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

New onset status epilepticus and its long-term outcome: A cohort study

PURPOSE

New onset status epilepticus (NOSE), a subtype of status epilepticus, is a neurological emergency associated with significant morbidity and mortality. This study aimed to analyze the phenotypic spectrum and outcomes of patients presenting with NOSE.

METHODS

This prospective and retrospective descriptive study included patients presenting with NOSE over a 10-year period. Data collected included patient demographics, phenotypic characteristics of SE and its etiology, Status Epilepticus Severity Score (STESS), SE classification Axis-II, and Modified Rankin Scale (mRS) scores at admission and discharge. Functional outcomes and seizure status were assessed at least 6 months post-discharge. Prognostic factors for mortality and the development of epilepsy were also analyzed.

RESULTS

A total of 208 patients were included, with a mean age of 41.97 ± 21.66 years, and a male predominance (57.1 %). Focal to bilateral tonic-clonic seizures were observed in 47.5 % of patients. The etiology was acute symptomatic in 35.57 % and remote symptomatic in 24 %. The median hospital stay was 4 days (range: 2.25-10.75 days). The mortality rate was 26.5 %, and 23 % of patients developed epilepsy with a median follow-up of 9 months. Higher age (≥ 50 years), elevated STESS, ICU admission, use of anesthetic agents, refractory status epilepticus (RSE), and new-onset refractory status epilepticus (NORSE) were significant risk factors for mortality (p<0.05). The development of epilepsy was associated with a higher number of antiseizure medications (ASM) at discharge, ICU admission, use of anesthetic agents, RSE, and NORSE (p<0.05).

CONCLUSION

NOSE is a neurological emergency with a variable etiology and significant long-term consequences. Approximately one-fourth of patients presenting with NOSE died, and another quarter developed epilepsy during a median follow-up of 9 months. Identifying and addressing the predictors of mortality and epilepsy development following NOSE may improve long-term outcomes.

Febrile infection-related epilepsy syndrome with claustrum lesion: an underdiagnosed inflammatory encephalopathy

OBJECTIVE

To summarize the clinical characteristics and prognosis of febrile infection-related epilepsy syndrome with claustrum lesions (FIRES-C).

METHOD

Clinical data of FIRES-C patients were collected retrospectively. The study reviewed and analyzed their clinical manifestations, treatment strategies, and prognosis.

RESULT

Twenty patients were enrolled, including 13 females and 7 males, with a median onset age of 20.5 years. All patients developed seizures after fever, with a median interval of 5 days. Brain MRI showed symmetric lesions in the claustrum in all patients. The median interval from seizure onset to abnormal MRI signals detection was 12.5 days. All patients had negative results for comprehensive tests of neurotropic viruses and antineuronal autoantibodies. Seventy percent of cases had been previously empirically diagnosed with autoimmune encephalitis or viral encephalitis before. All patients received anti-seizure medicine. Eleven patients (55%) received antiviral therapy. All patients received immunotherapy, including glucocorticoids (100%), intravenous immunoglobulin (IVIg) (65%), plasma exchange (PLEX) (10%), tocilizumab (10%), rituximab (5%), and cyclophosphamide (5%). Sixty percent of patients received long-term immunotherapy (≥ 3 months). The median follow-up was 11.5 months;60% of patients were diagnosed with refractory epilepsy.

CONCLUSION

Bilateral claustrum lesion on MRI is a distinctive neuroimage feature for FIRES, which may serve as an indication for the initial clinical assessments. FIRES-C should be classified as a type of inflammatory encephalopathy characterized by a monophasic nature. Some FIRES-C patients respond to immunotherapy and antiseizure treatments but most experience refractory epilepsy as a long-term outcome.

Time to FIRE NORSE: A single acronym for a heterogeneous presentation. Further information from a case series and discussion of the literature

PURPOSE

New-Onset Refractory Status Epilepticus (NORSE) is a rare and severe form of refractory status epilepticus without an apparent underlying cause at presentation or prior history of epilepsy. We aimed to describe the clinical features, etiology, treatment, and outcomes of NORSE in adults in a quaternary-level hospital in Saudi Arabia.

METHODOLOGY

In this retrospective cohort study, inclusion criteria involved patients over 14 years old who met the 2018 consensus definition for NORSE. Patients were identified using a combination of medical record admission labels 'status epilepticus' and 'encephalitis', and continuous EEG reports documenting status epilepticus. Demographic, clinical, and radiological data were collected and then analyzed for factors correlated with specific etiologies, better functional outcomes, and future diagnosis of epilepsy.

RESULTS

We found 24 patients presenting with NORSE between 2010 and 2021. Fever/infectious symptoms were the most common prodrome. Elevated inflammatory serum and cerebrospinal fluid markers in most patients. Brain MRI revealed T2/FLAIR hyperintensity patterns, predominantly affecting limbic and perisylvian structures. The etiology of NORSE varied, with immune-related causes being the most common. Long-term outcomes were poor, with a high mortality rate and most survivors developing drug-resistant epilepsy.

CONCLUSION

This study provides valuable insights into NORSE's clinical characteristics, highlighting the heterogeneity of this condition. The poor outcome is likely related to the progressive nature of the underlying disease, where refractory seizures are a clinical symptom. Thus, we propose to focus future research on the etiology rather than the NORSE acronym.

