Nonconvulsive status epilepticus in the elderly: a case-control study

BACKGROUND: Nonconvulsive status epilepticus (NCSE) is a usually underdiagnosed and potentially treatable cause of altered awareness in the elderly. To assess etiologies, associations with other medical problems, and prognosis of NCSE in a population aged >75 years we performed a nested case-control study. METHODS: We retrospectively evaluated the clinical manifestations and EEG findings in 19 consecutive elderly patients (mean age 83.3 years) presenting with NCSE and compared them with 34 elderly patients (mean age 83.3 years) with altered mental status but without EEG evidence of NCSE. The variables compared included brain lesions on CT or MRI, number of concomitant chronic active diseases, previous neurological disorders, acute medical problems, the use and withdrawal of medications, and outcome. Statistical analysis was performed using chi-square test, t-test, Fisher's exact two-tailed test, and Wilcoxon rank sum test. RESULTS: The etiology of NCSE was epilepsy in 2, acute medical disorders in 14, and a cryptogenic cause in 4. The NCSE group had a more frequent history of epilepsy, 35% versus 8.8% (p = 0.028); tramadol use, 31% versus 0% (p = 0.00151); longer hospitalization, 25 days versus 7 days (p = 0.0004); and unfavorable outcome, 50% versus 5.8% (p = 0.00031). No significant differences were found in the other variables. Unfavorable outcome was associated with a higher number of comorbidities (>2) and to a severely altered mental status. CONCLUSIONS: NCSE is a serious cause of altered mental status in the elderly. Although its direct role in brain damage is controversial, elderly patients with NCSE have higher morbidity and worst prognosis than those with altered mental status without NCSE.     

Nonconvulsive status epilepticus and coma

Nonconvulsive status epilepticus (NCSE) in a comatose patient cannot be diagnosed without electroencephalography (EEG). In many advanced coma stages, the EEG exhibits continuous or periodic EEG abnormalities, but their causal role in coma remains unclear in many cases. To date there is no consensus on whether to treat NCSE in a comatose patient in order to improve the outcome or to retract from treatment, as these EEG patterns might reflect the end stages of a dying brain. On the basis of EEG, NCSE in comatose patients may be classified as generalized or lateralized. This review aims to summarize the ongoing debate of NCSE and coma and to critically reassess the available literature on coma with epileptiform EEG pattern and its prognostic and therapeutic implications. The authors suggest distinguishing NCSE proper and comatose NCSE, which includes coma with continuous lateralized discharges or generalized epileptiform discharges (coma‐LED, coma‐GED). Although NCSE proper is accompanied by clinical symptoms suggestive of status epilepticus and mild impairment of consciousness, such as in absence status or complex focal status epilepticus, coma‐LED and coma‐GED represent deep coma of various etiology without any clinical motor signs of status epilepticus but with characteristic epileptiform EEG pattern. Hence coma‐LED and coma‐GED can be diagnosed with EEG only. Subtle or stuporous status epilepticus and epilepsia partialis continua–like symptoms in severe acute central nervous system (CNS) disorders represent the borderland in this biologic continuum between NCSE proper and comatose NCSE (coma‐LED/GED). This pragmatic differentiation could act as a starting point to solve terminologic and factual confusion.     

