Demographics and outcomes of patients with pediatric febrile convulsive status epilepticus

A Dynamic Balance between Neuronal Death and Clearance in an in Vitro Model of Acute Brain Injury

In in vitro models of acute brain injury, neuronal death may overwhelm the capacity for microglial phagocytosis, creating a queue of dying neurons awaiting clearance. Neurons undergoing programmed cell death are in this queue, and are the most visible and frequently quantified measure of neuronal death after injury. However, the size of this queue should be equally sensitive to changes in neuronal death and the rate of phagocytosis. Using rodent organotypic hippocampal slice cultures as a model of acute perinatal brain injury, serial imaging demonstrated that the capacity for microglial phagocytosis of dying neurons was overwhelmed for 2 weeks. Altering phagocytosis rates (e.g., by changing the number of microglia) dramatically changed the number of visibly dying neurons. Similar effects were generated when the visibility of dying neurons was altered by changing the membrane permeability for stains that label dying neurons. Canonically neuroprotective interventions, such as seizure blockade, and neurotoxic maneuvers, such as perinatal ethanol exposure, were mediated by effects on microglial activity and the membrane permeability of neurons undergoing programmed cell death. These canonically neuroprotective and neurotoxic interventions had either no or opposing effects on healthy surviving neurons identified by the ongoing expression of transgenic fluorescent proteins.SIGNIFICANCE STATEMENT In in vitro models of acute brain injury, microglial phagocytosis is overwhelmed by the number of dying cells. Under these conditions, the assumptions on which assays for neuroprotective and neurotoxic effects are based are no longer valid. Thus, longitudinal assays of healthy cells, such as serial assessment of the fluorescence emission of transgenically expressed proteins, provide more accurate estimates of cell death than do single-time point anatomic or biochemical assays of the number of dying neurons. More accurate estimates of death rates in vitro will increase the translatability of preclinical studies of neuroprotection and neurotoxicity.

A dynamic balance between neuronal death and clearance after acute brain injury

After acute brain injury, neuronal apoptosis may overwhelm the capacity for microglial phagocytosis, creating a queue of dying neurons awaiting clearance. The size of this queue should be equally sensitive to changes in neuronal death and the rate of phagocytosis. Using rodent organotypic hippocampal slice cultures as a model of acute perinatal brain injury, serial imaging demonstrated that the capacity for microglial phagocytosis of dying neurons was overwhelmed for two weeks. Altering phagocytosis rates, e.g. by changing the number of microglia, dramatically changed the number of visibly dying neurons. Similar effects were generated when the visibility of dying neurons was altered by changing the membrane permeability for vital stains. Canonically neuroprotective interventions such as seizure blockade and neurotoxic maneuvers such as perinatal ethanol exposure were mediated by effects on microglial activity and the membrane permeability of apoptotic neurons, and had either no or opposing effects on healthy surviving neurons.

Significance

After acute brain injury, microglial phagocytosis is overwhelmed by the number of dying cells. Under these conditions, the assumptions on which assays for neuroprotective and neurotoxic effects are based are no longer valid. Thus longitudinal assays of healthy cells, such as assessment of the fluorescence emission of transgenically-expressed proteins, provide more accurate estimates of cell death than do single-time-point anatomical or biochemical assays. More accurate estimates of death rates will increase the translatability of preclinical studies of neuroprotection and neurotoxicity.

Early steroid pulse therapy for children with suspected acute encephalopathy: An observational study

