Perinatal outcome in anti-NMDAr encephalitis during pregnancy-a systematic review with individual patients' data analysis.

INTRODUCTION: Anti-N-methyl-D-aspartate receptor (NMDAr) antibody encephalitis is an autoimmune disorder characterized by synaptic NMDAr current disruption and receptor hypofunction, often affecting women during pregnancy. Clinical manifestations associated with anti-NMDAr encephalitis can occur both in the mother and fetus. METHODS: We generated a systematic search of the literature to identify epidemiological, clinical, and serological data related to pregnant women with anti-NMDAr encephalitis and their children, analyzing the fetal outcomes. We examined the age and neurologic symptoms of the mothers, the presence of an underlying tumor, immunotherapies used during pregnancy, duration of the pregnancy, and type of delivery. RESULTS: Data from 41 patients were extrapolated from the included studies. Spontaneous interruption of pregnancy, premature birth, and cesarean section were reported in pregnant women with NMDAr encephalitis. Several fetal and neonatal symptoms (e.g., movement disorders, spina bifida, poor sucking, respiratory distress, cardiac arrhythmias, infections, icterus, hypoglycemia, and low birth weight) depending on the mother's serum anti-NR1 concentration were also reported. CONCLUSIONS: We characterized the outcomes of children born from mothers with anti-NMDAr encephalitis, analyzing the pivotal risk factors related to pregnancy and maternal disorder. Neuropsychiatric involvement seems strictly related to pathogenic NMDAr antibodies detected in maternal and/or neonatal serum. These findings clarify a complex condition to manage, outlining the risks associated with pregnant women with anti-NMDAr encephalitis and also providing a concrete guide for therapeutic strategies to prevent potential harm to the fetus and the child's neurodevelopment.

FLAMES overlaying anti-N-methyl-D-aspartate receptor encephalitis: a case report and literature review.

BACKGROUND: In recent years, simultaneous or sequential occurrence of MOG antibody disease and anti-NMDAR encephalitis in the same patient has been reported with increasing frequency. Scholars refer to the overlapping occurrence of these two disorders as MOG antibody disease and anti-NMDAR encephalitis overlap syndrome (MNOS). Cortical T2-weighted fluid-attenuated inversion recovery (FLAIR) -hyperintense lesions in anti-MOG-associated encephalitis with seizures (FLAMES) is a rare clinical phenotype of MOGAD in which cortical FLAIR high-signal lesions are unilateral, with little spread to the cortex and meninges bilaterally. Although cases of FLAMES have been consistently reported. However, to our knowledge, such cases of FLAMES combined with NMDARE are rare. CASE PRESENTATION: Here, we describe a case of FLAMES combined with anti-NMDARE. The patient was a young male, 29 years old, admitted to our hospital with isolated seizures, whose MRI showed unilateral thalamic and bilateral frontal and parietal leptomeningeal involvement. Since we were unaware of the possibility of bilateral meningo-cortical MOGAD manifestations, the case was initially diagnosed as viral encephalitis and was given antiviral therapy. The diagnosis was not clarified until anti-NMDAR-IgG and MOG-IgG positivity was detected in the cerebrospinal fluid and serum. The patient was then treated with high-dose corticosteroids and his symptoms responded well to the steroids. Therefore, this case expands the clinical spectrum of MNOS overlap syndrome. In addition, we describe the clinical features of MNOS by summarizing the existing literature and exploring the possible mechanisms of its immune response. CONCLUSIONS: Our case serves as a reminder to clinicians that when patients present with atypical clinical manifestations such as seizures, consideration should be given to MNOS and conduct testing for various relevant autoantibodies (including MOG abs) and viruses in both serum and cerebrospinal fluid, as it is easy to misdiagnose the disease as other CNS diseases, such as viral meningoencephalitis. This syndrome exhibits a high responsiveness to steroids, highlighting the critical importance of recognizing the clinical and neuroimaging features of this overlap syndrome for prompt diagnosis and treatment. Furthermore, it enriches the disease spectrum of MNOS.

