Status epilepticus in children: etiology, clinical features, and outcome

A systematic review and meta-analysis of ketamine in pediatric status epilepticus

OBJECTIVE

Status epilepticus (SE) is a common neurological medical emergency in the pediatric population, with 10%-40% of cases progressing to refractory SE (RSE), requiring treatment with anesthetic infusions. We present a systematic review and meta-analysis of the use of ketamine for the treatment of pediatric SE and its potential advantages over other anesthetic infusions.

METHODS

This review follows the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. Electronic databases, including PubMed, Cochrane Library, Ovid, Embase, and Google Scholar, were searched with the keywords "pediatrics," "status epilepticus," and "ketamine treatment." Randomized trials, prospective and retrospective cohort studies, and case reports were considered for inclusion.

RESULTS

Eighteen publications met the initial inclusion criteria. The 18 publications comprise 11 case reports, one nonconclusive clinical trial, two case series, and four retrospective cohorts. After excluding the case reports because of reporting bias, only the six case series and cohorts were included in the final analysis. There were 172 patients in the six included studies. The weighted age was 9.93 (SD = 10.29) years. The weighted maximum dose was 7.44 (SD = 9.39) mg/kg/h. SE cessation was attained in 51% (95% confidence interval = 43-59) of cases with the addition of ketamine. The heterogeneity was I2 = 0%, t2 = 0, χ2 (5) = 3.39 (p = .64).

SIGNIFICANCE

Pediatric RSE is difficult to treat, resulting in increased morbidity and mortality. Without strong recommendations and evidence regarding preferred agents, this review provides evidence that ketamine may be considered in managing SE in the pediatric population.

An Insight into the Current Understanding of Status Epilepticus: From Concept to Management

Status epilepticus (SE), a subset of epilepsy, represents a debilitating neurological disorder often associated with alarming mortality and morbidity numbers. Even though SE is one of the extensively researched topics with conspicuous data available in the literature, a scientific gap exists in understanding the heterogeneous facets of the disorder like occurrence, definition, classification, causes, molecular mechanisms, etc., thereby providing a defined management program. Cognizance of this heterogeneity and scientific limitation with its subsequent correlation to the recent advancements in medical and scientific domains would serve not only in bridging the gap but also in developing holistic and prompt management programs. Keeping this as an objective, an extensive literature survey was performed during this study, and key findings have been shared. The present study provides a semantic and perspective synopsis toward acknowledging the diversified nature of SE and its variants with respect to their definition, classification, etiology, diagnosis, and management.

Clinical Effectiveness of Levetiracetam Compared to Fosphenytoin in the Treatment of Benzodiazepine Refractory Convulsive Status Epilepticus

OBJECTIVES

To determine whether levetiracetam is an alternative to fosphenytoin to control Benzodiazepine Refractory Status Epilepticus (BRSE) in pediatric population and also to compare the acute drug related side-effects and ventilation requirement among the both arms of anti-epileptic drug therapy.

METHODS

All consecutive children admitted with BRSE were randomized to group A, who received fosphenytoin at 20 mg/kg phenytoin equivalents (PE) dose and group B who received levetiracetam at 40 mg/kg over 10 min. Time to terminate seizure (response latency) was measured. If seizure remained refractory after 20 min of test drug administration, appropriate drug escalation was made according to pediatrician's discretion. All primary and secondary outcome measures were compared between the two therapeutic groups.

RESULTS

Of 61 children enrolled over 18 mo period, 29 (47.5%) were randomized to group A and 32 (52.5%) were randomized to Group B. Baseline characteristics were comparable between the two groups. Among 61 children, 58(98%) required Pediatric Intensive Care Unit (PICU) admission and among those 5(8.2%) children required mechanical ventilation. Duration of PICU stay, hospital stay, the response latency and seizure recurrence were compared between both groups. Significant number of children received additional anti-epileptic drugs (AEDs) in fosphenytoin group [9/29(31%)] compared to levetiracetam group [2/32(7%)] to control seizure.

CONCLUSIONS

Levetiracetam may be an effective alternative to fosphenytoin in management of BRSE in children but multicentric trials with large sample size are needed to substantiate this observation.

Conventional and quantitative EEG in status epilepticus

PURPOSE

To summarize the use of continuous electroencephalographic monitoring (cEEG) in the diagnosis and management of pediatric convulsive status epilepticus (CSE) and subsequent non-convulsive seizures (NCS) with a focus on available guidelines and infrastructure. In addition, we provide an overview of quantitative EEG (QEEG) for the identification of NCS in critically ill children.

METHODS

We performed a review of the medical literature on the use of cEEG and QEEG in pediatric CSE. This included published guideline, consensus statements, and literature focused on the use of cEEG and QEEG to detect NCS.

RESULTS

cEEG monitoring is recommended for prompt recognition of ongoing seizures that may be subtle, masked by pharmacologic paralysis, and or converted from convulsive seizures to NCS after administration of anti-seizure medications. Evidence indicating that high seizure burden is associated with worse outcome has motivated prompt recognition and management of NCS. The American Clinical Neurophysiology Society's consensus statement recommends a minimum of 24 h to exclude electrographic seizures, while the Neurocritical Care Society's guideline suggests 48 h in patients that are comatose. The use of QEEG amongst electroencephalographers and critical care medicine providers is increasing for NCS detection in critically ill children. The sensitivity and specificity of QEEG to detect NCS ranges from 65 to 83% and 65-92%, respectively.

CONCLUSION

The use of cEEG is important to the diagnosis and treatment of NCS or subtle clinical seizures after pediatric CSE. QEEG allows cEEG data to be reviewed and interpreted quickly and is a useful tool for detection of NCS after CSE.

Retrospective review of pediatric status epilepticus in 116 Saudi patients: predictors of outcome

BACKGROUND

Status epilepticus (SE) is a common, life-threatening condition. Multiple factors are used to predict its outcome and evaluate its risks, and there have been only a few studies in Saudi Arabia.

OBJECTIVES

Investigate predictors of SE outcome.