Nonconvulsive status epilepticus in children: clinical and EEG characteristics

BACKGROUND: Nonconvulsive status epilepticus (NCSE) is a highly heterogeneous clinical condition that is understudied in the pediatric population. OBJECTIVE: To analyze the epidemiological, clinical, and electroencephalograpic features in pediatric patients with NCSE. METHODS: We identified 19 pediatric patients with NCSE from the epilepsy database of the Comprehensive Epilepsy Center at, Columbia University between June 2000 and December 2003. Continuous electroencephalographic (EEG) monitoring was analyzed and chart review was performed. RESULTS: The patients ranged from 1 month old to 17 years of age. Five patients developed NCSE following convulsive status epilepticus (CSE), and a further 12 patients developed NCSE after brief convulsions. Two developed NCSE as the first manifestation during a comatose state following hypoxic events. Acute hypoxic-ischemic injury was the most frequent etiology of NCSE in our population (5 of 19; 26%), followed by exacerbation of underlying neurometabolic disease (4 of 19; 21%), acute infection (3 of 19; 16%), change in antiepileptic drug regimen (3 of 19;16%), refractory epilepsy (2 of 19; 11%) and intracranial hemorrhage (2 of 19; 11%). Six patients had associated periodic lateralized epileptiform discharges (PLEDs), one had generalized periodic epileptiform discharges (GPEDs). Five (5 of 19; 26%) patients died of the underlying acute medical illness. Periodic discharges were associated with worse outcome. CONCLUSION: The majority of our patients with NCSE had preceding seizures in the acute setting prior to the diagnosis of NCSE, though most of these seizures were brief, isolated convulsions (12 patients) rather than CSE (five patients). Prolonged EEG monitoring to exclude NCSE may be warranted in pediatric patients even after brief convulsive seizures. Prompt recognition and treatment may be necessary to improve neurological outcome.     

Prevalence of nonconvulsive status epilepticus in comatose patients

BACKGROUND: Nonconvulsive status epilepticus (NCSE) is a form of status epilepticus (SE) that is an often unrecognized cause of coma. OBJECTIVE: To evaluate the presence of NCSE in comatose patients with no clinical signs of seizure activity. METHODS: A total of 236 patients with coma and no overt clinical seizure activity were monitored with EEG as part of their coma evaluation. This study was conducted during our prospective evaluation of SE, where it has been validated that we identify over 95% of all SE cases at the Medical College of Virginia Hospitals. Only cases that were found to have no clinical signs of SE were included in this study. RESULTS: EEG demonstrated that 8% of these patients met the criteria for the diagnosis of NCSE. The study included an age range from 1 month to 87 years. CONCLUSION: This large-scale EEG evaluation of comatose patients without clinical signs of seizure activity found that NCSE is an underrecognized cause of coma, occurring in 8% of all comatose patients without signs of seizure activity. EEG should be included in the routine evaluation of comatose patients even if clinical seizure activity is not apparent.     

Diagnosis and management of nonconvulsive status epilepticus in children

Nonconvulsive status epilepticus (NCSE) encompasses a wide range of diagnoses with variable outcomes and treatment recommendations. In children, NCSE can be observed in various conditions, including acute neurological injuries, specific childhood epilepsy syndromes and other neurological conditions, and can also be observed in individuals with learning difficulties. NCSE in children is thought to be under-recognized, and further studies examining the electrographic characteristics of very young children in NCSE would aid the prompt recognition of additional patients. Some subtypes of NCSE are probably more harmful than others, and long-term prospective studies are needed to evaluate the damaging potential of NCSE itself as opposed to that of the underlying circumstances in which it occurs. Specific data in childhood are clearly lacking, but extrapolation from adult studies indicates that aggressive treatment is most warranted in comatose patients. By contrast, a cautious approach seems to be indicated for absence status epilepticus, complex partial status epilepticus and electrical status epilepticus during sleep.     

Nonconvulsive status epilepticus following rotavirus gastroenteritis in two pediatric patients

BackgroundNonconvulsive status epilepticus (NCSE) comprises a range of conditions in which prolonged electrographic seizures result in nonconvulsive clinical symptoms. An understanding of NCSE is especially important in emergency care. Among the various causes of NCSE, an infectious etiology has been rarely reported to date.Case reportsWe report two pediatric cases of rotavirus gastroenteritis complicated by NCSE. In both cases, bilateral rhythmic delta activity (2.5–3 Hz) with occipital predominance fluctuated with the patient’s consciousness level. The paroxysmal waves disappeared completely and consciousness immediately and remarkably improved after intravenous midazolam infusion. The patients remained alive 10 and 2 years, respectively, after short-term oral anticonvulsant administration, with no epileptic seizures.ConclusionThe etiology of NCSE was identical and the clinical presentations were analogous in the two patients. The seizure semiology differed from that in benign convulsion with gastroenteritis. NCSE was considered the prominent cause of neurological symptoms; however, the pathogenic mechanism remains unclear, including the coexistence of acute encephalopathy.     