Molecular dissection of an immunodominant epitope in Kv1.2-exclusive autoimmunity.

Introduction: Subgroups of autoantibodies directed against voltage-gated potassium channel (Kv) complex components have been associated with immunotherapy-responsive clinical syndromes. The high prevalence and the role of autoantibodies directly binding Kv remain, however, controversial. Our objective was to determine Kv autoantibody binding requirements and to clarify their contribution to the observed immune response. Methods: Binding epitopes were studied in sera (n = 36) and cerebrospinal fluid (CSF) (n = 12) from a patient cohort positive for Kv1.2 but negative for 32 common neurological autoantigens and controls (sera n = 18 and CSF n = 5) by phospho and deep mutational scans. Autoantibody specificity and contribution to the observed immune response were resolved on recombinant cells, cerebellum slices, and nerve fibers. Results: 83% of the patients (30/36) within the studied cohort shared one out of the two major binding epitopes with Kv1.2-3 reactivity. Eleven percent (4/36) of the serum samples showed no binding. Fingerprinting resolved close to identical sequence requirements for both shared epitopes. Kv autoantibody response is directed against juxtaparanodal regions in peripheral nerves and the axon initial segment in central nervous system neurons and exclusively mediated by the shared epitopes. Discussion: Systematic mapping revealed two shared autoimmune responses, with one dominant Kv1.2-3 autoantibody epitope being unexpectedly prevalent. The conservation of the molecular binding requirements among these patients indicates a uniform autoantibody repertoire with monospecific reactivity. The enhanced sensitivity of the epitope-based (10/12) compared with that of the cell-based detection (7/12) highlights its use for detection. The determined immunodominant epitope is also the primary immune response visible in tissue, suggesting a diagnostic significance and a specific value for routine screening.

Case report: Atypical case of autoimmune glial fibrillary acidic protein astrocytopathy following COVID-19 vaccination refractory to immunosuppressive treatments.

A 54-year-old Japanese man presented with headache and fever the day after SARS-CoV-2 vaccination. He became deeply unconscious within a week. Brain MRI showed periventricular linear enhancements and a few spotty lesions in the cerebral white matter. Cerebrospinal fluid (CSF) testing showed mild pleocytosis. He was treated with intravenous methylprednisolone and plasma exchange. However, the white matter lesions enlarged to involve the brainstem and cerebellum, and long cord spinal lesions appeared. Anti-glial fibrillary acidic protein (GFAP) antibody was positive in the CSF and serum, and he was therefore diagnosed as autoimmune GFAP-astrocytopathy (GFAP-A). In addition, high-dose immunoglobulin therapy was administered twice, but his symptoms did not improve; the white matter lesions enlarged further, and modified Rankin Scale score increased to 5. A brain biopsy specimen showed infiltration of macrophages and CD4 + lymphocytes together with neuron and oligodendrocytic injuries and glial scar. Although GFAP-A generally responds well to steroids, the present case developed GFAP-A following SARS-CoV-2 vaccination, with refractory to intensive immunosuppressive therapy and atypical pathologic findings of infiltration of CD4 + lymphocytes and demyelination.

Diagnostic Challenges and Treatment Approach to Seronegative Autoimmune Encephalitis.

Seronegative autoimmune encephalitis (AE) is a rare, immune-mediated inflammatory syndrome that presents with a wide spectrum of neuropsychiatric symptoms, such as cognitive impairment, seizures, psychosis, focal neurological defects, and altered consciousness. This disease process presents with no identifiable autoimmune antibodies, which leads to uncertain diagnosis, delayed treatment, and prolonged hospital admissions. Early diagnosis and prompt treatment of AE should not be delayed, as early recognition and treatment leads to improved outcomes and disease reversibility for these patients. In this study, we present a case report of a 77-year-old male who presented with acutely altered mental status. This patient underwent an extensive workup and demonstrated no signs of clinical improvement throughout a prolonged hospital admission. The diagnostic challenges and treatment obstacles encountered during our care of this patient are described in this case report, along with recommendations for early diagnosis and prompt treatment for patients with suspected seronegative AE.

