileptic encephalopathies. While intravenous (IV) medications are used inpatient for treatment of critical illness-related NCSE, there is no consensus on treatment of ambulatory NCSE. Up to 50% of patients with Angelman syndrome (AS) have NCSE with myoclonic or atypical absence status. Here we report our experience in pediatric patients with AS and NCSE treated outpatient with a tapering course of oral diazepam. We conducted a chart review of 104 patients seen in the Angelman Syndrome Clinic at Massachusetts General Hospital from January 2008 to March 2017, who met the criteria. Response to treatment was defined as cessation of NCSE symptoms with electroencephalogram (EEG) confirmation when possible. Twenty-one patients with NCSE were identified, and 13 patients (9 male) with 25 episodes of NCSE were included. Mean age at NCSE episode was 5years 4months (15months-12years). Six patients had one episode of NCSE, and 7 patients had recurrent episodes (mean: 2.7; range: 2-4). Median diazepam treatment was 6days (4-12days), with a mean dose of 0.32mg/kg/day divided over 2-3 administrations, decreased every 2days. Nine episodes required multiple courses; however, oral diazepam alone was ultimately successful in 80% (20/25) of NCSE episodes. Oral diazepam was well-tolerated with no major side effects. A short course of oral diazepam is well-tolerated and effective in patients with AS who have ambulatory NCSE. It may be considered prior to escalating to inpatient care in AS and possibly other epilepsy syndromes.

Clinical presentation, epidemiology, neurophysiological findings, treatment and outcome of nonconvulsive status epilepticus: a 3-year prospective, hospital-based study

Objective: This study reports the prevalence of Nonconvulsive Status Epilepticus (NCSE) in patients with altered mental status (AMS), and describes the clinical presentation, etiology, neurophysiological findings, neuroimaging, treatment, and outcome of NCSE in Qatar. Recording duration of continuous EEG monitoring was also discussed.

Methods: This was a 3-year, prospective, hospital-based study involving patients with AMS and continuous EEG monitoring admitted to the Emergency and ICUs of Hamad Hospital, Qatar. Patients with confirmed diagnosis of NCSE were compared to the patients who did not show EEG and clinical features compatible with NCSE. Descriptive statistics in terms of mean with standard deviation, as well as frequency and percentages for categorical variables, were calculated; Student’s t test as well as Chi-square tests or Fisher’s exact tests were applied. Logistic regressions NSCE was performed using significance level 0.05 for independent variables at univariate analysis.

Results: Number of patients with AMS and continuous EEG monitoring was 250. Number of patients with EEG compatible with NCSE: 65 (age range, 12–79 ys; m, 37; f, 28). Number of controls (defined as patients with EEG not compatible with NCSE): 185 (age range, 12–80 ys; m, 101; f, 84). Rate of occurrence of NCSE in patients with AMS: 26%. NCSE group was younger than controls (p < .001). Twenty patients with NCSE (31%) and 35 patients in the control group (19%) died. Death was more frequent in comatose NCSE compared to controls (p < .0007). NCSE proper and comatose NCSE had longer hospital stays than controls (p < .02 and p < .03, respectively). Complete recovery occurred in 26 NCSE patients (40%) and in 98 controls (53%) (p < .08). Twenty-one patients (31%) presented with refractory NCSE: 12 patients survived, 9 died.

Conclusion: This was the first prospective study reporting a high number of NCSE in Qatar, a small country in the MENA region. This prevalence (26%) was in the middle range. NCSE patients did not perform better than controls, outcome being worse with comatose NCSE. NCSE is an emergent condition warranting expedited diagnosis and management. Three days of continuous EEG monitoring were able to diagnose most cases of NCSE.

An update on the recognition and treatment of non-convulsive status epilepticus in the intensive care unit

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.

Nonconvulsive status epilepticus in adults - insights into the invisible

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.

Use of BIS VISTA bilateral monitor for diagnosis of intraoperative seizures, a case report

Changes in BIS (bispectral index) VISTA bilateral monitoring system associated with intraoperative episodes of generalized and focal seizures, during total intravenous anesthesia for resection of a left frontal parasagittal meningioma, are herein described.

Rhythmic and periodic EEG patterns of 'ictal-interictal uncertainty' in critically ill neurological patients

OBJECTIVES

To study periodic and rhythmic EEG patterns classified according to Standardized Critical Care EEG Terminology (SCCET) of the American Clinical Neurophysiology Society and their relationship to electrographic seizures.

