Efficacy of ketogenic diet in severe refractory status epilepticus initiating fever induced refractory epileptic encephalopathy in school age children (FIRES)

Autoimmunity and inflammation in status epilepticus: from concepts to therapies

The understanding of immunological mechanisms underlying some forms of epilepsy and encephalitis has rapidly increased for the last 10 years leading to the concept of status epilepticus of autoimmune origin. Actual treatment recommendations regarding autoimmune status epilepticus are based on retrospective case studies, pathophysiological considerations and experts' opinion. In addition, there are no clear indicators to predict outcome. In situations where autoimmune mechanisms are suspected in patients with status epilepticus, there is evidence that earlier treatment is related to better outcome. Increased awareness is mandatory to decrease the number of patients with major neurological problems or fatal outcome, which is overall about 50%. We here summarize findings of all pediatric and adult patients reported to date, and review the current state of knowledge in the field of immune therapeutic approaches of status epilepticus.

Occasional seizures, epilepsy, and inborn errors of metabolism

Seizures are a common paediatric problem, with inborn errors of metabolism being a rare underlying aetiology. The clinical presentation of inborn errors of metabolism is often associated with other neurological symptoms, such as hypotonia, movement disorders, and cognitive disturbances. However, the occurrence of epilepsy associated with inborn errors of metabolism represents a major challenge that needs to be identified quickly; for some cases, specific treatments are available, metabolic decompensation might be avoided, and accurate counselling can be given about recurrence risk. Some clinical presentations are more likely than others to point to an inborn error of metabolism as the cause of seizures. Knowledge of important findings at examination, and appropriate biochemical investigation of children with seizures of uncertain cause, can aid the diagnosis of an inborn error of metabolism and ascertain whether or not the seizures are amenable to specific metabolic treatment.

Management of pediatric status epilepticus

OPINION STATEMENT

Status epilepticus (SE) is a medical emergency consisting of persistent or recurring seizures without a return to baseline mental status. SE can be divided into subtypes based on seizure types and underlying etiologies. Management should be implemented rapidly and based on pre-determined care pathways. The aim is to terminate seizures while simultaneously identifying and managing precipitant conditions. Seizure management involves "emergent" treatment with benzodiazepines (lorazepam intravenously, midazolam intramuscularly, or diazepam rectally) followed by "urgent" therapy (phenytoin/fosphenytoin, phenobarbital, levetiracetam or valproate sodium). If seizures persist, "refractory" treatments include infusions of midazolam or pentobarbital. Prognosis is dependent on the underlying etiology and seizure persistence. This article reviews the current management strategies for pediatric convulsive SE.

Role of antineuronal antibodies in children with encephalopathy and febrile status epilepticus

Status epilepticus in childhood is more common, with a different range of causes and a lower risk of death, than convulsive status epilepticus in adults. Acute central nervous system infections appear to be markers for morbidity and mortality. Nevertheless, central nervous infection is usually presumed in these conditions. Many aspects of the pathogenesis of acute encephalitis and acute febrile encephalopathy with status epilepticus have been clarified in the past decade. The pathogenesis is divided into direct pathogens invasion or immune-mediated mechanisms. Over the past few decades, the number of antineuronal antibodies to ion channels, receptors, and other synaptic proteins described in association with central nervous system disorders has increased dramatically, especially their role in pediatric encephalitis and status epilepticus. These antineuronal antibodies are divided according to the location of their respective antigens: (1) intracellular antigens, including glutamic acid decarboxylase and classical onconeural antigens such as Hu (antineuronal nuclear antibody 1, ANNA1), Ma2, Yo (Purkinje cell autoantibody, PCA1), Ri (antineuronal nuclear antibody 2, ANNA2), CV2/CRMP5, and amphiphysin; and (2) cell membrane ion channels or surface antigens including voltage-gated potassium channel receptor, N-methyl-d-aspartate receptor, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor, γ-aminobutyric acid(B) receptor, leucine-rich glioma-inactivated protein 1, and contactin-associated protein-like 2. Identifying the mechanism of the disease may have important therapeutic implications.