Steroid pulse therapy is widely used to treat virus-associated acute encephalopathy, especially the cytokine storm type; however, its effectiveness remains unknown. We sought to investigate the effectiveness of early steroid pulse therapy for suspected acute encephalopathy in the presence of elevated aspartate aminotransferase (AST) levels.We enrolled children admitted to Hyogo Children's Hospital between 2003 and 2017 with convulsions or impaired consciousness accompanied by fever (temperature >38°C). The inclusion criteria were: refractory status epilepticus or prolonged neurological abnormality or hemiplegia at 6 hours from onset, and AST elevation >90 IU/L within 6 hours of onset. We excluded patients with a neurological history. We compared the prognosis between the groups with or without steroid pulse therapy within 24 hours. A good prognosis was defined as a Pediatric Cerebral Performance Category Scale (PCPC) score of 1-2 at the last evaluation, within 30 months of onset. Moreover, we analyzed the relationship between prognosis and time from onset to steroid pulse therapy.Fifteen patients with acute encephalopathy and 5 patients with febrile seizures were included in this study. Thirteen patients received steroid pulse therapy within 24 hours. There was no between-group difference in the proportion with a good prognosis. There was no significant correlation between PCPC and timing of steroid pulse therapy (rs = 0.253, P = .405). Even after excluding 2 patients with brainstem lesions, no significant correlation between PCPC and steroid pulse therapy timing (rs = 0.583, P = .060) was noted. However, the prognosis tended to be better in patients who received steroid pulse therapy earlier.Steroid pulse therapy within 24 hours did not improve the prognosis in children with suspected acute encephalopathy associated with elevated AST. Still, even earlier administration of treatment could prevent the possible neurological sequelae of this condition.

Thiamylal anaesthetic therapy for febrile refractory status epilepticus in children

PURPOSE

To evaluate barbiturate anaesthetic therapy using thiamylal for febrile refractory status epilepticus (fRSE) in children.

METHODS

This was a review of a prospectively-collected database between April 2012-March 2016 for fRSE cases treated with thiamylal anaesthetic therapy in a single paediatric hospital in Japan. The sample comprised 23 children (median age, 23 months) with fRSE that underwent thiamylal anaesthetic therapy for convulsive seizures lasting longer than 60 min, sustained after intravenous administration of benzodiazepine and non-benzodiazepine anticonvulsants. The intervention comprised protocol-based thiamylal anaesthetic therapy with bolus administration. We measured the dose and time required to achieve the burst suppression pattern (BSP) on electroencephalography, seizure recurrence, death, neurological sequelae, and complications.

RESULTS

All patients except one reached the BSP. The thiamylal median dose until reaching the BSP was 27.5 mg/kg, and the median time from thiamylal administration to reaching the BSP was 109.5 min. There was one case of immediate treatment failure and one of withdrawal seizure, but no breakthrough seizure. No deaths occurred during treatment, and neurological sequelae occurred in four cases (17%). Vasopressors were administered in all cases. Other complications included 11 cases of pneumonia and one of enterocolitis.

CONCLUSION

We revealed the time and dose required to reach the BSP with thiamylal anaesthetic therapy using bolus administration in children. Our results suggested that reaching the BSP with bolus administration requires markedly less time than without bolus administration, rarely causes seizure recurrence in paediatric fRSE, and causes haemodynamic dysfunction and infections as often as observed without bolus administration.

Recent treatment patterns and variations for pediatric acute encephalopathy in Japan

BACKGROUND

Treatments for pediatric acute encephalopathy are largely empiric with limited evidence to support. This study investigated recent trends in clinical practice patterns for pediatric acute encephalopathy at a national level.

METHOD

Discharge records were extracted for children with acute encephalopathy for the fiscal years 2010-2015 using a national inpatient database in Japan. We ascertained the secular trends in medications, diagnostic and therapeutic procedures, healthcare costs, in-hospital mortality, and length of hospital stays (LOS), using mixed effect linear or logistic regression models. We also ascertained variations and clustering of the practice patterns across different hospitals using hierarchical cluster analyses.

RESULTS

A total of 4692 eligible inpatients were identified. From 2010 to 2015, we observed increasing trends in hospitalization costs, corticosteroid and edaravone use and a decreasing trend in LOS. Despite changes in treatments, the rates of home respiratory support and in-hospital mortality were constant during the study period. Hierarchical cluster analyses showed that 6 hospital groups showed largely different therapeutic strategies to the same disease regardless of mortality rates. Hospitals with more intensive treatment practices were likely to have higher mortality, while hospitals with less intensive treatment practices were likely to have the lower mortality. However, hospitals in one group (group 1) had less intensive treatment practice even though they had the highest mortality.