A practical approach to in-hospital management of new-onset refractory status epilepticus/febrile infection related epilepsy syndrome

New-onset refractory status epilepticus (NORSE) is "a clinical presentation, not a specific diagnosis, in a patient without active epilepsy or other preexisting relevant neurological disorder, with new onset of refractory status epilepticus without a clear acute or active structural, toxic, or metabolic cause." Febrile infection related epilepsy syndrome (FIRES) is "a subcategory of NORSE that requires a prior febrile infection, with fever starting between 2 weeks and 24 h before the onset of refractory status epilepticus, with or without fever at the onset of status epilepticus." These apply to all ages. Extensive testing of blood and CSF for infectious, rheumatologic, and metabolic conditions, neuroimaging, EEG, autoimmune/paraneoplastic antibody evaluations, malignancy screen, genetic testing, and CSF metagenomics may reveal the etiology in some patients, while a significant proportion of patients' disease remains unexplained, known as NORSE of unknown etiology or cryptogenic NORSE. Seizures are refractory and usually super-refractory (i.e., persist despite 24 h of anesthesia), requiring a prolonged intensive care unit stay, often (but not always) with fair to poor outcomes. Management of seizures in the initial 24-48 h should be like any case of refractory status epilepticus. However, based on the published consensus recommendations, the first-line immunotherapy should begin within 72 h using steroids, intravenous immunoglobulins, or plasmapheresis. If there is no improvement, the ketogenic diet and second-line immunotherapy should start within seven days. Rituximab is recommended as the second-line treatment if there is a strong suggestion or proof of an antibody-mediated disease, while anakinra or tocilizumab are recommended for cryptogenic cases. Intensive motor and cognitive rehab are usually necessary after a prolonged hospital stay. Many patients will have pharmacoresistant epilepsy at discharge, and some may need continued immunologic treatments and an epilepsy surgery evaluation. Extensive research is in progress now via multinational consortia relating to the specific type(s) of inflammation involved, whether age and prior febrile illness affect this, and whether measuring and following serum and/or CSF cytokines can help determine the best treatment.

New-onset refractory status epilepticus and febrile infection-related epilepsy syndrome

PURPOSE OF REVIEW

The concept and understanding of new-onset refractory status epilepticus (NORSE), and its subtype with prior fever known as febrile infection-related epilepsy syndrome (FIRES) have evolved in the recent past. This review aims to summarize the recent developments in the pathophysiology, diagnosis and management of these challenging conditions.

RECENT FINDINGS

NORSE and FIRES can have many different causes. Although the list of possible causes is still growing, they mostly fall in the categories of autoimmune encephalitis and genetic disorders. However, despite extensive investigations, most cases of NORSE and FIRES remain cryptogenic. Recent studies have pointed towards the key role of autoinflammation as a unifying pathophysiological mechanism in these cases. These findings also support the use of immunomodulatory treatment in this setting. Consensus recommendations on the management of NORSE and FIRES have recently been published.

SUMMARY

NORSE and FIRES remain challenging conditions to diagnose and treat. Recent findings from clinical and basic research and new recommendations, reviewed in this article, contribute to an emerging framework for management and future research.

Blood-brain barrier damage and new onset refractory status epilepticus: An exploratory study using dynamic contrast-enhanced magnetic resonance imaging

OBJECTIVE

This study was undertaken to characterize the blood-brain barrier (BBB) dysfunction in patients with new onset refractory status epilepticus (NORSE) using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI).

METHODS

This study included three groups of adult participants: patients with NORSE, encephalitis patients without status epilepticus (SE), and healthy subjects. These participants were retrospectively included from a prospective DCE-MRI database of neurocritically ill patients and healthy subjects. The BBB permeability (Ktrans) in the hippocampus, basal ganglia, thalamus, claustrum, periventricular white matter, and cerebellum were measured and compared between these three groups.

RESULTS

A total of seven patients with NORSE, 14 encephalitis patients without SE, and nine healthy subjects were included in this study. Among seven patients with NORSE, only one had a definite etiology (autoimmune encephalitis), and the rest were cryptogenic. Etiology of encephalitis patients without SE included viral (n = 2), bacterial (n = 8), tuberculous (n = 1), cryptococcal (n = 1), and cryptic (n = 2) encephalitis. Of these 14 encephalitis patients without SE, three patients had seizures. Compared to healthy controls, NORSE patients had significantly increased Ktrans values in the hippocampus (.73 vs. .02 × 10^-3 /min, p = .001) and basal ganglia (.61 vs. .003 × 10^-3 /min, p = .007) and a trend in the thalamus (.24 vs. .08 × 10^-3 /min, p = .017). Compared to encephalitis patients without SE, NORSE patients had significantly increased Ktrans values in the thalamus (.24 vs. .01 × 10^-3 /min, p = .002) and basal ganglia (.61 vs. .004 × 10^-3 /min, p = .013).

SIGNIFICANCE

This exploratory study demonstrates that BBBs of NORSE patients were impaired diffusely, and BBB dysfunction in the basal ganglia and thalamus plays an important role in the pathophysiology of NORSE.

Specific profiles of new-onset vs. non-inaugural status epilepticus: From diagnosis to 1-year outcome

