Prevalence of Neural Autoantibodies in Epilepsy of Unknown Etiology: Systematic Review and Meta-Analysis

Case report: Refractory focal motor seizure associated with cerebrospinal fluid neurochondrin antibody

Background

Focal onset seizures, characterized by localized neuronal hyperexcitability in the brain, can be related to various structural, immune, genetic, or metabolic abnormalities. Autoimmune epilepsies are increasingly recognized. Neurochondrin antibody has been reported in a variety of rare autoimmune neurological disorders. This article aims to highlight the relevance of anti-neurochondrin in autoimmune epilepsy.

Methods

This is a case presentation and literature review of autoimmune epilepsy associated with anti-neurochondrin antibody.

Case presentation

A 26-year-old African American right-handed man with a history of Sjogren's syndrome presented with near constant, rhythmic left-sided facial twitching movements, and one episode of generalized tonic clonic seizure. Magnetic resonance imaging (MRI) of the brain revealed borderline low volume right hippocampus. Cerebrospinal fluid (CSF) studies yielded elevated protein and mild lymphocytic pleocytosis. Antibody Prevalence in Epilepsy 2 (APE2) score was 6, and autoimmune workup was initiated. Anti-neurochondrin antibody returned positive in the CSF autoimmune encephalitis panel with a titer of 1:512 (Mayo Clinic TEST ID: ENC2). Seizures remained refractory to anti-seizure medications including divalproex, lacosamide, and oxcarbazepine. Immunotherapy with methylprednisolone and immunoglobulin improved his epileptic seizures.

Conclusion

This is the first reported case of refractory autoimmune epilepsy with positive CSF anti-neurochondrin antibody. This study contributes to the body of evidence supporting the role of neurochondrin antibody in epilepsy. Considering autoimmune testing in individuals with seizures having APE2 score > 4 can aid in timely diagnosis of immune-mediated epilepsy and initiation of immunotherapy, which can result in favorable clinical outcomes. Diagnosis of autoimmune epilepsy, in most cases, is based on clinical characteristics, MRI results, and CSF findings. In addition to the traditional antibody panel for autoimmune encephalitis, some novel antibodies, such as anti-neurochondrin, should also be considered.

The three pillars in treating antibody-mediated encephalitis

The rapid initiation of immunotherapy has a decisive impact on the course of the disease in patients with antibody-mediated encephalitis (AE). The importance of treating AE with antiseizure medication and antipsychotics is discussed controversially; however, standardized procedures should be ensured, especially for the initiation of treatment in severe disease. Recommendations and guidelines for further interventions in refractory courses are needed. In this review, we contrast the three mainstays of treatment options in patients with AE and attempt to highlight the importance of 1) antiseizure therapy, 2) antipsychotic therapy, and 3) immunotherapy/tumor resection from today's perspective.

Kelch-like Protein 11 (KLHL11) Antibodies in Children With Seizures of Undetermined Cause

BACKGROUND/AIM

Kelch-like protein 11 (KLHL11)-antibody may be found in paraneoplastic neurological disorders presenting with epileptic seizures. The aim of this study was to investigate the prevalence and clinical significance of KLHL11-antibody in epilepsy.

PATIENTS AND METHODS

Sera of 42 pediatric and 59 adult patients with seizures of undetermined cause were screened using a cell-based assay.

RESULTS

KLHL11-antibody was found in three of 168 control patients with paraneoplastic neurological disorders and four pediatric patients (4-8-year-old, 2 boys/2 girls) with seizures of unknown cause presenting with myoclonic-atonic epilepsy, generalized epilepsy or childhood epilepsy with centrotemporal spikes. In these four cases, seizures continued for 2-7 months, responded promptly and favorably to conventional anti-seizure drugs and did not recur in follow-up durations ranging between 2-5 years. Patients had normal brain MRI findings and motor-mental development before and after seizures. KLHL11-antibody was not detected in adult epilepsy patients with undetermined cause, MOG antibody-positive patients and healthy controls.

CONCLUSION

KLHL11-antibody may be detected in pediatric epilepsy patients with a relatively benign disease course.

