Seizures and risk of epilepsy in autoimmune and other inflammatory encephalitis

MicroRNA 322-5p reduced neuronal inflammation via the TLR4/TRAF6/NF-κB axis in a rat epilepsy model

This study aimed to determine whether microRNA-322-5p regulates seizure and seizure damage by targeting the TLR4/TRAF6/NF-κB-associated inflammatory signaling pathway. In a pilocarpine-induced epileptic rat model, the expressions of miR-322-5p, TLR4, NF-κB, TRAF6, IRF5, IL-1β, and GABA were assessed by a quantitative polymerase chain reaction and western blotting. Tunel detects hippocampal neuron apoptosis. The results showed that the expression of miR-322-5p significantly decreased in status epilepticus (SE) rats. The reduction of miR-322-5p was accompanied by increased levels of pro-inflammatory cytokines, an increased NF-κB expression, and reduced γ-aminobutyric acid (GABA) levels. Exogenous miR-322-5p reduced the expression of inflammatory molecules and increased the GABA levels in SE rats, and also reduced hippocampal neuronal cell apoptosis caused by epilepsy. In conclusion, the miR-322-5p significantly inhibited the TLR4/TRAF6/NF-κB-associated inflammation and reduced neuronal apoptosis, suggesting that its induction may be of potential interest for novel antiseizure medications.

Histopathologic Characterization and Neurodegenerative Markers in Patients With Limbic Encephalitis Undergoing Epilepsy Surgery

Purpose

Limbic encephalitis is an increasingly recognized cause of medial temporal lobe epilepsy (mTLE) and associated cognitive deficits, potentially resulting in hippocampal sclerosis (HS). For several reasons, these patients usually do not undergo epilepsy surgery. Thus, histopathologic examinations in surgical specimens of clearly diagnosed limbic encephalitis are scarce. The purpose of this study was a detailed histopathologic analysis of surgical tissue alterations, including neurodegenerative markers, in patients with limbic encephalitis undergoing epilepsy surgery.

Methods

We investigated the surgical specimens of six patients operated on with mTLE related to limbic encephalitis (among them four patients were with GAD65 and one with Ma1/2 antibodies), and compared the findings to a control group with six patients matched according to age at the time of surgery without limbic encephalitis and without early inciting events.

Results

Histopathologic analysis in the group with limbic encephalitis revealed HS in four patients, while three of them also displayed signs of an active inflammatory reaction with lymphocytes. In one of the patients with GAD65-encephalitis who was suffering from a late-onset mTLE and a long disease course, neurodegenerative protein markers (β-amyloid and hyperphosphorylated tau) were found coexisting with inflammatory reactions and HS. Investigations in the control group did not reveal any inflammatory reaction or neurodegenerative marker.

Conclusion

Our findings suggest a possible link between long-lasting immune reactions in the medial temporal lobe, HS, and further toward the development of neurodegenerative diseases. Presently, however, a causal relationship between these entities cannot yet be established. Furthermore, our results suggest that an immunological etiology should always be considered in late onset (> 18 years) mTLE, also in cases of long disease duration and the presence of HS.

Autoimmune-Associated Seizures

PURPOSE OF REVIEW

This article focuses on the seizure manifestations and presentations of autoimmune-associated epilepsy and acute symptomatic seizures in autoimmune encephalitis. It discusses the specificity of the various central nervous system autoantibodies and clarifies when their presence can be considered indicative of an immune etiology. Finally, current recommendations regarding patient selection for autoimmune antibody evaluation are reviewed, and an approach to immunotherapy is provided.

RECENT FINDINGS

Although autoimmune seizures are caused by a heterogeneous group of autoantibodies, key features reported in the literature should alert clinicians to the possible diagnosis. In particular, seizure characteristics including frequency, timing, duration, and symptomatology can provide vital clues to help differentiate autoimmune-associated seizures from other causes of epilepsy. Diagnostic certainty also requires an understanding and integration of the spectrum of clinical and paraclinical presentations, and several scoring systems have been developed that may be useful to aid the identification of autoimmune seizures.

SUMMARY

Seizures due to autoimmune etiology are increasingly encountered in clinical practice. It is critical that clinicians recognize immune seizure etiologies early in their course given they are often responsive to immunotherapy but are usually resistant to antiseizure medications. Currently, however, it is unfortunately not uncommon for autoimmune-associated seizure disorders to remain undiagnosed, resulting in missed opportunities to administer effective therapies. Efforts to better understand autoimmune seizure manifestations and treatment strategies are ongoing.

Contemporary advances in anti-NMDAR antibody (Ab)-mediated encephalitis

The study of antibody (Ab)-mediated encephalitis has advanced dramatically since the discovery of antibodies directed against the N-methyl-D-aspartate receptor (NMDAR) in association with a unique neuro-psychiatric syndrome, over a decade-and-a-half ago. Anti-NMDAR Ab-mediated encephalitis now represents the most well characterised form of autoimmune encephalitis. The disease most commonly manifests in young women, but all ages and both sexes can be affected. Autoantibodies may arise in the context of two well-recognised disease triggers in a proportion of patients, and ultimately facilitate NMDAR displacement from synapses. Various CSF cytokines, chemokines, and other molecules have been explored as candidate biomarkers but are limited in sensitivity and specificity. The clinical spectrum is diverse, with evolution and a combination of neuro-psychiatric abnormalities at disease nadir common. Anti-NMDAR Ab-mediated encephalitis is immunotherapy responsive, and a near-majority ultimately acquire a broadly favourable clinical outcome. The diagnosis, and more particularly, the management of the disease can still hold considerable challenges. Moreover, well-defined biomarkers remain elusive. The present review will therefore delineate pathogenic and clinical advances to date in anti-NMDAR antibody-mediated encephalitis.

The many faces of the AMPA-type ionotropic glutamate receptor

Knowledge of the biology of ionotropic glutamate receptors (iGluRs) is a prerequisite for any student of the neurosciences. But yet, half a century ago, the situation was quite different. There was fierce debate on whether simple amino acids, such as l-glutamic acid (L-Glu), should even be considered as putative neurotransmitter candidates that drive excitatory synaptic signaling in the vertebrate brain. Organic chemist, Jeff Watkins, and physiologist, Dick Evans, were amongst the pioneering scientists who shed light on these tribulations. By combining their technical expertise, they performed foundational work that explained that the actions of L-Glu were, in fact, mediated by a family of ion-channels that they named NMDA-, AMPA- and kainate-selective iGluRs. To celebrate and reflect upon their seminal work, Neuropharmacology has commissioned a series of issues that are dedicated to each member of the Glutamate receptor superfamily that includes both ionotropic and metabotropic classes. This issue brings together nine timely reviews from researchers whose work has brought renewed focus on AMPA receptors (AMPARs), the predominant neurotransmitter receptor at central synapses. Together with the larger collection of papers on other GluR family members, these issues highlight that the excitement, passion, and clarity that Watkins and Evans brought to the study of iGluRs is unlikely to fade as we move into a new era on this most interesting of ion-channel families.

