Seizure semiology: an important clinical clue to the diagnosis of autoimmune epilepsy

Autoimmune-associated seizure disorders

With the discovery of an expanding number of neural autoantibodies, autoimmune etiologies of seizures have been increasingly recognized. Clinical phenotypes have been identified in association with specific underlying antibodies, allowing an earlier diagnosis. These phenotypes include faciobrachial dystonic seizures with LGI1 encephalitis, neuropsychiatric presentations associated with movement disorders and seizures in NMDA-receptor encephalitis, and chronic temporal lobe epilepsy in GAD65 neurologic autoimmunity. Prompt recognition of these disorders is important, as some of them are highly responsive to immunotherapy. The response to immunotherapy is highest in patients with encephalitis secondary to antibodies targeting cell surface synaptic antigens. However, the response is less effective in conditions involving antibodies binding intracellular antigens or in Rasmussen syndrome, which are predominantly mediated by cytotoxic T-cell processes that are associated with irreversible cellular destruction. Autoimmune encephalitides also may have a paraneoplastic etiology, further emphasizing the importance of recognizing these disorders. Finally, autoimmune processes and responses to novel immunotherapies have been reported in new-onset refractory status epilepticus (NORSE) and febrile infection-related epilepsy syndrome (FIRES), warranting their inclusion in any current review of autoimmune-associated seizure disorders.

Predicting factors for acute encephalopathy in febrile seizure children with SARS-CoV-2 omicron variant: a retrospective study

BACKGROUND

SARS-CoV-2 posed a threat to children during the early phase of Omicron wave because many patients presented with febrile seizures. The study aimed to investigate predicting factors for acute encephalopathy of children infected by SARS-CoV-2 Omicron variant presenting with febrile seizures.

METHODS

The retrospective study analyzed data from pediatric patients who visited the emergency department of Chang Gung Memorial Hospital in Taiwan between April and July 2022. We specifically focused on children with COVID-19 who presented with febrile seizures, collecting demographic, clinical, and laboratory data at the pediatric emergency department, as well as final discharge diagnoses. Subsequently, we conducted a comparative analysis of the clinical and laboratory characteristics between patients diagnosed with acute encephalopathy and those with other causes of febrile seizures.

RESULTS

Overall, 10,878 children were included, of which 260 patients presented with febrile seizures. Among them, 116 individuals tested positive for SARS-CoV-2 and of them, 14 subsequently developed acute encephalopathy (12%). Those with acute encephalopathy displayed distinctive features, including older age (5.1 vs. 2.6 years old), longer fever duration preceding the first seizure (1.6 vs. 0.9 days), cluster seizure (50% vs. 16.7%), status epilepticus (50% vs. 13.7%) and occurrences of bradycardia (26.8% vs. 0%) and hypotension (14.3% vs. 0%) in the encephalopathy group. Besides, the laboratory findings in the encephalopathy group are characterized by hyperglycemia (mean (95% CI) 146 mg/dL (95% CI 109-157) vs. 108 mg/dL (95% CI 103-114) and metabolic acidosis (mean (95% CI) pH 7.29(95% CI 7.22-7.36) vs. 7.39 (95%CI 7.37-7.41)).

CONCLUSIONS

In pediatric patients with COVID-19-related febrile seizures, the occurrence of seizures beyond the first day of fever, bradycardia, clustered seizures, status epilepticus, hyperglycemia, and metabolic acidosis should raise concerns about acute encephalitis/encephalopathy. However, the highest body temperature and the severity of leukocytosis or C-reactive protein levels were not associated with poor outcomes.

Autoimmune epilepsy, retrospective case series of clinical features, management, and outcomes

OBJECTIVES

To evaluate the clinical and electrographic features of patients with autoimmune epilepsy and assess the influence of early diagnosis and treatment on reducing seizure frequency.

METHODS

A retrospective observational case series was conducted utilizing medical records from King Abdullah Medical Hospital between 2017 and 2022. Cases of newly diagnosed seizures were chosen based on laboratory-proven autoimmunity.