While new-onset status epilepticus (NOSE) is a harbinger of chronic epilepsy, prospective medical data are sparse in terms of specifying whether the evolution of status epilepticus (SE) and seizure expression in NOSE resembles what occurs in patients who have already been diagnosed with epilepsy [non-inaugural SE (NISE)] in all aspects apart from its inaugural nature. The aim of this study was to compare the clinical, MRI, and EEG features that could distinguish NOSE from NISE. We conducted a prospective monocentric study in which all patients ≥18 years admitted for SE over a 6-month period were included. A total of 109 patients (63 NISE and 46 NOSE cases) were included. Despite similar modified Rankin scores before SE, several aspects of the clinical history distinguished NOSE from NISE patients. NOSE patients were older and frequently had neurological comorbidity and preexisting cognitive decline, but they had a similar prevalence of alcohol consumption to NISE patients. NOSE and NISE evolve in the same proportions as refractory SE (62.5% NOSE, 61% NISE) and share common features such as the same incidence (33% NOSE, 42% NISE, and p = 0.53) and volumes of peri-ictal abnormalities on MRI. However, in NOSE patients, we observed greater non-convulsive semiology (21.7% NOSE, 6% NISE, and p = 0.02), more periodic lateral discharges on EEG (p = 0.004), later diagnosis, and higher severity according to the STESS and EMSE scales (p < 0.0001). Mortality occurred in 32.6% of NOSE patients and 21% of NISE patients at 1 year (p = 0.19), but with different causes of death occurring at different time points: more early deaths directly linked to SE at 1 month occurred in the NOSE group, while there were more remote deaths linked to causal brain lesions in the NISE group at final follow-up. In survivors, 43.6% of the NOSE cases developed into epilepsy. Despite acute causal brain lesions, the novelty related to its inaugural nature is still too often associated with a delay in diagnosing SE and a poorer outcome, which justifies the need to more clearly specify the various types of SE to constantly raise awareness among clinicians. These results highlight the relevance of including novelty-related criteria, clinical history, and temporality of occurrence in the nosology of SE.

Inflammatory epilepsy (FIRES) and haemophagocytic lymphohistiocytosis (HLH): an adult case

We describe a man in his 30s with haemophagocytic lymphohistiocytosis (HLH), secondary to an upper respiratory tract infection, with subsequent febrile infection-related epilepsy syndrome. He had a prolonged hospital admission, during which he was treated with chemotherapy for HLH and antiepileptic medications for refractory seizures. He was discharged fully dependent to a care facility and died from aspiration pneumonia 11 months later. This case report highlights his management and discusses these conditions' pathophysiology and future management.

Long-term outcomes of adult cryptogenic febrile infection-related epilepsy syndrome (FIRES)

Background

Cryptogenic febrile infection-related epilepsy syndrome (FIRES) is a rare but catastrophic encephalopathic condition. We aimed to investigate the long-term outcome in adult cryptogenic FIRES.

Methods

This was a retrospective study based on the prospective database in the neuro-intensive care unit of a tertiary hospital in China. Consecutive adult patients with cryptogenic FIRES between July 2007 to December 2021 were included. Long-term outcomes included function independence, the development of drug-resistant epilepsy (DRE), remote recurrent status epilepticus (SE), anti-seizure medications (ASMs), and changes in the brain Magnetic Resonance Imaging (MRI).

Results

A total of 11 adult patients with cryptogenic FIRES were identified from 270 patients with SE. Four (36%) patients died in the hospital, with three of them withdrawing treatments, and one patient died 12 months after discharge. After the follow-up ranging from 12 to 112 months, 6 (55%) patients were still alive, and all of them achieved functional independence [modified Rankin Scale (mRS) 0-3]. 45% (5/11) patients developed DRE, 18% (2/11) had remote recurrent SE, and 55% (6/11) were on polytherapy with ASMs at the last follow-up. Most of the patients with initial normal or abnormal MRI had abnormalities in the hippocampus at follow-up, and most of the other MRI abnormalities found in the acute stage disappeared over time.

Conclusion

The outcome of adult cryptogenic FIRES is daunting. More than one-third of patients die in the hospital. Survivors of cryptogenic FIRES may regain functional independence, but they usually develop DRE and receive polytherapy of ASMs for a long time.

Seizures, Epilepsy, and NORSE Secondary to Autoimmune Encephalitis: A Practical Guide for Clinicians

The most recent International League Against Epilepsy (ILAE) classification has included "immune etiology" along with other well-known causes of epilepsy. This was possible thanks to the progress in detection of pathogenic neural antibodies (Abs) in a subset of patients, and resulted in an increased interest in identifying potentially treatable causes of otherwise refractory seizures. Most autoimmune encephalitides (AE) present with seizures, but only a minority of cases evolve to long-term epilepsy. The risk of epilepsy is higher for patients harboring Abs targeting intracellular antigens (T cell-mediated and mostly paraneoplastic, such as Hu, CV2/CRMP5, Ma2, GAD65 Abs), compared with patients with neuronal surface Abs (antibody-mediated and less frequently paraneoplastic, such as NMDAR, GABAbR, LGI1, CASPR2 Abs). To consider these aspects, conceptual definitions for two entities were provided: acute symptomatic seizures secondary to AE, and autoimmune-associated epilepsy, which reflect the different pathophysiology and prognoses. Through this manuscript, we provide an up-to-date review on the current state of knowledge concerning diagnosis and management of patients with Ab-mediated encephalitis and associated epilepsy. Special emphasis is placed on clinical aspects, such as brain magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) specificities, electroencephalographic (EEG) findings, cancer screening and suggestions for a rational therapeutic approach.

New-onset refractory status epilepticus due to autoimmune encephalitis after vaccination against SARS-CoV-2: First case report

Background:

Vaccination against SARS-CoV-2 has been conducted frequently to limit the pandemic but may rarely be associated with postvaccinal autoimmune reactions or disorders.

Case presentation

We present a 35-year-old woman who developed fever, skin rash, and headache 2 days after the second SARS-CoV-2 vaccination with BNT162b2 (Pfizer/Biontech). Eight days later, she developed behavioral changes and severe recurrent seizures that led to sedation and intubation. Cerebral magnetic resonance imaging showed swelling in the (para-) hippocampal region predominantly on the left hemisphere and bilateral subcortical subinsular FLAIR hyperintensities. Cerebrospinal fluid analysis revealed a lymphocytic pleocytosis of 7 cells/μl and normal protein and immunoglobulin parameters. Common causes of encephalitis or encephalopathy such as viral infections, autoimmune encephalitis with well-characterized autoantibodies, paraneoplastic diseases, and intoxications were ruled out. We made a diagnosis of new-onset refractory status epilepticus (NORSE) due to seronegative autoimmune encephalitis. The neurological deficits improved after combined antiepileptic therapy and immunomodulatory treatment including high-dose methylprednisolone and plasma exchange.