Role of N-Methyl-D-Aspartate Receptor NR2B Subunit in Inflammatory Arthritis-Induced Chronic Pain and Peripheral Sensitized Neuropathic Pain: A Systematic Review

Arthritis is a common clinical disease that affects millions of people in the world. The most common types of arthritis are osteoarthritis and rheumatoid arthritis. Inflammatory arthritis (IA), a chronic painful disease, is characterized by synovitis and cartilage destruction in the early stages. Pathologically, IA causes inflammatory changes in the joints and eventually leads to joint destruction. Pain is associated with inflammation and abnormal regulation of the nervous system pathways involved in pain promotion and inhibition. In addition, the occurrence of pain is associated with depression and anxiety. We found that there are many factors affecting pain, in addition to inflammatory factors, glutamate receptor may be the possible cause of long-term chronic pain caused by IA. N-methyl-d-aspartate receptor subunit 2B (NR2B) has been reported to involved in IA and nervous system diseases, especially peripheral neuropathic pain. In this review, we summarized the mechanisms of the NR2B subunit of the N-methyl-D-aspartate (NMDA) receptor in peripheral nerve sensitization during IA and chronic pain.

Immune Mechanism of Epileptogenesis and Related Therapeutic Strategies

Immunologic and neuroinflammatory pathways have been found to play a major role in the pathogenesis of many neurological disorders such as epilepsy, proposing the use of novel therapeutic strategies. In the era of personalized medicine and in the face of the exhaustion of anti-seizure therapeutic resources, it is worth looking at the current or future possibilities that neuroimmunomodulator or anti-inflammatory therapy can offer us in the management of patients with epilepsy. For this reason, we performed a narrative review on the recent advances on the basic epileptogenic mechanisms related to the activation of immunity or neuroinflammation with special attention to current and future opportunities for novel treatments in epilepsy. Neuroinflammation can be considered a universal phenomenon and occurs in structural, infectious, post-traumatic, autoimmune, or even genetically based epilepsies. The emerging research developed in recent years has allowed us to identify the main molecular pathways involved in these processes. These molecular pathways could constitute future therapeutic targets for epilepsy. Different drugs current or in development have demonstrated their capacity to inhibit or modulate molecular pathways involved in the immunologic or neuroinflammatory mechanisms described in epilepsy. Some of them should be tested in the future as possible antiepileptic drugs.

Prevalence of Neural Autoantibodies in Paired Serum and Cerebrospinal Fluid in Adult Patients with Drug-Resistant Temporal Lobe Epilepsy of Unknown Etiology

In order to determine the prevalence of neural autoantibodies in adult patients with drug-resistant temporal lobe epilepsy (DRTLE) of unknown etiology, we compared the characteristics of patients with and without autoantibodies and applied antibody predictive scores to the patients. Patients aged ≥18 years with DRTLE of unknown etiology and ≥12 months of evolution were prospectively recruited. Neural autoantibodies in serum and CSF were systematically determined in all patients. We created the ARTE (antibody in drug-resistant temporal lobe epilepsy) score based on the variables associated with the presence of neural autoantibodies. Twenty-seven patients were included. The mean (SD) age in years at the index date was 52 (±14.2) and at epilepsy onset was 32 (±17.1). The mean epilepsy duration was 19 (±12.5) years. Neural autoantibodies were detected in 51.85% (14/27) of patients. The presence of bitemporal, independent, interictal epileptiform discharges (BIIED) had a higher frequency in patients with neural autoantibodies (57.1% vs. 15.4%; p = 0.025) as well as those patients with a previous history of status epilepticus (49.2% vs. 0.0%; p = 0.007). The ARTE score showed an area under the curve (AUC) of 0.854. Using a cut-off point of ≥1, the sensitivity was 100% and the specificity was 46.1%, whereas when using a cut-off point of ≥3, the results were 35.7% and 100%, respectively. We found a high prevalence of neural autoantibodies in patients with DRTLE of unknown etiology, indicating an autoimmune mechanism. The presence of BIIED and a history of SE in DRTLE of unknown etiology are possible markers for autoimmune-associated epilepsy. The proposed ARTE score requires future validation in larger independent cohorts.