DESIGN

Retrospective chart review study.

SETTING

Tertiary center, Riyadh.

PATIENTS AND METHODS

We reviewed all pediatric cases (age 14 years or younger) of SE admitted between January 2005 and December 2015, collecting data on age, sex, date of birth, developmental status, pre-existing neurological diseases, SE etiology, Glasgow Outcome Scale (GOS) scores, and electroencephalogram (EEG) findings. The outcome was categorized as poor based on any decrease in baseline GOS score or moderate-to-severe developmental delay in young children; otherwise outcome was considered good.

MAIN OUTCOME MEASURE

Outcome of SE.

RESULTS

One hundred and sixteen patients (54% boys) with ages from 1 month to 10 years were included in the analysis. Fifty-five (47.4%) had a poor outcome. The overall mortality rate related to SE was 2.6%. Four patients had an SE duration of more than 24 hours. Univariate and multivariate analysis revealed that poor outcome was related to symptomatic SE etiology and a history of epilepsy. Age, sex, SE duration, and EEG findings were not predictors of poor outcome.

CONCLUSION

Pediatric status epilepticus is highly associated with neurological morbidity. The main pre.dictor of outcome is underlying symptomatic etiology of SE and to a lesser degree the presence of a history of epilepsy. Duration does not seem to play a major role.

LIMITATIONS

The main limitation is the retrospective chart review nature of the study with possible bias.

Management of status epilepticus

Status epilepticus is a neurologic and medical emergency manifested by prolonged seizure activity or multiple seizures without return to baseline. It is associated with substantial medical cost, morbidity, and mortality. There is a spectrum of severity dependent on the type of seizure, underlying pathology, comorbidities, and appropriate and timely medical management. This chapter discusses the evolving definitions of status epilepticus and multiple patient and clinical factors which influence outcome. The pathophysiology of status epilepticus is reviewed to provide a better understanding of the mechanisms which contribute to status epilepticus, as well as the potential long-term effects. The clinical presentations of different types of status epilepticus in adults are discussed, with emphasis on the hospital course and management of the most dangerous type, generalized convulsive status epilepticus. Strategies for the evaluation and management of status epilepticus are provided based on available evidence from clinical trials and recommendations from the Neurocritical Care Society and the European Federation of Neurological Societies.

Review of a Large Clinical Series: Outcome of Pediatric Status Epilepticus Admitted to Intensive Care

The authors determine the relationship between seizure duration, etiology, and outcome in a modern intensive care setting and assess the usefulness of computed tomography (CT) and the empiric use of antimicrobial therapy. The design was a retrospective chart review. The setting was a tertiary pediatric critical care unit. Patients included 161 consecutive admissions to the critical care unit at the Hospital for Sick Children, Toronto, with status epilepticus over a 3-year period. There were no interventions. The overall mortality was 5.6%. A further 11% experienced an adverse neurological outcome as determined on hospital discharge. Mean seizure duration was 1.5 ± 2.8 hours in those children with a normal outcome, 1.7 ± 1.2 hours in those survivors with an abnormal neurological outcome ( P > 0.05), and 6.8 ± 12 hours in those who died ( P < 0.05). The CT scan was abnormal in 41% of cases. New findings that directly affected immediate management decisions were found in 20% of CT scans. Both the duration and etiology of status epilepticus affect the outcome. CT scanning should be done without delay, once the patient is stable. Antiviral therapy should be started empirically now that encephalitis is far more common than bacterial meningitis in this group of patients. Studies are lacking that compare the efficacy of drugs available to treat status epilepticus. These studies need to be done, as the findings could affect the duration of status.

Management of Status Epilepticus in Children

Status epilepticus is a common pediatric neurological emergency. Management includes prompt administration of appropriately selected anti-seizure medications, identification and treatment of seizure precipitant(s), as well as identification and management of associated systemic complications. This review discusses the definitions, classification, epidemiology and management of status epilepticus and refractory status epilepticus in children.

Yield of emergent neuroimaging in children with new-onset seizure and status epilepticus

PURPOSE

To determine the yield of emergent neuroimaging among children with new-onset seizures presenting with status epilepticus.

METHOD

We performed a cross-sectional study of children seen at a single ED between 1995 and 2012 with new-onset seizure presenting with status epilepticus. We defined status epilepticus as a single seizure or multiple seizures without regaining consciousness lasting 30 min or longer. Our primary outcome was urgent or emergent intracranial pathology identified on neuroimaging. We categorized neuroimaging results as emergent if they would have changed acute management as assessed by a blinded neuroradiologist and neurologist. To ensure abnormalities were not missed, we review neuroimaging results for 30 days following the initial episode of SE.

RESULTS

We included 177 children presenting with new-onset seizure with status epilepticus, of whom 170 (96%) had neuroimaging performed. Abnormal findings were identified on neuroimaging in 64/177 (36%, 95% confidence interval 29-43%) children with 15 (8.5%, 95% confidence interval 5.2-14%) children having urgent or emergent pathology. Four (27%) of the 15 children with urgent or emergent findings had a normal non-contrast computed tomography scan and a subsequently abnormal magnetic resonance image. Longer seizure duration and older age were associated with urgent or emergent intracranial pathology.

CONCLUSION

A substantial minority of children with new-onset seizures presenting with status epilepticus have urgent or emergent intracranial pathology identified on neuroimaging. Clinicians should strongly consider emergent neuroimaging in these children. Magnetic resonance imaging is the preferred imaging modality when available and safe.

Early predictors of status epilepticus-associated mortality and morbidity in children

BACKGROUND

Early predictors of status epilepticus (SE)-associated mortality and morbidity have not been systematically studied in children, considerably impeding the identification of patients at risk.

OBJECTIVES

To determine reliable early predictors of SE-associated mortality and morbidity and identify the etiology of SE-associated sequelae in Japanese children.

METHODS

We conducted a prospective multicenter study of clinical findings and initial laboratory data acquired at SE onset, and assessed outcomes at the last follow-up examination. In-hospital death during the acute period and neurological sequelae were classified as poor outcomes.