Ketogenic diet therapy is effective in encephalitis with refractory seizures

OBJECTIVE AND IMPORTANCE

Although ketogenic diet therapy is effective in refractory seizures in childhood, its effect on adult encephalitis with similar refractory seizures and prolonged encephalopathy has not been well reported.

CLINICAL PRESENTATION

We report here a case of a 22-year-old man with acute encephalitis with refractory repetitive partial seizures (AERRPS).

INTERVENTION

Partial seizures of the face developed to repeated generalized convulsions, which were refractory against anti-epileptic drugs and a high dose of propofol. After struggling for 9 months, he dramatically recovered after ketogenic diet therapy.

CONCLUSION

Ketogenic diet therapy may be an important tool to help cure AERRPS.

The collective therapeutic potential of cerebral ketone metabolism in traumatic brain injury

The postinjury period of glucose metabolic depression is accompanied by adenosine triphosphate decreases, increased flux of glucose through the pentose phosphate pathway, free radical production, activation of poly-ADP ribose polymerase via DNA damage, and inhibition of glyceraldehyde dehydrogenase (a key glycolytic enzyme) via depletion of the cytosolic NAD pool. Under these post-brain injury conditions of impaired glycolytic metabolism, glucose becomes a less favorable energy substrate. Ketone bodies are the only known natural alternative substrate to glucose for cerebral energy metabolism. While it has been demonstrated that other fuels (pyruvate, lactate, and acetyl-L-carnitine) can be metabolized by the brain, ketones are the only endogenous fuel that can contribute significantly to cerebral metabolism. Preclinical studies employing both pre- and postinjury implementation of the ketogenic diet have demonstrated improved structural and functional outcome in traumatic brain injury (TBI) models, mild TBI/concussion models, and spinal cord injury. Further clinical studies are required to determine the optimal method to induce cerebral ketone metabolism in the postinjury brain, and to validate the neuroprotective benefits of ketogenic therapy in humans.

Rapid onset of hippocampal atrophy in febrile-infection related epilepsy syndrome (FIRES)

Febrile infection-related epilepsy syndrome (FIRES) is a catastrophic and usually refractory epilepsy syndrome that occurs after a febrile illness in previously normal children. The pathogenesis of the syndrome is unknown, and the diagnosis is typically made by exclusion after an exhaustive negative workup for central nervous system infections and autoimmune or metabolic disorders. Magnetic resonance imaging of patients with this condition has previously shown hippocampal abnormalities, typically found several months or longer after initial seizures. We report a previously healthy 5-year-old child who developed hippocampal atrophy by day 37 of his illness. The development of early hippocampal atrophy in this epileptic encephalopathy may provide insight into pathogenesis and highlights the need for aggressive and effective interventions early in the disease process.

Mechanisms of epileptogenesis in pediatric epileptic syndromes: Rasmussen encephalitis, infantile spasms, and febrile infection-related epilepsy syndrome (FIRES)

The mechanisms of epileptogenesis in pediatric epileptic syndromes are diverse, and may involve disturbances of neurodevelopmental trajectories, synaptic homeostasis, and cortical connectivity, which may occur during brain development, early infancy, or childhood. Although genetic or structural/metabolic factors are frequently associated with age-specific epileptic syndromes, such as infantile spasms and West syndrome, other syndromes may be determined by the effect of immunopathogenic mechanisms or energy-dependent processes in response to environmental challenges, such as infections or fever in normally-developed children during early or late childhood. Immune-mediated mechanisms have been suggested in selected pediatric epileptic syndromes in which acute and rapidly progressive encephalopathies preceded by fever and/or infections, such as febrile infection-related epilepsy syndrome, or in chronic progressive encephalopathies, such as Rasmussen encephalitis. A definite involvement of adaptive and innate immune mechanisms driven by cytotoxic CD8(+) T lymphocytes and neuroglial responses has been demonstrated in Rasmussen encephalitis, although the triggering factor of these responses remains unknown. Although the beneficial response to steroids and adrenocorticotropic hormone of infantile spasms, or preceding fever or infection in FIRES, may support a potential role of neuroinflammation as pathogenic factor, no definite demonstration of such involvement has been achieved, and genetic or metabolic factors are suspected. A major challenge for the future is discovering pathogenic mechanisms and etiological factors that facilitate the introduction of novel targets for drug intervention aimed at interfering with the disease mechanisms, therefore providing putative disease-modifying treatments in these pediatric epileptic syndromes.