CONCLUSIONS

We provided novel insights into the recent trends in treatments for pediatric acute encephalopathy. Therapeutic strategies varied between hospitals, suggesting the importance of pursuing evidence-based treatment strategy and promoting standardized practices to pediatric acute encephalopathy.

Intelligence and memory outcomes within 10 years of childhood convulsive status epilepticus

Long-term intelligence and memory outcomes of children post convulsive status epilepticus (CSE) have not been systematically investigated despite evidence of short-term impairments in CSE. The present study aimed to describe intelligence and memory outcomes in children within 10 years of CSE and identify potential risk factors for adverse outcomes. In this cohort study, children originally identified by the population-based North London Convulsive Status Epilepticus in Childhood Surveillance Study (NLSTEPSS) were prospectively recruited between July 2009 and February 2013 and invited for neuropsychological assessments and magnetic resonance imaging (MRI) scans. Full-scale intelligence quotients (FSIQs) were measured using the Wechsler Abbreviated Scales of Intelligence (WASI), and global memory scores (GMS) was assessed using the Children's Memory Scale (CMS). The cohort was analyzed as a whole and stratified into a prolonged febrile seizures (PFS) and non-PFS group. Their performance was compared with population norms and controls. Regression models were fitted to identify predictors of outcomes. With a mean of 8.9 years post-CSE, 28.5% of eligible participants were unable to undertake testing because of their severe neurodevelopmental deficits. Children with CSE who undertook formal testing (N = 94) were shown to have significantly lower FSIQ (p = 0.001) and GMS (p = 0.025) from controls; the PFS group (N = 34) had lower FSIQs (p = 0.022) but similar memory quotients (p = 0.88) with controls. Intracranial volume (ICV), developmental delay at baseline, and active epilepsy at follow-up were predictive of long-term outcomes in the non-PFS group. The relationship between ICV and outcomes was absent in the PFS group despite its presence in the control and non-PFS groups. Post-CSE, survivors reveal significant intelligence and memory impairments, but prognosis differs by CSE type; memory scores are uncompromised in the PFS group despite evidence of their lower FSIQ whereas both are compromised in the non-PFS group. Correlations between brain volumes and outcomes differ in the PFS, non-PFS, and control groups and require further investigation.

Fosphenytoin vs. continuous midazolam for pediatric febrile status epilepticus

BACKGROUND

Fosphenytoin (fPHT) and continuous intravenous midazolam (cMDL) had commonly been used as second-line treatments for pediatric status epilepticus (SE) in Japan. However, there is no comparative study of these two treatments.

METHODS

We included consecutive children who 1) were admitted to Kobe Children's Hospital because of convulsion with fever and 2) were treated with either fPHT or cMDL as second-line treatment for convulsive SE lasting for longer than 30 min. We compared, between the fPHT and cMDL groups, the proportion of barbiturate coma therapy (BCT), incomplete recovery of consciousness, mechanical ventilation, and inotropic agents.

RESULTS

The proportion of BCT was not significantly different between the two groups (48.7% [20/41] in fPHT and 35.3% [29/82] in cMDL, p = 0.17). The prevalence of incomplete recovery of consciousness, mechanical ventilation, and inotropic agents was not different between the two groups. After excluding 49 patients treated with BCT, incomplete recovery of consciousness 6 h and 12 h after onset was more frequent in the cMDL group than in the fPHT group (71.7% vs. 33.3%, p < 0.01; 56.6% vs. 14.2%, p < 0.01; respectively). Mechanical ventilation was more frequent in the cMDL group than in the fPHT group (32.0% vs. 4.7%, p = 0.01).

CONCLUSIONS

Our results suggest that 1) the efficacy of fPHT and cMDL is similar, although cMDL may prevent the need for BCT compared with fPHT, and 2) fPHT is relatively safe as a second-line treatment for pediatric SE in patients who do not require BCT.

