Autoimmunity, seizures, and status epilepticus

Functional changes in neuronal circuits due to antibody-driven autoimmune response

Autoimmune-mediated encephalitis syndromes are increasingly being recognized as important clinical entities. They need to be thought of as differential diagnosis in any patient presenting with fast-onset psychosis or psychiatric problems, memory deficits or other cognitive problems, including aphasias, as well as seizures or motor automatisms, but also rigidity, paresis, ataxia or dystonic / parkinsonian symptoms. Diagnosis including imaging and CSF search for antibodies needs to be fast, as progression of these inflammatory processes is often causing scarring of brain tissue, with hypergliosis and atrophy. As these symptoms show, the autoantibodies present in these cases appear to act within the CNS. Several of such antibodies have by now been identified such as IgG directed against NMDA-receptors, AMPA receptors, GABA_A and GABA_B receptors, and voltage gated potassium channels and proteins of the potassium channel complex (i.e. LGI1 and CASPR2). These are neuropil / surface antigens where antibody interaction can well be envisaged to cause dysfunction of the target protein, including internalization. Others, such as antibodies directed against GAD65 (an intracellular enzyme responsible for GABA-synthesis from glutamate), are discussed to constitute epiphenomena, but not causal agents in disease progression. This review will focus on the current knowledge of antibody interaction mechanisms, especially discussing cellular excitability changes and synaptic interactions in hippocampal and other brain networks. One challenge in this context is to find viable hypotheses for the emergence of both, hyperexcitability and seizures, and presumably reduced synaptic plasticity and underlying cognitive dysfunction.

Status epilepticus: review on diagnosis, monitoring and treatment

Status epilepticus (SE) is a frequent neurological emergency associated with high morbidity and mortality. According to the new ILAE 2015 definition, SE results either from the failure of the mechanisms responsible for seizure termination or initiation, leading to abnormally prolonged seizures. The definition has different time points for convulsive, focal and absence SE. Time is brain. There are changes in synaptic receptors leading to a more proconvulsant state and increased risk of brain lesion and sequelae with long duration. Management of SE must include three pillars: stop seizures, stabilize patients to avoid secondary lesions and treat underlying causes. Convulsive SE is defined after 5 minutes and is a major emergency. Benzodiazepines are the initial treatment, and should be given fast and an adequate dose. Phenytoin/fosphenytoin, levetiracetam and valproic acid are evidence choices for second line treatment. If SE persists, anesthetic drugs are probably the best option for third line treatment, despite lack of evidence. Midazolam is usually the best initial choice and barbiturates should be considered for refractory cases. Nonconvulsive status epilepticus has a similar initial approach, with benzodiazepines and second line intravenous (IV) agents, but after that, aggressiveness should be balanced considering risk of lesion due to seizures and medical complications caused by aggressive treatment. Usually, the best approach is the use of sequential IV antiepileptic drugs (oral/tube are options if IV options are not available). EEG monitoring is crucial for diagnosis of nonconvulsive SE, after initial control of convulsive SE and treatment control. Institutional protocols are advised to improve care.

Anti-Epileptic Effect of Crocin on Experimental Temporal Lobe Epilepsy in Mice

Temporal lobe epilepsy (TLE) is a common kind of refractory epilepsy. More than 30% TLE patients were multi-drug resistant. Some patients may even develop into status epilepticus (SE) because of failing to control seizures. Thus, one of the avid goals for anti-epileptic drug development is to discover novel potential compounds to treat TLE or even SE. Crocin, an effective component of Crocus sativus L., has been applied in several epileptogenic models to test its anti-epileptic effect. However, it is still controversial and its effect on TLE remains unclear. Therefore, we investigated the effects of crocin on epileptogenesis, generalized seizures (GS) in hippocampal rapid electrical kindling model as well as SE and spotaneous recurrent seizure (SRS) in pilocarpine-induced TLE model in ICR mice in this study. The results showed that seizure stages and cumulative afterdischarge duration were significantly depressed by crocin (20 and 50 mg/kg) during hippocampal rapid kindling acquisition. And crocin (100 mg/kg) significantly reduced the incidence of GS and average seizure stages in fully kindled animals. In pilocarpine-induced TLE model, the latency of SE was significantly prolonged and the mortality of SE was significantly decreased by crocin (100 mg/kg), which can also significantly suppress the number of SRS. The underlying mechanism of crocin may be involved in the protection of neurons, the decrease of tumor necrosis factor-α in the hippocampus and the increase of brain derived neurotrophic factor in the cortex. In conclusion, crocin may be a potential and promising anti-epileptic compound for treatment of TLE.

