Treatment of refractory convulsive status epilepticus in children: other therapies

Application of ketogenic diets for pediatric neurocritical care

In this review, we summarize the general mechanisms of the ketogenic diet, and the application of a ketogenic diet in pediatric intensive care units for the neurological disorders of children and young infants. A ketogenic diet is a high-fat, low-carbohydrate, adequate-protein diet. It can alter the primary cerebral energy metabolism from glucose to ketone bodies, which involves multiple mechanisms of antiepileptic action, antiepileptogenic properties, neuro-protection, antioxidant and anti-inflammatory effects, and it is potentially a disease-modifying intervention. Although a ketogenic diet is typically used for the chronic stage of pharmacoresistant of epilepsy, recent studies have shown its efficacy in patients with the acute stage of refractory/super-refractory status epilepticus. The application of a ketogenic diet in pediatric intensive care units is a challenge because of the critical status of the patients, who are often in a coma or have a nothing by mouth order. Moreover, a ketogenic diet needs to be started early and sometimes through parenteral administration in patients with critical conditions such as refractory status epilepticus or febrile infection-related epilepsy syndrome. Animal models and some case reports have shown that the neuro-protective effects of a ketogenic diet can be extended to other emergent neurological diseases, such as traumatic brain injury and ischemic stroke.

The ketogenic diet for super-refractory status epilepticus patients in intensive care units

OBJECTIVES

Super-refractory status epilepticus (SRSE) is one of the most challenging issues in intensive care units (ICUs) in that it is associated with high morbidity and mortality. Although the ketogenic diet (KD) has been reported to be effective in treating of SRSE, the use of the diet as therapy can be complicated by concomitant medical problems specific to critically ill patients. In this study, we aimed to describe our experience of the KD for SRSE patients in ICUs.

METHODS

We retrospectively reviewed the medical records of 16 patients (10 males, 6 females) with SRSE who were treated with the KD in the ICUs at Samsung Medical Center from July 2005 to July 2017.

RESULTS

The median age of seizure onset was 8 years (interquartile range 5-13.5). Prior to diet initiation, the patients were in convulsive or non-convulsive SRSE for a median of 23 days (range, 3-420). The median time to achieve ketosis was 3 days (range, 2-6). The KD was continued for a median of 2.1 months (range, 0.1-15.8). Of the 16 patients, nine (56.3%) achieved seizure freedom, six (37.5%) reported >50% seizure reduction, and one (6.2%) had <50% seizure improvement after the KD. There was no significant change in the number of antiepileptic drugs. The most commonly encountered complication during the KD was gastrointestinal disturbance.

CONCLUSIONS

Our experience indicates that the KD is an effective alternative therapeutic strategy for SRSE patients in ICUs with adequate efficacy and safety in reducing seizure frequency and weaning from prolonged mechanical ventilation, although functional outcome was not favorable for most patients. Close monitoring and preventive management of potential adverse effects are critical elements for success with the KD in patients with SRSE.

The etiology and prognosis of super-refractory convulsive status epilepticus in children

BACKGROUND

Both refractory convulsive status epilepticus (SE) and super-refractory SE are medical emergencies. However, there are limited data on super-refractory SE in children. Thus, this study focuses on characterizing the demographics, outcomes, and prognostic factors for super-refractory SE in children.

METHODS

This study was a retrospective analysis of super-refractory SE treated in a tertiary referral center in Taiwan. The functional outcome was evaluated by modified Rankin scale (mRS). Significant functional decline was defined as an mRS difference (before hospital admission and at discharge) of more than 2. The variates and the follow-up mRS values were then analyzed statistically.