Autoimmune Epilepsy - Novel Multidisciplinary Analysis, Discoveries and Insights

Epilepsy affects ~50 million people. In ~30% of patients the etiology is unknown, and ~30% are unresponsive to anti-epileptic drugs. Intractable epilepsy often leads to multiple seizures daily or weekly, lasting for years, and accompanied by cognitive, behavioral, and psychiatric problems. This multidisciplinary scientific (not clinical) 'Perspective' article discusses Autoimmune Epilepsy from immunological, neurological and basic-science angles. The article includes summaries and novel discoveries, ideas, insights and recommendations. We summarize the characteristic features of the respective antigens, and the pathological activity in vitro and in animal models of autoimmune antibodies to: Glutamate/AMPA-GluR3, Glutamate/NMDA-NR1, Glutamate/NMDA-NR2, GAD-65, GABA-R, GLY-R, VGKC, LGI1, CASPR2, and β2 GP1, found in subpopulations of epilepsy patients. Glutamate receptor antibodies: AMPA-GluR3B peptide antibodies, seem so far as the most exclusive and pathogenic autoimmune antibodies in Autoimmune Epilepsy. They kill neural cells by three mechanisms: excitotoxicity, Reactive-Oxygen-Species, and complement-fixation, and induce and/or facilitate brain damage, seizures, and behavioral impairments. In this article we raise and discuss many more topics and new insights related to Autoimmune Epilepsy. 1. Few autoimmune antibodies tilt the balance between excitatory Glutamate and inhibitory GABA, thereby promoting neuropathology and epilepsy; 2. Many autoantigens are synaptic, and have extracellular domains. These features increase the likelihood of autoimmunity against them, and the ease with which autoimmune antibodies can reach and harm these self-proteins. 3. Several autoantigens have 'frenetic character'- undergoing dynamic changes that can increase their antigenicity; 4. The mRNAs of the autoantigens are widely expressed in multiple organs outside the brain. If translated by default to proteins, broad spectrum detrimental autoimmunity is expected; 5. The autoimmunity can precede seizures, cause them, and be detrimental whether primary or epiphenomenon; 6. Some autoimmune antibodies induce, and associate with, cognitive, behavioral and psychiatric impairments; 7. There are evidences for epitope spreading in Autoimmune Epilepsy; 8. T cells have different 'faces' in the brain, and in Autoimmune Epilepsy: Normal T cells are needed for the healthy brain. Normal T cells are damaged by autoimmune antibodies to Glutamate/AMPA GluR3, which they express, and maybe by additional autoantibodies to: Dopamine-R, GABA-R, Ach-R, Serotonin-R, and Adrenergic-R, present in various neurological diseases (summarized herein), since T cells express all these Neurotransmitter receptors. However, autoimmune and/or cytotoxic T cells damage the brain; 9. The HLA molecules are important for normal brain function. The HLA haplotype can confer susceptibility or protection from Autoimmune Epilepsy; 10. There are several therapeutic strategies for Autoimmune Epilepsy.

Changes in Function and Muscle Strength of Encephalitis Survivors After Inpatient Rehabilitation

OBJECTIVE

To investigate the clinical demographics and rehabilitative assessments of encephalitis survivors admitted to a rehabilitation center, and to confirm the effects of inpatient rehabilitation manifested by changes in muscle strength and function after hospitalization.

METHODS

Data of encephalitis survivors who received rehabilitation at our institution from August 2009 to August 2019 were reviewed. Medical charts were retrospectively reviewed, and motor, functional, and cognitive assessments were collected. Manual muscle testing (MMT), Fugl-Meyer Assessment (FMA), Berg Balance Scale (BBS), Functional Ambulation Category (FAC), Korean version of Modified Barthel Index (K-MBI), grip strength, Box and Block Test (BBT), and Korean version of Mini-Mental State Examination (K-MMSE) were performed, and the results upon admission and discharge were compared and analyzed.

RESULTS

Most of the patients with encephalitis admitted to our institution had viral or autoimmune etiologies. The assessment results of 18 encephalitis patients upon admission and discharge were compared. The total K-MBI score, FAC, grip strength, and BBT significantly improved, but not the MMT and FMA. Subgroup analysis was performed for viral and autoimmune encephalitis, which are the main causes of the disease, but there was no difference in items with significant changes before and after hospitalization.

CONCLUSION

Encephalitis survivors showed a significant improvement in functional assessment scale during their hospital stay through rehabilitation, without significant changes in motor strength. Hence, we can conclude that encephalitis survivors benefit from inpatient rehabilitation, targeting functional gains in activities of daily living training more than motor strength.

Role of responsive neurostimulation and immunotherapy in refractory epilepsy due to autoimmune encephalitis: A case report

Autoimmune encephalitis (AE) frequently presents with seizures in the acute setting. Seizures are often refractory to anti-seizure medications (ASM) but have been shown to be responsive to immunomodulatory therapies. A subset of patients with AE continues to have refractory epilepsy, recently named "autoimmune-associated epilepsy (AAE)," for years after the acute AE presentation. Optimal treatment for AAE has not been determined. Furthermore, the efficacy of neuromodulation and immunotherapy has not been well established in AAE. Here, we report a patient with probable autoantibody negative AE who initially presented with new onset refractory status epilepticus (NORSE). After his acute presentation, he continued to have frequent seizures that were refractory to four ASMs at therapeutic doses. A responsive neurostimulation (RNS^®, NeuroPace) system was implanted for diagnostic and therapeutic purposes, with minimal change in seizure frequency. Due to continued frequent seizures despite ASMs and neurostimulation, he underwent a trial of immunotherapy consisting of high-dose intravenous (IV) corticosteroids and intravenous immunoglobulin (IVIG). Despite the addition of immunotherapy to his treatment regimen, the patient experienced no significant clinical or electrographic change in seizure frequency. This case does not support the use of immunotherapy for treatment of AAE and illustrates the need for consensus guidelines in the management of patients with AAE. Further, the use of electrocorticography (ECoG) data provided an objective surrogate measure of seizure frequency; this may support the role for early neuromodulation in the management of AAE.

Semiology, EEG, and neuroimaging findings in temporal lobe epilepsies

Temporal lobe epilepsy (TLE) is the most common type of focal epilepsy. First descriptions of TLE date back in time and detailed portraits of epileptic seizures of temporal origin can be found in early medical reports as well as in the works of various artists and dramatists. Depending on the seizure onset zone, several subtypes of TLE have been identified, each one associated with peculiar ictal semiology. TLE can result from multiple etiological causes, ranging from genetic to lesional ones. While the diagnosis of TLE relies on detailed analysis of clinical as well as electroencephalographic (EEG) features, the lesions responsible for seizure generation can be highlighted by multiple brain imaging modalities or, in selected cases, by genetic investigations. TLE is the most common cause of refractory epilepsy and despite the great advances in diagnostic tools, no lesion is found in around one-third of patients. Surgical treatment is a safe and effective option, requiring presurgical investigations to accurately identify the seizure onset zone (SOZ). In selected cases, presurgical investigations need intracerebral investigations (such as stereoelectroencephalography) or dedicated metabolic imaging techniques (interictal PET and ictal SPECT) to correctly identify the brain structures to be removed.

Autoimmune Encephalitis and Autism Spectrum Disorder

The concept of "acquired autism" refers to the hypothesis that amongst the massive heterogeneity that encompasses autism spectrum disorder (ASD) there may be several phenotypes that are neither syndromic nor innate. Strong and consistent evidence has linked exposure to various pharmacological and infective agents with an elevated risk of a diagnosis of ASD including maternal valproate use, rubella and herpes encephalitis. Autoimmune encephalitis (AE) describes a group of conditions characterised by the body's immune system mounting an attack on healthy brain cells causing brain inflammation. The resultant cognitive, psychiatric and neurological symptoms that follow AE have also included ASD or autism-like traits and states. We review the current literature on AE and ASD. Drawing also on associated literature on autoimmune psychosis (AP) and preliminary evidence of a psychosis-linked subtype of ASD, we conclude that AE may either act as a potentially causative agent for ASD, and/or produce symptoms that could easily be mistaken for or misdiagnosed as autism. Further studies are required to discern the connection between AE and autism. Where autism is accompanied by regression and atypical onset patterns, it may be prudent to investigate whether a differential diagnosis of AE would be more appropriate.

Clinical characteristics and prognosis of anti-alpha-Amino-3-Hydroxy-5-Methyl-4-Isoxazolepropionic acid receptor encephalitis

BACKGROUND

Encephalitis associated with antibodies against alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) is an extremely rare type of antibody-mediated encephalitis. This research aims to investigate the clinical characteristics and prognosis of anti-AMPAR encephalitis.

METHODS

This retrospective study enrolled nine patients with anti-AMPAR encephalitis. Demographic information, clinical manifestations, laboratory and radiological findings, treatment and response were collected and analyzed. These patients were followed up with an average period of 72 weeks to gather prognostic information.