RESULTS

Of the 201 children who experienced their first SE episode, 16 exhibited poor outcome that was most commonly associated with acute encephalopathy. Univariate analysis revealed that the following were associated with poor outcomes: young age (⩽24 months); seizure duration >90 min; seizure intractability (failure of the second anticonvulsive drug); biphasic seizures; abnormal blood glucose levels (<61 or >250 mg/dL); serum aspartate aminotransferase (AST) ⩾56 U/L; and C-reactive protein (CRP) levels >2.00 mg/dL. Multivariate analysis revealed that young age, seizure intractability, abnormal blood glucose levels, and elevated AST and CRP levels were statistically significant.

CONCLUSIONS

Young age and seizure intractability were highly predictive of poor outcomes in pediatric SE. Moreover, abnormal blood glucose levels and elevated AST and CRP levels were predictors that might be closely associated with the etiology, especially acute encephalopathy and severe bacterial infection (sepsis and meningitis) in Japanese children.

Status epilepticus and refractory status epilepticus management

Status epilepticus (SE) describes persistent or recurring seizures without a return to baseline mental status and is a common neurologic emergency. SE can occur in the context of epilepsy or may be symptomatic of a wide range of underlying etiologies. The clinician's aim is to rapidly institute care that simultaneously stabilizes the patient medically, identifies and manages any precipitant conditions, and terminates seizures. Seizure management involves "emergent" treatment with benzodiazepines followed by "urgent" therapy with other antiseizure medications. If seizures persist, then refractory SE is diagnosed and management options include additional antiseizure medications or infusions of midazolam or pentobarbital. This article reviews the management of pediatric SE and refractory SE.

Higher mortality rate is associated with advanced age and periodic lateralized epileptiform discharges in patients with refractory status epilepticus

ObjectiveTo evaluate clinical data, electroencephalogram, etiology, classification, treatment, morbidity, and mortality in acute refractory status epilepticus.MethodsFifteen patients, mean age of 41.3 years-old, six males, with refractory status epilepticus, were retrospectively studied. All of them were followed by serial electroencephalogram or continuous electroencephalographic monitoring.ResultsThe most common comorbidity was hypertension. Seven (46.7%) patients were diagnosed with previous symptomatic focal epilepsy. More than one etiology was identified in 40.0% of the cases. Status epilepticus partial complex was the most common (n=14, 93.3%), and discrete seizures were the most observed initial ictal pattern. Continuous intravenous midazolam was used in nine (60.0%) patients and continuous thiopental in three (20.0%). Nine (60.0%) participants died, one (6.6%) had neurological sequelae, and five (33.3%) presented no neurological sequelae.ConclusionsHigher mortality rate was associated with advanced age and periodic lateralized epileptiform discharges. Midazolam proved to be a safe drug. The refractory status epilepticus is related to high mortality.

Cerebrospinal fluid findings in children with fever-associated status epilepticus: results of the consequences of prolonged febrile seizures (FEBSTAT) study

This prospective multicenter study of 200 patients with fever-associated status epilepticus (FSE), of whom 136 underwent a nontraumatic lumbar puncture, confirms that FSE rarely causes cerebrospinal fluid (CSF) pleocytosis. CSF glucose and protein levels were unremarkable. Temperature, age, seizure focality, and seizure duration did not affect results. CSF pleocytosis should not be attributed to FSE.

Risk factors associated with death in in-hospital pediatric convulsive status epilepticus

Objective

To evaluate in-patient mortality and predictors of death associated with convulsive status epilepticus (SE) in a large, multi-center, pediatric cohort.

Patients and Methods

We identified our cohort from the KID Inpatient Database for the years 1997, 2000, 2003 and 2006. We queried the database for convulsive SE, associated diagnoses, and for inpatient death. Univariate logistic testing was used to screen for potential risk factors. These risk factors were then entered into a stepwise backwards conditional multivariable logistic regression procedure. P-values less than 0.05 were taken as significant.

Results

We identified 12,365 (5,541 female) patients with convulsive SE aged 0–20 years (mean age 6.2 years, standard deviation 5.5 years, median 5 years) among 14,965,571 pediatric inpatients (0.08%). Of these, 117 died while in the hospital (0.9%). The most frequent additional admission ICD-9 code diagnoses in addition to SE were cerebral palsy, pneumonia, and respiratory failure.

Independent risk factors for death in patients with SE, assessed by multivariate calculation, included near drowning (Odds ratio [OR] 43.2; Confidence Interval [CI] 4.4–426.8), hemorrhagic shock (OR 17.83; CI 6.5–49.1), sepsis (OR 10.14; CI 4.0–25.6), massive aspiration (OR 9.1; CI 1.8–47), mechanical ventilation >96 hours (OR9; 5.6–14.6), transfusion (OR 8.25; CI 4.3–15.8), structural brain lesion (OR7.0; CI 3.1–16), hypoglycemia (OR5.8; CI 1.75–19.2), sepsis with liver failure (OR 14.4; CI 5–41.9), and admission in December (OR3.4; CI 1.6–4.1). African American ethnicity (OR 0.4; CI 0.2–0.8) was associated with a decreased risk of death in SE.

Conclusion

Pediatric convulsive SE occurs in up to 0.08% of pediatric inpatient admissions with a mortality of up to 1%. There appear to be several risk factors that can predict mortality. These may warrant additional monitoring and aggressive management.

Management of acute seizure and status epilepticus in pediatric emergency

Acute seizure and status epilepticus constitute one of the major medical emergencies in children. Among children, the incidence ranges from 4-38/100,000 children per year respectively. The incidence in developing countries is somewhat higher because of infections. Although, the definition of status epilepticus is based on duration of seizures, the operational definition is to treat any child who is brought seizing to the emergency room, as status epilepticus. An urgent time bound approach is of paramount importance when managing a child in status epilepticus. Benzodiazepines remain the first line antiepileptic drugs in the emergency room; a long acting drug (Lorazepam) is preferred when available. This is followed by Phenytoin (20 mg/kg) loading. In patients refractory to above drugs, valproate (30 mg/kg) loading is commonly used and if effective, followed by an infusion (5 mg/kg/h) for seizure free period of 6 h. In non-responders, a trial of Levetiracetam (40 mg/kg infused at 5 mg/kg/min) can be used before starting benzodiazepine or thiopental coma (3-4 mg/kg loading dose, followed by 2 mg/kg/min infusion). When pharmacological coma is initiated, the child needs to be shifted to pediatric intensive care unit for proper monitoring and titration of medications.