RESULTS

We enrolled 134 patients with 191 episodes of convulsive SE and identified 30 patients with 38 episodes of convulsive super-refractory SE. The incidence of convulsive super-refractory SE in the group with SE was 19.9%, and the age ranged from 2.5 months to 17 years. In-hospital mortality was 13.3%, which was much lower than that of adult cohorts. Newly acquired epilepsy and cognitive deficit occurred in 100% and 88.5%, respectively. Newly acquired epilepsy, as a sequel of super-refractory SE, was observed in all 18 patients (100%) who survived and had no history of epilepsy. Significant functional decline (mRS difference of more than 2) at discharge occurred in 76.7%. Poor functional outcome was associated with acute symptomatic etiology (P < 0.001) and the number of anesthetic agents (P = 0.002). The functional outcome improved after 1 year of follow-up in our population.

CONCLUSIONS

Super-refractory SE is associated with significant morbidity and mortality in children. However, the in-hospital mortality rate is much lower compared with adults. The functional outcome in children is associated with acute symptomatic etiology and the number of anesthetic agents and may improve after long-term follow-up.

Pediatric refractory and super-refractory status epilepticus

PURPOSE

To summarize the available evidence related to pediatric refractory status epilepticus (RSE) and super-refractory status epilepticus (SRSE), with emphasis on epidemiology, etiologies, therapeutic approaches, and clinical outcomes.

METHODS

Narrative review of the medical literature using MEDLINE database.

RESULTS

RSE is defined as status epilepticus (SE) that fails to respond to adequately used first- and second-line antiepileptic drugs. SRSE occurs when SE persist for 24 h or more after administration of anesthesia, or recurs after its withdrawal. RSE and SRSE represent complex neurological emergencies associated with long-term neurological dysfunction and high mortality. Challenges in management arise as the underlying etiology is not always promptly recognized and therapeutic options become limited with prolonged seizures. Treatment decisions mainly rely on case series or experts' opinions. The comparative effectiveness of different treatment strategies has not been evaluated in large prospective series or randomized clinical trials. Continuous infusion of anesthetic agents is the most common treatment for RSE and SRSE, although many questions on optimal dosing and rate of administration remain unanswered. The use of non-pharmacological therapies is documented in case series or reports with low level of evidence. In addition to neurological complications resulting from prolonged seizures, children with RSE/SRSE often develop systemic complications associated with polypharmacy and prolonged hospital stay.

CONCLUSION

RSE and SRSE are neurological emergencies with limited therapeutic options. Multi-national collaborative efforts are desirable to evaluate the safety and efficacy of current RSE/SRSE therapies, and potentially impact patients' outcomes.

Plasmapheresis for refractory status epilepticus Part II: A scoping systematic review of the pediatric literature

BACKGROUND

Our goal was to perform a scoping systematic review of the literature on the use of plasmapheresis or plasma exchange (PE) for refractory status epilepticus (RSE) in children.

METHODS

Articles from MEDLINE, BIOSIS, EMBASE, Global Health, Healthstar, Scopus, Cochrane Library, the International Clinical Trials Registry Platform, clinicaltrials.gov (inception to May 2016), reference lists of relevant articles, and gray literature were searched. The strength of evidence was adjudicated using both the Oxford and GRADE methodology by two independent reviewers.

RESULTS

Twenty-two original articles were identified, with 37 pediatric patients. The mean age of the patients was 8.3 years (age median: 8.5, range: 0.6 years-17 years). Seizure response to PE therapy occurred in 9 of the 37 patients (24.3%) included in the review, with 7 patients (18.9%) displaying resolution of seizures and 2 patients (5.4%) displaying a partial reduction in seizure volume. Twenty-eight of the 37 patients (75.7%) had no response to PE therapy. No adverse events were recorded.

CONCLUSIONS

Oxford level 4, GRADE D evidence exists to suggest little to no benefit of PE in pediatric RSE. Routine application of PE for pediatric RSE cannot be recommended at this time.

From intravenous to enteral ketogenic diet in PICU: A potential treatment strategy for refractory status epilepticus

BACKGROUND

Ketogenic diet (KD) has been used to treat refractory status epilepticus (RSE). KD is a high-fat, restricted-carbohydrate regimen that may be administered with different fat to protein and carbohydrate ratios (3:1 and 4:1 fat to protein and carbohydrate ratios). Other ketogenic regimens have a lower fat and higher protein and carbohydrate ratio to improve taste and thus compliance to treatment. We describe a case of RSE treated with intravenous KD in the Pediatric Intensive Care Unit (PICU).