RESULTS

Five female inpatients were identified, primarily presenting with seizures suggestive of an autoimmune origin. Autoimmune antibodies were detected in all patients as follows: GAD (3), NMDA-R (2). One patient exhibited unilateral temporal lobe onset while three displayed bilateral onset. One patient had an associated malignancy. Rituximab was administered as an immunomodulatory therapy to four patients, resulting in successful seizure reduction post-immunotherapy initiation.

CONCLUSION

Autoimmune epilepsy is recognized as a distinct condition. The clinical presentation can be complex and antibody testing may warrant repetition if initial results are negative or if specific antibodies are not detected. Early initiation of immunosuppression, coupled with prompt treatment escalation when required, is vital for achieving optimal patient outcomes.

The value of immunotherapy in children with initial short-term frequent seizures

This study aimed to discuss clinical characteristics, therapy, and antibody prevalence in epilepsy (APE) score for short-term, frequent epileptic seizures in children who are autoimmune-antibody negative and respond well to immunotherapy. The clinical characteristics, imaging manifestations, electrophysiology, and effective treatment plan of 9 children who met the above criteria were retrospectively analyzed in the Pediatric Neurology Department of Qilu Hospital at Shandong University from June 2019 to December 2021. All 9 patients (6 boys, 3 girls; aged 13 months−11 years and 5 months, median 3.5 years) had acute-onset seizures within 3 months. All had previous normal growth/development with no family history of disease. Seizure types were focal motor seizures (6), generalized tonic-clonic seizures (2), and generalized secondary-to-focal (1); occurred >10 times/day; and lasted <1 min/episode. Formal treatment with ≥2 types of antiseizure medicine (ASM) achieved an unsatisfactory effect. Cranial magnetic resonance imaging showed an abnormal result in 1 case. The APE score was ≥4 in 3 cases and <4 in 6 cases. All patients experienced symptomatic relief with immunotherapy; subsequently, 8 patients were free of recurrence and 1 had significantly reduced seizure frequency. Autoimmune antibody screening is recommended for children who were previously well and have acute-onset epilepsy; high frequency, short-duration seizures; no good response to 2 types of ASM; and other etiologic factors excluded, even with APE score <4. Even with negative autoimmune antibody results, the possibility of autoimmune epilepsy should be considered for urgent initiation of immunotherapy, which can achieve good results.

Seizure underreporting in LGI1 and CASPR2 antibody encephalitis

Patients with anti-leucine-rich glioma-inactivated 1 protein (LGI1) or anti-contactin-associated protein 2 (CASPR2) antibody encephalitis typically present with frequent epileptic seizures. The seizures generally respond well to immunosuppressive therapy and the long-term seizure outcome seems to be favorable. Consequentially, diagnosing acute symptomatic seizures secondary to autoimmune encephalitis instead of autoimmune epilepsy was proposed. However, published data on long-term seizure outcomes in CASPR2 and LGI1 antibody encephalitis are mostly based on patient reports and seizure underreporting is a recognized issue. Clinical records from our tertiary epilepsy center were screened retrospectively for patients with LGI1 and CASPR2 antibody encephalitis who reported seizure freedom for at least three months and received video-EEG for >24 hours at follow-up visits. Twenty (LGI1: n=15; CASPR2: n=5) out of thirty-two patients with LGI1 (n=24) and CASPR2 (n=8) antibody encephalitis fulfilled these criteria. We recorded focal aware and impaired awareness seizures in four of these patients (20%) with reported seizure-free intervals ranging from 3 to 27 months. Our results question the favorable seizure outcome in patients with CASPR2 and LGI1 antibody encephalitis and suggest that the proportion of patients who have persistent seizures may be greater. Our findings underline the importance of prolonged video-EEG telemetry in this population.