Post-COVID-19 Neurological Sequelae of Polyneuropathy and Encephalitis: A Comprehensive Case Report.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, commonly known as COVID-19, has been associated with various neurological complications. However, the mechanisms underlying these neurological manifestations remain incompletely understood. We present a case of a 63-year-old male who was admitted to the intensive care unit with severe COVID-19 pneumonia. Following recovery from respiratory symptoms, he was found to have weakness in the limbs. Months later, he also developed altered mental status, hallucinations, and behavioral changes. Neurological examination revealed signs consistent with polyneuropathy and autoimmune encephalitis. Further investigations, including nerve conduction studies, cerebrospinal fluid analysis, and response to steroids, supported the diagnosis of COVID-19-related polyneuropathy and autoimmune encephalitis. This is a rare presentation of COVID-19 and has only been described in a few case reports. Further research is warranted to elucidate the pathophysiological mechanisms underlying neurological sequelae of COVID-19 and to develop targeted therapeutic strategies.

Atypical brain MRI findings in a patient with treatment responsive anti-IgLON5 disease.

Anti-IgLON5 disease is a rare autoimmune neurological condition which was relatively recently described in the literature. This syndrome encompasses a range of clinical manifestations with most cases showing unremarkable findings on brain magnetic resonance imaging (MRI). Here, we report a case of a 61-year-old female patient with unique brain MRI features that, to the best of our knowledge, has not been reported in the literature before. Following treatment including immunotherapy, the patient experienced significant improvement clinically accompanied by radiological improvement on the follow-up imaging.

Genetic causes of infection induced encephalitis.

INTRODUCTION: Patients with encephalitis following a viral infection are often thought to have a para infectious, inflammatory, or autoimmune cause for their presentation. These diagnoses usually result in treatments with immunosuppressant therapies which can have side effects. However, there is an increasing body of evidence demonstrating that patients can have a direct genetic cause mediating viral infection triggered encephalitis, where inflammation is a secondary response. These patients may benefit not from immunosuppressive therapies, but from protection from infection through dedicated immunisation programs and early antiviral therapies at times of infection. METHODS: A small case series of paediatric neurology patients (n = 2) from a single institution with infection induced encephalitis and an underlying genetic cause, is presented. Patients with a confirmed genetic cause of infection induced encephalitis were identified and consented by their treating neurologist for inclusion in this case series. Ethics approval was gained for this case series and review of the surrounding literature. CONCLUSION: A case of both DBR1 and NUP214 genetic changes resulting in infection induced encephalitis is presented. This case series raises awareness of this rare group of disorders and provides clues to their identification. Features to prompt clinician consideration of such genetic conditions are also highlighted. Although rare, identification of these patients is important due to implications on treatment, prognosis, and family planning.

A case of autoimmune encephalitis in a patient with a solitary intracranial plasmacytoma.

A 65-year-old woman presented with fever and abnormal behavior. Magnetic resonance imaging showed swelling of the left medial temporal lobe and an intracranial extra-axial occipital tumor. While her neurological symptoms improved after the administration of corticosteroid therapy under the suspicion of autoimmune encephalitis, the occipital tumor unexpectedly shrank, and the diagnosis of a solitary plasmacytoma was confirmed by biopsy. Additional examinations revealed elevated anti-glutamate receptor antibodies in the cerebrospinal fluid. The patient was diagnosed with autoimmune encephalitis concurrent with an intracranial solitary plasmacytoma. Central nervous system involvement can be considered a neurological complication in patients with a solitary plasmacytoma.

IgLON5 autoimmunity in a patient with Creutzfeldt-Jakob disease: case report and review of literature.