RESULTS

Nine patients (7 females and 2 males) were enrolled with a mean age at disease onset of 59 years old. Three clinical pictures, including limbic encephalitis (n = 7; 78%), pure amnesia (n = 1; 11%) and fulminant encephalitis (n = 1; 11%) were identified. New symptoms of dysphagia and deafness were identified in the clinical spectrum of anti-AMPAR encephalitis. All patients had positive blood AMPAR antibodies, and six of them (67%) had paired positive antibodies in cerebrospinal fluid (CSF). Brain magnetic resonance imaging (MRI) was abnormal in 75% of the patients with no specific patterns recognized. Six patients (67%) had tumors, including lung cancers and thymomas. After immunotherapy and oncotherapy, partial improvement of neurological symptoms was observed among all 6 patients with available records during their hospitalization. After a mean follow-up of 72 weeks, 3 patients had marked decrease of modified Rankin Scale (mRS) score, 1 patient had unchanged mRS score, 4 patients died and the other one was lost.

CONCLUSIONS

Anti-AMPAR encephalitis mainly presents as limbic encephalitis, and is paraneoplastic in 67% of cases. Thus, intensive screening for tumors is recommended for all anti-AMPAR patients. Although patients showed a good short-term therapeutic response, the overall prognosis was not satisfactory.

Neurofunctional outcomes in patients with anti-leucine-rich glioma inactivated 1 encephalitis

OBJECTIVE

To evaluate the cognitive and neurofunctional outcomes in patients with anti-leucine-rich glioma inactivated 1 (LGI1) encephalitis.

METHODS

A cohort follow-up study was performed after a median of 33 months (range 6-78) from disease onset to the last follow-up in patients diagnosed with anti-LGI1 encephalitis, to assess the neurofunctional outcomes using modified Rankin Scale (mRS), activities of daily living (ADL), neuropsychiatric inventory (NPI) and modified telephone interview for cognitive status (TICS-M). Remote symptomatic seizure and clinical relapses were also recorded. The clinical, laboratory features, and treatment responses that characterize the disability were analyzed.

RESULTS

The results showed that 81 of 86 (94.2%) patients with anti-LGI1 encephalitis were successfully followed up, while eight (9.9%) died after discharge. Among the 73 survivors, clinical relapses occurred in 18 (24.7%) patients, and those with relapses were at a higher risk of developing remote symptomatic seizure (p = .019). Although 85.2% of the patients became functionally independent (mRS ≤2), the sequelae of symptomatic seizure, neuropsychiatric symptoms, and cognitive deficits were found in 11.0%, 21.9%, and 39.7% of the patients, respectively. Residual cognitive deficits primarily occurred in the elderly subjects as well as those with symptoms of memory deficit, psychiatric disorders, sleep disturbance, disturbance of consciousness at diagnosis, and higher CSF protein levels.

CONCLUSIONS

Although most patients survived and became functionally independent, a subset of patients could not return to all premorbid activities. They may have clinical relapses or suffer from remote symptomatic seizure, neuropsychiatric symptoms, and cognitive impairment.

Occult Autoimmune Background for Epilepsy-The Preliminary Study on Antibodies Against Neuronal Surface Antigens

Objective: The objective of the study was to determine the incidence of antibodies against neuronal surface antigens (NSA-ab) in patients with different types of epilepsy, in comparison with the subjects diagnosed with immune-mediated disorders. Methods: Forty patients with drug-resistant epilepsy (DRE) of unknown origin, 16 with post-stroke epilepsy, and 23 with systemic autoimmune disorders (SAD) with CNS involvement were included. NSA-ab were sought in serum using indirect immunofluorescence method. Relationships were analyzed between presence of NSA-ab and clinical presentation. Results: NSA-ab was detected in the sera from five patients: anti-DPPX in one patient, anti-AMPAR1/R2 in two, anti-LGI1 in one and, in one case, both anti-CASPR2 and DPPX IgG. Out of these five patients, three represented the SAD subgroup and two the DRE subgroup. None of the patients with post-stroke epilepsy was positive for NSA-ab. Significance: Autoimmune etiology is worth considering in patients with drug-resistant epilepsy of unknown origin. The presence of NSA-ab in patients with systemic autoimmune disorders may be caused by unspecifically enhanced autoimmune reactivity. NSA-ab seem not to be related to epilepsy resulting from ischemic brain injury.

Glial fibrillary acidic protein (GFAP)-antibody in children with focal seizures of undetermined cause

Anti-neuronal antibodies that are related with autoimmune encephalitis syndromes may also be found in children with new onset seizures or chronic epilepsy. To unravel the significance of autoimmune astrocytopathy in epilepsy, we investigated serum antibody to glial fibrillary acidic protein (GFAP), another autoantigen described in autoimmune encephalitis with seizures, in 38 children with focal seizures of undetermined cause. GFAP antibody was screened with cell based assay and indirect immunohistochemistry and was found in two boys with normal brain MRI and unrevealing medical history prior to seizures. The 2-year-old boy had chronic treatment-resistant frontal lobe epilepsy. The 2.5-year-old boy had a single episode of focal seizures and remained seizure free thereafter in a follow-up period of 4 years. Nevertheless, he showed severe cognitive and language impairment. These results suggest that autoimmune astrocytopathy may be present in some epilepsy patients. Whether this immune response is a bystander effect generated by seizure-induced astrocytosis or directly involved in epileptogenesis needs to be further studied.

Bioinformatic analysis identifies potential key genes of epilepsy

Background

Epilepsy is one of the most common brain disorders worldwide. It is usually hard to be identified properly, and a third of patients are drug-resistant. Genes related to the progression and prognosis of epilepsy are particularly needed to be identified.

Methods

In our study, we downloaded the Gene Expression Omnibus (GEO) microarray expression profiling dataset GSE143272. Differentially expressed genes (DEGs) with a fold change (FC) >1.2 and a P-value <0.05 were identified by GEO2R and grouped in male, female and overlapping DEGs. Functional enrichment analysis and Protein-Protein Interaction (PPI) network analysis were performed.

Results

In total, 183 DEGs overlapped (77 ups and 106 downs), 302 DEGs (185 ups and 117 downs) in the male dataset, and 750 DEGs (464 ups and 286 downs) in the female dataset were obtained from the GSE143272 dataset. These DEGs were markedly enriched under various Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) terms. 16 following hub genes were identified based on PPI network analysis: ADCY7, C3AR1, DEGS1, CXCL1 in male-specific DEGs, TOLLIP, ORM1, ELANE, QPCT in female-specific DEGs and FCAR, CD3G, CLEC12A, MOSPD2, CD3D, ALDH3B1, GPR97, PLAUR in overlapping DEGs.

Conclusion

This discovery-driven study may be useful to provide a novel insight into the diagnosis and treatment of epilepsy. However, more experiments are needed in the future to study the functional roles of these genes in epilepsy.

Predictors and prognoses of epilepsy after anti-neuronal antibody-positive autoimmune encephalitis

PURPOSE

This study aimed to investigate the incidence and predictors of epilepsy after anti-neuronal antibody-positive autoimmune encephalitis (AIE). The clinical outcomes of patients with epilepsy after AIE were also explored.

METHODS

A total of 111 AIE patients were retrospectively evaluated. Post-AIE epilepsy (PAEE) was defined as at least one unprovoked seizure occurring six or more months after discharge from hospital.

RESULTS

The incidence of acute symptomatic seizures was 80.2% (89/111) in our AIE patients. Furthermore, of the 89 AIE patients with seizures, 29 (32.6%) presented with seizures as the initial symptom. Overall, 44 out of 111 AIE patients (39.6%) had unprovoked seizures after six months, meeting our definition of PAEE. The independent risk factors for PAEE incidence included an initial presentation with new-onset refractory status epilepticus (NORSE), delayed immunotherapy treatment, the complication of a lung infection during admission, the requirement for mechanical ventilation during hospitalization, parietal lesions observed in magnetic resonance imaging (MRI), and focal slow waves on electroencephalographic (EEG) monitoring.

CONCLUSIONS

Early initiation of immunotherapy and lung infection treatment may reduce the risk of conversion of symptomatic seizures to chronic epilepsy in the acute phase of AIE. In general, PAEE patients could have a good prognosis if treated properly and in a timely fashion.

Risk of Developing Epilepsy after Autoimmune Encephalitis

BACKGROUND

Acute symptomatic seizures (ASS) are a common manifestation of autoimmune encephalitis (AE), but the risk of developing epilepsy as a sequela of AE remains unknown, and factors predisposing the development of epilepsy have not been fully identified.