Diagnosis and Management of Status Epilepticus

Seizures are among the most common neurological presentations to the emergency room. They present on a spectrum of severity from isolated new-onset seizures to acute repetitive seizures and, in severe cases, status epilepticus. The latter is the most serious, as it is associated with high morbidity and mortality. Prompt recognition and treatment of both seizure activity and associated acute systemic complications are essential to improve the overall outcome of these patients. The purpose of this review is to provide the current viewpoint on the diagnostic evaluation and pharmacological management of patients presenting with status epilepticus, and the common associated systemic complications.

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

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

A Validated Nomogram That Predicts Prognosis of Autoimmune Encephalitis: A Multicenter Study in China

The aim of this retrospective study was to derive and validate a reliable nomogram for predicting prognosis of autoimmune encephalitis (AE). A multi-center retrospective study was conducted in four hospitals in China, using a random split-sample method to allocate 173 patients into either a training (n = 126) or validation (n = 47) dataset. Demographic, radiographic and therapeutic presentation, combined with clinical features were collected. A modified Rankin Scale (mRS) at discharge was the principal outcome variable. A backward-stepwise approach based on the Akaike information criterion was used to test predictors and construct the final, parsimonious model. Multivariable analysis was conducted using logistic regression to develop a prognosis model and validate a nomogram using an independent dataset. The performance of the model was assessed using receiver operating characteristic curves and a Hosmer-Lemeshow test. The final nomogram model considered age, viral prodrome, consciousness impairment, memory dysfunction and autonomic dysfunction as predictors. Model validations displayed a good level of discrimination in the validation set: area under the Receiver operator characteristic curve = 0.72 (95% Confidence Interval: 0.56–0.88), Hosmer–Lemeshow analysis suggesting good calibration (chi-square: 10.33; p = 0.41). The proposed nomogram demonstrated considerable potential for clinical utility in prediction of prognosis in autoimmune encephalitis.

[Ictal EEG pattern of transient epileptic amnesia in acute phase of non-herpetic limbic encephalitis]

A 60-year-old, right-handed woman was admitted to our hospital for amnesia as the only neurological abnormal findings following the autonomic symptoms and transient episodes of loss of awareness. EEG during the amnesia showed rhythmic alpha activity arising from the left mid-temporal region. Although this ictal activity showed evolution in the frequency and amplitude, the location was limited in the bilateral temporal areas. After the EEG evaluation, her amnesia was resolved immediately, suggesting that her presentation was transient epileptic amnesia (TEA). Meanwhile, given the clinical course and MRI findings (high intensity in the bilateral mesial temporal areas, more on the left), she was diagnosed with non-herpetic limbic encephalitis and treated with steroid and anti-epileptic drugs, leading to the positive outcome. The ictal EEG findings during TEA as the one of the presentation in acute phase of non-herpetic limbic encephalitis may contribute to further investigation of underlying mechanism of TEA.

Etiological assessment of status epilepticus

Status epilepticus (SE) is a potentially serious condition that can affect vital and functional prognosis and requires urgent treatment. Etiology is a determining factor in the patient's functional outcome and in almost half of all cases justifies specific treatment to stop progression. Therefore, identifying and addressing the cause of SE is a key priority in SE management. However, the etiology can be difficult to identify among acute and remote causes, which can also be multiple and interrelated. The most common etiologies are the discontinuation of antiepileptic medication in patients with a prior history of epilepsy, and acute brain aggression in cases of new onset SE (cerebrovascular pathologies are the most common). The list of remaining possible etiologies includes heterogeneous pathological contexts. Refractory SE and especially New-Onset Refractory Status Epilepticus (NORSE) lead to an extension of the etiological assessment in the search for encephalitis of autoimmune or infectious origin in adults and in children, as well as a genetic pathology in children in particular. This is an overview of current knowledge of SE etiologies and a pragmatic approach for carrying out an etiological assessment based on the following steps: - Which etiological orientation is identified according to the field and clinical presentation?; - Which etiologies to look for in an inaugural SE?; - Which first-line assessment should be carried out? The place of the biological, EEG and imaging assessment is discussed; - Which etiologies to look for in case of refractory SE?

New onset refractory status epilepticus research: What is on the horizon?