A bibliometric study of scientific literature on the dietary therapies for epilepsy in Scopus

OBJECTIVES

The aim of this study was to provide a descriptive overview of the impact and production of literature on dietary therapies for epilepsy and perform a citation analysis of the related research articles.

METHODS

We searched for 'ketogenic OR low-glycemic OR medium chain OR modified Atkins in TITLE AND epilep*' in Title/Abstract/Keyword in Scopus database.

RESULTS

A total of 661 references were retrieved, 80% had been published after 2000s, 87% were published in English, and 39% of the publications were published in nine journals. The majority (76.3%) of research articles describe the clinical application of the dietary therapies regarding the classical ketogenic diet (80%), followed by the modified Atkins diet (11.5%), medium chain triglyceride diet (6.4%), and low glycemic index treatment (2.0%); the remaining are basic science studies on the mechanisms of action. The citation analysis revealed that the latter have the highest percentage variation in citation per publication across the years. Concerning the article cohorts, the greatest number of citations per publication was in 1998.

DISCUSSION

The overview of the literature on the dietary therapy of epilepsy evidences a growing interest in the field with a striking prevalence of clinical over basic science studies. The most cited clinical studies have validated the efficacy of the dietary therapies; the few studies on the mechanisms of action received a great number of citations. Bibliometric analysis measuring the trends and the impact of the scientific literature would help researchers to a best knowledge of this specific topic.

Ketogenic diet for adults in super-refractory status epilepticus

OBJECTIVE

To describe a case series of adult patients in the intensive care unit in super-refractory status epilepticus (SRSE; refractory status lasting 24 hours or more despite appropriate anesthetic treatment) who received treatment with the ketogenic diet (KD).

METHODS

We performed a retrospective case review at 4 medical centers of adult patients with SRSE treated with the KD. Data collected included demographic features, clinical presentation, diagnosis, EEG data, anticonvulsant treatment, and timing and duration of the KD. Primary outcome measures were resolution of status epilepticus (SE) after initiation of KD and ability to wean from anesthetic agents.

RESULTS

Ten adult patients at 4 medical centers were started on the KD for SRSE. The median age was 33 years (interquartile range [IQR] 21), 4 patients (40%) were male, and 7 (70%) had encephalitis. The median duration of SE before initiation of KD was 21.5 days (IQR 28) and the median number of antiepileptic medications used before initiation of KD was 7 (IQR 7). Ninety percent of patients achieved ketosis, and SE ceased in all patients achieving ketosis in a median of 3 days (IQR 8). Three patients had minor complications of the KD including transient acidosis and hypertriglyceridemia and 2 patients ultimately died of causes unrelated to the KD.

CONCLUSION

We describe treatment of critically ill adult patients with SRSE with the KD, with 90% of patients achieving resolution of SE. Prospective trials are warranted to examine the efficacy of the KD in adults with refractory SE.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that for intensive care unit patients with refractory SE, a KD leads to resolution of the SE.

The ketogenic diet for the treatment of pediatric status epilepticus

BACKGROUND

Refractory status epilepticus carries a high risk of morbidity and mortality for children. Traditional treatment of status epilepticus consists of multiple anticonvulsant drugs and, if needed, induction of a medical coma. The ketogenic diet has been used for intractable epilepsy for many years. The purpose of this article is to report a case series of five patients with refractory status epilepticus successfully managed with the ketogenic diet.