Aborted and refractory status epilepticus in children: a comparative analysis

PURPOSE: The aims of this retrospective study were: (1) to compare the demographics, clinical characteristics, etiology, and EEG findings of status epilepticus aborted with medication (ASE) and refractory status epilepticus (RSE), (2) to describe the treatment response of status epilepticus (SE), and (3) to determine predictors of long-term outcome in children with SE. METHODS: Medical records and EEG lab logs with ICD-9 diagnostic codes related to SE were reviewed. Patients younger than 18 years of age, hospitalized in 1994-2004 at the Mayo Clinic, Rochester, were included. RESULTS: One hundred fifty-four children had SE; 94 (61%) had ASE, and 60 (39.0%) had RSE. Family history of seizures, higher seizure frequency score, higher number of maintenance antiepileptic drugs (AEDs), nonconvulsive SE, and focal or electrographic seizures on initial EEG were associated with RSE by univariate analysis. In-hospital mortality was significantly higher in RSE (13.3%) than in ASE (2.1%). In the long term, survivors with RSE developed more new neurological deficits (p < 0.001) and more epilepsy (p < 0.004) than children with ASE. Children treated in a more aggressive fashion appeared to have better treatment responses (p < 0.001) and outcomes (p = 0.03). Predictors of poor outcome were long seizure duration (p < 0.001), acute symptomatic etiology (p = 0.04), nonconvulsive SE (NCSE) (p = 0.01), and age at admission <5 years (p = 0.05). DISCUSSION: Several patient and clinical characteristics are associated with development of RSE and poor outcome. Prospective, randomized trials that assess different treatment protocols in children with SE are needed to determine the optimal sequence and timing of medications.     

Nonconvulsive status epilepticus

Nonconvulsive status epilepticus (NCSE) is a heterogeneous disorder with multiple subtypes. Although attempts have been made to define and classify this disorder, there is yet no universally accepted definition or classification that encompasses all subtypes or electroclinical scenarios. Developing such a classification scheme is becoming increasingly important, because NCSE is more common than previously thought, with a bimodal peak, in children and the elderly. Recent studies have also shown a high incidence of NCSE in the critically ill. Although strong epidemiological data are lacking, NCSE constitutes about 25-50% of all cases of status epilepticus. For the purposes of this review, we propose an etiological classification for NCSE including NCSE in metabolic disorders, NCSE in coma, NCSE in acute cerebral lesions, and NCSE in those with preexisting epilepsy with or without epileptic encephalopathy. NCSE is still underrecognized, yet potentially fatal if untreated. Diagnosis can be established using an electroencephalogram (EEG) in most cases, sometimes requiring continuous monitoring. However, in comatose patients, diagnosis can be difficult, and the EEG can show a variety of rhythmic or periodic patterns, some of which are of unclear significance. Although some subtypes of NCSE are easily treatable, such as absence status epilepticus, others do not respond well to treatment, and debate exists over how aggressively clinicians should treat NCSE. In particular, the appropriate treatment of NCSE in patients who are critically ill and/or comatose is not well established, and large-scale trials are needed. Overall, further work is needed to better define NCSE, to determine which EEG patterns represent NCSE, and to establish treatment paradigms for different subtypes of NCSE.     

非抽搐性癫痫持续状态五例及文献复习

目的 探讨非抽搐性癫痫持续状态(NCSE)患者的临床表现及持续脑电监测的脑电图(EEG)特征.方法 对自2008年11月至2009年12月北京大学人民医院急诊科收治的5例NCSE患者行持续EEG监测检查,观察其EEG特征及临床表现.结果 5例均出现发作性意识障碍,其中4例出现烦躁、易怒或躁狂,3例表现出精神运动迟滞和遗忘,2例出现言语自动症和失认,1例出现定向障碍.所有患者的EEG均出现广泛性但一侧明显的异常放电.静脉注射地两泮后,3例患者临床症状迅速改善.结论 NCSE并非罕见,持续EEG监测能查出本病,早期诊断,及时治疗可改善患者预后,临床应注意与其他引起意识紊乱的疾病相鉴别.     