Status epilepticus

Status epilepticus is a common neurological emergency in childhood and associated with significant morbidity and mortality. Status epilepticus (SE) has been defined as continuous seizure activity lasting more than 30 min or 2 or more seizures in this duration without gaining consciousness between them. However, the operational definition has brought the time down to 5 min. Management can be broadly divided into initial stabilization, seizure termination, and evaluation and treatment of the underlying cause. Diagnostic evaluation and seizure control should be achieved simultaneously to improve outcome. Seizure termination is achieved by pharmacotherapy. Benzodiazepines are the first line drugs for SE. Commonly used drugs include lorazepam, diazepam, and midazolam. In children without an IV access, buccal or nasal midazolam or rectal diazepam can be used. Phenytoin as a second line agent is usually indicated when seizure is not controlled after one or more doses of benzodiazepines. If the seizures continue to persist, valproate, phenobarbitone or levetiracetam is indicated. Midazolam infusion is useful in refractory status epilepticus. Thiopentone, propofol or high dose phenobarbitone are considered for treatment of refractory status epilepticus. Prolonged SE is associated with higher morbidity and mortality. Long term neurological sequelae include epilepsy, behavioural problems, cognitive decline, and focal neurologic deficits.

Prognostic factors, morbidity and mortality in tonic-clonic status epilepticus: a review

OBJECTIVES

to determine how the duration of SE, the EEG findings during/after SE, the depth of coma at presentation and age impact on the prognosis of convulsive status epilepticus indepedent of aetiology and to analyse the outcome of status epilepticus with respect to mortality and morbidity (the latter measured in terms of functional decline, cognitive/intellectual decline and the prospective risk of epilepsy).

DESIGN

a systematic review of all studies of status epilepticus (SE) with greater then 30 patients published from the 01/01/1990 up until 31/12/2009.

RESULTS

oveall the longer the duration of SE the worse the prognosis particularly after 1-2h of continuous seizures although this affect may be lost after 10h. The depth of coma correlates well with outcome. Only periodic epileptiform discharges (PEDs) have been shown to be associated with a poorer outcome in most (but not all) studies although this is probably related to the underlying aetiology. Age is an important prognostic factor with children having a better prognosis then adults.

CONCLUSIONS

age and depth of coma at presentation appear to be the strongest predictors of outcome of SE independent of aetiology with the duration of SE and the EEG findings less important.

Outcome and prognosis of status epilepticus in children

The ultimate goal of treating status epilepticus is to provide the best opportunity for a good outcome. This review discusses the current literature on the outcome after status epilepticus in children, including the risk of recurrence, morbidity, and mortality. The outcome seems most dependent on etiology, with age and duration of status epilepticus also contributing. Convulsive status epilepticus has considerably more supporting literature, whereas the data on nonconvulsive status epilepticus are hindered by the lack of a standard definition and presumed under recognition. Future studies will need to address some of these methodological issues to provide the best information when discussing outcome with the family members of children with status epilepticus.

Lower plasma neuropeptide Y level in patients with atypical febrile convulsions

Febrile convulsion (FC) is the most common neurological disease in children. Cases with seizures that persist for more than 15 minutes or recurrent seizures within the same febrile illness are considered to be atypical and may have a different prognosis. Neuropeptide Y (NPY), an endogenous anticonvulsant that is widely distributed throughout the central nervous system, including the hippocampus, is known to prevent seizures by increasing the seizure threshold. Based on our previously finding that patients with atypical FC have lower concentrations of NPY, we hypothesized that the concentration of NPY may play a role in the development of atypical FC. To investigate this hypothesis, we used a radioimmunoassay to measure the plasma NPY concentration of 60 children with FC (typical FC, n = 46; atypical FC, n = 14) and 56 age-matched controls. The atypical FC group had significantly lower concentrations of NPY than children with typical FC and controls (66.47 +/- 19.11 pmol/L vs. 88.68 +/- 28.50 pmol/L and 86.82 +/- 22.66 pmol/L, respectively). Very low NPY levels were found in two patients; one patient (NPY level: 44.75 pmol/L) experienced prolonged seizures lasting for up to 1 hour and the other had recurrent seizures (three seizures) during the same febrile illness (NPY level: 33.53 pmol/L). These results suggest that patients with inadequate NPY inhibitory activity are more susceptible to atypical FC.

Hemorrhagic shock and encephalopathy syndrome--the markers for an early HSES diagnosis

Background

The hemorrhagic shock and encephalopathy syndrome (HSES) is a devastating disease that affects young children. The outcomes of HSES patients are often fatal or manifesting severe neurological sequelae. We reviewed the markers for an early diagnosis of HSES.

Methods

We examined the clinical, biological and radiological findings of 8 patients (4 months to 9 years old) who met the HSES criteria.

Results

Although cerebral edema, disseminated intravascular coagulopathy (DIC), and multiple organ failure were seen in all 8 cases during their clinical courses, brain computed tomography (CT) scans showed normal or only slight edema in 5 patients upon admission. All 8 patients had normal platelet counts, and none were in shock. However, they all had severe metabolic acidosis, which persisted even after 3 hours (median base excess (BE), -7.6 mmol/L). And at 6 hours after admission (BE, -5.7 mmol/L) they required mechanical ventilation. Within 12 hours after admission, fluid resuscitation and vasopressor infusion for hypotension was required. Seven of the patients had elevated liver enzymes and creatine kinase (CK) upon admission. Twenty-four hours after admission, all 8 patients needed vasopressor infusion to maintain blood pressure.