METHODS

A summary of pediatric patients with refractory status epilepticus treated with diet was performed.

CONCLUSIONS

Ketogenic diet therapy should be considered as a treatment option in pediatric patients with refractory status epilepticus.

Characterisation of a syndrome of autoimmune adult onset focal epilepsy and encephalitis

We report a series of patients with a clinical syndrome characterised by the explosive onset in adulthood of recurrent focal seizures of frontotemporal onset and features suggestive of autoimmune encephalitis. We propose that this presentation of "autoimmune adult onset focal epilepsy and encephalitis" is a recognisable clinical syndrome, and provide evidence it may be associated with heterogeneous immunological targets. Between 2008 and 2011 we encountered six patients with new-onset epilepsy in whom we suspected an autoimmune aetiology. We first characterised the clinical, electroencephalographic, cerebrospinal fluid (CSF), imaging, and pathological findings of this syndrome. We subsequently tested them for antibodies against both intracellular and neuronal cell surface antigens. All patients presented with recurrent seizures with focal frontotemporal onset, refractory to multiple anticonvulsants. Four had focal T2-weighted hyperintensities on MRI. CSF mononuclear cells were variably elevated with positive oligoclonal bands in four. Brain biopsy in one patient demonstrated perivascular lymphocytic infiltration. Two were treated with immunosuppression and went on to achieve complete seizure control and return to baseline cognition. Three of four patients who received only pulsed steroids or no treatment had ongoing frequent seizures, with two dying of sudden unexpected death in epilepsy. Subsequently, three had antibodies identified against neuronal cell surface antigens including N-methyl-D-aspartate receptor and leucine-rich glioma inactivated 1. We suggest that patients with such a presentation should be carefully evaluated for a suspected autoimmune aetiology targeting cell surface antigens and have a therapeutic trial of immunosuppression as this may improve their long-term outcome.

FIRES and IHHE: Delineation of the syndromes

Idiopathic hemiconvulsion hemiplegia and epilepsy syndrome (IHHE) and febrile infection-related epilepsy syndrome (FIRES) are rare epileptic syndromes characterized by the occurrence of status epilepticus in a previously healthy child during or closely after a febrile episode. In both syndromes, there is no evidence of central nervous system infection (encephalitis) and the etiology remains unclear. Treatment is disappointing, particularly in FIRES, except for a response to ketogenic diet (KD) in half of patients. In IHHS, children develop hemispheric brain atrophy with contralateral hemiplegia, epilepsy, and a variable degree of cognitive deficit. Patients with FIRES develop refractory epilepsy with severe cognitive deficit affecting the temporal and frontal lobe functions. The role of inflammation is hypothesized with a vicious circle involving inflammation and seizure activity facilitated by brain maturation putting them under the concept of "acute encephalopathy with inflammation-mediated status epilepticus."

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.

Gaps and opportunities in refractory status epilepticus research in children: a multi-center approach by the Pediatric Status Epilepticus Research Group (pSERG)

PURPOSE

Status epilepticus (SE) is a life-threatening condition that can be refractory to initial treatment. Randomized controlled studies to guide treatment choices, especially beyond first-line drugs, are not available. This report summarizes the evidence that guides the management of refractory convulsive SE (RCSE) in children, defines gaps in our clinical knowledge and describes the development and works of the 'pediatric Status Epilepticus Research Group' (pSERG).

METHODS

A literature review was performed to evaluate current gaps in the pediatric SE and RCSE literature. In person and online meetings helped to develop and expand the pSERG network.

RESULTS

The care of pediatric RCSE is largely based on extrapolations of limited evidence derived from adult literature and supplemented with case reports and case series in children. No comparative effectiveness trials have been performed in the pediatric population. Gaps in knowledge include risk factors for SE, biomarkers of SE and RCSE, second- and third-line treatment options, and long-term outcome.