OBJECTIVE

To assess the risk of developing epilepsy in AE and study related risk factors.

MATERIALS AND METHODS

This was a retrospective single centre study including patients diagnosed with AE according to criteria described by Graus et al., with a minimum follow-up of 12 months after AE resolution. The sample was divided according to whether patients developed epilepsy or not.

RESULTS

A total of 19 patients were included; 3 (15.8%) had AE with intracellular antibodies, 9 (47.4%) with extracellular antibodies, and 7 (36.8%) were seronegative. During follow-up, 3 patients (15.8%) died, 4 (21.1%) presented relapses of AE, and 11 (57.89%) developed epilepsy. There was a significant association between the development of epilepsy and the presence of hippocampal atrophy in control brain magnetic resonance imaging (MRI) (p = 0.037), interictal epileptiform discharges (IED) on control electroencephalogram (EEG) (p = 0.045), and immunotherapy delay (p = 0.016).

CONCLUSIONS

Hippocampal atrophy in neuroimaging, IED on EEG during follow-up, and immunotherapy delay could be predictors of the development of epilepsy in patients with AE.

Clinical features of nine cases of leucine-rich glioma inactivated 1 protein antibody-associated encephalitis

To investigate clinical features of leucine-rich glioma inactivated 1 protein (LGI1) antibody-associated autoimmune encephalitis (AE). The clinical data were collected and analyzed in nine patients with LGI1 AE. All nine patients (100%) presented acute/subacute onset, had seizures, cognitive impairment, mental/behavioral abnormalities, six had sleep disorders and seven showed hyponatremia. Seizures manifested in three types: faciobranchial dystonia seizure (FBDS) (44%), mesial temporal lobe epilepsy (MTLE)-like seizure (66%), and focal to bilateral tonic-clonic seizure (FBTCS) (77%). Six of nine cases (66%) showed abnormalities in brain MRI, among them four showed high T2/flair signal on unilateral/bilateral hippocampus, two showed high T1/T2 signal on unilateral basal ganglia. All nine patients (100%) showed abnormalities in EEG, among them 1 (11%) showed diffuse slow waves, 8 (88%) showed focal slow waves; 6 (66%) revealed interictal epileptic discharges; ictal EEG was recorded in five patients, two were FBDS, three were MTLE-like seizure.LGI1 antibodies in serum and cerebrospinal fluid were both positive. No signs of tumor were found in all patients. Eight of nine patients received immunotherapy and antiepileptic drug (AED) treatment, one only treated with AED without immunotherapy. Eight patients improved significantly with seizure-free after immunotherapy, only one still had FBDS after immunotherapy and AED treatment. In LGI1 AE hippocampus and basal ganglia were two main targets, the corresponding seizure type was MTLE-like seizure and FBDS respectively. Diagnosis depended on detection of LGI1 antibodies in CSF. The incidence of tumor was low. The effect of immunotherapy was good and AEDs should be considered as add-on symptomatic treatment.

Diagnostic challenges in patients with temporal lobe seizures and features of autoimmune limbic encephalitis

BACKGROUND AND PURPOSE

Consensus criteria for autoimmune limbic encephalitis (ALE) allow for a diagnosis even without neuronal antibodies (Abs), but it remains unclear which clinical features should prompt neuronal Ab screening in temporal lobe epilepsy patients. The aim of the study was to investigate whether patients with temporal lobe seizures associated with additional symptoms or signs of limbic involvement may harbor neuronal Abs, and which clinical features should prompt neuronal Ab screening in these patients.

METHODS

We identified 47 patients from a tertiary epilepsy center with mediotemporal lobe seizures and additional features suggestive of limbic involvement, including either memory deficits, psychiatric symptoms, mediotemporal magnetic resonance imaging (MRI) hyperintensities or inflammatory cerebrospinal fluid (CSF). Neuronal Ab testing was carried out at two independent reference laboratories (Bielefeld-Bethel, Germany, and Barcelona, Spain). All brain MRI scans were assessed by two reviewers independently.

RESULTS

Temporal lobe seizures were accompanied by memory deficits in 35/46 (76%), psychiatric symptoms in 27/42 (64%), and both in 19/42 patients (45%). Limbic T2/fluid-attenuated inversion recovery signal hyperintensities were found in 26/46 patients (57%; unilateral: n = 22, bilateral: n = 4). Standard CSF studies were abnormal in 2/37 patients (5%). Neuronal Abs were confirmed in serum and/or CSF in 8/47 patients (17%) and were directed against neuronal cell-surface targets (leucine-rich glioma inactivated protein 1: n = 1, contactin-associated protein-2: n = 1, undetermined target: n = 3) or glutamic acid decarboxylase in its 65-kD isoform (n = 3, all with high titers). Compared to Ab-negative patients, those who harbored neuronal Abs were more likely to have uni- or bilateral mediotemporal MRI changes (8/8, 100% vs. 18/38, 47%; p = 0.01, Fisher's exact test).

CONCLUSIONS

In patients with temporal lobe seizures and additional limbic signs, 17% had neuronal Abs affirming ALE diagnosis. Mediotemporal MRI changes were found in all Ab-positive cases and had a positive likelihood ratio of 2.11 (95% confidence interval 1.51-2.95).

Clinical Course and Features of Seizures Associated With LGI1-Antibody Encephalitis

OBJECTIVE

To determine risk factors associated with clinical relapses and development of chronic epilepsy in patients with anti-leucine-rich glioma-inactivated 1 (LGI1) IgG encephalitis.

METHODS

Patients with seizures related to LGI1-antibody encephalitis with ≥ 24 months of follow-up from disease onset were identified in the Mayo Clinic electronic medical record and Neuroimmunology lab records. Charts were reviewed to determine clinical factors, seizure types, imaging, treatment, occurrence of relapse, and outcome. Binary logistic regression analysis was performed to identify predictors of the development of chronic epilepsy. Univariate Cox proportional hazards regression was used to examine the influence of baseline characteristics on relapse risk.

RESULTS

Forty-nine patients with LGI1-antibody encephalitis and acute symptomatic seizures were identified. Almost all patients (n=48, 98%) were treated with immunotherapy. Eight had definite, and two had possible chronic epilepsy at last follow-up (10/49, 20.4%). Female sex (P=0.048) and younger age at disease onset (P=0.02) were associated with development of chronic epilepsy. Relapses occurred in 20 (40.8%), with a median time to first relapse of 7.5 months (range 3-94 months). Initial treatment with chronic steroid sparing immunotherapy was associated with reduced risk of relapse (hazards ratio=0.28, 95% CI 0.11-0.73, P=0.009).

CONCLUSIONS

Chronic epilepsy occurred in 20.4% of our patients with LGI1-antibody encephalitis despite aggressive immunotherapy. Risk factors for chronic epilepsy were female sex and earlier age of onset. Relapses occurred in 40.8% of patients with prolonged follow-up, and chronic steroid sparing immunotherapy was associated with a lower relapse rate.

Informed DEcision for cerebrospinal fluid analysis after epiLeptic seizures- the IDEAL-score: A development and validation study

BACKGROUND

This observational study was done to develop a score based on clinical predictors that enables a guided decision for the necessity of cerebrospinal fluid (CSF) analysis after first unprovoked epileptic seizures and to validate this score in a retrospective patient cohort.

METHODS

Clinical predictors were identified by two panels of epilepsy experts and selected according to content validity ratios. Based on these predictors a score was created and applied to a cohort of patients with first epileptic seizures.

RESULTS

The "IDEAL score" consists of 9 items (fever, prolonged disturbance of consciousness, headache, imaging results, cognitive dysfunction, status epilepticus, malignancy, autoimmune encephalitis symptoms) that are collected at two different time points (< 3 h [A-score]; > 3 h [B-score] after hospital admittance). A CSF analysis is recommended, if at least one clinical finding is present, either one of the items evaluated during the acute phase (A-score) or later in the diagnostic process (B-score). In 41 patients (13%) CSF analysis provided essential clues to the cause of the seizure. The combined IDEAL score reached a sensitivity of 98%, a specificity of 53%, a positive predictive value of 24% and a negative predictive value of 99% in this patient cohort.

