Background/Objectives: Anti-mGluR1 encephalitis is a rare form of autoimmune encephalitis predominantly manifesting as acute/subacute cerebellar ataxia. We describe a newly diagnosed case series from our center and conduct a comprehensive review of reported cases worldwide to compare clinical manifestations, treatment options, and outcomes. Methods: We consecutively identified 11 patients at Peking Union Medical College Hospital, and additionally extracted clinical data from 42 previously published cases identified via PubMed and Google Scholar (search updated to 1 August 2025). Demographics, phenotypes, laboratory findings, imaging, treatment, and outcomes were systematically summarized. This pooled review was not prospectively registered, and extracted data from 21 published articles were analyzed alongside our 11 newly diagnosed cases. Results: The integrated cohort comprised 53 patients with anti-mGluR1 encephalitis, including 29 males and 24 females, with patients reported from Asia (n = 18), North America (n = 11), and Europe (n = 24). The median age at onset was 50 years (IQR 29.5–58.5; range 3–81), with North American patients presenting later than their Asian and European counterparts (median 60 vs. 48 and 45 years, respectively; all p < 0.05). Disease onset was subacute in most cases (58.7%). Comorbid tumors were present in nine patients, most commonly lymphomas. Clinical phenotypes were classified as pure cerebellar syndrome (n = 31), cerebellar ataxia with encephalitic features (n = 20), and non-cerebellar presentations (n = 2). Baseline severity differed across phenotypes (χ2 = 35.7, p < 0.001). Regional variability in severity was observed but did not reach significance. CSF analyses revealed pleocytosis in 59% (23/39), elevated protein in 31.3% (5/16), and oligoclonal bands in 52.2% (12/23). MRI abnormalities were detected in 34.7% (17/49) of patients, with 21.9% (7/32) developing cerebellar atrophy on follow-up. Therapeutic strategies varied significantly across regions (p = 0.041), with Asian cohorts more frequently receiving long-term immunosuppression, European cohorts favoring combined regimens, and North American cases relying predominantly on first-line therapies. Overall, 65.9% (29/44) of patients clinically improved, 13.6% (6/44) relapsed and 20.5% (9/44) remained unaffected. Conclusions: Anti-mGluR1 encephalitis presents with significant clinical heterogeneity, ranging from cerebellar-dominant ataxia to neuropsychiatric or non-cerebellar phenotypes, and demonstrates differences in reported age of onset, disease severity, and therapeutic approaches across publication regions. Our findings underscore the importance of early recognition, sustained immunotherapy, and international collaboration to establish standardized, evidence-based management for this rare but disabling disorder.

This case provides clinicopathological evidence supporting the association between FBDS and basal ganglia involvement in anti-LGI1 encephalitis. It highlights the diagnostic challenge posed by tumour-like unilateral basal ganglia lesions on MRI and underscores the importance of neuronal autoantibody testing before invasive procedures. In addition, this report contributes the first neuropathological description of basal ganglia involvement in anti-LGI1 encephalitis and summarises previously reported pathological findings.

OBJECT:Glutamic acid decarboxylase antibody-associated neurological disease (GADAND) is a rare autoimmune disorder with elusive immunogenetic underpinnings. We aimed to investigate HLA associations with GADAND susceptibility in a Chinese cohort. METHODS:We performed HLA genotyping at the HLA-A, -B, -C, -DRB1, -DQA1, and -DQB1 loci in 62 Chinese patients with GADAND and compared them with 990 healthy controls. Haplotype frequencies were estimated using the expectation-maximization (EM) algorithm. Allele and haplotype associations with disease susceptibility and clinical phenotypes were assessed. RESULTS:We identified the HLA class I haplotype A*11:01 ~ B*40:01 ~ C*07:02 as a susceptibility haplotype for GADAND (OR = 10.22, 95% CI 3.86-25.57, padj = 0.003), and the association was stronger for the extended haplotype including DQA1*01:03 (OR = 25.61, 95% CI 4.99-89.11, padj < 0.001). Three haplotypes showed suggestive but non-significant associations: B*44:02 ~ C*05:01 (OR = 8.32, 95% CI 2.52-24.48, padj = 0.069), DQA1*01:03 ~ DQB1*06:01 ~ DRB1*08:03 (OR = 3.15, 95% CI 1.67-5.63, padj = 0.066), and DQA1*05:05 ~ DQB1*03:01, which showed a suggestive protective effect (OR = 0.15, 95% CI 0.018-0.556, padj = 0.088). T1DM risk haplotypes, including DQA1*03:01 ~ DQB1*03:02 ~ DRB1*04:03 (OR = 5.04, 95% CI 1.18-16.62, padj = 0.744) and DQA1*05:01 ~ DQB1*02:01 ~ DRB1*03:01 (OR = 2.50, 95% CI 1.07-5.24, padj = 0.829), were more frequent in GADAND patients, and A*11:01 ~ B*40:01 ~ C*07:02 was enriched in those with comorbid AITD. No statistically significant associations were identified between HLA haplotypes and clinical phenotypes. CONCLUSIONS:The haplotype A*11:01 ~ B*40:01 ~ C*07:02 was associated with GADAND susceptibility in the Chinese population, implicating T cell involvement. T1DM-associated haplotypes were overrepresented in GADAND, and A*11:01 ~ B*40:01 ~ C*07:02 was enriched in comorbid AITD, suggesting HLA as a shared immunogenetic basis for autoimmune comorbidities. No significant HLA associations with clinical phenotypes were identified, warranting validation in larger cohorts.