New-onset refractory status epilepticus (NORSE) is a clinical presentation, not a specific diagnosis, in a patient without active epilepsy or other preexisting relevant neurologic disorder, with new onset of refractory status epilepticus (RSE) that does not resolve after 2 or more rescue medications, without a clear acute or active structural, toxic, or metabolic cause. Febrile infection-related epilepsy syndrome is a subset of NORSE in which fever began at least 24 hours prior to the RSE. Both terms apply to all age groups. Until recently, NORSE was a poorly recognized entity without a consistent definition or approach to care. We review the current state of knowledge in NORSE and propose a roadmap for future collaborative research. Research investigating NORSE should prioritize the following 4 domains: (1) clinical features, etiology, and pathophysiology; (2) treatment; (3) adult and pediatric evaluation and management approaches; and (4) public advocacy, professional education, and family support. We consider international collaboration and multicenter research crucial in achieving these goals.

Autoimmune encephalitis: a review of diagnosis and treatment

Autoimmune encephalitis (AIE) is one of the most common causes of noninfectious encephalitis. It can be triggered by tumors, infections, or it may be cryptogenic. The neurological manifestations can be either acute or subacute and usually develop within six weeks. There are a variety of clinical manifestations including behavioral and psychiatric symptoms, autonomic disturbances, movement disorders, and seizures. We reviewed common forms of AIE and discuss their diagnostic approach and treatment.

Updates in Refractory Status Epilepticus

Refractory status epilepticus is defined as persistent seizures despite appropriate use of two intravenous medications, one of which is a benzodiazepine. It can be seen in up to 40% of cases of status epilepticus with an acute symptomatic etiology as the most likely cause. New-onset refractory status epilepticus (NORSE) is a recently coined term for refractory status epilepticus where no apparent cause is found after initial testing. A large proportion of NORSE cases are eventually found to have an autoimmune etiology needing immunomodulatory treatment. Management of refractory status epilepticus involves treatment of an underlying etiology in addition to intravenous anesthetics and antiepileptic drugs. Alternative treatment options including diet therapies, electroconvulsive therapy, and surgical resection in case of a focal lesion should be considered. Short-term and long-term outcomes tend to be poor with significant morbidity and mortality with only one-third of patients reaching baseline neurological status.

Autoimmune Neurologic Disorders

The practice of autoimmune neurology focuses on the diagnosis and treatment of a wide spectrum of neurological conditions driven by abnormal immune responses directed against neural tissues. These include autoimmune, paraneoplastic, postinfectious, and iatrogenic conditions. Symptoms of autoimmune neurologic disorders can be diverse and often difficult to recognize in their early stages, complicating the diagnosis. This review discusses the classification and management of common autoimmune neurological conditions, placing an emphasis on the rapid identification of autoimmune etiology and mechanism of immune dysfunction to allow for the timely institution of appropriate treatment.

MicroRNA-129-5p inhibits the development of autoimmune encephalomyelitis-related epilepsy by targeting HMGB1 through the TLR4/NF-kB signaling pathway

The study aimed to explore the effects of microRNA-129-5p (miR-129-5p) on the development of autoimmune encephalomyelitis (AE)-related epilepsy by targeting HMGB1 through the TLR4/NF-kB signaling pathway in a rat model. AE-related epilepsy models were established. Sprague-Dawley (SD) rats were randomly divided into control, model, miR-129-5p mimics, miR-129-5p inhibitor, HMGB1 shRNA, TLR4/NF-kB (TLR4/NF-kB signaling pathway was inhibited) and miR-129-5p mimics+HMGB1 shRNA groups respectively. Latency to a first epilepsy seizure attack was recorded. Neuronal injuries in the hippocampus regions were detected using HE, Nissl and FJB staining methods 24h following model establishment. Microglial cells were detected by OX-42 immunohistochemistry. Expressions of miR-129-5p, HMGB1 and TLR4/NF-kB signaling pathway-related proteins were detected by qRT-PCR. Protein expressions of HMGB1 and TLR4/NF-kB signaling pathway-related proteins were detected by Western blotting. Dual luciferase reporter gene assay showed that miR-129-5p was negatively targeting HMGB1. Neurons of hippocampal tissues in rats were heavily injured by an injection of lithium chloride. Compared with the model and control groups, neuronal injury of the hippocampus and AE-related epilepsy decreased and microglial cells increased in the miR-129-5p mimics, HMGB1 shRNA and TLR4/NF-kB groups; however, in the miR-129-5p inhibitor group, miR-129-5p expression decreased, HMGB1 expression increased, TLR4/NF-kB signaling pathway was activated, latency to a first epilepsy seizure attack was shortened, and neuronal injury increased. This study provides evidence that miR-129-5p inhibits the development of AE-related epilepsy by suppressing HMGB1 expression and inhibiting TLR4/NF-kB signaling pathway.