Conclusions

Although a causal relationship cannot be established, the onset of symptoms shortly after receiving the SARS-CoV-2 vaccine suggests a potential association between the vaccination and NORSE due to antibody-negative autoimmune encephalitis. After ruling out other etiologies, early immunomodulatory treatment may be considered in such cases.

Human lesions and animal studies link the claustrum to perception, salience, sleep and pain

The claustrum is the most densely interconnected region in the human brain. Despite the accumulating data from clinical and experimental studies, the functional role of the claustrum remains unknown. Here, we systematically review claustrum lesion studies and discuss their functional implications. Claustral lesions are associated with an array of signs and symptoms, including changes in cognitive, perceptual and motor abilities; electrical activity; mental state; and sleep. The wide range of symptoms observed following claustral lesions do not provide compelling evidence to support prominent current theories of claustrum function such as multisensory integration or salience computation. Conversely, the lesions studies support the hypothesis that the claustrum regulates cortical excitability. We argue that the claustrum is connected to, or part of, multiple brain networks that perform both fundamental and higher cognitive functions. As a multifunctional node in numerous networks, this may explain the manifold effects of claustrum damage on brain and behaviour.

Alcohol abuse has a potential association with unfavourable clinical course and brain atrophy in patients with status epilepticus

AIM

To evaluate chronological changes on serial magnetic resonance imaging (MRI) examinations and clinical prognosis in patients with status epilepticus (SE), as well as the effect of alcohol abuse and heavy alcohol use on clinicoradiological findings.

MATERIALS AND METHODS

This retrospective, single-centre study was approved by the institutional review board. Among 345 patients with seizures between January 2010 and October 2021, 27 patients with SE who had undergone both initial MRI (within a week after onset) and follow-up MRI (within 1 month after the initial MRI) were included. Five and three patients with concurrent or previous alcohol abuse and heavy alcohol-use history were included, respectively, and they were classified into the AL (Alcohol use) group. The remaining 19 patients were classified into the non-AL group. Two neuroradiologists independently evaluated both initial and follow-up MRI examinations of each patient; MRI findings were compared between the AL and non-AL groups using Fisher's exact test. In 15 patients, including four patients from the AL group, clinical information 6 months after the onset of SE was available; this information was compared between the two groups.

RESULTS

Brain atrophy (5/8 versus 2/19, p=0.011; odds ratio, 12.29 [95% confidence interval, 1.32-189.2]) and unfavourable clinical course with uncontrollable seizures (3/4 versus 1/11, p=0.033; odds ratio, 30[1.43-638.19]) were significantly more frequent in the AL group than in the non-AL group.

CONCLUSION

Among patients with SE, alcohol abuse and heavy alcohol-use history were associated with unfavourable seizure control and brain atrophy.

New onset refractory status epilepticus: State of the art

NORSE (new onset refractory status epilepticus) has recently been defined as a clinical presentation, not a specific diagnosis, in a patient without active epilepsy or other preexisting relevant neurological disorder, with new onset of refractory status epilepticus without a clear acute or active structural, toxic or metabolic cause. It includes the concept of FIRES described in children with a similar condition but preceded by a 2-14-day febrile illness. NORSE constitutes the acute phase of an entity preceded by a prodromal phase which may be accompanied by numerous manifestations (febrile episode, behavioural changes, headache, …), and followed by a chronic phase marked by long-term neurological sequelae, cognitive impairment, epilepsy and functional disability. There are many causes of NORSE: autoimmune, infectious, genetic, toxic, … but in half of the cases, despite an exhaustive assessment, the cause remains undetermined. Paraneoplastic and non-paraneoplastic autoimmune encephalitis remains by far the leading cause of NORSE. For these reasons, immunotherapy should be considered rapidly in parallel with the treatment of the status epilepticus, including in cryptogenic NORSE. Good communication with the family is important because the management of the acute phase is long and difficult. Although mortality remains high (11-22%), and sequelae can be severe, the majority of survivors can have a good or fair outcome.

Connections Between Febrile Infection-Related Epilepsy Syndrome and Autoimmune Encephalitis. A Case Report of a Child With New Anti-neuronal Antibodies

Acute encephalitis and febrile infection-related epilepsy syndrome (FIRES) are debilitating neurological disorders. It is increasingly accepted that FIRES should be considered an autoinflammation-mediated epileptic encephalopathy, but the debate about its etiopathogenesis is still very much open. Despite showing a considerable overlap with encephalitis, it continues to be regarded as a distinct entity. We describe the case of a previously healthy 5-year-old child who, following a fever, developed acute encephalopathy, status epilepticus, neurological, neuropsychological, and psychiatric manifestations, and claustrum involvement on MRI. At symptom onset, his clinical and instrumental data met the diagnostic criteria for both FIRES and acute encephalitis. He received benzodiazepines, levetiracetam, phenytoin, phenobarbital, thiopental, and first-line immunotherapy for acute inflammatory encephalopathy (intravenous methylprednisolone and immunoglobulins), without substantial improvement. Following the detection of anti-neuronal antibodies through immunohistochemistry performed on rat brain slices, he received therapeutic plasma exchange (TPE). His neurological and behavioral conditions improved drastically and his antibody titer fell sharply from the first to the last course of PE. Claustrum abnormalities on MRI disappeared. The patient's long-term outcome is favorable. At 13 months after discharge, he experienced a focal seizure and carbamazepine was started, achieving seizure control. At 10 years of age, he is still on carbamazepine, with well-controlled seizures, focal EEG abnormalities, and an otherwise normal neurological and cognitive profile and normal MRI. This case strengthens the view that FIRES might constitute the initial clinical presentation of a CNS inflammatory disease that could have, among multiple distinct etiologies, an autoimmune cause. Immunological and specific second- or third-level investigations including immunohistochemistry should be included in the diagnostic work up of patients with FIRES-like phenotypes. PE could be effective in this subset of patients, protecting them from long-term neurological sequelae.

