Long-term follow-up of febrile infection-related epilepsy syndrome

Effect of levetiracetam in acute encephalitis with refractory, repetitive partial seizures during acute and chronic phase

AIM

To clarify the effect of levetiracetam (LEV) for acute and chronic seizure control in acute encephalitis with refractory, repetitive partial seizures (AERRPS).

METHODS

We retrospectively reviewed the clinical course of six AERRPS cases treated with LEV, and explored the acute phase termination by withdrawal from barbiturate-induced coma under artificial ventilation, and the reduction in seizure frequency during the chronic phase. LEV was administrated orally or via nasogastric tubes as an add-on agent during acute (n=3; age 8-10 years) and chronic (n=3; age 19-30 years) AERRPS.

RESULTS

In the acute phase, administration of LEV (50-60 mg/kg/d) in combination with phenobarbital (n=3; peak 57.9-76.1 μg/ml) and potassium bromide (n=2; 30-36 mg/kg/d)) resulted in successful reduction of intravenous barbiturate dosage and withdrawal from artificial ventilation. In the chronic phase, seizure frequency reduced by >75% for 5-18 months with LEV 750-1500 mg/d.

CONCLUSION

LEV may affect seizure control in AERRPS, particularly during the chronic phase, through its unique action of inhibition of excitatory neurotransmitter release. The regimen of oral barbiturate, potassium bromide and LEV would be worth for trial during the acute phase of AERRPS.

Use of Magnesium Sulfate Infusion for the Management of Febrile Illness-Related Epilepsy Syndrome: A Case Series

Febrile illness-related epilepsy syndrome is a catastrophic epileptic encephalopathy that is highly refractory to most antiepileptic drugs leading to high morbidity and mortality. The authors report the use of a pediatric infusion protocol of continuous intravenous magnesium sulfate for the control of seizures in 2 children with febrile illness-related epilepsy syndrome refractory to multiple antiepileptic drugs in a pediatric intensive care unit of a tertiary care children’s hospital. Both patients, 2 and 16 years of age, respectively, were treated with continuous magnesium sulfate infusion. Serum magnesium concentrations ranging from 2.1 to 5 mmol/L were achieved. Seizure reduction and cessation were noted in 1 patient with magnesium more than 3.0 mmol/L. No significant adverse effects were observed. Magnesium sulfate infusions can be safely used in pediatric refractory status epilepticus. Magnesium sulfate can be considered in the management of children with febrile illness-related epilepsy syndrome.

Inflammation and epilepsy in the developing brain: clinical and experimental evidence

There is an increasing evidence to support a role of inflammatory processes in epilepsy. However, most clinical and experimental studies have been conducted in adult patients or using adult rodents. The pediatric epilepsies constitute a varied group of diseases that are most frequently age specific. In this review, we will focus on the possible role of inflammation in pediatric epilepsy syndromes. We will first describe the clinical data available and provide an overview of our current understanding of the role of inflammation in these clinical situations. We will then review experimental data regarding the role of inflammation in epilepsy in the developing brain. To summarize, inflammation contributes to seizure precipitation, and reciprocally, prolonged seizures induce inflammation. There is also a relationship between inflammation and cell injury following status epilepticus, which differs according to the developmental stage. Finally, inflammation seems to contribute to epileptogenesis even in the developing brain. Based on the available data, we highlight the need for further studies dissecting the exact role of inflammation in epilepsy during development.

Outcome of children with acute encephalitis and refractory status epilepticus

Acute encephalitis in children is a life-threatening neurological emergency. However, little is reported about the outcome of this devastating illness in the United States. The authors retrospectively reviewed the charts of patients admitted to a regional pediatric intensive care unit with the diagnosis of acute encephalitis between 2006 and 2011. In 41 cases that met the inclusion criteria, the most common presenting symptoms were fever (65.9%), altered mental status (61%), and seizures (58.5%). Eight patients (19.5%) who presented with refractory status epilepticus had a longer median length of stay in the pediatric intensive care unit (46 vs. 4 days; P < .0001) and a significant worsening of Pediatric Cerebral Performance Category score on discharge by 2 or more points (odds ratio 20.38; 95% confidence interval, 2.89-143.52). All children survived to hospital discharge. In conclusion, children with acute encephalitis who present with refractory status epilepticus have a worse neurological outcome and a longer stay in the pediatric intensive care unit.