New-Onset Refractory Status Epilepticus with Claustrum Damage: Definition of the Clinical and Neuroimaging Features

New-onset refractory status epilepticus (NORSE) is a rare but challenging condition occurring in a previously healthy patient, often with no identifiable cause. We describe the electro-clinical features and outcomes in a group of patients with NORSE who all demonstrated a typical magnetic resonance imaging (MRI) sign characterized by bilateral lesions of the claustrum. The group includes 31 patients (12 personal and 19 previously published cases; 17 females; mean age of 25 years). Fever preceded status epilepticus (SE) in 28 patients, by a mean of 6 days. SE was refractory/super-refractory in 74% of the patients, requiring third-line agents and a median of 15 days staying in an intensive care unit. Focal motor and tonic–clonic seizures were observed in 90%, complex partial seizures in 14%, and myoclonic seizures in 14% of the cases. All patients showed T2/FLAIR hyperintense foci in bilateral claustrum, appearing on average 10 days after SE onset. Other limbic (hippocampus, insular) alterations were present in 53% of patients. Within the personal cases, extensive search for known autoantibodies was inconclusive, though 7 of 11 patients had cerebrospinal fluid lymphocytic pleocytosis and 3 cases had oligoclonal bands. Two subjects died during the acute phase, one in the chronic phase (probable sudden unexplained death in epilepsy), and one developed a persistent vegetative state. Among survivors, 80% developed drug-resistant epilepsy. Febrile illness-related SE associated with bilateral claustrum hyperintensity on MRI represents a condition with defined clinical features and a presumed but unidentified autoimmune etiology. A better characterization of de novo SE is mandatory for the search of specific etiologies.

Diagnostic Value of 18F-FDG PET/CT Versus MRI in the Setting of Antibody-Specific Autoimmune Encephalitis

Diagnosis of autoimmune encephalitis presents some challenges in the clinical setting because of varied clinical presentations and delay in obtaining antibody panel results. We examined the role of neuroimaging in the setting of autoimmune encephalitides, comparing the utility of ¹⁸F-FDG PET/CT versus conventional brain imaging with MRI. Methods: A retrospective study was performed assessing the positivity rate of MRI versus ¹⁸F-FDG PET/CT during the initial workup of 23 patients proven to have antibody-positive autoimmune encephalitis. ¹⁸F-FDG PET/CT studies were analyzed both qualitatively and semiquantitatively. Areas of cortical lobar hypo (hyper)-metabolism in the cerebrum that were 2 SDx from the mean were recorded as abnormal. Results: On visual inspection, all patients were identified as having an abnormal pattern of ¹⁸F-FDG uptake. In semiquantitative analysis, at least 1 region of interest with metabolic change was identified in 22 of 23 (95.6%) patients using a discriminating z score of 2. Overall, ¹⁸F-FDG PET/CT was more often abnormal during the diagnostic period than MRI (10/23, 43% of patients). The predominant finding on brain ¹⁸F-FDG PET/CT imaging was lobar hypometabolism, being observed in 21 of 23 (91.3%) patients. Hypometabolism was most commonly observed in the parietal lobe followed by the occipital lobe. An entire subset of antibody-positive patients, anti-N-methyl-d-aspartate receptor (5 patients), had normal MRI results and abnormal ¹⁸F-FDG PET/CT findings whereas the other subsets demonstrated a greater heterogeneity. Conclusion: Brain ¹⁸F-FDG PET/CT may play a significant role in the initial evaluation of patients with clinically suspected antibody-mediated autoimmune encephalitis. Given that it is more often abnormal when compared with MRI in the acute setting, this molecular imaging technique may be better positioned as an early biomarker of disease so that treatment may be initiated earlier, resulting in improved patient outcomes.