Repetitive seizures after febrile period exclusively involving bilateral claustrum

The purpose of this study is to demonstrate the relationship between acute repetitive seizures and claustrum damage, and to provide basis for the treatment of repetitive seizures exclusively involved the bilateral claustrum.Between August 2014 and October 2015, 5 patients with repetitive seizures after a febrile period were admitted to our hospital, showing exclusive involvement of bilateral claustrum on magnetic resonance images (MRI). All patients underwent serum virology testing, autoimmune antibody test, MRI, and electroencephalograph examination.All patients were young women (16-29 years) with an unremarkable previous medical history, and 2 of them were pregnant. Similar clinical symptoms like antecedent febrile illness in the 3 to 7 days preceding seizures, psychiatric disorder, or dysautonomia occurred in 5 patients. Abnormal MRI signals exclusively confined to the bilateral claustrum appeared in 4 patients during the acute phase and in 1 patient during the chronic phase. All patients accepted empirical treatment with anti-viral and anti-seizure drugs and had good outcomes (seizure-free, though with some residual short-term memory loss) at the 3rd year follow-up.Although the clinical and associated brain imaging findings were characteristic, the etiology was still unclear. Contrary to previous studies, the patients presented here have all received a good prognosis.

Understanding new-onset refractory status epilepticus from an immunological point of view

New-onset refractory status epilepticus (NORSE) is unexpected onset of refractory status epilepticus in individuals with no preexisting relevant neurologic condition. The etiologies remain largely cryptogenic; treatment is challenging after failure to control seizures despite use of multiple antiepileptic drugs and anesthetic agents. Frequent fever and other infectious prodromes, elevated proinflammatory cytokine/chemokine levels, and limbic or multifocal brain lesions indicate active inflammation in NORSE. Among identified causes, autoimmune encephalitis is the most common and accounts for more than one-third of all known NORSE cases, followed by infection-related etiologies. Although more evidence is needed, anti-cytokine therapies with tocilizumab and anakinra along with other immunotherapeutic agents used in autoimmune encephalitis can aid in alleviating or hindering the inflammatory cascade and controlling seizures.

Clinical presentation of new onset refractory status epilepticus in children (the pSERG cohort)

Objective

We aimed to characterize the clinical profile and outcomes of new onset refractory status epilepticus (NORSE) in children, and investigated the relationship between fever onset and status epilepticus (SE).

Methods

Patients with refractory SE (RSE) between June 1, 2011 and October 1, 2016 were prospectively enrolled in the pSERG (Pediatric Status Epilepticus Research Group) cohort. Cases meeting the definition of NORSE were classified as "NORSE of known etiology" or "NORSE of unknown etiology." Subgroup analysis of NORSE of unknown etiology was completed based on the presence and time of fever occurrence relative to RSE onset: fever at onset (≤24 h), previous fever (2 weeks–24 h), and without fever.

Results

Of 279 patients with RSE, 46 patients met the criteria for NORSE. The median age was 2.4 years, and 25 (54%) were female. Forty (87%) patients had NORSE of unknown etiology. Nineteen (48%) presented with fever at SE onset, 16 (40%) had a previous fever, and five (12%) had no fever. The patients with preceding fever had more prolonged SE and worse outcomes, and 25% recovered baseline neurological function. The patients with fever at onset were younger and had shorter SE episodes, and 89% recovered baseline function.

Significance

Among pediatric patients with RSE, 16% met diagnostic criteria for NORSE, including the subcategory of febrile infection‐related epilepsy syndrome (FIRES). Pediatric NORSE cases may also overlap with refractory febrile SE (FSE). FIRES occurs more frequently in older children, the course is usually prolonged, and outcomes are worse, as compared to refractory FSE. Fever occurring more than 24 h before the onset of seizures differentiates a subgroup of NORSE patients with distinctive clinical characteristics and worse outcomes.

New-onset refractory status epilepticus (NORSE)

New-onset refractory status epilepticus and its subcategory febrile infection-related epilepsy syndrome are rare devastating clinical presentations in those without pre-existing relevant history, often in schoolchildren or young adults, without a clear cause on initial investigations. A cause is later identified in up to half of adults, but in many fewer children. Patients often require protracted intensive care and are at significant risk of dying. Functional disability is common and subsequent chronic epilepsy is the norm, but some people do have good outcomes, even after prolonged status epilepticus. Patients need prompt investigations and treatment. Anaesthetic and antiseizure medications are supplemented by other treatment modalities, including the ketogenic diet. Despite limited evidence, it is appropriate to try to modify the presumed underlying pathogenesis with immune modulation early, with a more recent focus on using interleukin inhibitors. Optimising management will require concerted multicentre international efforts.