CASE REPORT

An 8-year-old boy was referred to the PICU because of continuous tonic-clonic and myoclonic generalized seizures despite several antiepileptic treatments. After admission he was intubated and treated with intravenous thiopental followed by ketamine. Seizures continued with frequent myoclonic jerks localized on the face and upper arms. EEG showed seizure activity with spikes on rhythmic continuous waves. Thus we decided to begin KD. The concomitant ileus contraindicated KD by the enteral route and we therefore began IV KD. The ketogenic regimen consisted of conventional intravenous fat emulsion, plus dextrose and amino-acid hyperalimentation in a 2:1 then 3:1 fat to protein and carbohydrate ratio. Exclusive IV ketogenic treatment, well tolerated, was maintained for 3 days; peristalsis then reappeared so KD was continued by the enteral route at 3:1 ratio. Finally, after 8 days and no seizure improvement, KD was deemed unsuccessful and was discontinued.

CONCLUSIONS

Our experience indicates that IV KD may be considered as a temporary "bridge" towards enteral KD in patients with partial or total intestinal failure who need to start KD. It allows a prompt initiation of KD, when indicated for the treatment of severe diseases such as RSE.

Selective head cooling during neonatal seizures prevents postictal cerebral vascular dysfunction without reducing epileptiform activity

Epileptic seizures in neonates cause cerebrovascular injury and impairment of cerebral blood flow (CBF) regulation. In the bicuculline model of seizures in newborn pigs, we tested the hypothesis that selective head cooling prevents deleterious effects of seizures on cerebral vascular functions. Preventive or therapeutic ictal head cooling was achieved by placing two head ice packs during the preictal and/or ictal states, respectively, for the ∼2-h period of seizures. Head cooling lowered the brain and core temperatures to 25.6 ± 0.3 and 33.5 ± 0.1°C, respectively. Head cooling had no anticonvulsant effects, as it did not affect the bicuculline-evoked electroencephalogram parameters, including amplitude, duration, spectral power, and spike frequency distribution. Acute and long-term cerebral vascular effects of seizures in the normothermic and head-cooled groups were tested during the immediate (2-4 h) and delayed (48 h) postictal periods. Seizure-induced cerebral vascular injury during the immediate postictal period was detected as terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling-positive staining of cerebral arterioles and a surge of brain-derived circulating endothelial cells in peripheral blood in the normothermic group, but not in the head-cooled groups. During the delayed postictal period, endothelium-dependent cerebral vasodilator responses were greatly reduced in the normothermic group, indicating impaired CBF regulation. Preventive or therapeutic ictal head cooling mitigated the endothelial injury and greatly reduced loss of postictal cerebral vasodilator functions. Overall, head cooling during seizures is a clinically relevant approach to protecting the neonatal brain by preventing cerebrovascular injury and the loss of the endothelium-dependent control of CBF without reducing epileptiform activity.

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.

Single Center Outcomes of Status Epilepticus at a Paediatric Intensive Care Unit

BACKGROUND

Status epilepticus (SE) is a frequent admission diagnosis to paediatric intensive care units (PICUs) and is associated with variable outcomes. We have audited our experience of patients presenting in SE at a Canadian PICU to determine unfavorable outcome variables.

METHODS

Charts of patients <18 years of age presenting in SE to a tertiary care PICU over a 10-year period were audited. Data were analyzed at three care-points: transport, the emergency department (ED) and the PICU. Patient outcome before PICU discharge was categorized as "favorable" for return to pre-status functioning level or "unfavorable" for new deficit/death. Student's t-test and the Kruskal-Wallis test were used for analysis of normal and skewed continuous variables, respectively, and either Chi-square test or Fisher's exact test for categorical variables.