Abstract Neuropsychiatric systemic lupus erythematosus (NPSLE) is a potentially severe complication of systemic lupus erythematosus (SLE), yet its pathogenesis remains largely elusive. By jointly probing the immune dynamics of subjects’ cerebrospinal fluid (CSF) and peripheral blood, we showed that both innate and adaptive immune responses jointly contribute to the pathogenesis of NPSLE. In particular, we found the remarkable enrichment of BAM-CCL3, a subtype of border-associated macrophages with strong recruitment capacity, implicating its potential role in central nervous system (CNS) inflammation. We also observed pronounced activation of memory B cells and CD4 + regulatory T cells in NPSLE CSF, along with the preferential blood-to-CSF migration and subsequent within-CSF clonal expansion of CD8 + effector memory T cells in NPSLE patients, suggesting a persistent CNS-localized adaptive immune dysregulation. Finally, we developed the single-cell CNS disease CSF–Blood Atlas (scCDCB), a comprehensive collection for CSF and peripheral blood of multiple CNS diseases, which is publicly available at ( https://sccdcb.gao-lab.org ) to serve as a reference for future research on CNS diseases.

Background : Anaplastic pleomorphic xanthoastrocytoma (APXA) and epithelioid glioblastoma (eGBM) are rare central nervous system tumors with overlapping clinical and histopathological features, making their distinction challenging. Accurate classification is clinically important because of their markedly different biological behavior and prognosis. Beyond canonical BRAF alterations, the genetic landscape of these tumors remains incompletely characterized. Methods We report a 46-year-old man presenting with rapidly progressive neurological symptoms, including seizures and cognitive decline. Diagnostic evaluation included magnetic resonance imaging, cerebrospinal fluid analysis, histopathology, immunohistochemistry, and next-generation sequencing of tumor and germline DNA. A focused review of the literature was performed to contextualize the molecular findings within the APXA–eGBM spectrum. Results Integrated clinicopathological assessment identified a high-grade neuroepithelial tumor with overlapping features of APXA and eGBM, precluding definitive classification based on morphology alone. Molecular analysis revealed a novel deleterious germline FANCA frameshift variant (p.Pro615fs), homozygous NF1 inactivation, extensive copy number alterations, including complete deletion of CDKN2A/B , and a mutational signature consistent with homologous recombination deficiency, in the absence of canonical BRAF mutations. While the final diagnostic interpretation was primarily guided by histopathological features and aggressive clinical behavior, the molecular profile provided important biological context for the unusually rapid progression and diffuse leptomeningeal dissemination observed. Conclusion : This case highlights the diagnostic complexity of rare high-grade neuroepithelial tumors at the interface of APXA and eGBM and underscores the value of integrated molecular analysis in biologically aggressive and diagnostically ambiguous cases. Our identification of a deleterious germline FANCA variant suggests a potential role of genetic predisposition like DNA repair defects as biological modifiers that may contribute to genomic instability, tumor aggressiveness, and malignant evolution, particularly in BRAF -negative tumors.