Objective: We present the case of a patient with clinical and imaging features of sporadic Creutzfeldt-Jakob disease (sCJD) and positive IgLON5 antibodies (Abs) in the serum and CSF. Case report: A 66-year-old Chinese man presented to the hospital with a stroke-like episode, followed by rapidly progressive cognitive decline, mutism, and parkinsonism. The MRI results showed a cortical ribboning sign in diffusion-weighted MRI, periodic triphasic waves with a slow background in EEG, and positive protein 14-3-3 in CSF. There were matching IgLON5 Abs in the serum and CSF. A literature review showed positive autoimmune encephalitis Abs or autoimmune inflammatory disease between 0.5 and 8.6% among patients with clinical suspicion of CJD, most commonly anti-voltage-gated potassium channel (VGKC) complex and anti-N-methyl-D-aspartate receptor (NMDAR) Abs; however, IgLON5 autoimmunity in CJD has been rarely reported. This is an intriguing association as both conditions have been associated with brain deposits of phosphorylated tau protein. Conclusion: IgLON5 Abs may be observed in patients with a diagnosis of CJD; it is unknown whether a synergistic effect of IgLON5 Abs with CJD exists, increasing neurodegenerative changes.

Treatment of cryptogenic new-onset refractory status epilepticus (C-NORSE) with tocilizumab: A case report.

A 35-year-old woman with no prior history of epilepsy developed status epilepticus (SE), which was highly resistant to multiple antiseizure medications and sedatives. The etiology of SE was not identified despite extensive investigation, and the patient was diagnosed with cryptogenic new-onset refractory status epilepticus (C-NORSE). Although first-line immunotherapies such as high-dose corticosteroids and plasma exchange were ineffective, the patient manifested a resolution of SE after the administration of tocilizumab, which inhibits interleukin-6. Non-antibody-mediated inflammation has been hypothesized to be a probable pathophysiology of C-NORSE in recent studies, and tocilizumab may be a plausible second-line treatment.

Corticospinal tract hyperintensity in patients with LGI1-antibody encephalitis and other central nervous system disorders with neuroglial antibodies.

The frequency of corticospinal tract (CST) T2/FLAIR hyperintensity in disorders with neuroglial antibodies is unclear. Herein, we retrospectively reviewed brain MRIs of 101 LGI1-antibody encephalitis patients, and observed CST hyperintensity in 30/101 (30%). It was mostly bilateral (93%), not associated with upper motor neuron signs/symptoms (7%), and frequently decreased over time (39%). In a systematic review including patients with other neuroglial antibodies, CST hyperintensity was reported in 110 with neuromyelitis optica (94%), myelin oligodendrocyte glycoprotein-associated disease (2%), Ma2-antibody (3%) and GAD65-antibody paraneoplastic neurological syndrome (1%). CST hyperintensity is not an infrequent finding in LGI1-Ab encephalitis and other disorders with neuroglial antibodies.

A Case Report of Autoimmune Encephalitis after Anti-SARS-CoV-2 Vaccination: The Role of Cognitive Impairments in the Diagnostic Process.

OBJECTIVE: Autoimmune encephalitis includes a heterogeneous group of rare and complex diseases, usually presenting with severe and disabling symptoms, such as behavioral changes, cognitive deficits, and seizures. METHOD: This report presents the case of a 26-year-old man who was diagnosed with autoimmune encephalitis following SARS-CoV-2 vaccination (<40 days). Symptoms first appeared in February 2022 with a temporal seizure, associated with confusion and memory loss. Psychiatric manifestations such as disorientation and altered thought contents emerged soon after. RESULTS: Neuroimaging testing showed signs of hypometabolism in occipital, prefrontal, and temporal regions, whereas an extensive neuropsychological assessment revealed the presence of multiple alterations in memory, executive, and visuoconstructive processes. CONCLUSIONS: In this case, a combination of neuroimaging testing, psychiatric evaluation, and neuropsychological assessment provided evidence for a diagnosis of autoimmune encephalitis post-vaccination. Early recognition is essential in order to prevent clinical progression; avoid intractable epilepsy, brain atrophy, and cognitive impairment; and improve prognosis.