RESULTS

189 patients (54% males) were identified with a median age of 1.9 years. Idiopathic SE had the highest incidence; infectious/vascular etiologies were associated with more unfavorable outcomes. Progression to refractory SE in the ED had a higher incidence of death (p<0.05). Patients with an unfavorable outcome had a higher incidence of apnea during transport (p=0.01), longer hospital stays (p<0.05), need for therapeutic coma (p=0.01), longer duration of therapeutic coma (p<0.05), need for mechanical ventilation (p<0.05), and recurrent or refractory seizures during inpatient stay (p<0.05). Multivariate analysis of unfavorable outcomes of patients in SE presenting to the PICU included renal failure, cerebral edema, apnea during transport, refractory seizures, and recurrent seizures.

CONCLUSIONS

Refractory seizures in children presenting with SE are associated with worsened outcomes in the PICU.

Effect of Antiepileptic Drugs for Acute and Chronic Seizures in Children with Encephalitis

BACKGROUND

Encephalitis presents with seizures in the acute phase and increases the risk of late unprovoked seizures and epilepsy. This study aimed to evaluate the effect of antiepileptic drugs in pediatric patients with acute seizures due to encephalitis and epilepsy.

PATIENTS AND METHODS

Cases of acute pediatric encephalitis between January 2000 and December 2010 were reviewed. Clinical data, including onset at age, seizure type, seizure frequency, effects of antiepileptic drugs, and prognosis were analyzed.

RESULTS

During the study period, 1038 patients (450 girls, 588 boys) were enrolled. Among them, 44.6% (463) had seizures in the acute phase, 33% had status epilepticus, and 26% (251) developed postencephalitic epilepsy. At one year of follow-up, 205 of the 251 patients with postencephalitic epilepsy were receiving antiepileptic drugs while 18% were seizure free even after discontinuing the antiepileptic drugs. Among those with postencephalitic epilepsy, 67% had favorable outcomes and were using <2 anti-epileptic drugs while 15% had intractable seizures and were using ≥ 2 antiepileptic drugs. After benzodiazepines, intravenous phenobarbital was preferred over phenytoin as treatment of postencephalitic seizures in the acute phase. For refractory status epilepticus, high-dose topiramate combined with intravenous high-dose phenobarbital or high-dose lidocaine had less side effects.

CONCLUSIONS

Children with encephalitis have a high rate of postencephalitic epilepsy. Phenobarbital and clonazepam are the most common drugs used, alone or in combination, for postencephalitic epilepsy.

Treatment of Generalized Convulsive Status Epilepticus in Pediatric Patients

Generalized convulsive status epilepticus (GCSE) is one of the most common neurologic emergencies and can be associated with significant morbidity and mortality if not treated promptly and aggressively. Management of GCSE is staged and generally involves the use of life support measures, identification and management of underlying causes, and rapid initiation of anticonvulsants. The purpose of this article is to review and evaluate published reports regarding the treatment of impending, established, refractory, and super-refractory GCSE in pediatric patients.

The ketogenic diet as broad-spectrum treatment for super-refractory pediatric status epilepticus: challenges in implementation in the pediatric and neonatal intensive care units

Refractory status epilepticus carries significant morbidity and mortality. Recent reports have promoted the use of the ketogenic diet as an effective treatment for refractory status epilepticus. We describe our recent experience with instituting the ketogenic diet for 4 critically ill children in refractory status epilepticus, ranging in age from 9 weeks to 13.5 years after failure of traditional treatment. The ketogenic diet allowed these patients to be weaned off continuous infusions of anesthetics without recurrence of status epilepticus, though delayed ketosis and persistently elevated glucose measurements posed special challenges to effective initiation, and none experienced complete seizure cessation. The ease of sustaining myocardial function with fatty acid energy substrates compares favorably over the myocardial toxicity posed by anesthetic doses of barbiturates and contributes to the safety profile of the ketogenic diet. The ketogenic diet can be implemented successfully and safely for the treatment of refractory status epilepticus in pediatric patients.

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.