Background:Prognostic determinants in anti-glutamic acid decarboxylase (GAD) antibody-associated epilepsy remain unclear, and no validated predictive model exists. We aimed to identify prognostic factors and develop a predictive model. Methods:This multicenter cohort included patients diagnosed with anti-GAD antibody-associated epilepsy before September 2024. Data encompassed demographics, seizure semiology, cellular and serological parameters, neuroimaging and electrophysiological findings, and treatment regimens. Favorable outcome was defined as seizure-free for ≥12 months following immunotherapy and antiseizure medications, poor outcome was defined as persistent seizures. Prognostic factors were analyzed and a predictive model was constructed. Results:Among 91 patients, 22 (24%) achieved seizure freedom, whereas 69 (76%) continued to experience seizures despite appropriate treatment. Poor prognosis was associated with focal seizures (50% vs. 81%, p = 0.004), temporal lobe epilepsy (TLE) (23% vs. 75%, p < 0.001), musicogenic epilepsy (n = 5, all with poor seizure control), and higher seizure frequency [≥1 seizure/month (67% vs. 97%, p < 0.001)]. In contrast, a shorter disease duration from symptom onset to diagnosis [3 (IQR 0.9-26.0) vs. 8 (IQR 1.5-36.0) months, p = 0.025], a shorter interval to initiation of immunotherapy [3 (IQR 1.0-14.0) vs. 7 (IQR 1.9-27.3) months, p = 0.005], higher CD8+T-cell counts (829.5 ± 473.9 vs. 619.5 ± 338.6 cells/µL, p = 0.035) were associated with favorable outcomes. Multivariate logistic regression identified TLE (OR = 0.098, 95% CI: 0.028-0.341, p < 0.001) and seizure frequency (OR = 0.067, 95% CI: 0.010-0.450, p = 0.005) as independent predictors of prognosis. The prognostic model based on these two variables demonstrated good discrimination (AUC = 0.807, 95% CI: 0.696-0.919, p < 0.001) and calibration (Hosmer-Lemeshow χ² = 0.124, p = 0.740), with sensitivity of 81.8%, specificity of 72.5%, and overall accuracy of 74.7%. Internal validation with bootstrapping confirmed model stability. Risk stratification further classified patients into low- (8.7%), intermediate- (49.3-58.9%), and high-risk (93.6%) groups for poor prognosis. Conclusion:Focal seizures, TLE, and higher seizure frequency were associated with poor prognosis, whereas early diagnosis, timely treatment, and higher peripheral CD8+T-cell counts were associated with favorable outcomes. TLE and seizure frequency independently predicted clinical outcomes in anti-GAD antibody-associated epilepsy. The logistic regression model effectively stratified patients, identifying those likely to achieve seizure freedom versus refractoriness.

BackgroundAutoimmune neurological syndromes (AINS) associated with anti-GAD65 antibodies encompass a spectrum of disorders, including limbic encephalitis (LE), stiff-person syndrome (SPS), and cerebellar ataxia (CA). Despite the universal presence of anti-GAD65 antibodies across these syndromes, patients exhibit remarkable clinical phenotypic diversity. Exploring the overall B-cell receptor (BCR) profile of patients with anti-GAD65 AINS may provide clues to the molecular pathological mechanisms underlying this phenotypic diversity.MethodsWe performed high-throughput B-cell receptor (BCR) heavy-chain sequencing (Illumina NovaSeq 6000) on peripheral blood samples from 9 anti-GAD65 AINS patients (7 LE, 1 SPS, 1 CA/SPS overlapping) and 11 healthy controls (HC). Analysis encompasses clonotype profiling, somatic hypermutation (SHM) rates, CDR3 physicochemical characterization, repertoire diversity, and machine learning-based VDJ feature identification.ResultsAnti-GAD65 LE showed significantly reduced repertoire diversity versus HC (Chao1: p-adjusted = 0.0023; Hill: p-adjusted = 3.7 × 10–⁵), lower SHM rates (3.54% vs. 4.73%), and enrichment of hyperexpanded clones. Distinct IGHV/IGHJ usage was identified, notably decreased IGHV1-2 and IGHV1-46 with elevated IGHV3-7. A random forest classifier built on characteristic VDJ clonotypes achieved near-perfect diagnostic performance (AUC > 0.99). Cross-patient shared clonal clusters further highlighted disease-associated BCR convergence.ConclusionsBCR repertoire heterogeneity across anti-GAD65 AINS subtypes illuminates the immunological underpinnings of phenotypic diversity. The identified VDJ signatures and common clonotypes represent candidate biomarkers for precise diagnosis and rational targets for BCR-lineage-directed immunotherapy.