Conclusion

CT scan, platelet count, hemoglobin level and renal function upon admission are not useful for an early diagnosis of HSES. However, the elevated liver enzymes and CK upon admission, hypotension in the early stage after admission with refractory acid-base disturbance to fluid resuscitation and vasopressor infusion are useful markers for an early HSES diagnosis and helpful to indicate starting intensive neurological treatment.

Anticonvulsant medications in the pediatric emergency room and intensive care unit

Seizures are common in pediatric emergency care units, either as the main medical issue or in association with an additional neurological problem. Rapid treatment prolonged and repetitive seizures or status epilepticus is important. Multiple anti-convulsant medications are useful in this setting, and each has various indications and potential adverse effects that must be considered in regard to individual patients. This review discusses new data regarding anticonvulsants that are useful in these settings, including fosphenytoin, valproic acid, levetiracetam, and topiramate. A status epilepticus treatment algorithm is suggested, incorporating changes from traditional algorithms based on these new data. Treatment issues specific to complex medical patients, including patients with brain tumors, renal dysfunction, hepatic dysfunction, transplant, congenital heart disease, and anticoagulation, are also discussed.

Treatment of refractory status epilepticus: literature review and a proposed protocol

Refractory status epilepticus describes continuing seizures despite adequate initial pharmacologic treatment. This situation is common in children, but few data are available to guide management. We review the literature related to the pharmacologic treatment and overall management of refractory status epilepticus, including midazolam, pentobarbital, phenobarbital, propofol, inhaled anesthetics, ketamine, valproic acid, topiramate, levetiracetam, pyridoxine, corticosteroids, the ketogenic diet, and electroconvulsive therapy. Based on the available data, we present a sample treatment algorithm that emphasizes the need for rapid therapeutic intervention, employs consecutive medications with different mechanisms of action, and attempts to minimize the risk of hypotension. The initial steps suggest using benzodiazepines and phenytoin. Second steps suggest using levetiracetam or valproic acid, which exert few hemodynamic adverse effects and have multiple mechanisms of action. Additional management strategies that could be employed in tertiary-care settings, such as coma induction guided by continuous electroencephalogram monitoring and surgical options, are also discussed.

Incidence and outcome of convulsive status epilepticus in Kenyan children: a cohort study

Background

Convulsive status epilepticus (CSE) is the most common neurological emergency in childhood and is often associated with fever. In sub-Saharan Africa, the high incidence of febrile illnesses might influence the incidence and outcome of CSE. We aimed to provide data on the incidence, causes, and outcomes of childhood CSE in this region.

Methods

Between March, 2006, and June, 2006, we studied all children who had been admitted with CSE to a Kenyan rural district hospital in 2002 and 2003. Confirmed CSE had been observed directly; probable CSE was inferred from convulsions on arrival, requirement for phenobarbital or phenytoin, or coma with a recent history of seizures. We estimated the incidence with linked demographic surveillance, and risk factors for death and neurological sequelae were analysed by multivariable analysis.

Findings

Of 388 episodes of CSE, 155 (40%) were confirmed CSE and 274 (71%) were caused by an infection. The incidence of confirmed CSE was 35 (95% CI 27–46) per 100 000 children per year overall, and was 52 (21–107) and 85 (62–114) per 100 000 per year in children aged 1–11 months and 12–59 months, respectively. The incidence of all CSE was 268 (188–371) and 227 (189–272) per 100 000 per year in these age-groups. 59 (15%) children died in hospital, 81 (21%) died during long-term follow-up, and 46 (12%) developed neurological sequelae. Mortality of children with confirmed CSE while in hospital was associated with bacterial meningitis (adjusted relative risk [RR]=2·6; 95% CI 1·4–4·9) and focal onset seizures (adjusted RR=2·4; 1·1–5·4), whereas neurological sequelae were associated with hypoglycaemia (adjusted RR=3·5; 1·8–7·1) and age less than 12 months (adjusted RR=2·5; 1·2–5·1).

Interpretation

Prevention of infections and appropriate early management of seizures might reduce the incidence and improve the outcome of CSE in children in sub-Saharan Africa.

Outcome of convulsive status epilepticus: a review

The outcome of CSE in childhood depends mainly upon the cause but length of seizure may also be important

Mechanisms of status epilepticus: an evidence-based review

(1) Status epilepticus is a significant health problem that is under-recognized, yet is associated with major morbidity and mortality. (2) Mechanisms accounting for status epilepticus emergence from a single seizure, and for prolonged status epilepticus duration, remain unclear. (3) No randomized controlled trials, systematic reviews, or meta-analyses were found in any of the databases searched regarding the pathophysiologic mechanisms of status epilepticus in humans. (4) Ongoing and future research is likely to more clearly define the pathogenetic mechanisms of status epilepticus. This, in turn, is likely to encourage better treatment 'targeting' for particular aspects of the condition.

Aetiology, course and outcome of children admitted to paediatric intensive care with convulsive status epilepticus: a retrospective 5-year review

A retrospective case note study of the aetiology and course of children in convulsive status epilepticus (CSE) admitted to a large paediatric intensive care unit (PICU) was undertaken between January 1999 and April 2004. Status epilepticus was defined as a prolonged (>30 min) tonic-clonic seizure irrespective of whether the seizure had stopped prior to admission to PICU. During this period, 137 (74 male) children aged 1 month to 15 years were admitted to PICU with 147 episodes of status epilepticus. Forty-seven of the 137 children (34%) were admitted following a prolonged febrile seizure. Thirty-eight of the 137 children (28%) had a remote symptomatic cause for the CSE, 24 (18%) were admitted for an acute symptomatic cause and 15 (11%) were admitted with an acute exacerbation of a pre-existing idiopathic/cryptogenic epilepsy. Six children had a progressive encephalopathy and no cause was identified in the remaining 7 of the 137 children (5%). Forty-nine (36%) of the 137 children had pre-existing epilepsy. The mean duration of CSE was 44 min. Forty-nine (36%) children admitted to PICU who had received a benzodiazepine with either phenobarbital or phenytoin, required further treatment to terminate the presenting episode of CSE. Forty-two of these 49 were treated with thiopentone anaesthesia and the remaining 7 with a continuous infusion of midazolam, successfully terminating status in all. No child died. Of the 70 children considered to be previously neurologically and developmentally normal prior to admission, only 1 child demonstrated a new gross neurological abnormality at the time of latest follow-up. Seven patients (5%) developed new or de novo epilepsy.