CONCLUSION

The care of children with RCSE is based on limited evidence. In order to address these knowledge gaps, the multicenter pSERG was established to facilitate prospective collection, analysis, and sharing of de-identified data and biological specimens from children with RCSE. These data will allow identification of treatment strategies associated with better outcomes and delineate evidence-based interventions to improve the care of children with SE.

Use of dietary therapy for status epilepticus

One of the newest and yet fastest growing indications for dietary therapy is the emergency treatment of refractory status epilepticus. Ten retrospective publications since 2008 have reported benefits in 32 children and adults, of whom 25 (78%) became seizure-free. Most of the patients who responded did so within 7 to 10 days of the initiation of nasogastrically administered ketogenic formulas. Encephalitis and febrile-illness related epilepsy syndrome causing status epilepticus highly refractory to antiepileptic drugs may be particularly amenable to dietary treatment. Prospective, multicenter studies are under way to help clarify who best will respond, how quickly, and the optimal diet duration after success.

New research with diets and epilepsy

The ketogenic diet is not a new treatment for the treatment of epilepsy, but the degree of literature now available seems to have given it a new lease of life. Over the past 12 years, there has been more scientific data on both benefits and effect of the ketogenic diet. Data demonstrate a clear benefit in efficacy. We also have a clearer idea in utilization, type of diet to use, and in whom. Questions however remain and further work is required, not least in recognizing likely candidates and in simplifying administration.

Advancing the management of childhood epilepsies

Childhood epilepsies comprise a heterogeneous group of disorders and syndromes that vary in terms of severity, prognosis and treatment requirements. Effective management requires early, accurate recognition and diagnosis, and a holistic approach that addresses each individual's medical and psychosocial needs within the context of their overall health status and quality of life. With increasing understanding of underlying aetiologies, new approaches to management and treatment are emerging. For example, genetic testing is beginning to provide a tool to aid differential diagnosis and a means of predicting predisposition to particular types of epilepsy. Despite the availability of an increasing number of antiepileptic drugs (AEDs)--due not only to the development of new AEDs, but also to changes in regulatory requirements that have facilitated clinical development--seizure control and tolerability continue to be suboptimal in many patients, and there is therefore a continuing need for new treatment strategies. Surgery and other non-pharmacological treatments (e.g. vagus nerve stimulation, ketogenic diet) are already relatively well established in paediatric epilepsy. New pharmacological treatments include generational advances on existing AEDs and AEDs with novel modes of action, and non-AED pharmacological interventions, such as immunomodulation. Emerging technologies include novel approaches allowing the delivery of medicinal agents to specific areas of the brain, and 'closed-loop' experimental devices employing algorithms that allow treatment (e.g., electrical stimulation) to be targeted both spatially and temporally. Although in early stages of development, cell-based approaches (e.g., focal targeting of adenosine augmentation) and gene therapy may also provide new treatment choices in the future.

Ketogenic diet

About one third of patients with epilepsy are pharmacoresistent. For a subgroup of this population, the ketogenic diet can be highly efficacious and should be considered early. This review discusses the different types of ketogenic diet, proposed mechanism of actions and its evidence for use in children and adults with both generalized and focal epilepsies where surgery is not feasible. In addition we discuss a practical approach to diet initiation, maintenance and monitoring for side effects. We also summarize the emerging evidence for the use of ketogenic diet in a broad range of neurological disorders.

Febrile infection-related epilepsy syndrome: a study of 12 patients

PURPOSE

To analyze the electroclinical features, neuroimaging findings, treatment, and outcome of 12 patients with febrile infection-related epilepsy syndrome (FIRES).

METHODS

This is a retrospective study of 12 children with FIRES with a mean time of follow-up of 6.5 years carried out at the Garrahan Hospital of Buenos Aires between 1997 and 2012.