NORSE seasonality may vary geographically in adults.

The mechanisms causing new onset refractory status epilepticus (NORSE) are often unknown. Recently, a seasonal variation with NORSE peaking during the summer was described in a mixed cohort of adults and children why we here studied the seasonal variation in a Danish status epilepticus (SE) cohort. This retrospective cohort study comprised SE patients aged ≥18 diagnosed and treated 2008-2017 at the Odense University Hospital. Clinical characteristics and seasonality of patients fulfilling the diagnostic criteria for NORSE were compared with patients with refractory SE (RSE) due to other reasons and with the seasonal variation of autoantibodies associated with autoimmune encephalitis in the Danish autoimmune encephalitis register. In this cohort, 26 patients met NORSE criteria. As compared to RSE patients not fulfilling NORSE criteria (n = 152), NORSE patients were more likely to have symptoms of systemic inflammation (C-reactive protein concentrations ≥10 mg/L or fever ≥38°C) at admission; nine fulfilled the criteria for febrile infection related epilepsy syndrome (FIRES). In contrast to the even seasonal distribution of patients with RSE not fulfilling the NORSE criteria, admissions due to NORSE peaked during the winter (46.1%, p = 0.04 as compared to non-NORSE RSE); six out of nine FIRES episodes occurred in the winter season. The seasonal variation was not explained by a seasonal variation of the detection rates of autoantibodies associated with autoimmune encephalitis (incl. NMDAR, LGI1, CASPR2, GABAR, GFAP) in a Danish nationwide register (n = 259). In conclusion, we confirm the seasonality of NORSE in a Danish cohort, however, with a peak during winter suggesting a geographical variation not solely explained by autoimmune encephalitis associated with known autoantibodies. PLAIN LANGUAGE SUMMARY: The study investigated the seasonal patterns of new-onset refractory status epilepticus (NORSE), i.e. severe seizures that occur without an obvious cause and require very intensive treatment. In contrast to the previously observed peak frequency in summer, this Danish study found that NORSE cases peak in winter. Furthermore, the seasonal variation in NORSE cases was not found to be associated with autoimmune encephalitis caused by known autoantibodies. Together with the high rate of patients showing symptoms of systemic inflammation compared to other status epilepticus patients, the data suggest a link between misdirected immune system responses and NORSE. The study can therefore help in the further search for the currently unknown causes of NORSE.

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.

Enhancing Tone and Strength in a Patient With Autoimmune Encephalitis and Guillain-Barré Syndrome Using Rood's Facilitatory Techniques and Neuromuscular Electrical Stimulation: A Case Report.

This case report documents the comprehensive management of a 21-year-old female resident of Gadchiroli presenting with a 10-day history of fever, altered consciousness, and neurological sequelae following a traumatic incident. The patient exhibited a Glasgow Coma Scale score of 6/15, hypotonia in both upper and lower limbs, diminished deep tendon reflexes, and respiratory complications. This case study describes a thorough physiotherapeutic strategy that focuses on tone facilitation and muscle weakness improvement. The intervention used Rood's facilitative approaches as well as neuromuscular electrical stimulation (NMES). Rood's treatments, which emphasized mobilizing touch and tactile stimulation, brushing, quick icing, quick stretching, tapping, massaging the skin, heavy joint compression, and rolling, were used deliberately to move the patient from flaccidity to better muscle tone. These techniques' repetitive and task-specific nature coincided with motor learning principles, enabling adaptive modifications in brain networks. Concurrently, NMES was used to improve muscle activation, create a controlled environment for neurorehabilitation, and promote strength increases. The successful integration of various modalities highlights the possibility of favorable neuronal adaptations and functional improvements in individuals suffering from complicated neuromuscular disorders. This case demonstrates the need for individualized and diversified physiotherapeutic techniques in improving rehabilitation outcomes.