CONCLUSIONS

A CSF analysis after first epileptic seizures provided decisive etiological findings in only 13% of all investigated patients. The IDEAL score offers clinicians a simple and easy-to-implement algorithm to assess the necessity of a CSF analysis, and to prevent unnecessary diagnostic procedures.

Clinical Characteristics and Long-Term Prognosis of Anti-LGI1 Encephalitis: A Single-Center Cohort Study in Beijing, China

Background: This study aimed to analyze the clinical characteristics of anti-leucine-rich glioma-inactivated protein 1 (LGI1) encephalitis patients and investigate prognostic factors by using a large-sample and long-term follow-up cohort.

Methods: The clinical data of 45 patients (29 males; mean age, 57.0 years) from May 2014 to August 2019 were collected. All patients were followed up by face-to-face interviews in the third month after discharge and then by telephone and/or face-to-face interviews every 6 months until November 2020. We evaluated each patient's response to the initial treatments at the first interview and divided them into “responders” and “nonresponders.” Relapses were recorded. At the end of follow-up, each patient was evaluated and reclassified into “complete recovery” or “unhealed” groups. Intergroup differences were assessed.

Results: All patients presented with seizures at the initial consultation. Other common manifestations included cognitive dysfunction (82.2%), psychiatric disturbance (66.7%), sleep disorder (54.5%), and hyponatremia (66.7%). During the follow-up period (32.8 ± 13.5 months), six patients experienced relapse within 6–37 months. We observed that the patients who did not respond to the initial treatments and those who relapsed all had a poor long-term prognosis. The patients in the “unhealed” group were older (p = 0.009), had a lower incidence of generalized tonic–clonic seizures (p = 0.041), and had a higher probability of cerebrospinal fluid (CSF) abnormalities (p = 0.024) than those in the “complete recovery” group.

Conclusion: Anti-LGI1 encephalitis was characterized by seizures, cognitive impairment, psychiatric disturbance, and sleep disorders and was often accompanied by hyponatremia. Patients who responded poorly to the initial treatments and those patients who relapsed had dismal long-term prognoses. Advanced age and CSF abnormalities may be risk factors for poor prognosis, but these still need to be verified.

Antibody-Mediated Encephalitis in Children: Focus on Diagnostic Clues and Acute Symptom Management

Antibody-mediated encephalitis is a treatable cause of encephalitis that manifests over days to weeks as changes in behavior and cognition, seizures, movement disorders, and autonomic dysfunction. Patients with autoimmune encephalitis develop a variety of symptoms. As such, they require a multidisciplinary approach to care. In this review we summarize the clinical presentation and practical diagnostic approach to pediatric autoimmune encephalitis, review treatments of the autoimmune process, and discuss the management of the acute symptoms encountered in children.

Characteristics and outcome-related factors of seizure at the first onset of autoimmune encephalitis: A retrospective study

Aims

Seizure outcome of autoimmune encephalitis (AE) varies from seizure‐free to refractory epilepsy, and the associated factors remain unclear. We aimed to describe seizure characteristics, identify seizure outcome‐related factors, and discuss the medication strategy of antiepileptic drugs (AEDs) at the first onset of AE.

Methods

We retrospectively studied the data of 86 patients with clinically diagnosed AE. The clinical characteristics were described using a chi‐square test. Seizure outcome‐related factors were assessed using multivariable logistic regression analysis.

Results

56 patients were finally enrolled, with antibodies to N‐methyl‐D‐aspartate receptor found in 29, to γ‐aminobutyric acid receptor B found in 13, and to leucine‐rich glioma‐inactivated protein 1 found in 14. Status epilepticus occurrence and onset with seizure lead to a poor seizure outcome, while administration of human gamma globulin and a low antibody titer contributed to a good seizure outcome.

Conclusions

In the acute phase, seizure characteristics may be considered in the utilization of AEDs. For patients with seizure‐free status in the acute phase, clinical manifestation (onset with seizure or not, whether status epilepticus occurs or not), therapy regimen (human gamma globulin administered or not), and antibody titer may be considered when formulating the strategy for withdrawal of AEDs post‐acute phase.

Seizures and Epilepsy in Autism Spectrum Disorder

Epilepsy and autism frequently co-occur. Epilepsy confers an increased risk of autism and autism confers an increased risk of epilepsy. Specific epilepsy syndromes, intellectual disability, and female gender present a particular risk of autism in individuals with epilepsy. Epilepsy and autism are likely to share common etiologies, which predispose individuals to either or both conditions. Genetic factors, metabolic disorders, mitochondrial disorders, and immune dysfunction all can be implicated.

Seizures and memory impairment induced by patient-derived anti-N-methyl-D-aspartate receptor antibodies in mice are attenuated by anakinra, an interleukin-1 receptor antagonist

OBJECTIVE

Neuroinflammation associated with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis may facilitate seizures. We previously showed that intraventricular administration of cerebrospinal fluid from patients with anti-NMDAR encephalitis to mice precipitates seizures, thereby confirming that antibodies are directly pathogenic. To determine whether interleukin (IL)-1-mediated inflammation exacerbates autoimmune seizures, we asked whether blocking the effects of IL-1 by anakinra, a selective IL-1 receptor antagonist, blunts antibody-induced seizures.

METHODS

We infused C57BL/6 mice intraventricularly with purified serum IgG from patients with anti-NMDAR encephalitis or monoclonal anti-NMDAR IgG; subdural electroencephalogram was continuously recorded. After a 6-day interval, mice received anakinra (25 mg/kg sc, twice daily) or vehicle for 5 days. Following a 4-day washout period, we performed behavioral tests to assess motor function, anxiety, and memory, followed by hippocampus tissue analysis to assess astrocytic (glial fibrillary acidic protein [GFAP]) and microglial (ionized calcium-binding adapter molecule [Iba]-1) activation.

RESULTS

Of 31 mice infused with purified patient NMDAR-IgG (n = 17) or monoclonal NMDAR-IgG (n = 14), 81% developed seizures. Median baseline daily seizure count during exposure to antibodies was 3.9; most seizures were electrographic. Median duration of seizures during the baseline was 82.5 s. Anakinra administration attenuated daily seizure frequency by 60% (p = .02). Anakinra reduced seizure duration; however, the effect was delayed and became apparent only after the cessation of treatment (p = .04). Anakinra improved novel object recognition in mice with antibody-induced seizures (p = .03) but did not alter other behaviors. Anakinra reduced the expression of GFAP and Iba-1 in the hippocampus of mice with seizures, indicating decreased astrocytic and microglial activation.

SIGNIFICANCE

Our evidence supports a role for IL-1 in the pathogenesis of seizures in anti-NMDAR encephalitis. These data are consistent with therapeutic effects of anakinra in other severe autoimmune and inflammatory seizure syndromes. Targeting inflammation via blocking IL-1 receptor-mediated signaling may be promising for developing novel treatments for refractory autoimmune seizures.

Seizures in autoimmune encephalitis-A systematic review and quantitative synthesis

OBJECTIVE

This study aimed to evaluate the proportion of patients with seizures and electroencephalography (EEG) abnormalities in autoimmune encephalitis (AE) and its most common subtypes.

METHODS

This systematic review followed Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) standards and was registered with the International Prospective Register of Systematic Reviews (PROSPERO). We searched Medline All, Embase, and PsychINFO in Ovid from inception to June 2019 for articles pertaining to AE and seizure. Included studies reported seizure and/or EEG data in cohorts of ≥10 AE patients. Patient demographics, antibody type, seizure incidence, and EEG findings were extracted. Review of studies and data extraction were performed in duplicate. In addition to descriptive analysis, quantitative synthesis stratified by autoantibody subtype was performed with logistic regression and chi-square analyses.