Etiology and prognosis of non-convulsive status epilepticus

Although non-convulsive status epilepticus (NCSE) is an important type of epilepsy, it is not often recognized. In order to analyze the clinical characteristics and outcome in patients with NCSE, we examined the medical records of patients with NCSE admitted to the Seoul National University Hospital between June 2005 and October 2008. The clinical details and electroencephalography records of 34 adult NCSE patients (aged over 16 years) were collected. Their mean age was 47 years (standard deviation 20 years, range, 16–87 years), and 20 were female. Twenty-seven patients (79.4%) showed decreased awareness with acute onset, and seven (20.6%) were obtunded or comatose. Ten patients (29.4%) had a history of epilepsy, and four (11.8%) had a history of stroke. NCSE was etiologically attributed to acute medical or neurological problems in 25 patients (73.5%), was cryptogenic in three (8.8%), and was secondary to underlying epilepsy in six (17.7%). Acute symptomatic etiology was associated with poor recovery (p = 0.048), with all unresponsive patients in this acute symptomatic group. Eight (23.5%) of the 34 NCSE patients did not recover or died, whereas nine (26.5%) recovered. Our study shows that the presence of acute symptoms or central nervous system infection is associated with poor outcome, suggesting that a high level of vigilance is required to identify and prevent complications.     

Efficacy and safety of perampanel oral loading in postanoxic super‐refractory status epilepticus: A pilot study

Refractory nonconvulsive status epilepticus (NCSE) occurs in 10%‐30% of patients following resuscitation after cardiac arrest. Both the optimal treatment and prognosis of postanoxic status epilepticus remain uncertain. We analyzed acute electroencephalographic changes, neurological outcome at 3 months, and adverse effects in consecutive postanoxic patients with super‐refractory NCSE treated with add‐on oral loading of perampanel. Eight postanoxic patients with super‐refractory NCSE were treated with perampanel (dose range = 6‐12 mg). All patients had continuous electroencephalographic monitoring showing definite generalized NCSE and favorable multimodal prognostic indicators (presence of brainstem reflexes, presence of bilateral N20 responses, absence of periodic discharges/generalized epileptic periodic discharges). In six patients (75%), status epilepticus resolved within 72 hours after administration of perampanel, without changing the comedication. Neurological outcomes at 3 months were return to normal or minimal disability in four patients (50%). A mild cholestatic liver injury, which required no specific treatment, was observed in five patients (62.5%). Perampanel 6‐12 mg oral loading appeared to be an effective option in selected patients with postanoxic super‐refractory NCSE with good prognostic indicators. In this patient population, our safety data indicate a risk of cholestasis.     

脑炎后癫痫持续状态进展为难治性癫痫持续状态及超级难治性癫痫持续状态的早期预测因素

目的 探讨脑炎后癫痫持续状态(SE)进展为难治性SE(RSE)及超级RSE(SRSE)的早期预测因素.方法 根据疾病进展情况将89例脑炎后SE患者分为非RSE组、RSE组及SRSE组.比较各组临床资料.结果 非RSE组、RSE组及SRSE组年龄、SE严重程度评分量表(STESS)评分、基于流行病学SE病死率评分(EMS...     

Nonconvulsive status epilepticus due to drug induced neurotoxicity in chronically ill children

Nonconvulsive status epilepticus (NCSE) is a specific form of status epilepticus and is defined as epileptic activity on an EEG without seizures and as an alteration in mental status lasting more than 30 min. NCSE may be caused by drugs, cerebrovascular events, metabolic disorders or toxins. Herein, we present four cases of patients with drug-induced NCSE who were chronically ill due to renal failure or childhood leukemia. NCSE should be suspected in patients with an altered mental status without clinical seizures who are being treated with multiple drugs.     