RESULTS

Eight males and four females had focal status epilepticus preceded by febrile infection with a mean age at presentation of 8.5 years. In the acute period, the treatment included antiepileptic drugs (AEDs) in all cases, immunotherapy in 10 cases, and burst-suppression coma in eight. The ketogenic diet was tried in two, plasmapheresis in one, and rituximab in one. Two patients treated with IVIG and one patient given steroids had a good response, but in this phase only three patients had a prolonged good response to IVIG and a ketogenic diet. No patients died in this period. In the chronic epilepsy phase, all children had seizures arising from neocortical regions. All patients had refractory epilepsy, and most mental retardation, and behavioral disturbances. All received different AEDs and in this phase a third patient was put on a ketogenic diet. One patient was operated without good results. Only two cases had a good outcome after 2 and 10 years of follow-up.

CONCLUSION

FIRES is a well-defined severe epileptic syndrome, probably in the group of epileptic encephalopathies, characterized by focal or multifocal seizures arising from the neocortical regions with an unknown etiology. Immunoglobulin and the ketogenic diet may be considered a potentially efficacious treatment.

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.

Guidelines for the evaluation and management of status epilepticus

Status epilepticus (SE) treatment strategies vary substantially from one institution to another due to the lack of data to support one treatment over another. To provide guidance for the acute treatment of SE in critically ill patients, the Neurocritical Care Society organized a writing committee to evaluate the literature and develop an evidence-based and expert consensus practice guideline. Literature searches were conducted using PubMed and studies meeting the criteria established by the writing committee were evaluated. Recommendations were developed based on the literature using standardized assessment methods from the American Heart Association and Grading of Recommendations Assessment, Development, and Evaluation systems, as well as expert opinion when sufficient data were lacking.

Autoimmune and inflammatory epilepsies

The role of immunity and inflammation in epilepsy have long been suggested by the anticonvulsant activity of steroids in some infancy and childhood epilepsies. The role of fever and infection in exacerbating seizures due to possible proinflammatory molecules, the increased frequency of seizures in systemic autoimmune diseases like systemic lupus erythematous, and, recently, the detection of autoantibodies in some unexplained epilepsies reinforced the causal place of immunity and inflammation in epilepsies with unknown etiology. In this article, we summarize epilepsies where clinical and biologic data strongly support the pathogenic role of autoantibodies (e.g., limbic encephalitides, N-methyl-d-aspartate [NMDA] encephalitis) and epilepsies where immune-mediated inflammation occurs, but the full pathogenic cascade is either not clear (e.g., Rasmussen's encephalitis) or only strongly hypothesized (idiopathic hemiconvulsion-hemiplegia syndrome [IHHS] and fever-induced refractory epilepsy in school-aged children [FIRES]). We emphasize the electroclinical features that would help to diagnose these conditions, allowing early immunomodulating therapy. Finally, we raise some questions that remain unclear regarding diagnosis, mechanisms, and future therapies.

Fever and fever-related epilepsies

Febrile seizures are a common emergency faced by general pediatricians. They are mostly self-limiting, isolated events with no sequelae in later life. A minority are more complex. In the acute stage, there are a small number of underlying etiologies that are important to recognize in order to determine the prognosis accurately and to optimize management. There has been a long-standing debate about the relationship of early febrile seizures to the later development of epilepsy. It is now clear that this risk differs for simple and complex febrile seizures: complex febrile seizures may herald the presentation of a number of epilepsy syndromes of which febrile and illness-related seizures are part of the phenotype. This review examines the existing knowledge on febrile seizures and the various clinical phenotypes to which they are linked.