BACKGROUND:To investigate whether exposure to pet hamsters may act as a potential trigger for autoimmune cerebellar ataxia (ACA). METHODS:We conducted a hospital-based case-control study based on our institutional ACA cohort. 57 patients were enrolled in the ACA group and 67 age-matched and sex-matched patients with other autoimmune central nervous system disorders served as controls. Clinical and paraclinical data were collected. Exposure to hamsters and other animals was defined as daily or near-daily contact for at least 2 months. RESULTS:Hamster exposure was significantly more common in the ACA group than in controls (56.1% vs 4.5%, p<0.001; adjusted OR 38.46, 95% CI 10 to 142.86, p<0.001), whereas exposure to other animals did not differ between groups. Among patients with ACA with hamster exposure, the median interval from contact to ataxia onset was 12 months and 11 patients had a history of hamster bites. Compared with patients with ACA without hamster contact, those with hamster exposure more frequently presented with pyramidal signs, diplopia and peripheral neuropathy/radiculopathy, together with higher cerebrospinal fluid (CSF) white blood cell counts, protein concentrations and positivity rates for oligoclonal bands. CSF pathogen testing was negative in all subjects. Neuronal autoantibodies were detected in nine patients with ACA with hamster exposure. HLA-A*24:02 and HLA-B*15:01 showed nominal correlations with hamster exposure, but these did not remain significant after Benjamini-Hochberg false discovery rate correction. CONCLUSIONS:Pet hamster exposure may be a risk factor for ACA. Hamster-associated ACA showed distinctive clinical and CSF inflammatory features. These findings support pet hamster exposure as a novel potential environmental trigger for ACA.

OBJECTIVE:To compare the pathological features of patients with different forms of vasculitic neuropathy (VN). METHODS:Patients with clinically probable VN were enrolled. Clinical characteristics and ancillary examinations were collected and evaluated. Nerve biopsies were performed. RESULTS:A total of 48 patients with VN were involved, including 20 primary systemic VN (PSVN), 17 secondary systemic VN (SSVN), and 11 non-systemic VN (NSVN). Patients that fulfilled the pathologically definite, probable, and possible VN were 20 (41.67%), 8 (16.67%), and 12 (25.00%), respectively. The frequencies of acute vascular damage showed no significant difference across three subgroups (PSVN 80.00%, SSVN 82.35%, NSVN 90.91%). Chronic vascular damage was more frequently observed in PSVN (90.00%) and SSVN (76.47%) than in NSVN (54.55%) with no significance. Perivascular inflammatory cell infiltration in the endoneurium was more common in NSVN (45.45%) than PSVN (15.00%, p = 0.004) and none with SSVN (0.00%, p = 0.002). CONCLUSION:The overall rate of pathologically definite and probable VN in nerve biopsy was 58%. Acute vascular lesion is commonly seen in all forms of VN, while chronic vascular damage is more frequently observed in SVN. Perivascular inflammatory cell infiltration in the epineurium is primarily found in NSVN. SIGNIFICANCE:The study further elucidated the clinical significance of nerve biopsy in VN.