Status Epilepticus Due to Cat Scratch Disease: Recognition, Diagnosis, and Thoughts on Pathogenesis

Despite the publication of a number of case reports since the 1950s, physician awareness of the unique relationship between cat scratch disease (CSD) and acute encephalopathy remains limited. This report alerts emergency medicine physicians to include CSD encephalopathy (CSDE) in the differential diagnosis when a previously healthy child presents with status epilepticus. Prompt recognition of this relationship impacts the selection of initial diagnostic studies and antibiotic choices and permits reliable insight into prognosis. The 2 cases are from different eras and demonstrate the significant diagnostic advances in the past 3 decades for Bartonella henselae infection. Both children were treated with antibiotics, and both had resolution of all neurological symptoms. However, the role of antibiotics in the treatment and outcome of CSDE remains speculative. Lastly, the report suggests potential areas of investigation to address immune-mediated mechanisms in the pathogenesis of CSDE.

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.

Abnormal movements in critical care patients with brain injury: a diagnostic approach

Abnormal movements are frequently encountered in patients with brain injury hospitalized in intensive care units (ICUs), yet characterization of these movements and their underlying pathophysiology is difficult due to the comatose or uncooperative state of the patient. In addition, the available diagnostic approaches are largely derived from outpatients with neurodegenerative or developmental disorders frequently encountered in the outpatient setting, thereby limiting the applicability to inpatients with acute brain injuries. Thus, we reviewed the available literature regarding abnormal movements encountered in acutely ill patients with brain injuries. We classified the brain injury into the following categories: anoxic, vascular, infectious, inflammatory, traumatic, toxic-metabolic, tumor-related and seizures. Then, we identified the abnormal movements seen in each category as well as their epidemiologic, semiologic and clinicopathologic correlates. We propose a practical paradigm that can be applied at the bedside for diagnosing abnormal movements in the ICU. This model seeks to classify observed abnormal movements in light of various patient-specific factors. It begins with classifying the patient’s level of consciousness. Then, it integrates the frequency and type of each movement with the availability of ancillary diagnostic tests and the specific etiology of brain injury.

Utility of Neurodiagnostic Studies in the Diagnosis of Autoimmune Encephalitis in Children

BACKGROUND

Autoimmune encephalitis is currently a clinical diagnosis without widely accepted diagnostic criteria, often leading to a delay in diagnosis. The utility of magnetic resonance imaging (MRI) and electroencephalography (EEG) in this disease is unknown. The objective of this study was to identify disease-specific patterns of neurodiagnostic studies (MRI and EEG) for autoimmune encephalitis in children.

METHODS

We completed a retrospective chart review of encephalopathic patients seen at a large pediatric hospital over a four year interval. Clinical presentation, autoantibody status, and MRI and EEG findings were identified and compared. Individuals with autoantibodies were considered "definite" cases, whereas those without antibodies or those with only thyroperoxidase antibodies were characterized as "suspected."

RESULTS

Eighteen patients met the inclusion criteria and autoantibodies were identified in nine of these. The patients with definite autoimmune encephalitis had MRI abnormalities within limbic structures, most notably the anteromedial temporal lobes (56%). Only individuals with suspected disease had nontemporal lobe cortical lesions. Sixteen patients had an EEG and 13 (81%) of these were abnormal. The most common findings were abnormal background rhythm (63%), generalized slowing (50%), focal slowing (43%), and focal epileptiform discharges (31%). Sleep spindle abnormalities occurred in 38% of patients. There were no specific differences in the EEG findings between the definite and suspected cases. Focal EEG findings only correlated with a focal lesion on MRI in a single definite case.

CONCLUSIONS

Pediatric patients with definite autoimmune encephalitis have a narrow spectrum of MRI abnormalities. Conversely, EEG abnormalities are mostly nonspecific. All patients in our cohort had abnormalities on one or both of these neurodiagnostic studies.

Effect of Immunotherapy on Seizure Outcome in Patients with Autoimmune Encephalitis: A Prospective Observational Registry Study

Objective

To evaluate the seizure characteristics and outcome after immunotherapy in adult patients with autoimmune encephalitis (AE) and new-onset seizure.

Methods

Adult (age ≥18 years) patients with AE and new-onset seizure who underwent immunotherapy and were followed-up for at least 6 months were included. Seizure frequency was evaluated at 2–4 weeks and 6 months after the onset of the initial immunotherapy and was categorized as “seizure remission”, “> 50% seizure reduction”, or “no change” based on the degree of its decrease.

Results

Forty-one AE patients who presented with new-onset seizure were analysed. At 2–4 weeks after the initial immunotherapy, 51.2% of the patients were seizure free, and 24.4% had significant seizure reduction. At 6 months, seizure remission was observed in 73.2% of the patients, although four patients died during hospitalization. Rituximab was used as a second-line immunotherapy in 12 patients who continued to have seizures despite the initial immunotherapy, and additional seizure remission was achieved in 66.6% of them. In particular, those who exhibited partial response to the initial immunotherapy had a better seizure outcome after rituximab, with low adverse events.