Transient peripheral leukocytosis in children with afebrile seizures

The purpose of this study was (1) to demonstrate whether peripheral blood leukocytosis accompanies first afebrile seizures without bacterial infection, (2) to investigate the duration of leukocytosis, and (3) to assess the relationship between peripheral blood leukocytosis and seizure characteristics. Complete blood count was routinely obtained from all the patients. Blood and urine cultures were obtained from patients with leukocytosis. On the 24th hour of admission, a second complete blood count was obtained from patients with initial leukocytosis. Sixty-two children aged 4.0 +/- 3.6 years (range, 6 months-13 years)-31 boys (50%) and 31 girls (50%)--enrolled in the study. The findings showed that peripheral blood leukocytosis was found in 8% of afebrile children without status epilepticus and 41.6% of afebrile children with status epilepticus. An interesting finding of the study was that peripheral blood leukocytosis accompanied by afebrile seizures subsided in 24 hours. Transient leukocytosis could be found in children with afebrile seizures without bacterial infection.

Outcome of paediatric convulsive status epilepticus: a systematic review

We did a systematic review on the outcome of paediatric convulsive status epilepticus (CSE) and investigated the role of biological and non-biological variables in reported outcomes. The methodological quality of the 63 studies that met our inclusion criteria was assessed. Study design, type of study, and length of follow-up influenced the outcome. The studies with highest methodological quality are associated with better outcome: short-term mortality between 2.7% and 5.2% and morbidity other than epilepsy less than 15%. The incidence of subsequent epilepsy is not increased after cryptogenic CSE. Causal factor is the main determinant of outcome and the effect of age or duration is difficult to separate from the underlying cause. The risk of sequelae in unprovoked and febrile CSE is low. There is some evidence that CSE, especially febrile CSE, might cause hippocampal injury, although its role in the development of mesial temporal sclerosis is unknown.

[Markers of poor prognosis in convulsive status epilepticus]

OBJECTIVE

To characterize the variables that might be associated with mortality and the development of neurological deficits in children with convulsive status epilepticus.

PATIENTS AND METHODS

Children older than 1 month and younger than 15 years who were admitted to the pediatric intensive care unit of a university hospital between 2001 and 2004 were reviewed. Epidemiologic and clinical factors that might be related to neurological outcome at discharge from the unit were analyzed.

RESULTS

Forty-one patients (median age 24 months) were included. A total of 48.3% developed refractory convulsive status epilepticus. Six patients died (mortality 14.6%) during their intensive care unit stay and neurologic worsening was observed in 8.6% of survivors (adverse outcome in 22%). Symptomatic epilepsy was present in all patients who died and in 88.9% of those who recovered with severe neurologic sequelae. Uni- and multivariate analysis showed that adverse outcome was related to symptomatic origin and refractory convulsive status epilepticus (p < 0.05).

CONCLUSIONS

Mortality and morbidity is high in childhood convulsive status epilepticus. Refractory convulsive status and symptomatic origin were markers of poor outcome. Children who did not have symptomatic epilepsy had a favorable outcome.

Intellectual Prognosis of Status Epilepticus in Adult Epilepsy Patients: Analysis with Wechsler Adult Intelligence Scale-Revised

PURPOSE

Status epilepticus (SE) appears to cause cognitive dysfunction as well as other serious neurologic sequelae. To confirm whether SE produces a subsequent intellectual decline, we evaluated intellectual function prospectively in adult epilepsy patients with and without SE.

METHODS

Of 1,685 patients with epilepsy who underwent comprehensive neuropsychological testing in two national hospitals in Japan, 15 patients experienced an episode of SE afterward and underwent the second neuropsychological examination after the SE episode. Forty clinically matched patients with epilepsy, but without an episode of SE since their initial neuropsychological examination, were also reevaluated. We compared IQs and subscores from the Wechsler Adult Intelligence Scale-Revised between the two groups by repeated measures analysis of variance. In the patients who experienced an SE episode, SE-related variables (i.e., age at the SE episode and type and duration of SE) and epilepsy-related variables such as epilepsy type, lateralization of EEG abnormalities, the presence of mesial temporal sclerosis, and previous history of SE, were evaluated in relation to intellectual outcome.

RESULTS

Patients with SE, in comparison to those without SE, failed to show any significant post-SE intellectual decline. Furthermore, neither the SE-related variables nor the clinical characteristics were correlated with intellectual outcome.

CONCLUSIONS

Our findings suggest that SE does not lead to a significant intellectual decline in adult patients receiving treatment for epilepsy.

A systematic review of the epidemiology of status epilepticus

Population-based data on the incidence, aetiology, and mortality associated with status epilepticus (SE) are required to develop preventative strategies for SE. Through a systematic review, we aimed to assess the methodological quality as well as similarities, and differences between available population based studies in order to arrive at conclusions on the epidemiology of SE. All population-based studies where primary outcome was incidence, aetiology or mortality of SE were identified through a systematic search and synthesized. Methodological quality of studies were independently rated by two examiners using a unique scoring system. Seven population-based projects on SE yielding nine published reports and five abstracts were reviewed. Quality scores were in the range of 19-34 with a possible maximum of 40 (kappa scores 0.67-1.0). The incidence of SE has a bimodal distribution with peaks in children aged less than a year and the elderly. Most SE were acute symptomatic. Short-term mortality was 7.6-22% and long-term mortality was 43%. Age and aetiology were the major determinants of mortality. There are few population-based studies on SE but most are of good quality. Most studies are primarily or exclusively based on adult populations. There is limited information on the association of ethnicity and socio-economic status and SE.