Pediatric status epilepticus management

PURPOSE OF REVIEW

This review discusses the management of status epilepticus in children, including both anticonvulsant medications and overall management approaches.

RECENT FINDINGS

Rapid management of status epilepticus is associated with a greater likelihood of seizure termination and better outcomes, yet data indicate that there are often management delays. This review discusses an overall management approach aiming to simultaneously identify and manage underlying precipitant causes, administer anticonvulsants in rapid succession until seizures have terminated, and identify and manage systemic complications. An example management pathway is provided.

SUMMARY

Status epilepticus is a common neurologic emergency in children and requires rapid intervention. Having a predetermined status epilepticus management pathway can expedite management.

Refractory status epilepticus

Refractory status epilepticus is a potentially life-threatening medical emergency. It requires early diagnosis and treatment. There is a lack of consensus upon its semantic definition of whether it is status epilepticus that continues despite treatment with benzodiazepine and one antiepileptic medication (AED), i.e., Lorazepam + phenytoin. Others regard refractory status epilepticus as failure of benzodiazepine and 2 antiepileptic medications, i.e., Lorazepam + phenytoin + phenobarb. Up to 30% patients in SE fail to respond to two antiepileptic drugs (AEDs) and 15% continue to have seizure activity despite use of three drugs. Mechanisms that have made the treatment even more challenging are GABA-R that is internalized during status epilepticus and upregulation of multidrug transporter proteins. All patients of refractory status epilepticus require continuous EEG monitoring. There are three main agents used in the treatment of RSE. These include pentobarbital or thiopental, midazolam and propofol. RSE was shown to result in mortality in 35% cases, 39.13% of patients were left with severe neurological deficits, while another 13% had mild neurological deficits.

Ketogenic diet in 3 cases of childhood refractory status epilepticus

INTRODUCTION

Refractory status epilepticus (RSE) in children is associated with a significant risk of death or neurological morbidity. Recently attention has been drawn to the ketogenic diet (KD) as an acute treatment, as it has shown promise in controlling seizures in otherwise refractory status epilepticus in several cases. We have listed these and reviewed all cases of KD used in RSE at our centre. KD was given as 4:1 fat:carbohydrate-protein solution.

RESULTS

A 3-year-old girl with RSE due to Hemiconvulsion-Hemiplegia Epilepsy syndrome. KD was instigated on day 6. Seizures stopped with ketosis on day 7. A 10-year-old boy rapidly developing RSE. After months a mitochondrial disorder was discovered. KD was tried twice with severe side-effects but no seizure control. 11-year-old healthy boy with RSE as FIRES. On KD seizures stopped for 24 h one day after reaching ketosis. He improved over 3-4 weeks.

DISCUSSION

KD was efficient in two of three cases of RSE. The non-responder had severe side-effects and proved to have a mitochondrial disorder which is arguably a contraindication for KD. More studies are needed to prove efficacy of KD in RSE, to define optimal timing of KD and possible contraindications for KD in RSE.

Pediatric intensive care treatment of uncontrolled status epilepticus

The critically ill mechanically ventilated child with ongoing seizures that are refractory to any treatment presents a distinct challenge in pediatric neurocritical care. The evidence base from randomized controlled trials on which anti-epileptic drug (AED) strategy should be used is inadequate. This review of refractory and super-refractory status epilepticus summarizes recent pediatric case series regarding definitions, the second-tier AED therapies once initial anticonvulsants have failed, and the experience of high-dose midazolam, barbiturate anesthesia, and volatile anesthetics for uncontrolled status epilepticus.

Recooling for rebound seizures after rewarming in neonatal encephalopathy

Infants undergoing therapeutic hypothermia for hypoxic ischemic encephalopathy are at risk for rebound seizures during and after the rewarming phase. We report a term male infant who was cooled for hypoxic ischemic encephalopathy. He developed electrographic seizures for the first time during the warming phase, which continued in the hours after rewarming. The seizures stopped within 30 minutes of recooling to 33.5°C without anticonvulsant medication. He was uneventfully cooled for an additional 24 hours and then rewarmed with no recurrence of seizures. Hypothermia appeared to have an antiepileptic effect in this case and may be worthy of additional investigation as an adjunct to antiepileptic drug therapy in newborns.