Conclusion

AE frequently presented as seizure, but only 18.9% of the living patients suffered from seizure at 6 months after immunotherapy. Aggressive immunotherapy can improve seizure outcome in patients with AE.

[A case of new-onset refractory status epilepticus (NORSE) with an autoimmune etiology]

A 23-year-old man presented tonic-clonic seizure a week after an episode of antecedent infection. Although several anticonvulsants were used, convulsive attacks were not resolved and intravenous anesthetics were used to stop status epileptics. After combination of immunotherapies (high-dose intravenous methylprednisolone, immune absorbance and intravenous immunoglobulin (IVIg) therapies), frequency of convulsive attacks decreased, however, disturbance of consciousness was not recovered. All anti-neuronal antibodies tested were negative. Indirect immunofluorescence using the serum and rat brain section revealed positive signals in cytoplasm and nucleus in hippocampal neurons, strongly suggesting that this case has an autoimmune pathogenesis. The clinical features and course of this patient are well consistent with those in new-onset refractory status epilepticus (NORSE). The result of immunohistochemical analysis supports the hypothesis that NORSE has an autoimmune pathomechanism.

The spectrum of autoimmune encephalopathies

Despite being a potentially reversible neurological condition, no clear guidelines for diagnosis or management of autoimmune encephalitis exist. In this study we analyzed clinical presentation, laboratory and imaging characteristics, and outcome of autoimmune encephalitis from three teaching hospitals. Non-paraneoplastic autoimmune encephalitis associated with antibodies against membrane antigens was the most common syndrome, especially in the pediatric population. Clinical outcome was better for patients with shorter latency from symptom onset to diagnosis and initiation of immunomodulation. Patients with underlying malignancy were less likely to respond well to immunomodulatory therapy. The clinical spectrum of autoimmune encephalitis is fairly broad, but prompt recognition and treatment often leads to excellent outcome.

New-onset refractory status epilepticus: Etiology, clinical features, and outcome

OBJECTIVES

The aims of this study were to determine the etiology, clinical features, and predictors of outcome of new-onset refractory status epilepticus.

METHODS

Retrospective review of patients with refractory status epilepticus without etiology identified within 48 hours of admission between January 1, 2008, and December 31, 2013, in 13 academic medical centers. The primary outcome measure was poor functional outcome at discharge (defined as a score >3 on the modified Rankin Scale).

RESULTS

Of 130 cases, 67 (52%) remained cryptogenic. The most common identified etiologies were autoimmune (19%) and paraneoplastic (18%) encephalitis. Full data were available in 125 cases (62 cryptogenic). Poor outcome occurred in 77 of 125 cases (62%), and 28 (22%) died. Predictors of poor outcome included duration of status epilepticus, use of anesthetics, and medical complications. Among the 63 patients with available follow-up data (median 9 months), functional status improved in 36 (57%); 79% had good or fair outcome at last follow-up, but epilepsy developed in 37% with most survivors (92%) remaining on antiseizure medications. Immune therapies were used less frequently in cryptogenic cases, despite a comparable prevalence of inflammatory CSF changes.

CONCLUSIONS

Autoimmune encephalitis is the most commonly identified cause of new-onset refractory status epilepticus, but half remain cryptogenic. Outcome at discharge is poor but improves during follow-up. Epilepsy develops in most cases. The role of anesthetics and immune therapies warrants further investigation.

ILAE type 3 hippocampal sclerosis in patients with anti-GAD-related epilepsy

Objective:

To describe the neuropathologic findings and clinical course of 2 patients who underwent temporal lobectomy for medically refractive epilepsy and were later found to have high anti–glutamic acid decarboxylase (GAD) concentrations.

Methods:

Small case series.

Results:

Neuropathologic examination of both patients revealed International League Against Epilepsy (ILAE) type 3 hippocampal sclerosis. Following surgery, both developed signs and symptoms of stiff person syndrome and later cerebellar ataxia. Laboratory studies demonstrated high concentrations of anti-GAD antibodies in both patients.

Conclusions:

These cases suggest that ILAE type 3 hippocampal sclerosis may be immunologically related to and may exist as part of a broader anti-GAD–related neurologic syndrome in some instances.