ObjectivesTo investigate the human leukocyte antigen (HLA) associations and clinical characteristics of anti-Leucine-rich glioma-inactivated 1 (LGI1) encephalitis in a Chinese cohort, focusing on potential differences between early-onset and late-onset patients.MethodsEighty patients diagnosed with anti-LGI1 encephalitis at Peking Union Medical College Hospital between the years 2016 and 2024 were included. Patients were stratified into early-onset (<50 years, n=22) and late-onset (≥50 years, n=58) groups for clinical features analysis. High-resolution NGS HLA genotyping was performed and compared with 984 healthy controls. Logistic and linear regressions were used to analyze disease susceptibility, age of onset associations, and prognostic factors.ResultsCompared with the late-onset group, the early-onset group more frequently presented with generalized tonic-clonic seizures (GTCS) as the initial symptom (45.5% vs. 10.3%, post-hoc p = 0.001), and a lower frequency of psychiatric symptoms (p = 0.047) and amnesia (p = 0.002) during the disease course, presenting with lower mRS scores at onset (p = 0.020). Genetically, DRB1*07:01 was confirmed as the primary risk allele (OR = 10.4, 95% CI 6.01-18.02, pc = 6.78×10−15). DRB1*09:01(OR = 3.67, 95% CI 2.17-6.20, pc = 1.16×10-5) and DQB1*03:03 (OR = 3.25, 95% CI 1.98-5.33, pc = 1.32×10-5) were identified as novel secondary risk alleles in this Chinese cohort. Importantly, specific HLA genotypes were significantly associated with the age of onset. A*02:01 was linked to an earlier onset (β = -9.26; pc = 0.019) and served as a risk factor for the early-onset group, while DRB1*07:01 was associated with a later onset (β = 13.44, pc = 0.006). Diagnostic delay (OR = 1.01, 95% CI 1.00-1.02, p = 0.037) and GTCS (OR = 5.01, 95% CI 1.11-22.66, p = 0.036) were independent predictors of poor prognosis.ConclusionsThis study suggests that early-onset and late-onset anti-LGI1 encephalitis may possess differential immunogenetic and clinical profiles. In addition to the broad susceptibility conferred by DRB1*07:01, the presence of A*02:01 is significantly associated with an earlier onset age. These findings provide insights into the role of HLA genotyping in accounting for the observed differences between early-onset and late-onset patients.

BackgroundAutoimmune cerebellar ataxia (ACA) is a significant and treatable cause of sporadic cerebellar syndrome. Pyramidal tract damage affects approximately 30% of ACA patients, profoundly impacts motor function and prognosis, yet this complex form remains under-investigated.MethodsWe retrospectively analyzed patients with pyramidal signs from our institutional ACA cohort, excluding those with intrinsic upper motor neuron impairment due to specific ACA subtypes. Clinical and paraclinical data were compared between patients with and without pyramidal signs.ResultsAmong the 48 ACA patients with pyramidal signs, primary autoimmune cerebellar ataxia was the most common subtype (50%), and neuronal antibodies were detected in 66.7%. Compared to ACA patients without pyramidal signs, those with pyramidal signs were younger at onset (44 vs 47 years, p=0.048) and more frequently presented with limb ataxia (97.9% vs 78.8%, p=0.002) and diplopia (48.9% vs 18.2%, p<0.001). Brain MRI revealed pyramidal tract and/or semiovale centrum lesions in 29.8% of patients with pyramidal signs, a finding absent in the non-pyramidal sign group (p<0.001), which could subside with immunotherapy. Cerebrospinal fluid (CSF) analysis showed higher protein concentration and a significantly higher rate of specific oligoclonal bands in the pyramidal sign group. Patients with pyramidal signs had a significantly higher risk of relapse (52.5% vs 32.8%, p=0.034).ConclusionsAutoimmune cerebellopyramidal syndrome represents a distinct and complex ACA phenotype, characterized by unique clinical and imaging features, CSF abnormalities indicative of a more pronounced autoimmune response, and a higher relapse rate. Comprehensive evaluation and long-term maintenance immunotherapy may be warranted in these patients.

PURPOSE:Anti-immunoglobulin-like cell adhesion molecule 5 (IgLON5) disease is a rare autoimmune encephalitis that shares clinical features with progressive supranuclear palsy (PSP), complicating differential diagnosis. Here, we sought to investigate whether PET imaging using [18F]Florzolotau and [18F]FDG could distinguish these disorders through characteristic patterns of tau deposition and cerebral glucose metabolism. PATIENTS AND METHODS:Eleven patients with serologically confirmed anti-IgLON5 disease, 20 patients with PSP diagnosed according to the 2017 Movement Disorder Society criteria, and 40 age-matched and sex-matched healthy controls were enrolled. Participants underwent [18F]Florzolotau and/or [18F]FDG PET imaging. Visual interpretation and semiquantitative analyses, including voxel-based and region-of-interest approaches, were performed. RESULTS:Anti-IgLON5 patients showed significant [18F]Florzolotau binding in subcortical regions, including the midbrain, pons, caudate, putamen, and thalamus, along with additional involvement of the parietal lobe and cerebellum. PSP patients demonstrated overlapping [18F]Florzolotau uptake in the caudate, putamen, thalamus, midbrain, and pons, but with distinct additional binding in the frontal lobe. [18F]FDG PET revealed contrasting metabolic profiles: anti-IgLON5 disease was associated with diffuse cortical hypometabolism, whereas PSP showed regionally restricted hypometabolism, mainly in the frontal lobe, caudate, putamen, midbrain, and pons. CONCLUSIONS:We identified distinct PET signatures that can reliably differentiate anti-IgLON5 disease from PSP. The complementary application of [18F]Florzolotau and [18F]FDG PET imaging may provide valuable biomarkers for differential diagnosis in clinically ambiguous cases, potentially enabling timely immunotherapeutic interventions for patients with imaging patterns suggestive of anti-IgLON5 disease.