RESULTS

Our search yielded 3856 abstracts: 1616 were selected for full-text review and 118 studies met eligibility criteria. Of 3722 antibody-positive AE patients, 2601 (69.9%) had clinical seizures during the course of their illness. Of the 2025 patients with antibody-positive AE and available EEG data, 1718 (84.8%) had some EEG abnormality (eg, epileptiform discharges, slowing, and so on). Anti- N-methyl-d-aspartate (NMDA) receptor encephalitis (anti-NMDARE) was the most commonly reported type of AE (1985/3722, 53.3%). Of the anti-NMDARE patients with available seizure or EEG data, 71.8% (n = 1425/1985) had clinical seizures during their illness, and 89.7% (n = 1172/1306) had EEG abnormalities. For all AE patients and in the anti-NMDARE subpopulation, seizures were more common in younger patients (p < .05).

SIGNIFICANCE

This systematic review provides an estimate of the proportion of AE patients with seizures, confirming the magnitude of seizure burden in this population. Prospective studies are needed to understand population-based prevalence of seizures, identify factors associated with seizures, and evaluate particular EEG findings as biomarkers of seizures and outcomes in AE.

Clinical features of paediatric and adult autoimmune encephalitis: A multicenter sample

BACKGROUND

Autoimmune encephalitis (AE) is a heterogeneous class of inflammatory diseases of the brain that can present with a wide spectrum of neuropsychiatric symptoms. Patients may be negative for CSF anti-neuronal antibodies, which can make the diagnosis of AE challenging. Distinguishing features between paediatric and adult patients with AE are not well characterized.

OBJECTIVE

Describe the clinical presentation, seizure type, EEG and sleep patterns in paediatric and adult patients with AE.

METHODS/DESIGN

Retrospective review of clinical data from paediatric and adult patients diagnosed with AE from three medical centers between 1/2008-12/2019.

RESULTS

We included 100 patients with AE, including 65 children. Median age at presentation was 14 years (1-88years). Fifty-five patients had positive CSF autoantibody results (NMDAR 36%, VGKC Ab 10%, anti-GAD65 4%, miscellaneous 3%), and 47 patients were autoantibody-negative. Paediatric patients were more likely to present with psychiatric symptoms, focal seizures and/or status epilepticus, and sleep disturbances compared to adult patients (p < 0.05). There was a higher incidence of NMDA-R encephalitis in children compared to adults.

CONCLUSION

Paediatric patients with AE were more likely to present with psychiatric symptoms, sleep disturbances, focal seizures, and/or status epilepticus compared to adults (p < 0.05). Insomnia and hypersomnia are common sleep problems associated with AE that should be screened early in the diagnostic evaluation. Further studies can be performed to explore the relationship between sleep disturbances and long-term cognitive effects and the incidence of chronic epilepsy in this subset of patients.

Diagnostic Value of Structural and Functional Neuroimaging in Autoimmune Epilepsy

Epilepsy is a common nervous system disease, which affects about 70 million people all over the world. In 2017, the International League Against Epilepsy (ILAE) considered immune factors as its independent cause, and the concept of autoimmune epilepsy (AE) was widely accepted. Early diagnosis and timely treatment can effectively improve the prognosis of the disease. However, due to the diversity of clinical manifestations, the expensive cost of autoantibody detection, and the increased prevalence in Western China, the difficulty for clinicians in early diagnosis and treatment has increased. Fortunately, convenient and fast imaging examinations are expected to help even more. The imaging manifestations of AE patients were characteristic, especially the combined application of structural and functional neuroimaging, which improved the diagnostic value of imaging. In this paper, several common autoantibodies associated with AE and their structure and function changes in neuroimaging were reviewed to provide help for neurologists to achieve the goal of precision medicine.

Inflammation, ictogenesis, and epileptogenesis: An exploration through human disease

Epilepsy is seen historically as a disease of aberrant neuronal signaling manifesting as seizures. With the discovery of numerous auto-antibodies and the subsequent growth in understanding of autoimmune encephalitis, there has been an increasing emphasis on the contribution of the innate and adaptive immune system to ictogenesis and epileptogenesis. Pathogenic antibodies, complement activation, CD8+ cytotoxic T cells, and microglial activation are seen, to various degrees, in different seizure-associated neuroinflammatory and autoimmune conditions. These aberrant immune responses are thought to cause disruptions in neuronal signaling, generation of acute symptomatic seizures, and, in some cases, the development of long-term autoimmune epilepsy. Although early treatment with immunomodulatory therapies improves outcomes in autoimmune encephalitides and autoimmune epilepsies, patient identification and treatment selection are not always clear-cut. This review examines the role of the different components of the immune system in various forms of seizure disorders including autoimmune encephalitis, autoimmune epilepsy, Rasmussen encephalitis, febrile infection-related epilepsy syndrome (FIRES), and new-onset refractory status epilepticus (NORSE). In particular, the pathophysiology and unique cytokine profiles seen in these disorders and their links with diagnosis, prognosis, and treatment decision-making are discussed.

Continuous Visual Focal Status Epilepticus as the Primary Presentation of NMDA-R and GAD65-R Autoimmune Epilepsy

Epilepsia partialis continua (EPC) has changed in its clinical and pathophysiological definition throughout time. Several etiologies have been described in addition to classic causes of EPC. The following case depicts a young woman who had a peculiar onset of epilepsy with a continuous visual aura becoming a form of chronic recurrent and non-progressive EPC. The patient was initially misdiagnosed as a non-neurological entity (assumed psychiatric in origin), but finally, an immune-mediated epilepsy was diagnosed, and EEG showed focal status epilepticus during evolution. Once the diagnosis was achieved and immune treatment was established, the patient is seizure free. Early identification of an immune basis in patients with epilepsy is important because immunotherapy can reverse the epileptogenic process and reduce the risk of chronic epilepsy. To date, this is the only case reported with EPC manifesting as a continuous visual aura associated with antiglutamic acid decarboxylase 65 (anti-GAD65) and anti-N-methyl-d-aspartate (anti-NMDA) antibodies.

Basics of modern epilepsy classification and terminology

BACKGROUND

The terminology and classification of seizures and epilepsy has undergone multiple revisions in the last several decades, which can lead to confusion and miscommunication amongst physicians and researchers. In 2017, the International League Against Epilepsy (ILAE) revised the classification of both seizures and epilepsy types in an effort to use less ambiguous terminology. Over time, definitions for status epilepticus, febrile seizures, and neonatal seizures have also evolved, as has the delineation of various epilepsy syndromes by age.

METHODS

Review of the literature for old and new terminology and various epilepsy syndromes was accomplished using the PubMed database system.

RESULTS

In the following article, we review old terminology for classifying seizures and epilepsy as compared to the new (2017) ILAE guidelines. We discuss neonatal seizures, status epilepticus, febrile seizures, autoimmune epilepsy and various epilepsy syndromes by age of onset.

CONCLUSION

Adopting a classification system that uses plain language allows for more effective and efficient communication between individuals and across specialties. Definitions of various syndromes and seizure types have evolved over time and are reviewed.

Seizures in autoimmune encephalitis: Findings from an EEG pooled analysis

PURPOSE

Seizures are common in autoimmune encephalitis (AE), and an extensive work-up is required to exclude alternative etiologies. The aim of our study was to identify possible clinical/EEG peculiarities suggesting the immune-mediated origin of late-onset seizures.

METHODS

Thirty patients diagnosed with AE (19 men, median age 68 years, 18 seronegative) were included. Overall 212 video-electroencephalographic (EEG) and 31 24-h ambulatory EEG (AEEG) recordings were retrospectively reviewed. Posterior dominant rhythm, interictal epileptiform discharges (IEDs), clinical (CSs) and subclinical seizures (SCSs) were analyzed.

RESULTS

Six-hundred-nineteen ictal events were recorded in 19/30 subjects, mostly (568/619) during AE acute stage. Among ten patients with CSs other than faciobrachial dystonic seizures, 7 showed prominent autonomic and emotional manifestations. SCSs were detected in 11 subjects, mainly via AEEG (260/287 SCSs vs 150/332 CSs, p < 0.001). Eight patients presented seizures during hyperventilation. IEDs, documented in 21 cases, were bilateral in 14 and focal temporal in 13. Multiple ictal EEG patterns were detected in 9/19 patients, 6 of whom had both CSs and SCSs, bilateral asynchronous seizures and ictal activities arising from temporal and extra-temporal regions. No correlation was found between the lateralization of MRI alterations and that of EEG findings.