Status epilepticus of inflammatory etiology: a cohort study

OBJECTIVE

Inflammation-related epilepsy is increasingly recognized; however, studies on status epilepticus (SE) are very infrequent. We therefore aimed to determine the frequency of inflammatory etiologies in adult SE, and to assess related demographic features and outcomes.

METHODS

This was a retrospective analysis of a prospective registry of adult patients with SE treated in our center, from January 2008 to June 2014, excluding postanoxic causes. We classified SE episodes into 3 etiologic categories: infectious, autoimmune, and noninflammatory. Demographic and clinical variables were analyzed regarding their relationship to etiologies and functional outcome.

RESULTS

Among the 570 SE consecutive episodes, 33 (6%) were inflammatory (2.5% autoimmune; 3.3% infectious), without any change in frequency over the study period. Inflammatory SE episodes involved younger patients (mean age 53 vs 61 years, p = 0.015) and were more often refractory to initial antiepileptic treatment (58% vs 38%, odds ratio = 2.19, 95% confidence interval = 1.07-4.47, p = 0.041), despite similar clinical outcome. Subgroup analysis showed that, compared with infectious SE episodes, autoimmune SE involved younger adults (mean age 44 vs 60 years, p = 0.017) and was associated with lower morbidity (return to baseline conditions in 71% vs 32%, odds ratio = 5.41, 95% confidence interval = 1.19-24.52, p = 0.043) without any difference in mortality.

CONCLUSIONS

Despite increasing awareness, inflammatory SE etiologies were relatively rare; their occurrence in younger individuals and higher refractoriness to treatment did not have any effect on outcome. Autoimmune SE episodes also occurred in younger patients, but tended to have better outcomes in survivors than infectious SE.

Seizures and epilepsy: an overview for neuroscientists

Epilepsy is one of the most common and disabling neurologic conditions, yet we have an incomplete understanding of the detailed pathophysiology and, thus, treatment rationale for much of epilepsy. This article reviews the clinical aspects of seizures and epilepsy with the goal of providing neuroscientists an introduction to aspects that might be amenable to scientific investigation. Seizures and epilepsy are defined, diagnostic methods are reviewed, various clinical syndromes are discussed, and aspects of differential diagnosis, treatment, and prognosis are considered to enable neuroscientists to formulate basic and translational research questions.

What Elements of the Inflammatory System Are Necessary for Epileptogenesis In Vitro?

The inflammatory and central nervous systems share many signaling molecules, compromising the utility of traditional pharmacological and knockout approaches in defining the role of inflammation in CNS disorders such as epilepsy. In an in vitro model of post-traumatic epileptogenesis, the development of epilepsy proceeded in the absence of the systemic inflammatory system, and was unaffected by removal of cellular mediators of inflammation, including macrophages and T-lymphocytes.

Epileptogenesis in vivo can be altered by manipulation of molecules such as cytokines and complement that subserve intercellular signaling in both the inflammatory and central nervous systems. Because of the dual roles of these signaling molecules, it has been difficult to precisely define the role of systemic inflammation in epileptogenesis. Organotypic hippocampal brain slices can be maintained in culture independently of the systemic inflammatory system, and the rapid course of epileptogenesis in these cultures supports the idea that inflammation is not necessary for epilepsy. However, this preparation still retains key cellular inflammatory mediators. Here, we found that rodent hippocampal organotypic slice cultures depleted of T lymphocytes and microglia developed epileptic activity at essentially the same rate and to similar degrees of severity as matched control slice cultures. These data support the idea that although the inflammatory system, neurons, and glia share key intercellular signaling molecules, neither systemic nor CNS-specific cellular elements of the immune and inflammatory systems are necessary components of epileptogenesis.

Therapeutic choices in convulsive status epilepticus

INTRODUCTION

Convulsive status epilepticus (SE) is one of the most frequent and severe neurological emergencies in both adults and children. A timely administration of appropriate antiepileptic drugs (AEDs) can stop seizures early and markedly improve outcome.

AREAS COVERED

The main treatment strategies for SE are reviewed with an emphasis on initial treatments. The established first-line treatment consists of benzodiazepines, most frequently intravenous lorazepam. Benzodiazepines that do not require intravenous administration like intranasal midazolam or intramuscular midazolam are becoming more popular because of easier administration in the field. Other benzodiazepines may also be effective. After treatment with benzodiazepines, treatment with fosphenytoin and phenobarbital is usually recommended. Other intravenously available AEDs, such as valproate and levetiracetam, may be as effective and safe as fosphenytoin and phenobarbital, have a faster infusion time and better pharmacokinetic profile. The rationale behind the need for an early treatment of SE is discussed. The real-time delays of AED administration in clinical practice are described.