Evaluation and treatment of autoimmune neurologic disorders in the pediatric intensive care unit

Autoimmunity is being increasingly recognized as a cause of neurologic presentations both inside and outside the intensive care unit (ICU) setting. Pediatric autoimmune neurologic diseases likely to be seen in the ICU include autoimmune encephalitidies such as N-Methyl-D-aspartate (NMDA) receptor encephalitis, central nervous system vasculitis, demyelinating disorders, and neurologic involvement of systemic autoimmune disorders. In addition, there are conditions of suspected autoimmune etiology such as febrile infection-related epilepsy syndrome (FIRES) and rapid-onset obesity, hypoventilation, hypothalamic dysfunction, and autonomic dysregulation (ROHHAD) syndrome that are rare, but when they do present, it is often to the ICU. Refractory seizures, altered mental status, and disordered breathing are the most common indications for intensive care for these patients.

Long-term seizure outcome for international consensus classification of hippocampal sclerosis: a survival analysis

PURPOSE

Surgery is regarded as a common treatment option for patients with mesial temporal lobe epilepsy (MTLE) as a result of hippocampal sclerosis (HS). However, approximately one-third of patients with intractable epilepsy did not become seizure-free after tailored resection strategies. It would be compelling to identify predictive factors of postoperative seizure outcomes. Our aim was to assess the correlation between HS classification and long-term postoperative seizure outcome in patients with MTLE due to HS.

METHODS

To investigate HS classification, semi-quantitative analysis and immunohistochemical staining of neuronal nuclei (NeuN) were performed on 100 postoperative hippocampal specimens. All patients had a 1-7 year postoperative follow-up. The postoperative seizure outcome was evaluated using International League Against Epilepsy (ILAE) outcome classification.

RESULTS

Three types of HS were recognized. The highest incidence of initial precipitating injury (IPI) was noted in the HS ILAE type 1 group (53.1%). The most favorable long-term seizure outcome was also noted in the HS ILAE type 1 group. The shortest epilepsy duration was recorded in the HS ILAE type 2 group (mean epilepsy duration=6.64 ± 5.83 years). The completely seizure free rate of patients in all groups declined with an increase in time.

CONCLUSIONS

Our study for the first time demonstrated a significant correlation between HS ILAE types and long-term postoperative seizure outcome in patients with MTLE due to HS. Therefore, HS ILAE types have predictive value in long-term seizure outcome following epilepsy surgery.

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.

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.

Treatment of epileptic encephalopathies

Epileptic encephalopathy is defined as a condition where the epileptic activity itself may contribute to the severe neurological and cognitive impairment seen, over and above that which would be expected from the underlying pathology alone. The epilepsy syndromes at high risk of this are a disparate group of conditions characterized by epileptic seizures that are difficult to treat and developmental delay. In this review, we discuss the ongoing debate regarding the significance of inter-ictal discharges and the impact of the seizures themselves on the cognitive delay or regression that is a common feature of these syndromes. The syndromes also differ in many ways and we provide a summary of the key features of the early-onset epileptic encephalopathies including Ohtahara and West syndromes in addition to later childhood-onset syndromes such as Lennox Gastaut and Doose syndromes. An understanding of the various severe epilepsy syndromes is vital to understanding the rationale for treatment. For example, the resolution of hypsarrhythmia in West syndrome is associated with an improvement in cognitive outcome and drives treatment choice, but the same cannot be applied to frequent inter-ictal discharges in Lennox Gastaut syndrome. We discuss the evidence base for treatment where it is available and describe current practice where it is not. For example, in West syndrome there is some evidence for preference of hormonal treatments over vigabatrin, although the choice and duration of hormonal treatment remains unclear. We describe the use of conventional and newer anti-epileptic medications in the various syndromes and discuss which medications should be avoided. Older possibly forgotten treatments such as sulthiame and potassium bromide also have a role in the severe epilepsies of childhood. We discuss hormonal treatment with particular focus on the treatment of West syndrome, continuous spike wave in slow wave sleep (CSWS)/electrical status epilepticus in slow wave sleep (ESES) and Landau Kleffner syndrome. The role of the ketogenic diet has in recent years come to the fore of the management of these severe epilepsies and we describe successful use in myoclonic astatic epilepsy, Lennox Gastaut syndrome and Dravet syndrome. It is important that resective epilepsy surgery is not ignored in the management of these children, particularly those with hemi-pathology who may present with ESES and respond well to hemispheric disconnection. Adjunctive and symptomatic surgical treatments such as vagal nerve stimulation and corpus callosotomy may improve seizure burden. Finally, it is vital that the identification and treatment of developmental, behavioural and psychiatric co-morbidities are not neglected and that a rational, holistic approach is taken to the management of epileptic encephalopathies.

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.

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.