To evaluate the clinical efficacy of tocilizumab, a interleukin-6 (IL-6) receptor blocker, for the treatment of acute necrotizing encephalopathy (ANE). PubMed, Cochrane Library, Embase, and Web of Science were searched for systematic review based on PRISMA guidelines. ANE patients treated with and without tocilizumab were included. Methodological quality was assessed independently by two authors. Data on clinical features, neuroimaging patterns and outcomes were analyzed. In total, 77 cases from 21 studies were included. Most patients had fever and seizures. Respiratory viruses were common precipitating infection. All patients had bilateral thalamic lesions, and brainstem lesions were more frequently observed in the tocilizumab group (88.0

Objective:To investigate the clinical features, neuroimaging characteristics, and prognosis of patients with anti-leucine-rich glioma-inactivated 1 (LGI1) antibody associated encephalitis. Methods:We conducted a retrospective study of 87 patients diagnosed with anti-LGI1 encephalitis during the acute phase, admitted to two tertiary hospitals in China between January 2022 and September 2024. Clinical data, neuroimaging findings, and follow-up outcomes were systematically analyzed. Results:The primary clinical manifestations included memory impairment, epileptic seizures, psychiatric and behavioral disturbances, sleep dysfunction, involuntary movements, faciobrachial dystonic seizures (FBDS), and autonomic dysfunction. Among 53 patients tested for thyroid function, 9 (17.0%) exhibited abnormalities. Hyponatremia was observed in 41 of 82 patients (50.0%), and hyperhomocysteinemia (HHCY) in 23 of 80 (28.7%). Among 68 patients who underwent cerebrospinal fluid (CSF) analysis, elevated intracranial pressure was observed in 10 (14.7%), pleocytosis in 22 (32.4%), and elevated protein levels in 27 (39.7%). Electrocardiographic abnormalities were identified in 26 of 42 patients (61.9%) without prior cardiovascular disease. MRI abnormalities were present in 75 of 80 patients (93.8%), most commonly affecting the temporal lobe (55.0%), hippocampus (51.2%), and amygdala (11.2%). PET imaging in 39 patients frequently revealed hypermetabolism in the basal ganglia and temporal lobe. All patients received first-line immunotherapy. Of the 63 patients with follow-up data, 59 (93.7%) achieved favorable outcomes. Conclusion:Anti-LGI1 encephalitis is an immune-mediated autoimmune disorder characterized by memory impairment, epileptic seizures, FBDS, psychiatric and behavioral disturbances, autonomic dysfunction, hyponatremia, and HHCY. Immunotherapy is generally effective, leading to favorable prognosis in the majority of patients.

Objective To investigate the clinical features and treatment outcomes of anti-leucine-rich glioma-inactivated 1 (anti-LGI1) encephalitis in patients with SLE.Methods Between October 2014 and April 2024, serum or cerebrospinal fluid samples were collected from 332 patients with SLE suspected of autoimmune encephalitis. Cell-based assays were used to detect autoimmune antibodies, including anti-LGI1 antibodies. Four patients tested positive for anti-LGI1 antibodies, and their clinical, radiological and treatment data were analysed.Results All four patients exhibited signs of limbic encephalitis, including short-term memory deficits, seizures and psychiatric disturbances. Two cases also presented with faciobrachial dystonic seizures. MRI findings revealed hyperintense basal ganglia lesions in two patients. Treatment with corticosteroids, intravenous immunoglobulin and mycophenolate mofetil led to significant improvement in three patients, with no relapses during a follow-up period ranging from 33 to 60 months. One patient succumbed to pneumonia despite initial improvement of neurological function.Conclusion Screening for anti-LGI1 antibodies in patients with neuropsychiatric systemic lupus erythematosus (NPSLE) is crucial when limbic encephalitis presents, as it enables timely and effective treatment, potentially improving patients’ outcomes. Additional basic and clinical research is required to clarify the pathogenic role of these antibodies in NPSLE.