Non-convulsive status epilepticus; the rate of occurrence in a general hospital

BackgroundNon-convulsive status epilepticus (NCSE) has been increasingly recognized as a cause of impaired level of consciousness in the ICU and emergency rooms. The diagnosis can be easily missed without an electroencephalogram (EEG) given the paucity of overt clinical signs in this condition. Recently few published data estimated the prevalence to be between 3% and 8%.ObjectiveTo assess the rate of occurrence of NCSE among patients with various degrees of impaired consciousness referred to the Neurophysiology Laboratory at Vancouver General Hospital.MethodWe conducted a retrospective analysis of 451 adult patients (>16 years of age) with a question of NCSE or with an unknown cause of impaired level of consciousness between the years 2002 and 2004. NCSE was defined according to the Young's criteria of electrographic status epilepticus. NCSE was categorized into focal and generalized epileptic activity based on the continuous EEG monitoring (CEEG). Further analysis of age, gender and etiology was performed.ResultsOf 451 patients, EEG demonstrated electrographic status epilepticus with no overt clinical signs in 42 patients (9.3%). Median age was 61.8 years (range 21–94). According to etiology, 38.1% of patients with NCSE had hypoxic–anoxic injury, 19% had intracerebral hemorrhage (including trauma), 11.9% had the diagnosis of idiopathic or cryptogenic epilepsy, 7.1% had ischemic stroke, 4.8% were secondary to tumors and 4.8% to viral encephalitis.ConclusionThe rate of occurrence of NCSE in patients with decreased level of consciousness was 9.3%. The cohort represented a group of patients who were comatose and required assisted ventilation or had altered level of consciousness. Hypoxic brain injury was the most responsible etiology of NCSE in the cohort studied.     

Prognostic factors of status epilepticus in adults

Aim. Status epilepticus (SE) can lead to sequelae or even death. Identifying characteristics associated with poor outcome is crucial in guiding patient treatment. Based on our retrospective patient cohorts, potential prognostic factors were analysed. Methods. Patients consecutively treated for refractory convulsive status epilepticus (CSE) between 2001 and 2010 and non‐convulsive status epilepticus (NCSE) between 2004 and 2009 were studied. Outcome was compared to prognostic variables. Index SE episodes were used for the statistical analyses. Crosstabs and independent samples t‐test were applied. Due to sample size, logistic regression was performed for the combined groups. Results. In total, 50% (9/18) of index refractory CSE and 42% (16/38) of index NCSE episodes led to sequelae. Refractory CSE requiring narcosis for >20 hours was associated with poor outcome (p=0.05). De novo presentation (p=0.0001), long‐lasting SE (>2 hours) (p=0.014), age >65 years (p=0.002), and refractory SE (p=0.047) were predictors of poor outcome following NCSE. Based on logistic regression for combined refractory CSE and NCSE, de novo presentation was identified as the strongest predictor of sequelae. Conclusions. Older age and de novo SE are predictors of sequelae following NCSE. Prolonged SE is a risk factor for poor outcome, both for refractory CSE and NCSE. Aggressive initial treatment to terminate seizures during the early phase is therefore essential.     

Levetiracetam as a treatment option in non-convulsive status epilepticus

Non-convulsive status epilepticus (NCSE) is characterized by continuous or recurrent, generalized or focal epileptiform activity on the electroencephalogram and diverse clinical symptoms with alterations of mental state and vigilance. NCSE is not rare but certainly under diagnosed. There is some debate about how aggressive NCSE should be treated, as high dose anticonvulsants maybe partially responsible for the morbidity and mortality of patients with NCSE. We hypothesized that levetiracetam (LEV) as a well tolerated, highly effective new anticonvulsant, may be a safe treatment option. We retrospectively analyzed all (8) patients with NCSE who received levetiracetam from our database, compared with 11 patients with NCSE treated with conventional intravenous status medication as controls. These eight patients showed a marked clinical improvement with final cessation of ictal EEG-activity and clinical symptoms of NCSE after initiation of LEV within 3 days (mean 1.5 days). The response to conventional treatment was similarly effective but there were severe side effects whereas no relevant side effects in the LEV-treated group were noticed. A long-term follow up (6-36 months from discharge) revealed six patients with a persisting reduction in seizure frequency on medication with LEV. One patient changed the anticonvulsive medication because of inefficacy and one died from other causes than epilepsy 2 months after discharge from hospital. We found no significant differences in hospitalisation time, time in intensive care unit and outcome between the LEV group and the control group. This retrospectively acquired data suggests that LEV may be a well tolerated, effective treatment option in NCSE. This highlights the need for a prospective controlled study to further elucidate the utility of LEV in the treatment of NCSE, particularly as an intravenous formulation is now available.     