CONCLUSION

Our study confirms that adult-onset, high frequency focal seizures with prominent autonomic and emotional manifestations should be investigated for AE. Multiple ictal EEG patterns could represent a 'red flag', reflecting a widespread neuronal excitability related to the underlying immune-mediated process. Finally, our work enhances the crucial role of long-lasting EEG monitoring in revealing subclinical and relapsing seizures.

Seizures associated with antibodies against cell surface antigens are acute symptomatic and not indicative of epilepsy: insights from long-term data

Background

Clinicians have questioned whether any disorder involving seizures and neural antibodies should be called “(auto)immune epilepsy.” The concept of “acute symptomatic seizures” may be more applicable in cases with antibodies against neural cell surface antigens. We aimed at determining the probability of achieving seizure-freedom, the use of anti-seizure medication (ASM), and immunotherapy in patients with either constellation. As a potential pathophysiological correlate, we analyzed antibody titer courses.

Methods

Retrospective cohort study of 39 patients with seizures and neural antibodies, follow-up ≥ 3 years.

Results

Patients had surface antibodies against the N-methyl-d-aspartate receptor (NMDAR, n = 6), leucine-rich glioma inactivated protein 1 (LGI1, n = 11), contactin-associated protein-2 (CASPR2, n = 8), or antibodies against the intracellular antigens glutamic acid decarboxylase 65 kDa (GAD65, n = 13) or Ma2 (n = 1). Patients with surface antibodies reached first seizure-freedom (88% vs. 7%, P < 0.001) and terminal seizure-freedom (80% vs. 7%, P < 0.001) more frequently. The time to first and terminal seizure-freedom and the time to freedom from ASM were shorter in the surface antibody group (Kaplan–Meier curves: P < 0.0001 for first seizure-freedom; P < 0.0001 for terminal seizure-freedom; P = 0.0042 for terminal ASM-freedom). Maximum ASM defined daily doses were higher in the groups with intracellular antibodies. Seizure-freedom was achieved after additional immunotherapy, not always accompanied by increased ASM doses. Titers of surface antibodies but not intracellular antibodies decreased over time.

Conclusion

Seizures with surface antibodies should mostly be considered acute symptomatic and transient and not indicative of epilepsy. This has consequences for ASM prescription and social restrictions. Antibody titers correlate with clinical courses.

Electronic supplementary material

The online version of this article (10.1007/s00415-020-10250-6) contains supplementary material, which is available to authorized users.

Anti-inflammatory and immunomodulatory effects of baicalin in cerebrovascular and neurological disorders

Inflammatory responses play an extraordinary role in the pathogenesis of cerebrovascular and neurological disorders. Baicalin is one of the important flavonoids, which is extracted from Scutellaria baicalensis Georgi. Recently, numerous in vivo and in vitro studies have shown that baicalin has salutary effects for anti-inflammatory and immunomodulatory and has been demonstrated to exert beneficial therapeutic properties in cerebrovascular and neurological diseases. In this review, we aim to discuss that baicalin exerts anti-inflammatory effects through multiple pathways and targets, thus affecting the production of a variety of inflammatory cytokines and neuroprotective process of neurological diseases; furthermore, the related targets of the anti-inflammatory effects of baicalin were analyzed via using the tools of network pharmacology, to provide theoretical basis and innovative ideas for the future clinical application of baicalin.

Seizures and risk of epilepsy in anti-NMDAR, anti-LGI1, and anti-GABAB R encephalitis

Background

Accumulating data have suggested seizures occur frequently in patients with neuronal surface antibody‐mediated autoimmune encephalitis. We aimed to evaluate seizure outcomes and potential factors associated with the development of epilepsy in patients with anti‐N‐methyl‐D‐aspartate receptor (NMDAR), anti‐leucine‐rich glioma‐inactivated 1 (LGI1), and anti‐gamma‐aminobutyric‐acid B receptor (GABA_BR) encephalitis.

Methods

Patients with anti‐NMDAR, anti‐LGI1, and anti‐GABA_BR encephalitis were prospectively recruited from 2014 to June 2019, with a median follow‐up period of 30.5 months (range 8–67 months). Seizure outcomes were assessed and risk factors of epilepsy were analyzed.

Results

A total of 119 patients with anti‐NMDAR, anti‐LGI1, and anti‐GABA_BR encephalitis were included, and 83 (69.7%) of them developed new‐onset seizures. By the end of follow‐up, 17 (21.3%) of 80 patients had seizure relapses after intermittent seizure remission or exhibited uncontrolled seizure episodes, contributing to epilepsy. Immunotherapy delay and interictal epileptic discharges (IEDs) were identified to be associated with the development of epilepsy in patients with anti‐NMDAR, anti‐LGI1, and anti‐GABA_BR encephalitis, particularly anti‐NMDAR encephalitis. Furthermore, multivariate logistic regression analysis demonstrated that immunotherapy delay was an independent predictor for epilepsy.

Conclusion

Our study suggested that immunotherapy delay and IEDs were associated with the development of epilepsy in patients with anti‐NMDAR, anti‐LGI1, and anti‐GABA_BR encephalitis. Early diagnosis and treatment were required, and particular consideration should be given to patients with these risk factors.

Seizures and epilepsy of autoimmune origin: A long-term prospective study

OBJECTIVE

To follow prospectively a group of patients with seizures or epilepsy and suggestive clinical features of autoimmune aetiology and find out how many are finally diagnosed with acute symptomatic seizures (ASS) secondary to autoimmune encephalitis or autoimmune-related epilepsy, and how many develop epilepsy.

METHODS

Consecutive patients meeting the inclusion criteria from 2010 to 2018 were identified. Patients were classified as confirmed, probable autoimmune, non-autoimmune, or unknown.

RESULTS

One-hundred and nine patients were included, 64 (48.7 %) women, mean age 55.2 years (SD 17.9). ASS were reported by 61 patients (56 %), while 48 presented epilepsy (44 %). During follow-up 18 patients died (16.5 %). Final diagnosis was autoimmune-relatedepilepsy (confirmed + probable) in 22 cases and ASS secondary to autoimmune encephalitis (confirmed or probable) in 27, non-autoimmune aetiologies or other diagnosis in 49 (44 %), and unknown aetiology in 11 (10.2 %). Neuronal antibodies (ab) were found in 27 patients (24.7 %). T-lymphocyte infiltration in temporal lobes was observed in 2/8 patients (20 %). Neuronal ab were more frequent in the autoimmune groups: 17 patients (29.8 %) vs 1(2.3 %), p:0.001, and they suffered more autoimmune diseases: 37 (75.5 %) vs 12 (24.48 %), p:0.0001, and 34 (69 %) vs 22 (44.9 %) p:0.027, respectively. All patients with GAD ab 17/17 (100 %) evolved to chronic disease. Four patients (29 %) with ASS secondary to autoimmune encephalitis developed epilepsy.

SIGNIFICANCE

ASS secondary to autoimmune encephalitis or autoimmune-related epilepsy will be diagnosed in nearly half of patients who have been suspected of it. The only diagnostic clue is neuronal ab. Patients who have suffered ASS secondary to autoimmune encephalitis may develop epilepsy over time.

Rituximab for Autoimmune Encephalitis with Epilepsy

Intractable epilepsy remains a significant medical challenge, resulting in recurrent and prolonged intensive care unit (ICU) admissions. Autoimmune encephalitis is emerging as a treatable cause of intractable epilepsy. It is characterized by antibodies against cerebral antigens, such as potassium channels such as leucine-rich, glioma inactivated 1 (LGI1) and contactin-associated protein 2 (CASPR2), calcium channels such as the voltage-gated calcium channel (VGCC), or neurotransmitter receptors such as the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR), gamma aminobutyric acid receptor (GABAR), and N-methyl-D-aspartate receptor (NMDAR). Diagnosis requires a syndrome consistent with an antibody identified in serum or cerebrospinal fluid (CSF) using methods that minimize risk of false-positives. Although there is no officially approved therapy for these disorders, typical approaches involve chronic high-dose steroids, intravenous immunoglobulin (IVIG), or plasma exchange. Rituximab is effective for antibody-associated disorders such as lupus, myasthenia gravis, and neuromyelitis optica. Here, we present three patients who were admitted with recalcitrant status epilepticus and demonstrated serum antibodies against NMDAR, LGI1, or VGCC using a cell-based assay. All patients demonstrated complete, long-term epilepsy control and improvement in symptoms with rituximab.