Effect of mild hypothermia on glutamate receptor expression after status epilepticus

Hypothermia has been shown to have neuroprotective effects in various models of neurological damage. However, its therapeutic effect on pediatric status epilepticus (SE) is still unknown. We conducted a study to investigate whether hypothermia can have an adjuvant effect on pilocarpine-induced status epilepticus in immature rats when combined with diazepam treatment. Pilocarpine-induced status epilepticus was maintained for either 30 min or 60 min, which was followed by injection with diazepam (10mg/kg body weight) and/or treatment with mild hypothermia (core temperature to 33°C). We found that the spike-wave amplitude and frequency after SE during treatment with diazepam and hypothermia was significantly lower than treatment with diazepam alone. Mild hypothermia significantly reduced the number of cells undergoing necrosis and apoptosis. In addition, α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA) receptor subunit GluR1 was shown to be up-regulated by SE, while GluR2 was shown to be down-regulated. However, after combination therapy with diazepam and mild hypothermia for 8h, the expression of GluR1 was decreased and GluR2 was increased relative to the levels of diazepam alone treated juveniles. We also found that the expression of mGluR-1a was also decreased relative to diazepam alone. These findings suggest that mild hypothermia might further protect against pilocarpine-induced status epilepticus in immature rats by regulating glutamate receptor expression. This study was conducted using a pediatric model of SE so as to gain a better understanding of the role of hypothermia in the developing brain.

An update on the ketogenic diet, 2012

The ketogenic diet has been in use for the last 90 years, and its role in the treatment of epilepsy in the pediatric population has been gaining recognition. It can be helpful in many types of epilepsies, even the more severe ones, and has a beneficial effect on the child's alertness and cognition, which can be impaired by both the condition and the medications needed for controlling it. Parental compliance is good in spite of the inconveniences inherent in following the diet. The significant advancements in understanding the nature of the diet are in better defining when its use is contraindicated and in validating its application in severe epilepsies in infancy, such as infantile spasms. Although most neurologists do not consider it as being the preferred first-line therapy, it is often a reasonable option when two medications have already failed.

The role of ketogenic diet in the treatment of refractory status epilepticus

Ketogenic diet (KD) is known to be effective in intractable epilepsy. However, the role of KD in refractory status epilepticus (RSE) has not been well described. The aim of this study is to explore the role of KD in patients with RSE. We retrospectively reviewed the medical records of four children and one adult with RSE between October 2006 and August 2010. All presented with status epilepticus (SE) that was presumed to be associated with viral encephalitis. After we failed to control the seizures with standard measures for SE, we tried KD. The overall seizure frequency decreased to <50% of baseline in median eight (1-19) days. At one month of KD, two patients were seizure-free, one patient showed >90% seizure reduction, and the others had >75% decrease without generalized seizures. With improvement in the RSE, we were able to taper the antiepileptic drugs (AEDs) and wean patients from prolonged mechanical ventilation. The adverse events of KD in RSE included aspiration pneumonia, gastroesophageal reflux, constipation, and hypertriglyceridemia. Those results demonstrate that KD can be a valuable therapeutic option for patients with RSE.

Metabolic treatments for intractable epilepsy

When a child on anticonvulsant medications continues to have seizures, what other options should be considered? Over the past 100 years, dietary therapies for the treatment of intractable epilepsy have become more widely recognized, and their use has continued to expand throughout the world. An increasing number of studies has shown efficacy of these metabolic treatments in improving seizure control. Currently, 4 types of dietary therapy are available in the clinic: the classic long chain fatty acid "ketogenic" diet, the medium chain triglyceride diet, the modified Atkins diet, and the low glycemic index treatment. These therapies should be considered earlier in the treatment of intractable epilepsy because they offer a different approach to treatment that has proven efficacious, tolerable, and cost-effective.