METHODS

We classified 655 routine EEGs in 371 consecutive critically ill neurological patients into (1) normal EEGs or EEGs with non-specific abnormalities or interictal epileptiform discharges, (2) EEGs containing unequivocal ictal EEG patterns, and (3) EEGs showing rhythmic and periodic EEG patterns of 'ictal-interictal uncertainty' (RPPIIIU) according to SCCET.

RESULTS

313 patients (84.4%) showed normal EEGs, non-specific or interictal abnormalities, 14 patients (3.8%) had EEGs with at least one electrographic seizure, and 44 patients (11.8%) at least one EEG containing RPPIIIU, but no EEG with electrographic seizures. Electrographic seizures occurred in 11 of 55 patients (20%) with RPPIIIU, but only in 3 of 316 patients (0.9%) without RPPIIIU (p⩽0.001). Conversely, we observed RPPIIIU in 11 of 14 patients (78.6%) with electrographic seizures, but only in 44 of 357 patients (12.3%) without electrographic seizures (p⩽0.001).

CONCLUSIONS

On routine-EEG in critically ill neurological patients RPPIIIU occur 3 times more frequently than electrographic seizures and are highly predictive for electrographic seizures.

SIGNIFICANCE

RPPIIIU can serve as an indication for continuous EEG recordings.

Super-refractory nonconvulsive status epilepticus secondary to fat embolism: A clinical, electrophysiological, and pathological study

BACKGROUND

Fat embolism syndrome (FES) is a rare complication of long-bone fractures and joint reconstruction surgery. To the best of our knowledge, we describe the clinical, electrophysiological, neuroimaging, and neuropathological features of the first case of super-refractory nonconvulsive status epilepticus (sr-NCSE) secondary to fat embolism.

CLINICAL CASE

An 82-year-old woman was transferred to our intensive care unit because of a sudden decrease of consciousness level, right hemiparesis, and acute respiratory failure in the early postoperative period of knee prosthesis surgery. Brain computed tomography (TC) including angio-CT and CT perfusion was normal. An urgent video-electroencephalography (v-EEG) evaluation showed continuous sharp-and slow-wave at 2.0-2.5 Hz in keeping with the diagnosis of generalized NCSE. Epileptiform discharges ceased after the administration of 5mg of intravenous diazepam, and background activity constituted by diffuse theta waves was observed without clinical improvement. Treatment with levetiracetam (1000 mg/day) and sedation with propofol and midazolam were initiated. Moreover, continuous v-EEG monitoring was also started. Despite antiepileptic therapy, epileptiform activity recurred after the interruption of profound sedation, and valproate and lacosamide were added during the ensuing days. Magnetic resonance imaging (MRI) disclosed small scattered foci of acute ischemic infarcts and diffuse petechiae involving the basal ganglia and pons and centrum semiovale in keeping with fat embolism. Super-refractory nonconvulsive status epilepticus remained without control for 2 weeks. Finally, the patient died. The clinical autopsy revealed a bilateral lung fat embolism associated with a hemorrhagic infarction in the left lower lobe. Fatty lesions were also seen in the intestine and pancreas. Scattered microscopic cerebral infarcts associated with fat emboli in the capillaries were noticed, affecting both supra- and infratentorial structures. In addition, occasional focal areas of ischemic injury showing filiform neurons with reactive astrocytic gliosis background consistent with acute lesions were observed in CA3.

CONCLUSIONS

Fat embolism should be considered a potential cause of sr-NCSE. This article is part of a Special Issue entitled "Status Epilepticus".

The Clinical Features and Prognosis of Patients With Nonconvulsive Status Epilepticus in the Neurological Intensive Care Unit of a Tertiary Referral Center in Turkey