Functional Immunoregulation by Heme Oxygenase 1 in Juvenile Autoimmune Diseases

An autoimmune disease is an inflammatory condition in which the human body's immune system attacks normal cells, resulting in decreased and abnormal immune function, which eventually leads to tissue damage or organ dysfunction. In the field of medicine, especially in pediatrics, knowledge about autoimmune diseases is still inadequate. Some common juvenile autoimmune diseases such as Henoch-Schonlein purpura, systemic juvenile idiopathic arthritis, mucocutaneous lymph node syndrome, and autoimmune encephalitis cause considerable public concern. Recent studies revealed that heme oxygenase 1 (HO-1), an enzyme that participates in heme degradation, plays a critical role in the pathogenesis and may regulate autoimmunity. Firstly, it may promote the differentiation of T lymphocytes into CD4+CD25+ regulatory T cells and may be associated with changes in the ratios of cytokines (Th1/Th2 and Th17/Treg) as well. Secondly, HO-1 can regulate the immune system through the secretion of proteins such as transforming growth factors and interleukins. Moreover, increasing the expression of HO-1 can improve vascular function by increasing antioxidant levels. Thus, HO-1 may provide a theoretical basis and guidance for therapeutic management of juvenile autoimmune diseases.

Seizures and Epilepsy in Autism Spectrum Disorder

Epilepsy and autism frequently co-occur. Epilepsy confers an increased risk of autism and autism confers an increased risk of epilepsy. Specific epilepsy syndromes, intellectual disability, and female gender present a particular risk of autism in individuals with epilepsy. Epilepsy and autism are likely to share common etiologies, which predispose individuals to either or both conditions. Genetic factors, metabolic disorders, mitochondrial disorders, and immune dysfunction all can be implicated.

Neurosyphilis Mimicking Autoimmune Encephalitis: A Case Report and Review of the Literature

Neurosyphilis may imitate a wide range of neurological and psychiatric diseases, including autoimmune encephalitis. To avoid further cognitive decline and morbidity, early recognition and adequate treatment are of particular importance in both neurosyphilis and autoimmune encephalitis. In case of a strong clinical suspicion of a diagnosis of autoimmune encephalitis, guidelines recommend initiating immunotherapy even in the absence of immunological confirmation. Here, a case of neurosyphilis is reported in which the potential overlap in clinical presentation of autoimmune encephalitis and parenchymatous neurosyphilis is discussed. The here reported data suggest that, in cases presenting with new onset focal epilepsy, slowing of electroencephalographic activity over the temporal regions and magnetic resonance imaging suggestive of swelling of the amygdala, neurosyphilis should be excluded prior to initiation of immunotherapy for suspected autoimmune encephalitis.

Clinical and Electroencephalographic Features of the Seizures in Neuronal Surface Antibody-Associated Autoimmune Encephalitis

Objectives: To investigate clinical and electroencephalographic features of the seizures in different types of neuronal surface antibody (NSAb)-associated autoimmune encephalitis (AE).

Methods: The clinical data of the seizures were analyzed in 18 patients with NSAb-associated AEs diagnosed in the First Affiliated Hospital of Dalian Medical University.

Results: From May 2013 to April 2019, a total of 18 cases of NSAb-associated AE were diagnosed, including 9 cases of leucine-rich glioma-inactivated 1 protein (LGI1) antibody-associated encephalitis, 7 cases of anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis, and 2 cases of anti-γ-aminobutyric acid B receptor (GABA_BR) encephalitis. All nine cases (100%) with LGI1 AE had seizures manifesting in three types: faciobranchial dystonia seizure (FBDS) (44.4%), mesial temporal lobe epilepsy (MTLE)-like seizure (66.7%), and focal to bilateral tonic–clonic seizure (FBTCS) (77.8%). Six of nine (66.7%) showed abnormal signal on hippocampus or basal ganglia in brain MRI. Five of seven cases (71%) with anti-NMDAR encephalitis had seizures manifesting in three types: focal aware seizure (40%), focal-impaired awareness seizure (20%), generalized tonic–clonic seizure (GTCS) (100%), and status epilepticus (SE) (40%). Three of seven (42.8%) showed abnormalities in brain MRI. Both patients with anti-GABA_BR encephalitis had seizures manifesting in two types: GTCS and MTLE-like seizure, one with SE. One showed abnormal signal on left hippocampus in brain MRI. All patients (100%) with three types of AE had abnormalities in electroencephalogram (EEG), showing diffuse (4/18) or focal slow waves (14/18) in background, interictal (10/18), or ictal (6/18) epileptic discharges in the temporal or other regions; two patients with anti-NMDAR encephalitis showed delta activity or rhythm in frontotemporal region. All patients with seizures showed good response to immunotherapy except one with LGI1 AE.

Conclusions: Most patients with NSAb-associated AE had seizures; seizure types varied between different types of AE. In LGI1 AE, the hippocampus and basal ganglia were two main targets; the corresponding seizure type was MTLE-like seizure and FBDS, respectively. Anti-NMDAR encephalitis had more generalized than focal seizures. Delta activity or rhythm in the frontotemporal region in EEG was helpful for diagnosis. Anti-GABA_BR encephalitis was characterized by refractory seizures as initial symptom, mainly GTCS or MTLE-like seizure. Most seizures in NSAb-associated AE showed good response to immunotherapy, and antiepileptic drugs should be considered as an add-on symptomatic treatment.

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?

Immune-mediated epilepsy with GAD65 antibodies

Anti-GAD65 antibodies have been identified in both acute/subacute seizures (limbic encephalitis and extralimbic encephalitis) and chronic isolated epilepsy. The evidence of high serum titers and intrathecal synthesis play a fundamental role in diagnosis but poorly correlate with disease severity or response to therapies. It remains controversial whether anti-GAD65 Abs are the pathogenic entity or only serve as a surrogate marker for autoimmune disorders mediated by cytotoxic T cells. Unlike other immune-mediated epilepsy, although multiple combinations of therapeutics are used, the efficacy and prognosis of patients with GAD65-epilepsy patients are poor. Besides, GAD65-epilepsy is more prone to relapse and potentially evolve into a more widespread CNS inflammatory disorder. This article reviews the recent advances of GAD65-epilepsy, focusing on the diagnosis, epidemiology, pathophysiology, clinical features, and treatment, to better promote the recognition and provide proper therapy for this condition.

Brain-responsive neurostimulation treatment in patients with GAD65 antibody-associated autoimmune mesial temporal lobe epilepsy

Glutamic acid decarboxylase 65‐kilodalton isoform (GAD65) antibodies have been associated with multiple nonneurological and neurological syndromes including autoimmune epilepsy (AE). Although immunotherapy remains the cornerstone for the treatment of AE, those with GAD65 Ab‐associated AE (GAD65‐AE) remain refractory to immunotherapy and antiseizure medication (ASM). Outcomes of epilepsy surgery in this patient population have also been unsatisfactory. The role of neuromodulation therapy, particularly direct brain‐responsive neurostimulation therapy, has not been previously examined in GAD65‐AE. Here, we describe four consecutive patients with refractory GAD‐65‐associated temporal lobe epilepsy (GAD65‐TLE) receiving bilateral hippocampal RNS System treatment. The RNS System treatment was well tolerated and effective in this study cohort. Three patients had a >50% clinical seizure reduction, and one patient became clinically seizure‐free following resective surgery informed by the RNS System data with continued RNS System treatment. In all four of our patients, the long‐term ambulatory data provided by the RNS System allowed us to gain objective insights on electrographic seizure lateralization, patterns, and burden as well as guided immunotherapy and ASM optimization. Our results suggest the potential utility of the RNS System in the management of ASM intractable GAD65‐AE.