Nonconvulsive status epilepticus in patients with brain tumors

PurposeThe prevalence of nonconvulsive status epilepticus (NCSE) in brain tumor patients is unknown. Since NCSE has been associated with significant mortality and morbidity, early identification is essential. This study describes the clinical and EEG characteristics, treatment, and outcome in brain tumor patients with NCSE.MethodAll patients admitted to Mount Sinai Hospital from 2009 to 2012 with an ICD-9 brain tumor code were cross-referenced with the epilepsy department's database. EEGs from matching patients were reviewed for NCSE. Relevant information from the medical records of the patients with NCSE was extracted.Results1101 brain tumor patients were identified, of which 259 (24%) had an EEG and 24 (2%) had NCSE. The vast majority of seizures captured were subclinical with 13 patients (54%) having only subclinical seizures. Treatment resolved the NCSE in 22 patients (92%) with accompanying clinical improvement in 18 (75%) of those patients. Tumor recurrence or progression on MRI was associated with decreased 2-month survival (75% mortality, p = 0.035) compared to stable tumors (20% mortality). Patients with metastatic disease had median survival from tumor diagnosis of 1.2 months.ConclusionNCSE in brain tumor patients may be under diagnosed due to the frequent lack of outward manifestations and highly treatable with improvement in the majority of patients. NCSE patients with progressing brain lesions, tumor recurrence, or metastatic disease are at serious risk of mortality within 2 months. Continuous EEG monitoring in brain tumor patients with recent clinical seizures and/or a depressed level of consciousness may be critical in providing appropriate care.     

成人非惊厥性癫(癎)持续状态的临床及脑电图特点

目的:探讨成人非惊厥性癫癎持续状态(NCSE)的临床及脑电图特点.方法:对7例NCSE患者的临床资料进行回顾性分析.结果:本组7例NCSE患者中,复杂部分性NCSE6例,全面性NCSE1例.临床表现以不同程度意识障碍为主,伴反应迟钝、定向力障碍、自动症、精神行为异常等.脑电图检查均可见癎性发放,且癫癎波形态与临床表现有关.按癫癎持续状态治疗原则治疗后均明显好转.结论:NCSE患者临床表现复杂多样;脑电图改变明显且与临床症状可能有某些相关性,有助于诊断;及时治疗预后良好.     

Ambulatory non-convulsive status epilepticus evolving into a malignant form

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

Anti-NMDA receptor encephalitis presenting with focal non-convulsive status epilepticus in a child

A previously healthy 9-year-old girl presented to an emergency department (ED) with headache, dizziness, blurry vision, and abnormal visual perceptions. She was diagnosed with migraine, treated symptomatically, and discharged. Over the course of days, she became progressively somnolent, and returned to the ED, where she was found to have a right inferior quadrantanopsia and sixth nerve palsy. Magnetic resonance imaging (MRI) of the brain showed gyral swelling of the left parieto-occipital lobe. Continuous electroencephalogram (EEG) monitoring revealed focal non-convulsive status epilepticus (NCSE) in the left occipital region. Cerebrospinal fluid (CSF) was positive for antibodies directed against the N-methyl-d-aspartate receptor (NMDAR). This case is the first report of anti-NMDAR encephalitis presenting with focal non-convulsive status epilepticus (NCSE).