Mammalian Target of Rapamycin (mTOR) Inhibitor Improves Local Immune Microenvironment and Reduces Seizures via Increasing miR-211 Level in Rat Brain

This study aims to analyze the role of mTOR inhibitor on the expression of miR-211 in rat brain tissue and the biological effect of miR-211 in attenuating seizure. Rats were randomly divided into four groups, and the number of seizures and the duration of single seizure were observed within 24 hours after intervention. The level of miR-211 in brain tissue was detected by RT qPCR, the apoptosis of nerve cells was assessed by TUNEL staining, the level of immune cells was detected by flow cytometry, and the level of serum inflammatory factors was determined by ELISA. The number of seizures and the duration of single seizure in the three groups treated by rapamycin within 24 hours were lower than those in the control group, and the symptom relief in group C was the best. After treatment, the expression level of miR-211 in the brain tissue of epileptic rats increased. TUNEL staining showed that neuronal apoptosis was obvious in epileptic rats. The anti apoptotic ability of group C was the most significant, followed by group D and group B. Compared with group A, the levels of CD3+ cells, CD8+ cells and CD4+/CD25+ cells in brain tissue of group C were decreased, while the levels of IL-2 and IFN-γ were lower in group C than those in control. In group C (n = 5), the levels of CD3+ cells, CD8+ cells and CD4+/CD25+ cells were elevated, and the levels of immune related cytokines IL-2 and IFN-γ were higher than those of rats without miR-211 inhibition. mTOR inhibitors can improve the local immune microenvironment, reduce the release of inflammatory factors, and finally decrease the frequency and duration of seizures by up regulating the level of miR-211 in rat brain tissue.

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.

Autoimmune epilepsy due to N-methyl-D-aspartate receptor antibodies in a child: a case report

Introduction

Seizures of autoimmune etiology may occur independent of or predate syndromes of encephalitis. We report a child with “pure” autoimmune epilepsy followed up for 7 years to highlight long-term effects of this epilepsy and the importance of early initiation and appropriate escalation of immunosuppression to achieve a good long-term outcome.

Case presentation

A previously healthy 5-year-old Sri Lankan boy presented with acute, frequent, brief focal seizures of temporal-lobe semiology without clinical and investigatory findings suggestive of central nervous system infection, tumor, structural abnormality, or metabolic causes. His epilepsy showed poor response to increasing doses and combinations of antiseizure medications. Further investigations detected N-methyl-d-aspartate receptor antibodies in serum, but not cerebrospinal fluid. Treatment with intravenous methyl prednisolone and maintenance on mycophenolate resulted in a rapid reduction, with seizure freedom achieved within 5–6 weeks. He relapsed when immunotherapy and anti seizure medications were reduced after seizure freedom for 24 months. This, and subsequent relapses, showed poor response to modification of anti-seizure medications, but treatment with immunotherapy (methyl prednisolone and rituximab) achieved complete seizure freedom. At 7-years of follow-up, he remains free of seizure for over 3 years, and has average academic performance and satisfactory quality of life.

Conclusions

Autoimmune epilepsy is a recognized independent entity. Diagnostic criteria have been suggested for its early recognition and confirmation of diagnosis. Early diagnosis and initiation of immunosuppression, with prompt escalation of treatment when necessary, remains key to good patient outcome.

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.

Recognition of seizure semiology and semiquantitative FDG-PET analysis of anti-LGI1 encephalitis

Aims

Anti‐leucine‐rich glioma‐inactivated 1 (LGI1) autoimmune encephalitis (AE) is characterized by complex manifestations of seizures. Here, we report a new seizure semiology, attempt to classify the disease by semiology type, and explore the metabolic pattern of each group.

Methods

Anti‐LGI1 AE patients were retrospectively screened between May 2014 and September 2019 in our tertiary epilepsy center. All enrolled patients had seizures during long‐range video electroencephalogram (EEG) recordings, and all patients (except one) underwent [¹⁸F] fluoro‐2‐deoxyglucose (FDG) positron emission tomography (PET) scans. Voxel‐based metabolic analysis and z‐distribution analysis were carried out to determine the metabolic pattern.

Results

Thirty‐three patients were enrolled. According to the patients’ seizure semiology, we divided the patients into four groups: focal impaired awareness seizures (FIAS, n = 17), faciobrachial dystonic seizures (FBDS)‐only (n = 6), FBDS‐plus (n = 8), and focal aware motor seizures (FAMS) (n = 2). No significant differences were found in the clinical manifestations or accessory tests except for the onset age (FIAS < FBDS‐plus) and seizure semiology. This was the first study to extensively describe the clinical manifestations and EEG of FAMS in anti‐LGI1 AE patients. In addition, we found that the patients with different semiologies all showed a wide range of abnormal metabolism, which is not limited to the temporal regions and basal ganglia, and extends far beyond our previous interpretation of FDG‐PET data.