Long-term behavioural outcomes after paediatric convulsive status epilepticus: a population-based cohort study

AIM

To describe behavioural and psychiatric outcomes of children within 10 years of convulsive status epilepticus (CSE).

METHOD

Children originally identified by the population-based North London Convulsive Status Epilepticus in Childhood Surveillance Study were followed-up between July 2009 and February 2013. They were grouped into epilepsy- and non-epilepsy-related CSE, and compared with population norms and healthy controls using the Strengths and Difficulties Questionnaire; the Autism Spectrum Screening Questionnaire; and the Swanson, Nolan, and Pelham questionnaire. Children who scored above recommended clinical cut-offs on any scale were invited for a neuropsychiatric assessment. Regression models were fitted to identify clinically relevant covariates associated with behavioural outcomes.

RESULTS

At a mean follow-up of 8.1 years post-CSE, 28% of enrolled children were found to have a psychiatric disorder. Children with epilepsy-related CSE scored higher than norms on all scales and children with non-epilepsy-related CSE scored higher than norms on the Strengths and Difficulties Questionnaire and the Autism Spectrum Screening Questionnaire. Presence of seizures at baseline and recurrence of CSE was associated with worse outcomes in the group with epilepsy. Intellectual abilities were associated with behavioural outcomes in all participants.

INTERPRETATION

A large proportion of children manifest behavioural issues 8 years after CSE. The present data highlight the need for behavioural screening in children with neurodevelopmental impairments post-CSE.

WHAT THIS PAPER ADDS

Eight years post convulsive status epilepticus (CSE), 37% of parents report behavioural issues. Of enrolled children, 28% were found to have a Diagnostic and Statistical Manual mental disorder. Intellectual abilities are strongly associated with behavioural outcomes in children post-CSE.

New-Onset Status Epilepticus in Pediatric Patients: Causes, Characteristics, and Outcomes

BACKGROUND

Many pediatric patients presenting with status epilepticus have no history of seizures.

METHODS

We retrospectively analyzed the clinical characteristics of patients aged one month to 21 years who presented during six consecutive years with convulsive status epilepticus and without a history of seizures. New-onset refractory status epilepticus was defined as status epilepticus refractory to two lines of treatment, without an identified cause in the first 48 hours.

RESULTS

Of 460 patients with status epilepticus, 79 (17.2%) presented with new-onset status epilepticus, including four (0.9%) with new-onset refractory status epilepticus. Of those patients, 54.4% were female, and the median age was 3.5 years (IQR: 1.08 to 6.75). The median seizure duration was 20 minutes (IQR: 10 to 40 minutes). Etiology was unknown in 36.7%, symptomatic in 30.3%, provoked in 16.5%, and provoked with an existing symptomatic etiology in 16.5%. Patients were followed for a median duration of 63 months (IQR: 21 to 97). The mortality rate was 3.8%. Of 55 patients who were developmentally normal at baseline, 29.1% had a significant cognitive impairment at the last follow-up, and 20% had academic difficulties or behavioral problems. Patients with symptomatic etiology had greater odds of having cognitive and behavioral problems compared with patients with unknown etiology (odds ratio = 3.83, P = 0.012).

CONCLUSIONS

Patients with new-onset status epilepticus are at risk for recurrent seizures, recurrent status epilepticus, death, and subsequent cognitive-behavioral impairment. Specific monitoring and care interventions might be required in this high-risk population.

Thermoregulation and age

The thermoregulatory functions may vary with age. Thermosensitivity is active in neonates and children; both heat production and heat loss effector mechanisms are functional but easily exhaustable. Proportional and lasting defense against thermal challenges is difficult, and both hypothermia and hyperthermia may easily develop. Febrile or hypothermic responses to infections or endotoxin can also develop, together with confusion. In small children febrile convulsions may be dangerous. In old age the resting body temperature may be lower than in young adults. Further, thermosensitivity decreases, the thresholds for activating skin vasomotor and evaporative responses or metabolism are shifted, and responses to thermal challenges are delayed or insufficient: both hypothermia and hyperthermia may develop easily. Infection-induced fevers are often limited or absent, or replaced by hypothermia. Various types of brain damage may induce special forms of hypothermia, hyperthermia, or severe fever. Impaired mental state often accompanies hypothermia and hyperthermia, and may occasionally be a dominant feature of infection (instead of the most commonly observed fever). Aging brings about a turning point in women's life: the menopause. The well-known influence of regular hormonal cycles on the thermoregulation of a woman of fertile age gives way to menopausal hot flushes caused by estrogen withdrawal. Not all details of this thermoregulatory anomaly are fully understood yet.