Epileptic encephalopathies (including severe epilepsy syndromes)

Epileptic encephalopathies represent a group of devastating epileptic disorders that appear early in life and are characterized by pharmacoresistant generalized or focal seizures, persistent severe electroencephalography (EEG) abnormalities, and cognitive dysfunction or decline. The ictal and interictal epileptic discharges are age-specific and are the main etiologic factors causing cognitive deterioration. This is most obvious in the idiopathic group. In the symptomatic group, the most common causes are structural, congenital, or acquired and rarely some metabolic disorders. In certain cases, clinical and EEG abnormalities persist and may evolve from one type to another as the child grows older. Various factors trigger and sustain the underlying pathophysiologic process and the ongoing epileptic and epileptiform activity during the most critical periods of brain maturation, perpetuating their deleterious effect on the brain. Immune-mediated mechanisms may have a role, suggested by certain encephalopathies responding to immune-modulating treatments and by the finding of various autoimmune antibodies. The chance of a better cognitive outcome improves with early diagnosis and treatment that is appropriate and effective. Current antiepileptic drugs are, in general, not effective: we urgently need new trials in this very special epileptic category. This article briefly reviews the most common epileptic encephalopathies and analyzes the most important clinical issues.

The use of ketogenic diet in special situations: expanding use in intractable epilepsy and other neurologic disorders

The ketogenic diet has been widely used and proved to be effective for intractable epilepsy. Although the mechanisms underlying its anti-epileptic effects remain to be proven, there are increasing experimental evidences for its neuroprotective effects along with many researches about expanding use of the diet in other neurologic disorders. The first success was reported in glucose transporter type 1 deficiency syndrome, in which the diet served as an alternative metabolic source. Many neurologic disorders share some of the common pathologic mechanisms such as mitochondrial dysfunction, altered neurotransmitter function and synaptic transmission, or abnormal regulation of reactive oxygen species, and the role of the ketogenic diet has been postulated in these mechanisms. In this article, we introduce an overview about the expanding use and emerging trials of the ketogenic diet in various neurologic disorders excluding intractable epilepsy and provide explanations of the mechanisms in that usage.

Ketogenic diets: new advances for metabolism-based therapies

PURPOSE OF REVIEW

Despite myriad anticonvulsants available and in various stages of development, there are thousands of children and adults with epilepsy worldwide still refractory to treatment and not candidates for epilepsy surgery. Many of these patients will now turn to dietary therapies such as the ketogenic diet, medium-chain triglyceride diet, modified Atkins diet, and low glycemic index treatment.

RECENT FINDINGS

In the past several years, neurologists are finding new indications to use these dietary treatments, perhaps even as first-line therapy, including infantile spasms, myoclonic-astatic epilepsy (Doose syndrome), Dravet syndrome, and status epilepticus (including FIRES syndrome). Adults are also one of the most rapidly growing populations being treated nowadays; this group of patients previously was not typically offered these treatments. In 2009, two controlled trials of the ketogenic diet were published, as well as an International Expert Consensus Statement on dietary treatment of epilepsy. Ketogenic diets are also now being increasingly studied for neurological conditions other than epilepsy, including Alzheimer's disease and cancer. Insights from basic science research have helped elucidate the mechanisms by which metabolism-based therapy may be helpful, in terms of both an anticonvulsant and possibly a neuroprotective effect.

SUMMARY

Dietary therapy for epilepsy continues to grow in popularity worldwide, with expanding use for adults and conditions other than epilepsy.

Is the ketogenic diet effective in specific epilepsy syndromes?

Is the ketogenic diet (KD) more effective in certain epilepsy syndromes? The KD has been shown to be effective in treating multiple seizure types and epilepsy syndromes. We review the effectiveness of the KD in Dravet syndrome, epilepsy with myoclonic-atonic seizures, mitochondrial disease, tuberous sclerosis, late infantile and juvenile neuronal ceroid lipofuscinosis, and febrile infection-related epilepsy syndrome. In certain epilepsy syndromes, like epilepsy with myoclonic-atonic seizures, the diet should be considered early in the course of treatment.