Severe refractory status epilepticus owing to presumed encephalitis

The severe refractory type of status epilepticus is very rare in the pediatric population. Eight children with the severe refractory type of status epilepticus owing to presumed encephalitis are described. The age at the onset of status epilepticus of the eight study children ranged between 2.5 and 15 years. Seven of the eight children presented with fever several days prior to the onset of seizures. A comprehensive clinical and laboratory investigation failed to delineate a cause for their seizures. Burst suppression coma was induced by pentothal, midazolam, propofol, or ketamine in all of the children. The mean duration of anesthesia was 28 days (range 4-62 days), but the seizures persisted in spite of repeated burst suppression cycles in all of them. Two children died. Four of the surviving children continued to suffer from seizures, and cognitive sequelae were present throughout follow-up in four children. In summary, the severe refractory type of status epilepticus of the acute symptomatic type owing to relatively mild encephalitis carries a high mortality rate and poor morbidity in terms of seizures and cognition at follow-up.

Inappropriate emergency management of status epilepticus in children contributes to need for intensive care

OBJECTIVES

To characterise the clinical features, emergency pre-paediatric intensive care (PIC) treatment, and course of status epilepticus (SE) in children admitted to PIC. This may provide insight into reasons for admission to PIC and provide a framework for the development of strategies that decrease the requirement for intensive care.

DESIGN

Cross sectional, retrospective study.

SETTING

A tertiary paediatric institution's intensive care unit.

PARTICIPANTS

The admission database and all discharge summaries of each admission to a tertiary paediatric institution's PIC over a three year period were searched for children aged between 29 days and 15 years with a diagnosis of SE or related diagnoses. The case notes of potential cases of SE were systematically reviewed, and clinical and demographic data extracted using a standard data collection form.

RESULTS

Most children with SE admitted to PIC are aged less than 5 years, male to female ratio 1:1, and most (77%) will have had no previous episodes of SE. Prolonged febrile convulsions, SE related to central nervous system infection, and SE associated with epilepsy occur in similar proportions. Contrary to the Advanced Paediatric Life Support guidelines many children admitted to PIC for SE receive over two doses, or inadequate doses, of benzodiazepine. There is a risk of respiratory depression following administration of over two doses of benzodiazepine (chi2 = 3.4, p = 0.066). Children with SE admitted to PIC who had prehospital emergency treatment are more likely to receive over two doses of benzodiazepines (chi2 = 11.5, p = 0.001), and to subsequently develop respiratory insufficiency (chi2 = 6.2, p = 0.01). Mortality is low. Further study is required to determine the morbidity associated with SE in childhood requiring intensive care.

CONCLUSIONS

As the risk of respiratory depression is greater with more than two doses of benzodiazepines, clinicians should not disregard prehospital treatment of SE. As pre-PIC treatment of SE is inadequate in many cases, appropriate audit and modifications of standard guidelines are required.

Utility of antiepileptic drug monitoring in the pediatric emergency department

Convulsive disorders are common in the pediatric age group, and measurement of serum concentration of an antiepileptic drug (AED) is frequently ordered for epileptic patients in the emergency department (ED). The objective of this study was to develop a better understanding of the indications for, and consequences of, monitoring AED serum concentrations in the pediatric ED. Charts of 116 patients who visited the ED and were tested for blood levels of AED were retrospectively reviewed. Main outcome measures were number and percentage of levels outside the therapeutic range, discontinuation of an AED or introduction of a new one, dosage modifications, and admission to hospital. Two pediatricians and a pediatric neurologist aware only of patients' age, weight, diagnosis, history, clinical presentation, and drug details reviewed each case and on the basis of predetermined criteria decided whether measurement of AED was indicated. Mean age (+/- SD) of the study population was 7 +/- 5 years (range, 2 months-17 years). Forty-two patients (36%) were on monotherapy, and 74 (64%) were on polytherapy. Sixty-eight patients (59%) presented with increased seizure frequency, 7 (6%) with status epilepticus, and 13 (11%) with suspected AED toxicity. The remainder of the children presented with problems unrelated to epilepsy. No significant difference was found between patients with AED levels within the therapeutic range and those with levels outside it in the proportion of children needing dosage change, change in medication, or hospital admission (P = 0.5, 0.8, and 0.8, respectively). None of the patients presenting with status epilepticus and only 15% of those with increased seizure activity had subtherapeutic levels. Review of the cases suggested that measuring serum AED level was not indicated in 57 (49.1%) patients. In the pediatric ED, abnormal AED levels do not correlate with clinical management. Before ordering tests, physicians should consider whether their results would alter patient treatment.

Febrile seizures

Febrile seizures are the most common form of childhood seizures, occurring in 2 to 5% of children in the United States. Most febrile seizures are considered simple, although those with focal onset, prolonged duration, or that occur more than once within the same febrile illness are considered complex. Risk factors for a first febrile seizure, recurrence of febrile seizures, and development of future epilepsy are identifiable and varied. Children with febrile seizures encounter little risk of mortality and morbidity and have no association with any detectable brain damage. Recurrence is possible, but only a small minority will go on to develop epilepsy. Although antiepileptic drugs can prevent recurrent febrile seizures, they do not alter the risk of subsequent epilepsy. This has led to a changing view of how we approach the treatment of these common and largely benign seizures. This chapter will review the current understanding of the prognosis and management of febrile seizures.

Infantile status epilepticus in Tunisia. Clinical, etiological and prognostic aspects

This retrospective study includes 139 infants (74 girls and 65 boys) treated for status epilepticus at two University hospitals in Tunisia between 1990 and 1997. Their mean age was 11 months. The majority of seizures were generalized (74%) and lasted between 30 minutes and 1 hour (70%). The cause of status epilepticus was classified as acute symptomatic in 56, febrile in 57, remote symptomatic in nine, progressive neurologic in 10 and idiopathic in seven. Overall mortality was 15.8% and neurological sequelae were identified in 36% of the cases during the mean follow-up time of 3.5 years. The incidence of significant sequelae was a function of aetiology (especially acute symptomatic causes) and age (under 1 year of age). We conclude that the most frequent causes of infantile status epilepticus in Tunisia were fever and acute symptomatic causes. Status epilepticus among infants is an important public health problem, with significant associated mortality and morbidity. Management of status epilepticus can be improved by more rapid access to appropriate medical care.