Conclusion

Our results showed that FAMS can serve as a rare indicative seizure semiology of anti‐LGI1 AE and that individuals with this disease exhibited widespread functional network alterations.

Association between autoimmune encephalitis and epilepsy: Systematic review and meta-analysis

BACKGROUND

Diverse neuronal antibodies are related to autoimmune encephalitis (AE) and AE-related epilepsy. However, the epidemiological characteristics of AE, AE-associated antibodies, and AE-related seizures are still unclear.

AIMS

This research evaluated the relationship between AE, AE-related seizures, and neuronal antibodies, as well as the morbidity of AE with early incidence.

METHODS

The PubMed, Embase, Cochrane, and Web of Science databases were searched. Pooled estimates and 95% confidence intervals (CIs) were calculated using a random-effects model.

RESULTS

Of the 4,869 citations identified, 100 articles were reviewed in full, and 42 subgroups were analyzed. The overall incidence of AE patients with seizures was 42% (95% CI: 0.40-0.44), and among them, the incidence of epilepsy in anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis patients was 73% (95% CI: 0.70-0.77). Subsequently, we found that the prevalence of AE as the cause of epilepsy within the pooled period was 1% (95% CI: 0.01-0.02), while the overall positive rate of neuronal antibodies in epilepsy patients was 4% (95% CI: 0.03-0.05). Additionally, the detection rates of different antibodies among epilepsy patients were as follows: anti-NMDAR, 1%; anti-leucine-rich glioma inactivated 1 (LGI1), 1%; anti-contactin-associated protein-like 2 (CASPR2), 2%.

CONCLUSION

Based on our findings, neuronal antibodies may serve as a bridge to study AE and immune-related epilepsy. To further understand the differences in outcomes following different treatment measures, and to provide more information for public health policy and prevention, more research is needed to improve the accuracy of estimations.

Glutamic acid decarboxylase 65-positive autoimmune encephalitis presenting with gelastic seizure, responsive to steroid: A case report

BACKGROUND

Anti-glutamic acid decarboxylase (GAD) antibody is known to cause several autoimmune-related situations. The most known relationship is that it may cause type I diabetes. In addition, it was also reported to result in several neurologic syndromes including stiff person syndrome, cerebellar ataxia, and autoimmune encephalitis. Decades ago, isolated epilepsy associated with anti-GAD antibody was first reported. Recently, the association between temporal lobe epilepsy and anti-GAD antibody has been discussed. Currently, with improvements in examination technique, many more autoimmune-related disorders can be diagnosed and treated easier than in the past.

CASE SUMMARY

A 44-year-old female Asian with a history of end-stage renal disease (without diabetes mellitus) under hemodialysis presented with diffuse abdominal pain. The initial diagnosis was peritonitis complicated with sepsis and paralytic ileus. Her peritonitis was treated and she recovered well, but seizure attack was noticed during hospitalization. The clinical impression was gelastic seizure with the presentation of frequent smiling, head turned to the right side, and eyes staring without focus; the duration was about 5–10 s. Temporal lobe epilepsy was recorded through electroencephalogram, and she was later diagnosed with anti-GAD65 antibody positive autoimmune encephalitis. Her seizure was treated initially with several anticonvulsants but with poor response. However, she showed excellent response to intravenous methylprednisolone pulse therapy. Her consciousness returned to normal, and no more seizures were recorded after 5 d of intravenous methylprednisolone treatment.

CONCLUSION

In any case presenting with new-onset epilepsy, in addition to performing routine brain imaging to exclude structural lesion and cerebrospinal fluid studies to exclude common etiologies of infection and inflammation, checking the autoimmune profile has to be considered. In the practice of modern medicine, autoimmune-related disorders are relatively treatable and should not be missed.