Analysis of Interictal Epileptiform Discharges in Mesial Temporal Lobe Epilepsy Using Quantitative EEG and Neuroimaging

Objective: Investigate areas of correlation between gray matter volumes by MRI and interictal EEG source maps in subtypes of mesial temporal lobe epilepsy (MTLE). Method: 71 patients and 36 controls underwent 3T MRI and and routine EEG was performed. Voxel-based morphometry (VBM) was used for gray matter analysis and analysis of interictal discharge sources for quantitative EEG. Voxel-wise correlation analysis was conducted between the gray matter and EEG source maps in MTLE subtypes. Results: The claustrum was the main structure involved in the individual source analysis. Twelve patients had bilateral HA, VBM showed bilateral hippocampal. Twenty-one patients had right HA, VBM showed right hippocampal and thalamic atrophy and negatively correlated involving the right inferior frontal gyrus and insula. Twenty-two patients had left HA, VBM showed left hippocampal atrophy and negatively correlated involving the left temporal lobe and insula. Sixteen patients had MTLE without HA, VBM showed middle cingulate gyrus atrophy and were negatively correlated involving extra-temporal regions, the main one located in postcentral gyrus. Conclusions: Negative correlations between gray matter volumes and EEG source imaging. Neuroanatomical generators of interictal discharges are heterogeneous and vary according to MTLE subtype. Significance: These findings suggest different pathophysiological mechanisms among patients with different subtypes of MTLE.

New-onset refractory status epilepticus and febrile infection-related epilepsy syndrome

New-onset refractory status epilepticus (NORSE) and febrile infection-related epilepsy syndrome (FIRES) are relatively rare clinical presentations. They are characterized by de novo onset of refractory status epilepticus (RSE) without clearly identifiable acute or active cause (structural, toxic, or metabolic). We reviewed the literature using PubMed reports published between 2003 and 2019 and summarized the clinical, neurophysiological, imaging, and treatment findings. Focal motor seizures, which tend to evolve into status epilepticus, characterize the typical presentation. Disease course is biphasic: acute phase followed by chronic phase with refractory epilepsy and neurological impairment. Aetiology is unknown, but immune-inflammatory-mediated epileptic encephalopathy is suspected. Electroencephalograms show variety in discharges (sporadic or periodic, focal, generalized, or more frequently bilateral), sometimes with a multifocal pattern. About 70% of adult NORSE have abnormal magnetic resonance imaging (MRI); in paediatric series of FIRES, 61.2% of patients have a normal brain MRI at the beginning and only 18.5% during the chronic phase. No specific therapy for FIRES and NORSE currently exists; high doses of barbiturates and ketogenic diet can be used with some effectiveness. Recently, anakinra and tocilizumab, targeting interleukin pathways, have emerged as potential specific therapies. Mortality rate is around 12% in children and even higher in adults (16-27%).

The timelines of MRI findings related to outcomes in adult patients with new-onset refractory status epilepticus

OBJECTIVE

To identify the timelines of magnetic resonance imaging (MRI) abnormalities and their relationships with the clinical outcomes of patients with new-onset refractory status epilepticus (NORSE).

METHODS

This retrospective observational study enrolled patients with NORSE who were admitted from March 2008 to July 2018. MRI abnormalities were analyzed visually with the readers blinded to the clinical characteristics of the patients. Poor functional outcome was defined as a Glasgow Outcome Scale score ≤ 3 at discharge. Subsequent pharmacoresistant epilepsy was defined as seizures not controlled by two or more anti-seizure medications 6 months after discharge.

RESULTS

Among 39 patients with NORSE, 32 (82.1%) exhibited an MRI abnormality. The most common abnormalities were persisting mesial temporal lobe signal abnormality (51.3%); initial diffuse leptomeningeal enhancement within 16 days from seizure onset (15/35, 42.9%); and hippocampal atrophy, which started to appear 26 days after seizure onset (15/26, 57.7%). Only three patients had claustrum abnormalities. Patients with insular involvement had longer treatment delay than those without (24.0 vs 5.5 hours, respectively, P = .02). Duration of status epilepticus (SE) tended to have a linear association with hippocampal atrophy (P = .055). Patients with diffuse leptomeningeal enhancement were more likely to have a poor functional outcome and to develop subsequent pharmacoresistant epilepsy than those without this finding (93.3% vs 15.0%, P < .001; 75.0% vs 22.2%, P = .004, respectively); the results were significant even after adjusting for age, sex, and duration of SE. Hippocampal atrophy and diffuse cortical atrophy were also significantly associated with poor functional outcomes (P = .001 and P = .002, respectively), and patients with these conditions were more likely to develop subsequent pharmacoresistant epilepsy than those without these conditions, after adjusting for age and sex (P = .035 and P = .048, respectively), but not after adjusting for duration of SE.

SIGNIFICANCE

Initial diffuse leptomeningeal enhancement and later hippocampal atrophy were associated with a poor functional outcome and subsequent pharmacoresistant epilepsy.

Neurocritical care and target immunotherapy for febrile infection-related epilepsy syndrome

Febrile infection-related epilepsy syndrome (FIRES) is an intractable neurological disease characterized by an unexplained refractory status epilepticus triggered by febrile infection. A Consensus definition of FIRES was proposed in 2018, and its clinical features and prognosis are gradually being clarified. However, the development of effective treatments has been hindered as the etiology of this rare disease is as yet unelucidated. The basic approach to the management of FIRES, like other forms of epilepsy, is based on the control of seizures, however seizures are extremely intractable and require intravenous administration of large doses of anticonvulsants, mainly barbiturates. This treatment strategy produces various complications including respiratory depression and drug hypersensitivity syndrome, which make it more difficult to control seizures. Consequently, it is crucial to predict these events and to formulate a planned treatment strategy. As well, it is important to grow out of conventional treatment strategies that rely on only anticonvulsants, and alternative therapies are gradually being developed. One such example is the adoption of a ketogenic diet which may lead to reduced convulsions as well as improve intellectual prognosis. Further, overproduction of inflammatory cytokines in the central nervous system has been shown to be strongly related to the pathology of FIRES which has led to attempts at immunomodulation therapy including anti-cytokine therapy.

