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

Clinical features, cerebrospinal fluid changes, and prognosis in Chinese patients with autoimmune encephalitis

INTRODUCTION

Autoimmune encephalitis (AE) is a rare, treatable disease of the central nervous system (CNS) caused by an antibody-related immune response. This study is to investigate the correlation of clinical features, cerebrospinal fluid (CSF) characteristics, and prognosis in patients with AE.

METHODS

A total of 71 patients diagnosed with antibody-positive AE were retrospectively analyzed. The patients were divided into three groups: anti-NMDAR group, anti-LGI1 group, and other types. Clinical data were collected to analyze clinical features and CSF results, and prognosis was determined by modified Rankin Scale (mRS).

RESULTS

There was statistical difference in the incidences of decreased consciousness level (P < 0.001), memory loss (P = 0.017), speech disorders (P = 0.035), and dyskinesia (P = 0.001) in different antibodies groups. Younger age (P = 0.018), elevated CSF chloride content (P = 0.006), and white blood cells > 50/mm3 (P = 0.026) were highly correlated with ICU admission. Anti-LGI1 encephalitis had a relatively small risk for ICU admission (P = 0.034), and a lower risk of poor functional recovery (P = 0.048) and recurrence (P = 0.041). Patients with first-line treatment failure (P = 0.021) had an increased risk of poor functional recovery. Delayed treatment (P = 0.011) would increase the risk of recurrence.

CONCLUSION

There are differences in age, gender, clinical characteristics, and CSF results in different subtypes of AE. First-line therapy failure would have poor functional recovery, and delayed therapy would increase the risk of relapse. Chloride ion content and white blood cell count in cerebrospinal fluid are positively correlated with the patient's exacerbation and admission to ICU. These indicators have certain clinical value for the prognosis of AE patients.

Paraneoplastic neurologic syndrome and autoantibody accompaniments of germ cell tumors

Paraneoplastic neurologic syndromes (PNSs) are a group of diseases affecting the central and/or peripheral nervous system caused by immune-mediated processes directed toward antigens with shared expression in tumor and neural tissue. Germ cell tumors (GCTs) are associated with PNSs with varied clinical phenotypes. Early diagnosis of PNS is vital to potentially uncover and treat underlying tumors, improving the chances of recovery, and preventing permanent neurologic complications. In this chapter, we outline the pathophysiology and epidemiology of PNS. We briefly provide a summary of GCTs in males and females. We review the neural-specific autoantibodies and PNSs associated with GCTs and their clinical and radiologic accompaniments. We also provide an overview of the treatment and prognosis of these disorders.

Anti-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor encephalitis developed after ovarian cancer cytoreduction surgery: a case report and literature review

BACKGROUND

Anti-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) encephalitis, a rare subtype of autoimmune encephalitis (AE), is often found associated with tumors such as thymoma, lung cancer, ovarian tumors, and breast cancer, and the tumors were generally detected during the screening process after the encephalitis initiated. The tumor is considered a trigger of AE, but the mechanism remains unclear.

CASE PRESENTATION

A 53-year-old woman presented short-term memory loss two days after the primary cytoreduction for high-grade serous ovarian cancer (HGSOC, FIGO stage IC3). Cell-based assay found AMPAR CluA2 IgG positive in both serum (1:3.2) and cerebrospinal fluid (1:32). Moreover, mild AMPAR GluA1 and strong GluA2 expressions were also found positive in the paraffin sections of ovarian tumor tissue, indicating the ovarian cytoreduction surgery might stimulate the release of receptor antigens into the circulation system. The patient's condition deteriorated within two weeks, developing consciousness and autonomic dysfunction, leading to ICU admission. With oral steroids, intravenous immunoglobulin, plasmapheresis, and rituximab treatment, the patient's consciousness markedly improved after three months.

CONCLUSION

We presented the first case of anti-AMPAR encephalitis developed right after the primary cytoreduction of a patient with HGSOC and retrieved paraneoplastic anti-AMPAR encephalitis cases (n = 66). Gynecologists should pay attention to patients who develop cognitive dysfunction or psychiatric symptoms shortly after the ovarian tumor resection and always include AE in the differentiation diagnosis.