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 ketogenic diet for medically and surgically refractory status epilepticus in the neurocritical care unit

BACKGROUND

Refractory status epilepticus carries a high risk of morbidity and mortality despite, and at times as a result of, aggressive pharmacologic interventions. Dietary therapies have been used for almost a century in children for controlling medically refractory seizures and status epilepticus and recent studies suggest efficacy and safety in adults as well.

METHODS

Case report and literature review.

RESULTS

We describe a case of medically and surgically refractory status epilepticus that was controlled after initiation of the ketogenic diet and maintenance with the modified Atkins diet in an adult in the neurocritical care unit.

CONCLUSIONS

Dietary therapy should be considered as a treatment option in adult patients with refractory status epilepticus.

Management of refractory status epilepticus in adults: still more questions than answers

Refractory status epilepticus (RSE) is defined as status epilepticus that continues despite treatment with benzodiazepines and one antiepileptic drug. RSE should be treated promptly to prevent morbidity and mortality; however, scarce evidence is available to support the choice of specific treatments. Major independent outcome predictors are age (not modifiable) and cause (which should be actively targeted). Recent recommendations for adults suggest that the aggressiveness of treatment for RSE should be tailored to the clinical situation. To minimise intensive care unit-related complications, focal RSE without impairment of consciousness might initially be approached conservatively; conversely, early induction of pharmacological coma is advisable in generalised convulsive forms of the disorder. At this stage, midazolam, propofol, or barbiturates are the most commonly used drugs. Several other treatments, such as additional anaesthetics, other antiepileptic or immunomodulatory compounds, or non-pharmacological approaches (eg, electroconvulsive treatment or hypothermia), have been used in protracted RSE. Treatment lasting weeks or months can sometimes result in a good outcome, as in selected patients after encephalitis or autoimmune disorders. Well designed prospective studies of RSE are urgently needed.

AERRPS, DESC, NORSE, FIRES: multi-labeling or distinct epileptic entities?

In this review, we report a case of an adolescent girl presenting with epileptic encephalopathy preceded by febrile illness, demarcate the clinical phenotypic homogeneity among previously reported cases, and hypothesize on potential mechanisms based on current experimental evidence. Our literature review revealed >249 cases that share several main features: febrile illness with no preceding condition, negative laboratory studies including cerebrospinal fluid (CSF) analysis, status epilepticus refractory to conventional pharmacotherapy, and long-term developmental delays. This condition appears to have many names, the most recent of which is "FIRES" (fever-induced refractory epileptic encephalopathy). It seems likely that the described cases are representing the same entity. The possibility of a genetic or acquired channelopathy can be raised in light of negative infectious, autoimmune, microscopic, and gross pathology findings.

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.

Neuroprotection in metabolism-based therapy

Metabolism-based therapy has been used successfully in the treatment of seizures but study of its use in other neurodegenerative disorders is growing. Data demonstrating the use of different forms of metabolism-based therapy in human trials of Alzheimer disease and Parkinson disease are discussed. Animal and in vitro studies have shed light on metabolism-based therapy's mechanisms in these diseases, as well as ALS, aging, ischemia, trauma and mitochondrial cytopathies. Additional insights may be obtained by considering the role of metabolism-based therapy in cell disability and death (specifically apoptosis, excitotoxicity, and autophagy).

Enteral and Parenteral Applications of Ketogenic Diet Therapy

Ketogenic diet therapy is a high-fat, low-carbohydrate, moderate-protein regimen that results in a sustained metabolic state of ketosis. The diet was originally designed in the 1920s for treatment of epilepsy, but its use has expanded in recent years to other disorders. Most individuals who undergo this therapy are able to consume the diet orally, but those with restricted oral intake require alternative methods of nutrition. Many of our patients have feeding tubes in place for receiving part or all of their nutrition. It is possible to administer the diet during an acute condition or illness in patients who have previously received their nutrition orally. This may be accomplished enterally via a feeding tube or intravenously as parenteral nutrition. This article addresses enteral and parenteral applications of ketogenic diet therapy and provides examples of the modifications that have been successfully implemented at 4 medical centers.