EXPERT OPINION

There is limited evidence to support what the best initial benzodiazepine or the best non-benzodiazepine AED is. Recent and developing multicenter trials are evaluating the best treatment options and will likely modify the recommended treatment choices in SE in the near future. Additionally, more research is needed to understand how different treatment options modify prognosis in SE. Timely implementation of care protocols to minimize treatment delays is crucial.

Pediatric status epilepticus: identification and evaluation

PURPOSE OF REVIEW

Status epilepticus is an acute neurologic emergency, the incidence of which is increasing in the United States as the definition evolves and our detection abilities improve. We will present the current definition of status epilepticus, including a recently modified operational definition for use in the clinical setting. We will also provide updates on identifying children in status epilepticus, etiologic considerations, and the rationale for diagnostic testing.

RECENT FINDINGS

Recent data reveal the benefits of MRI vs. computed tomography in new-onset status epilepticus, as well as high rates of identification of electrographic seizures in patients with unexplained acute encephalopathy in pediatric ICU settings. Genetic testing should be considered in young children with recurrent status epilepticus.

SUMMARY

Prompt recognition and diagnostic evaluation of the child in status epilepticus will help identify causes, which may require specific treatment, and help in the management of this life-threatening condition. Laboratory work, neuroimaging, electroencephalogram or continuous video electroencephalogram, lumbar puncture, and genetic testing may be considered in the evaluation of the child in status epilepticus.

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.

[Acute encephalitis with refractory partial status epilepticus treated with early immunotherapies including plasma exchange: a case report]

We describe a patient of acute encephalitis with refractory partial status epilepticus who was successfully treated with early immunotherapy. A 35-year-old male presented with generalized seizures a week after febrile upper respiratory illness. He developed refractory multifocal and generalized seizures despite multiple antiepileptic drug therapies, thereby requiring intubation on the 8(th) day after admission. No significant improvement was observed after steroid pulse and intravenous immunoglobulin (IVIG) therapies. On the 18(th) day, he received plasma exchange (PE) therapy in combination with intravenous thiamylal and lidocaine to achieve burst-suppression coma. This multidisciplinary treatment led to remission of refractory status epilepticus and subsequent withdrawal from general anesthesia. Although anti-N-methyl-D-aspartate receptor antibodies in cerebrospinal fluid were negative, other neural surface antibodies may responsible for the development of status epilepticus in this case. Clinical features in this case, including previous good health, an antecedent febrile illness, and prolonged treatment-resistant status epilepticus, were similar to those of the acute phase of new-onset refractory status epilepticus (NORSE) syndrome. Consecutive use of glucocorticoids, IVIG, and PE in the early phase was speculated to ameliorate seizures by suppressing abnormal activation of humoral immunity. This indicates that early aggressive immunotherapy may prevent complications resulting from immune-mediated treatment-resistant status epilepticus.

Anti-NMDAR autoimmune encephalitis

The N-methyl-D-aspartate receptor (NMDAR) is involved in normal physiological and pathological states in the brain. Anti-NMDAR encephalitis is characterized by memory deficits, seizures, confusion, and psychological disturbances in males and females of all ages. This type of encephalitis is often associated with ovarian teratoma in young women, but children are less likely to have tumors. Anti-NMDAR encephalitis is a neuroimmune syndrome in patients with autoantibodies recognizing extracellular epitopes of NMDAR, and the autoantibodies attenuate NMDAR function through the internalization of NMDAR. Following the initial symptoms of inflammation, the patients show the various symptoms such as memory loss, confusion, emotional disturbances, psychosis, dyskinesis, decrease in speech intelligibility, and seizures. About half of these patients improved with immunotherapy including high-dose intravenous corticosteroids and intravenous immunoglobulins is administrated to these patients, but the patients who had no improvement with these therapy require further treatments with rituximab or cyclophosphamide. It is necessary to detect anti-NMDAR antibodies at early stages, because the prognosis of these patients may be improved by early treatment. Recovery is slow, and the patients may have some disturbances in their motor function and cognition. The pathologic mechanism underlying the development of anti-NMDAR encephalitis has been elucidated gradually, but the optimal treatment has not yet been clarified. Further studies are required to clarify in detail the mechanism underlying anti-NMDA encephalitis and to develop effective treatments.