Autoimmune Encephalitis in Late-Onset Seizures: When to Suspect and How to Treat

Objective: This study was conducted to elucidate prevalence, clinical features, outcomes, and best treatment in patients with late-onset seizures due to autoimmune encephalitis (AE). Methods: This is a single-institution prospective cohort study (2012-2019) conducted at the Epilepsy Center at the University of Greifswald, Germany. A total of 225 patients aged ≥50 years with epileptic seizures were enrolled and underwent an MRI/CT scan, profiling of neural antibodies (AB) in serum and cerebrospinal fluid (CSF), and neuropsychological testing. On the basis of their work-up, patients were categorized into the following three cohorts: definite, suspected, or no AE. Patients with definite and suspected AE were subsequently treated with immunosuppressive therapy (IT) and/or anti-seizure drug (ASD) therapy and were followed up (FU) regarding clinical and seizure outcome. Results: Of the 225 patients, 17 (8%) fulfilled the criteria for definite or suspected AE according to their AB profile and MRI results. Compared with patients with no evidence of AE, those with AE were younger (p = 0.028), had mesial temporal neuropsychological deficits (p = 0.001), frequently had an active or known malignancy (p = 0.006) and/or a pleocytosis (p = 0.0002), and/or had oligoclonal bands in CSF (p = 0.001). All patients with follow-up became seizure-free with at least one ASD. The Modified Rankin scale (mRS) at hospital admission was low for patients with AE (71% with mRS ≤2) and further decreased to 60% with mRS ≤2 at last FU. Significance: AE is an important etiology in late-onset seizures, and seizures may be the first symptom of AE. Outcome in non-paraneoplastic AE was favorable with ASD and IT. AB testing in CSF and sera, cerebral MRI, CSF analysis, and neuropsychological testing for mesial temporal deficits should be part of the diagnostic protocol for AE following late-onset seizures.

Musicogenic epilepsy: Expanding the spectrum of glutamic acid decarboxylase 65 neurological autoimmunity

The objective of this study was to describe serological association of musicogenic epilepsy and to evaluate clinical features and outcomes of seropositive cases. Through retrospective chart review, musicogenic epilepsy patients were identified. Among 16 musicogenic epilepsy patients, nine underwent autoantibody evaluations and all had high-titer glutamic acid decarboxylase 65-immunoglobulin G (GAD65-IgG; >20 nmol·L^-1 , serum, normal ≤ .02 nmol·L^-1 , eight women). Median GAD65-IgG serum titer was 294 nmol·L^-1 (20.3-3005 nmol·L^-1 ), and median cerebrospinal fluid titer (n = 4) was 14.7 nmol·L^-1 . All patients had temporal lobe epilepsy, and bitemporal epileptiform abnormalities were common. Right temporal lobe seizures were most frequently captured when seizures were induced by music on electroencephalogram (3/4; 75%). Intravenous (IV) methylprednisolone and/or IV Ig (IVIG) was utilized in four patients, with one having greater than 50% reduction. Rituximab (n = 2) and mycophenolate (n = 1) were ineffective. Two patients underwent right temporal lobe resections but continued to have seizures. Vagus nerve stimulation was effective at reducing seizures in one patient by 50%, and an additional patient was seizure-free by avoiding provoking music. Right temporal lobe epilepsy was more common among patients with musicogenic epilepsy when compared to nonmusicogenic GAD65 epilepsies (n = 71, 89% vs. 47%, p = .03). GAD65-IgG should be tested in patients with musicogenic epilepsy, given implications for management and screening for comorbid autoimmune conditions.