Paraneoplastic Neurological Syndromes of the Central Nervous System: Pathophysiology, Diagnosis, and Treatment

Paraneoplastic neurological syndromes (PNS) include any symptomatic and non-metastatic neurological manifestations associated with a neoplasm. PNS associated with antibodies against intracellular antigens, known as "high-risk" antibodies, show frequent association with underlying cancer. PNS associated with antibodies against neural surface antigens, known as "intermediate- or low-risk" antibodies, are less frequently associated with cancer. In this narrative review, we will focus on PNS of the central nervous system (CNS). Clinicians should have a high index of suspicion with acute/subacute encephalopathies to achieve a prompt diagnosis and treatment. PNS of the CNS exhibit a range of overlapping "high-risk" clinical syndromes, including but not limited to latent and overt rapidly progressive cerebellar syndrome, opsoclonus-myoclonus-ataxia syndrome, paraneoplastic (and limbic) encephalitis/encephalomyelitis, and stiff-person spectrum disorders. Some of these phenotypes may also arise from recent anti-cancer treatments, namely immune-checkpoint inhibitors and CAR T-cell therapies, as a consequence of boosting of the immune system against cancer cells. Here, we highlight the clinical features of PNS of the CNS, their associated tumors and antibodies, and the diagnostic and therapeutic strategies. The potential and the advance of this review consists on a broad description on how the field of PNS of the CNS is constantly expanding with newly discovered antibodies and syndromes. Standardized diagnostic criteria and disease biomarkers are fundamental to quickly recognize PNS to allow prompt treatment initiation, thus improving the long-term outcome of these conditions.

Performance of the clinical assessment scale for autoimmune encephalitis in a pediatric autoimmune encephalitis cohort

Background

The Clinical Assessment Scale for Autoimmune Encephalitis (CASE), a new scale used for rating the severity of autoimmune encephalitis (AE), has demonstrated good validity and reliability in adults with AE, but there is a shortage of data on its performance in children with AE. This study aimed to assess the reliability and validity of the CASE in a cohort of children with AE.

Methods

Forty-seven pediatric inpatients with AE who visited Guizhou Provincial People’s Hospital between January 1, 2017, and October 31, 2021, were enrolled in the study. The CASE and mRS scores were obtained through a review of detailed medical records from the Health Information System by two pediatric neurologists. Finally, the performance of the CASE in this pediatric AE cohort was analyzed.

Results

The results showed that anti-NMDA receptor encephalitis was the most common (61.70%) type of AE in children. The most common clinical manifestations were language problems (85.1%), psychiatric symptoms (80.9%), and dyskinesia/dystonia (78.7%). The CASE had good item reliability and interevaluator reliability; the Cronbach’s alpha value of the total score was 0.825, and the intraclass correlation (ICC) was 0.980. The Cronbach’s alpha value by item ranged from 0.16 to 0.406; items 1 and 9 had the lowest and highest Cronbach’s alpha values, respectively. The criterion validity between CASE and mRS total scores, as quantified by Pearson correlation, was 0.459, indicating slight to good criterion validity. The area under the curve (AUC) was 0.992 (95% confidence interval: 0.974-1.00). A cutoff value of 14 was selected to determine whether a patient needed admission to the ICU; this cutoff had a sensitivity of 100% and a specificity of 92%. The changes in EEG, MRI, and antibody titers were not related to the severity of AE. A CASE score cutoff of 9 was selected to indicate whether second-line treatment would be needed.

Conclusion

The CASE has good reliability and validity in children with AE; however, some items of the CASE may not apply to this population. Thus, an in-depth study of the CASE is needed in children with AE.

Psychiatric manifestations of autoimmune encephalitis

Autoimmune encephalitis is increasingly recognized as a cause of psychiatric symptoms. A wide spectrum of psychiatric manifestations have been described which may precede, follow or occur independently of neurologic features. Patients typically respond to immunotherapy, however diagnosis is challenging due to phenotypic heterogeneity. The aim of this review is to provide an overview of the psychiatric features associated with encephalitis mediated by autoantibodies targeting neuronal cell-surface antigens and describe indicators of potential immunopathology underlying psychiatric manifestations.