Cerebrospinal fluid and blood biomarkers of status epilepticus

Status epilepticus is a condition resulting either from the failure of the mechanisms responsible for seizure termination or from the initiation of mechanisms that lead to abnormally prolonged seizures and require urgent administration of antiepileptic drugs. Refractory status epilepticus requires anesthetics drugs and may lead to brain injury with molecular and cellular alterations (eg, inflammation, and neuronal and astroglial injury) that could induce neurologic sequels and further development of epilepsy. Outcome scores based on demographic, clinical, and electroencephalography (EEG) condition are available, allowing prediction of the risk of mortality, but the severity of brain injury in survivors is poorly evaluated. New biomarkers are needed to predict with higher accuracy the outcome of patients admitted with status in an intensive care unit. Here, we summarize the findings of studies from patients and animal models of status epilepticus. Specific protein markers can be detected in the cerebrospinal fluid and the blood. One of the first described markers of neuronal death is the neuron-specific enolase. Gliosis resulting from inflammatory responses after status can be detected through the increase of S100-beta, or some cytokines, like the High Mobility Group Box 1. Other proteins, like progranulin may reflect the neuroprotective mechanisms resulting from the brain adaptation to excitotoxicity. These new biomarkers aim to prospectively identify the severity and development of disability, and subsequent epilepsy of patients with status. We discuss the advantages and disadvantages of each biomarker, by evaluating their brain specificity, stability in the fluids, and sensitivity to external interferences, such as hemolysis. Finally, we emphasize the need for further development and validation of such biomarkers in order to better assess patients with severe status epilepticus.

New-onset refractory status epilepticus: A retrospective cohort study

PURPOSE

To describe the clinical, laboratory, neuroimaging, electroencephalographic features, etiology, treatment, as well as short-term and long-term outcomes of adults with new-onset refractory status epilepticus (NORSE).

METHOD

A retrospective, single institution cohort study (2010-2018) of consecutive adult patients with NORSE.

RESULTS

Among 20 patients with NORSE, nine (45 %) had prodromal febrile illness, 12 (60 %) had evidence of inflammation on CSF profile. Six patients (30 %) met criteria for definite autoimmune encephalitis (AE) while 8 patients (40 %) had probable AE. Eleven out of 13 (85 %) patients had an abnormal FDG-PET scan with the most common finding being regional hypermetabolism. Fourteen patients (70 %) received immunotherapy and ten (50 %) received the ketogenic diet (KD). Fifteen patients (75 %) progressed to super-refractory status epilepticus (SRSE) and seven patients (35 %) died in the hospital or within six months of discharge. Among the surviving patients, eight (40 %) had a good outcome (i.e., modified Rankin Scale score 0-2); 12 (80 %) received a diagnosis of epilepsy of which nine (75 %) developed drug-resistant epilepsy.

CONCLUSIONS

New-onset refractory status epilepticus is a syndrome associated with multiple complications, high mortality, and subsequent intractable epilepsy. There are multiple causes, some of which are autoimmune encephalitides; however, in this series the majority of patients had no clear etiology identified after extensive evaluation. Prospective studies are needed to determine optimal evaluation and treatment.

Transcriptomic Characterization of the Human Insular Cortex and Claustrum

The insular cortex has been linked to a multitude of functions. In contrast, the nearby claustrum is a densely connected subcortical region with unclear function. To view the insula-claustrum region from the molecular perspective we analyzed the transcriptomic profile of these areas in six adult and four fetal human brains. We identified marker genes with specific expression and performed transcriptome-wide tests for enrichment of biological processes, molecular functions, and cellular components. In addition, specific insular and claustral expression of genes pertaining to diseases, addiction, and depression was tested. At the anatomical level, we used brain-wide analyses to determine the specificity of our results and to determine the transcriptomic similarity of the insula-claustrum region. We found UCMA to be the most significantly enriched gene in the insular cortex and confirmed specific expression of NR4A2, NTNG2, and LXN in the claustrum. Furthermore, the insula was found to have enriched expression of genes associated with mood disorders, learning, cardiac muscle contraction, oxygen transport, glutamate and dopamine signaling. Specific expression in the claustrum was enriched for genes pertaining to human immunodeficiency virus (HIV), severe intellectual disability, epileptic encephalopathy, intracellular transport, spine development, and macroautophagy. We tested for enrichment of genes related to addiction and depression, but they were generally not highly specific to the insula-claustrum region. Exceptions include high insular expression of genes linked to cocaine abuse and genes associated with ever smoking in the claustrum. Brain-wide, we find that markers of the adult claustrum are most specifically expressed in the fetal and adult insula. Altogether, our results provide a novel molecular perspective on the unique properties of the insula and claustrum.

Schizophrenia following new-onset refractory status epilepticus secondary to antiphospholipid syndrome

New-onset refractory status epilepticus (NORSE) is a drug-resistant status epilepticus that often has a catastrophic outcome. Our patient was diagnosed with NORSE and had an EEG reading that showed status epilepticus persisting for 8 months in general anesthesia. After autoimmune workup showed positive antiphospholipid antibodies, his seizure was controlled, and he was discharged with good condition apart from moderate cognitive impairment. However, he later developed schizophrenia. Although psychiatric disorders have been associated with antiphospholipid syndrome, to the best of our knowledge, it has not been reported to be associated with status epilepticus. We recommend vigilance of psychological complications of refractory status epilepticus’ patients for early psychiatric referral, diagnosis, and treatment.