Calibration of the Epilepsy Questionnaire for Use in a Low-Resource Setting

Background. Burden of epilepsy in sub-Saharan Africa is huge in the midst of shortage of human resource in its health sector. Using skilled staff to supervise and support lower level healthcare workers providing frontline primary healthcare is a pragmatic coping solution. But, lower level health providers face enormous challenges due to absent clinical algorithms or pragmatic rapid diagnostic tests. Objective. This study aimed to determine if the use of an epilepsy questionnaire in a traditional clinical setting would improve semiological details obtained and diagnostic accuracy. Methods. A prospective study was conducted involving patients diagnosed with epilepsy each with an eye witness who had regularly witnessed the seizures. Routine seizure history from clinical documentation and an interviewer-based questionnaire were compared. The data obtained were assessed for content, accuracy, intermethod and test-retest reliability. Results. Sixty-seven patients with a median age of 24 years were recruited. Routine seizure history had obtained less semiological details with inadequate description of nonmotor manifestations and lateralizing motor details. The questionnaire-obtained history showed higher accuracy for generalized onset seizure (0.83 vs. 0.56) and focal onset seizures (0.79 vs. 0.59). The questionnaire-obtained history also had good test-retest reliability for various semiological domains except automatisms. Conclusions. Routine seizure histories are not standardized. The use of a questionnaire goes a long way in improving semiology description in a low-resource setting and guides the health provider on what details to focus on. The use of epilepsy questionnaires should, therefore, be considered to improve semiology, especially in nonspecialist settings.

Clinical features and immunotherapy outcomes of anti-glutamic acid decarboxylase 65 antibody-associated neurological disorders

We described the clinical and neuroimaging characteristics of seven Chinese patients with anti-GAD65 antibody-associated neurological disorders of whom epileptic seizures were the initial and main symptoms. All patients were given immunotherapy and followed up monthly. The outcome demonstrates that immunotherapy is helpful for non-seizure manifestations of anti-GAD65-associated neurological autoimmunity and is less effective in the treatment of seizures, yet partial responses can still occur in the early stage. Taken together we suggest a trial with immunotherapy in all patients in the early stage of the disease, and in patients with non-epilepsy symptoms in the later stage.

HMGB1/CXCL12-Mediated Immunity and Th17 Cells Might Underlie Highly Suspected Autoimmune Epilepsy in Elderly Individuals

PURPOSE

Late-onset epilepsy due to autoimmune dysfunction has been reported. However, definitive diagnosis requires positive antibody results. As a result, patients with negative antibody results, but presenting with classical manifestation of autoimmune epilepsy, may be managed as suspected cases. In this study, we aim to isolate and profile the concentration of cytokines/chemokines in the cerebrospinal fluid (CSF) and the serum to ascertain if they could act as alternative diagnostic biomarkers.

PATIENTS AND METHODS

Twenty patients aged ≥50 years were considered in this study. Ten patients were diagnosed with suspected autoimmune epilepsy (sAE) based on clinic manifestation, electroencephalogram, magnetic resonance imaging, and with negative antibody results of the serum and the CSF. The equivalent control group exhibited neurological disorders due to non-inflammatory pathologies. Serum and CSF were analyzed for cytokines/chemokines concentration, including interleukin (IL)-6, IL-10, IL-17, chemokine (C-X-C motif) ligand (CXCL)12 and CXCL13, as well as high-mobility group box protein 1 (HMGB1) and B cell activation factor (BAFF)).

RESULTS

The CSF levels of IL-6, IL-17, HMGB1, and CXCL12 were significantly higher in the sAE group than in the control group. There was no difference in the CSF levels of IL-10, CXCL13 and BAFF. The serum levels of HMGB1 and CXCL12 were elevated in the sAE group compared with the control group, and there was no statistical difference in the serum levels of IL-6, IL-10, IL-17, CXCL13, and BAFF between the two groups.

CONCLUSION

Our study shows that cytokines/chemokines may act as alternative biomarkers for diagnosis of sAE. The activation of both HMGB1/CXCL12-mediated immunity and T helper cells 17 (Th17) cells may be playing a central role in the pathogenesis of sAE. We suggest that cytokines/chemokines be treated as adjuvant biomarkers, instead of solely relying on antibody screening test. However, a larger cohort in a prospective approach is required to validate our findings.