Brain magnetic resonance imaging (MRI) often appears normal in patients with autoimmune cerebellar ataxia (ACA), whereas case studies indicate [18F]fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) can detect abnormal metabolic patterns in these patients. This study aims to evaluate the brain FDG-PET characteristics of ACA, assess its clinical correlations and diagnostic utility. 55 ACA patients and 28 age and sex-matched healthy controls were included. PET results were evaluated using both visual analysis and voxel-based analysis. Before immunotherapy, FDG-PET of ACA patients typically exhibited widespread hypermetabolism, while post-treatment scans showed cerebellar hypometabolism compared to healthy controls. Patients with encephalopathy were more likely to show abnormal metabolic activity in the cerebral cortex or hippocampus. Abnormal metabolic activity in the basal ganglia was more common in patients with extrapyramidal symptoms. Relative vermis hypermetabolism was observed in 40

BACKGROUND:Anti-IgLON5 disease is a rare autoimmune neurological disorder with prominent Tau protein deposits in the brainstem and hypothalamus. The aim of this study was to visualize the in vivo distribution patterns of Tau protein in patients with anti-IgLON5 disease using the second-generation Tau PET tracer, Florzolotau (18F) PET imaging. METHODS:Patients diagnosed with anti-IgLON5 disease were enrolled consecutively. Age- and sex-matched healthy controls (HCs) were also enrolled. The uptake of Florzolotau (18F) and 18F-FDG was assessed using both visual and semi-quantitative analysis techniques. RESULTS:A total of 10 patients with anti-IgLON5 disease and 40 HCs were included in the study. All ten patients with anti-IgLON5 disease underwent Florzolotau (18F) PET scans, and five of them underwent 18F-FDG PET scans. Twenty HCs underwent Florzolotau (18F) PET scans, and the remaining 20 HCs underwent 18F-FDG PET scans. In patients with anti-IgLON5 disease, significant uptake of Florzolotau (18F) was observed predominantly in the midbrain, pons, cerebellum, caudate, and putamen. This uptake pattern was notably absent in the control group. Moreover, semi-quantitative analysis techniques demonstrated widespread hypometabolism in the cerebral cortex in patients with anti-IgLON5 disease. CONCLUSIONS:This study indicates distinct Tau protein deposition patterns in patients with anti-IgLON5 disease, potentially serving as imaging biomarkers.

ObjectivesAntibodies against voltage-gated potassium channel (VGKC) complexes include anti-LGI1 and anti-CASPR2. Anti-ADAM23 antibodies have not been previously reported in autoimmune encephalitis (AE).Case reportWe report a 71-year-old female patient who presented with rapidly progressive short-term memory loss, psychobehavioural abnormalities, and impaired consciousness. Six months earlier, she had recovered from herpes simplex encephalitis (HSE). Cerebrospinal fluid (CSF) analysis suggested lymphocytic inflammation. AE was considered after the exclusion of HSV reactivation and other infectious etiologies. A comprehensive screening for commercially available autoimmune and paraneoplastic antibodies yielded negative results. A tissue-based assay (TBA) of CSF revealed a pattern of neuropil reactivity (neuropil pattern, suggesting the presence of neuronal surface antibodies (NS-Ab). A laboratory-developed antibody panel screening using a cell-based assay (CBA) identified an anti-ADAM23 antibody. Immunofluorescence staining showed that ADAM23 colocalized with Tuj1, which is expressed on the surface of neurons. Subclass analysis revealed that the anti-ADAM23 antibody predominantly belonged to the IgG4 subclass. Finally, the patient was diagnosed with an anti-ADAM23 antibody-associated AE. During the early stages of the disease, the patient underwent several courses of intravenous immunoglobulin (IVIg) with limited efficacy. Following the addition of high-dose methylprednisolone pulse therapy, the patient's consciousness improved from coma to stupor and the seizures were relieved.ConclusionWe propose that anti-ADAM23 antibody, a previously overlooked autoantibody targeting the VGKC complex, may have diagnostic significance for autoimmune encephalitis.