New onset refractory status epilepticus (NORSE)

PURPOSE

To summarize the clinical features, suggested work-up, treatment and prognosis of new-onset refractory status epilepticus (NORSE), a condition recently defined as the occurrence of refractory status epilepticus (RSE) in a patient without active epilepsy, and without a clear acute or active structural, toxic or metabolic cause; and of the related syndrome of febrile infection-related epilepsy syndrome (FIRES), also recently defined as a subgroup of NORSE preceded by a febrile illness between 2 weeks and 24 h prior to the onset of RSE.

METHOD

Narrative review of the medical literature about NORSE and FIRES.

RESULTS

NORSE and FIRES mainly affect school-age children and young adults. A prodromal phase with flu-like symptoms precedes the SE onset in two third of NORSE cases, and by definition in all FIRES. Status epilepticus usually starts with repeated focal seizures with secondary bilateralization. Most cases evolve to super RSE (SRSE) and have unfavorable outcome, with short-term mortality of 12-27%, long-term disability and epilepsy. No specific imaging or laboratory abnormalities have been identified so far that allows an early diagnosis and half of adult cases remain of unknown etiology. A standardized diagnostic algorithm is provided and. Autoimmune encephalitis is the most frequent identified cause. In the absence of specific diagnosis, immunotherapy could be tried in addition to antiepileptic treatment.

CONCLUSIONS

This review presents the rare but devastating syndrome of NORSE, including the subcategory of FIRES. Early recognition with complete work-up is primordial to identify the underlying cause and promptly start appropriate treatment.

Practical issues in measuring autoantibodies to neuronal cell-surface antigens in autoimmune neurological disorders: 190 cases

OBJECTIVES

To address practical issues in measuring autoantibodies to neuronal cell-surface antigens (NSAs) in various autoimmune neurological disorders (ANDs).

METHODS

We retrospectively reviewed the clinical information of 221 patients with clinically suspected ANDs who underwent antibody testing for NSAs between January 2007 and September 2017. 31 were excluded. In 190 patients, antibody-detection rate (ADR) and antibody-phenotype association were assessed.

RESULTS

Fifty-four patients had NSA-antibodies: NMDA receptor (NMDAR) (n = 39), AMPA receptor (n = 3), leucine-rich glioma inactivated 1 (LGI1) (n = 3), glycine receptor (GlyR) (n = 3), GABA(A) receptor (n = 2), GABA(B) receptor (n = 1), metabotrophic glutamate receptor 5 (n = 1), or unknown (n = 6); 3 had multiple NSA-antibodies. ADR in patients with diagnostic criteria for "possible autoimmune encephalitis (AE)", "probable anti-NMDAR encephalitis", "definite autoimmune limbic encephalitis (ALE)", and "stiff-person spectrum disorder (SPSD)", was 34% (46/134), 85% (34/40), 46% (11/24), and 22% (4/18), respectively, but NSA-antibodies were not identified in 11 patients with systemic autoimmune disorders (SADs). Among 134 patients with "possible AE" criteria, NMDAR-antibodies were more frequently identified in patients with typical anti-NMDAR encephalitis than those without (34/40 [85%] vs. 4/94 [4%], p < 0.0001). LGI1-antibodies were identified in patients with ALE but not in the others (3/24 [13%] vs. 0/110 [0%], p = 0.005). GlyR-antibodies were identified in those with stiff-person syndrome plus (2/8, 25%) or stiff-limb syndrome (1/6, 17%).

CONCLUSIONS

NSA-antibodies were most frequently identified in "probable anti-NMDAR encephalitis", followed by "definite ALE", "possible AE", and "SPSD", but not identified in SADs. NMDAR, LGI1 and GlyR were associated with clinical phenotype. Cell-surface antigens should be determined based on individual phenotype.

A pilot study of the role of the claustrum in attention and seizures in rats

OBJECTIVE

The claustrum has been implicated in consciousness, and MRIs of patients with status epilepticus have shown increased claustral signal intensity. In an attempt to investigate the role of claustrum in cognition and seizures, we (1) assessed the effect of high-frequency stimulation (HFS) of the claustrum on performance in the operant chamber; (2) studied interclaustral and claustrohippocampal connectivity through cerebro-cerebral evoked potentials (CCEPs); and (3) investigated the role of claustrum in kainate-induced (KA) seizures.

METHODS

Adult male Sprague-Dawley rats were trained in operant conditioning and implanted with electrodes in bilateral claustra and hippocampi. Claustrum HFS (50 Hz) was delivered bilaterally and unilaterally with increasing intensities from 50 to 1000 μA, and performance scores were assessed. CCEPs were studied by averaging the responses to bipolar stimulations, 1-ms wide pulses at 0.1 Hz to the claustrum. KA seizures were analyzed on video-EEG recordings.

RESULTS

Generalized Estimating Equations analysis revealed that claustral stimulation reduced task performance scores relative to rest sessions (bilateral: -15.8 percentage points, p < 0.0001; unilateral: -15.2, p < 0.0001). With some stimulations, the rats showed a stimulus-locked decrease in attentiveness and, occasionally, an inability to complete the operant task. CCEPs demonstrated interclaustral and claustrohippocampal connectivity. Some KA seizures appeared to originate from the claustrum.

CONCLUSIONS

Findings from the operant conditioning task suggest stimulation of the claustrum can alter attention or awareness. CCEPs demonstrated connectivity between the two claustra and between the claustrum and the hippocampi. Such connectivity may be part of the circuitry that underlies the alteration of awareness in limbic seizures. Lastly, KA seizures showed early involvement of the claustrum, a finding that also supports a possible role of the claustrum in the alteration of consciousness that accompanies dyscognitive seizures.