Status epilepticus

Status epilepticus is a serious medical emergency that requires prompt and appropriate intervention. Maintenance of adequate vital function with attention to airway, breathing, and circulation; prevention of systemic complications; and rapid termination of seizures must be coupled with investigating and treating any underlying cause. In most patients with SE, the use of adequate dosages of first-line antiepileptic agents allows for the successful and rapid termination of SE and avoidance of potential neurologic complications. Refractory SE requires more aggressive treatment, often the use of intravenous anesthetic agents and intense monitoring, and therefore must be managed in a pediatric intensive care unit with a multidisciplinary approach. Large, controlled, multicenter, comparative studies are needed urgently to clarify better the optimal management of these patients.

Short-term outcomes of children with febrile status epilepticus

Febrile status epilepticus (SE) represents the extreme end of the complex febrile seizure spectrum. If there are significant sequelae to febrile seizures, they should be more common in this group. We have prospectively identified 180 children aged 1 month to 10 years who presented with febrile SE over a 10-year period in Bronx, New York, and Richmond, Virginia. They were compared with 244 children who presented with their first febrile seizure (not SE) in a prospective study done in the Bronx. The mean age of the children with febrile SE was 1.92 years, and of the comparison group, 1.85 years. Duration of SE was 30-59 min in 103 (58%), 60-119 min in 43 (24%), and > or =120 min in 34 (18%). Focal features were present in 64 (35%) of cases. There were no deaths and no cases of new cognitive or motor handicap. Children with febrile SE were more likely to be neurologically abnormal (20% vs. 5%; p < 0.001), to have a history of neonatal seizures (3% vs. 0; p = 0.006) and a family history of epilepsy (11% vs. 5%; p = 0.05) and less likely to have a family history of febrile seizures (15% vs. 27%; p = 0.01) than were children in the comparison group. The short-term morbidity and mortality of febrile SE are low. There are differences in the types of children who have febrile SE compared with those who experience briefer febrile seizures. Long-term follow-up of this cohort may provide insight into the relationship of prolonged febrile seizures and subsequent mesial temporal sclerosis.

[Morbidity and mortality of status epilepticus]

The outcome of status epilepticus (SE) depends on its cause, clinical presentation, duration, treatment, and the patient's age. It has been estimated that in nearly all cases (about 98%), mortality is directly or indirectly due to the underlying disorder. It is particularly significant in generalized tonic-clonic SE. The clinical presentation of SE is strongly cause-dependent, and its etiology is markedly age-dependent in infants, children, young adults and the elderly. When SE is of long duration, due to its etiology, delayed treatment, or inappropriate drug administration, it results in brain lesions and the accompanying risk of sequelae or death. The highest mortality rates in SE are those at the extremes of the average life-span, i.e., in infants and young children and in the elderly. Possible SE sequelae are neurologic deficits or cognitive impairment, and/or unprovoked seizures. The outcome in cases of SE has considerably improved due to the early prescription of effective antiepileptic drugs.

Epileptogenesis in immature rats following recurrent status epilepticus

Strong evidences link status epilepticus (SE) in childhood with the later development of epilepsy. Pilocarpine-induced SE in developing rats leads to late appearance of spontaneous epileptic seizures only when SE is induced after the 18th day of life. We examined the possibility that 3 consecutive episodes of pilocarpine-induced SE on postnatal days 7, 8 and 9 could induce behavioral, electrographic and histological epileptic changes in adult life. The animals also underwent behavioral tests (inhibitory step-down avoidance, skinner box, rota-rod, open field and elevated plus-maze). EEG recordings made at the age of 30, 60 and 90 days showed the occurrence of several episodes of spikes and/or polyspikes appearing simultaneously in hippocampus and cortex. Only three isolated spontaneous seizures were observed during the whole period of observation (120 days). The long-term effects of three consecutive episodes of SE include increased spontaneous exploratory activity, learning impairment, and reduced anxiety when tested on P60. Our findings provide evidence for EEG changes and cognitive deficits in adult life following recurrent SE on postnatal days 7-9.

Does status epilepticus in children cause developmental deterioration and exacerbation of epilepsy?

The aims of this study were to determine predictors of abnormal outcome, neurodevelopmental deterioration, new-onset epilepsy, refractory epilepsy, and recurrent status epilepticus in children presenting with status epilepticus. For all children presenting to Royal University Hospital, Saskatoon, Saskatchewan, Canada, with status epilepticus between January 1987 and December 1996, demographic data, details of status epilepticus (etiology, duration, treatment, and investigations), developmental milestones, seizures prior to and following status epilepticus, recurrent status epilepticus, and neurologic examination findings at status epilepticus and at follow-up were collected by chart review, patient interview, and neurologic examination. Neurodevelopmental outcome was determined for all subjects except those who died during the initial hospitalization. Predictors of new-onset epilepsy, refractory epilepsy, and recurrent status epilepticus were determined for children followed for 3 months or more after status epilepticus. At follow-up, 79% were abnormal neurologically. Predictors included etiology (nonfebrile or nonidiopathic), perinatal difficulties, preceding developmental delay, abnormal initial neurologic examination; and abnormal neuroimaging. Thirty-four percent showed neurodevelopmental deterioration; predictors included etiology (nonidiopathic or nonfebrile), young age at status epilepticus (12 months or less), and abnormal neuroimaging. Thirty-six percent with no history of seizures preceding status epilepticus developed epilepsy and 25% developed refractory epilepsy. Fifty percent of children had recurrent status epilepticus. In conclusion, very few children presenting in status epilepticus were normal at follow-up. Sequelae were seen predominantly in those with a nonidiopathic, nonfebrile etiology, whereas those with idiopathic or febrile status epilepticus did well.