Relevance of Surface Neuronal Protein Autoantibodies as Biomarkers in Seizure-Associated Disorders

The detection of neuronal surface protein autoantibody-related disorders has contributed to several changes in our understanding of central nervous system autoimmunity. The clinical presentation of these disorders may be associated (or not) with tumors, and often patients develop an inexplicable onset of epilepsy, catatonic or autistic features, or memory and cognitive dysfunctions. The autoantigens in such cases have critical roles in synaptic transmission and plasticity, memory function, and process learning. For months, patients with such antibodies may be comatose or encephalopathic and yet completely recover with palliative care and immunotherapies. This paper reviews several targets of neuronal antibodies as biomarkers in seizure disorders, focusing mainly on autoantibodies, which target the extracellular domains of membrane proteins, namely leucine-rich glioma-inactivated-1 (LGI1), contactin-associated protein-like 2 (CASPR2), the N-methyl-D-aspartate receptor (NMDAR), γ-aminobutyric acid receptor-B (GABA_BR), the glycine receptor (GlyR), and a-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs). In order to restore health status, limit hospitalization, and optimize results, testing these antibodies should be done locally, using internationally certified procedures for a precise and rapid diagnosis, with the possibility of initiating therapy as soon as possible.

Semi-quantitative FDG-PET Analysis Increases the Sensitivity Compared With Visual Analysis in the Diagnosis of Autoimmune Encephalitis

Objective: The purpose of this study is to evaluate the potential diagnostic benefit of SPM-based semi-quantitative FDG-PET analysis in autoimmune encephalitis (AE) compared with visual analysis by experienced neuroradiologists using a larger sample size.

Methods: This observational retrospective case series study was conducted from a tertiary epilepsy center between May 2014 and March 2017. Healthy individuals without any neurologic or psychiatric diseases were recruited as control. We determined brain FDG-PET abnormal glucose metabolism on medial temporal lobe and basal ganglia using semi-quantitative analysis and compared this method with visual analysis at the same time among patients with autoantibody positive AE.

Results: Twenty-eight patients with clinically diagnosed AE and 53 healthy individuals without any neurologic or psychiatric diseases were recruited. On the medial temporal lobe and the basal ganglia, semi-quantitative analysis showed consistency with the visual assessment for whom they had abnormal metabolism by visual assessment. More importantly, 56% patients on medial temporal lobe and 73% patients on the basal ganglia respectively who were not identified by visual inspection can be detected by semi-quantitative analysis, demonstrating the greater sensitivity of semi-quantitative analysis compared with visual assessment.

Significance: This study showed semi-quantitative brain FDG-PET analysis was better than visual analysis in view of observing the abnormal glucose metabolism of patients with autoantibody positive AE. Semi-quantitative FDG-PET analysis appears to be a helpful tool in early diagnosis of patients with AE.

Tonic Seizure as a Different Seizure Type Presented in Autoimmune Epilepsy Caused by Systemic Lupus Erythematosus

The diagnosis of autoimmune epilepsy is often challenging, and may be misdiagnosed as epileptic disorders or viral encephalitis. Autoimmune epilepsy has a strong association with other autoimmune diseases, especially systemic lupus erythematosus (SLE). In addition, autoimmune epilepsy was reported to present with complex partial seizure (CPS), simple partial seizure (SPS), and secondarily generalized tonic-clonic seizure (sGTCS). In our case, we present a different seizure type of tonic seizure in autoimmune epilepsy caused by SLE, which has not been reported, and it will provide with a new understanding of autoimmune epilepsy. A 17-year-old Chinese girl was diagnosed as having SLE for 1 month but with no epilepsy history. After this admission, she presented with different seizure types. Then EEG, magnetic resonance imaging, and lumbar puncture were performed. We have found generalized tonic seizure and excluded CNS infection and lupus encephalopathy. After antiepileptic therapy, no improvement has been found in seizure control. According to the previous history, clinical manifestation, and relevant examinations, we have made a clinical diagnosis of autoimmune epilepsy (tonic seizure) and SLE has been confirmed again by the immunological test. After the hormonotherapy, anti-inflammatory, and anti-tuberculosis therapy, the tonic seizure decreased significantly, and patient's consciousness improved. Autoimmune epilepsy should call the attentions of the clinicians, especially when the patient presented with SLE. Tonic seizure has not been described in autoimmune epilepsy before, which was different from other seizures reported, such as SPS, CPS, and sGTCS, and may bring a new insight into the autoimmune epilepsy.