Neurologic Outcomes Following Care in the Pediatric Intensive Care Unit

Purpose of review

With increasing survival of children requiring admission to pediatric intensive care units (PICU), neurodevelopmental outcomes of these patients are an area of increased attention. Our goal was to systematically review recently published literature on neurologic outcomes of PICU patients.

Recent Findings

Decline in neurofunctional status occurs in 3%-20% of children requiring PICU care. This proportion varies based on primary diagnosis and severity of illness, with children admitted for primary neurologic diagnosis, children who suffer cardiac arrest or who require invasive interventions during the PICU admission, having worse outcomes. Recent research focuses on early identification and treatment of modifiable risk factors for unfavorable outcomes, and on long-term follow-up that moves beyond global cognitive outcomes and is increasingly including tests assessing multidimensional aspects of neurodevelopment.

Summary

The pediatric critical care research community has shifted focus from survival to survival with favorable neurologic outcomes of children admitted to the PICU.

Epilepsy in children with a history of febrile seizures

PURPOSE

Febrile seizure, the most common type of pediatric convulsive disorder, is a benign seizure syndrome distinct from epilepsy. However, as epilepsy is also common during childhood, we aimed to identify the prognostic factors that can predict epilepsy in children with febrile seizures.

METHODS

The study comprised 249 children at the Korea University Ansan Hospital who presented with febrile seizures. The relationship between the subsequent occurrence of epilepsy and clinical factors including seizure and fever-related variables were analyzed by multivariate analysis.

RESULTS

Twenty-five patients (10.0%) had additional afebrile seizures later and were diagnosed with epilepsy. The subsequent occurrence of epilepsy in patients with a history of febrile seizures was associated with a seizure frequency of more than 10 times during the first 2 years after seizure onset (P<0.001). Factors that were associated with subsequent occurrence of epilepsy were developmental delay (P<0.001), preterm birth (P=0.001), multiple seizures during a febrile seizure attack (P=0.005), and epileptiform discharges on electroencephalography (EEG) (P=0.008). Other factors such as the age at onset of first seizure, seizure duration, and family history of epilepsy were not associated with subsequent occurrence of epilepsy in this study.

CONCLUSION

Febrile seizures are common and mostly benign. However, careful observation is needed, particularly for prediction of subsequent epileptic episodes in patients with frequent febrile seizures with known risk factors, such as developmental delay, history of preterm birth, several attacks during a febrile episode, and epileptiform discharges on EEG.

Febrile Seizures and Febrile Seizure Syndromes: An Updated Overview of Old and Current Knowledge

Febrile seizures are the most common paroxysmal episode during childhood, affecting up to one in 10 children. They are a major cause of emergency facility visits and a source of family distress and anxiety. Their etiology and pathophysiological pathways are being understood better over time; however, there is still more to learn. Genetic predisposition is thought to be a major contributor. Febrile seizures have been historically classified as benign; however, many emerging febrile seizure syndromes behave differently. The way in which human knowledge has evolved over the years in regard to febrile seizures has not been dealt with in depth in the current literature, up to our current knowledge. This review serves as a documentary of how scientists have explored febrile seizures, elaborating on the journey of knowledge as far as etiology, clinical features, approach, and treatment strategies are concerned. Although this review cannot cover all clinical aspects related to febrile seizures at the textbook level, we believe it can function as a quick summary of the past and current sources of knowledge for all varieties of febrile seizure types and syndromes.