The availability of video electroencephalography monitoring (VEEGM) in neurological intensive care units has allowed the recognition and treatment of nonconvulsive status epilepticus (NCSE). However, little is known about characteristics, management, and outcomes in patients with NCSE in developing countries. We retrospectively reviewed the video-EEG reports of 120 patients who were monitored from November 2009 to March 2013. Indications for video-EEG were mostly unexplained alterations of consciousness or witnessed convulsive seizures. We identified the clinical characteristics, treatment regimes, and outcomes of patients with NCSE and tried to determine which parameters were associated with prognosis. NCSE was detected in 12/120 (10%) patients (3 females, 9 males; age 24-86 years). Admission diagnoses were: stroke (3), epilepsy (3), autoimmune limbic encephalitis (3), herpes encephalitis (1), presumed encephalitis-cardiac arrest (1), and malignancy (1). Eight patients had witnessed convulsive seizures before video-EEG. Interictal periodic epileptiform discharges were detected in 9 patients. In one-third of patients, ≥2 EEG recordings were required to capture seizures. In addition to anticonvulsants, 3 patients received immunosuppressive therapy, while intravenous anesthetics were given to 7 patients. Four patients (33.3%; 1 female, 3 males; age 51-67 years; etiology: stroke, autoimmune encephalitis, encephalitis-cardiac arrest, and malignancy; Glasgow coma scale (GCS) score <8 in 3 patients; all had periodic discharges; intravenous anesthetics were used) died in the intensive care unit. NCSE is not an infrequent finding in neurological intensive care units, thus necessitating prolonged video-EEG monitoring in patients at risk. Witnessed convulsions may indicate the presence of nonconvulsive seizures in patients with altered consciousness. Repeated recordings may increase the detection of ictal events. Periodic epileptiform discharges are commonly observed and may predict poor prognosis. Mortality seems to be influenced mostly by the underlying etiology.

Brain resuscitation and prognosis after cardiac arrest

Brain injury represents the major cause of long-term disability and mortality among patients resuscitated from cardiac arrest. Brain-directed therapies include maintenance of normal oxygenation, hemodynamic support to optimize cerebral perfusion, glycemic control, and targeted temperature management. Pertinent guidelines and recommendations are reviewed for brain-directed treatment. The latest clinical trial data regarding targeted temperature management are also reviewed. Contemporary prognostication among initially comatose cardiac arrest survivors uses a combination of clinical and electrophysiologic tests. The most recent guidelines for prognostication after cardiac arrest are reviewed. Ongoing research regarding the effects of induced hypothermia on prognostic algorithms is also reviewed.

Clinical and electroencephalographic findings in acutely ill adults with non-convulsive vs convulsive status epilepticus

BACKGROUND

Non-convulsive status epilepticus (NCSE) indicates a change in the mental state with no motor manifestations, being a clinical expression of prolonged epileptiform activity. In contrast to convulsive status epilepticus (CSE), no unified treatment recommendations have been proposed so far. We were interested to review the clinical and encephalographic characteristics in hospitalized patients with NCSE and CSE and compare their treatment and outcome.

PATIENTS AND METHODS

The electroencephalographic recording records of adult patients with electrographic status epilepticus were retrieved. Patients' clinical records were then analyzed.

RESULTS

Fifty-three patients with CSE and 25 patients with NCSE were identified. Background diseases, neuroimaging findings and complications were similar in CSE and NCSE. Anoxia was a more frequent etiological factor only for myoclonic SE. Patients with CSE presented more often with coma. The number of drugs used for treatment was similar, but anesthetics drugs were administered more frequently in patients with CSE. The 30-day mortality rate was higher in myoclonic SE and generalized tonic-clonic SE, but the outcome on discharge in terms of survival and recovery was comparable between CSE and NCSE.

CONCLUSIONS

The results of the present study show that the clinical parameters of NCSE in acutely ill patients do not substantially differ from those of patients with CSE. Moreover, despite more severe mental changes and the need for more anesthetic drugs for treatment of CSE, the final outcome did not differ between both groups. This might indicate that NCSE in acutely ill patients should be regarded as seriously as CSE.

Good functional outcome after prolonged postanoxic comatose myoclonic status epilepticus in a patient who had undergone bone marrow transplantation

In anoxic coma, myoclonic status epilepticus and other nonreactive epileptiform patterns are considered as signs of poor prognosis. We report the case of a good recovery in a prolonged comatose myoclonic status epilepticus (MSE) after a cardiac arrest (CA) treated with mild therapeutic hypothermia (TH) in a patient who had undergone a bone marrow transplantation for Hodgkin's lymphoma. This case emphasizes the opportunity of performing an electroencephalogram (EEG) in the acute period after an hypoxic-ischemic insult and underlines the diagnostic difficulties between MSE and Lance-Adams syndrome, which classically occurs after the patient has regained consciousness, but can also begin while the patient is still comatose or sedated. Major problems in prognostication for postarrest comatose patients will also be pointed out.

Electroencephalographic criteria for nonconvulsive status epilepticus: synopsis and comprehensive survey

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.