B-cell targeted therapies in autoimmune encephalitis: mechanisms, clinical applications, and therapeutic potential.

Autoimmune encephalitis (AE) broadly refers to inflammation of the brain parenchyma mediated by autoimmune mechanisms. In most patients with AE, autoantibodies against neuronal cell surface antigens are produced by B-cells and induce neuronal dysfunction through various mechanisms, ultimately leading to disease progression. In recent years, B-cell targeted therapies, including monoclonal antibody (mAb) therapy and chimeric antigen receptor T-cell (CAR-T) therapy, have been widely used in autoimmune diseases. These therapies decrease autoantibody levels in patients and have shown favorable results. This review summarizes the mechanisms underlying these two B-cell targeted therapies and discusses their clinical applications and therapeutic potential in AE. Our research provides clinicians with more treatment options for AE patients whose conventional treatments are not effective.

Anti-NMDA Receptor Encephalitis Related to Renal Cell Carcinoma: A Case Report.

Anti-NMDA receptor (NMDAR) encephalitis is characterized by a well-defined neuropsychiatric syndrome and CSF antibodies against the GluN1 subunit of the NMDAR. 40% of cases are related to underlying tumors, the vast majority ovarian teratomas (94%). We report a case of anti-NMDAR encephalitis associated with renal cell carcinoma (RCC). A 20-year-old female presented to the ED with behavioral changes, involuntary movements, tachycardia, and alternating obtundation with agitation which progressed over 3 weeks. Involuntary movements were severe, requiring intubation and sedation for control, and were accompanied by rhabdomyolysis. Brain MRI showed bilateral mesiotemporal T2/FLAIR hyperintensities. Anti-NMDAR antibodies were present in the serum (1:640) and CSF (1:320). Malignancy screening revealed a renal mass concerning for RCC, which was confirmed upon resection. She was started on high dose IV methylprednisolone and plasmapheresis, followed by rituximab. Lack of response led to escalating immunotherapy with cyclophosphamide. Clinical course was complicated by prolonged ICU admission, prolonged sedation, severe dysautonomia and bacteremia. Improvement began 2 months after immunotherapy, and she was discharged to rehabilitation 100 days after admission with mild neuropsychiatric symptoms. Repeat malignancy screenings, including whole-body imaging and transvaginal ultrasound were consistently negative. Herein, we describe a case of definite anti-NMDAR encephalitis in the setting of newly diagnosed RCC. This case illustrates how tumors other than ovarian teratomas may act as immunological triggers, as well as the complex and prolonged symptomatic and immunosuppressive therapies required in severe presentations of anti-NMDAR encephalitis.

Steroid-Responsive Parkinsonism and Encephalopathy: A Case Report.

We describe a patient who presented with rapidly progressive parkinsonism and encephalopathy and was diagnosed with seronegative autoimmune encephalitis (AE). Subacute parkinsonism as a manifestation of seronegative AE is uncommon with only a handful of similar cases published in literature. A 71-year-old man presented with severe flu like symptoms, rapidly progressive cognitive decline and was found to have parkinsonian features on examination. Initial brain magnetic resonance imaging (MRI) was unremarkable however, cerebrospinal fluid (CSF) analysis revealed a lymphocytic pleocytosis and elevated protein level. Thorough searches for neural antibodies and infectious pathogens were negative. His symptoms fluctuated initially but markedly improved within days of starting prednisone and dramatically worsened after prednisone was tapered off. His CSF pleocytosis also improved on prednisone. Relapses again resolved with resumption of prednisone. The scope of autoimmune neurology Is constantly evolving, and physicians should be aware of the diverse and heterogenous clinical presentations of autoimmune encephalitis. We aim to emphasize the importance of ruling out autoimmune encephalitis in patients presenting with acute or subacute parkinsonism. This case additionally reinforces that negative antibody tests do not exclude the diagnosis of AE.

Mapping the global research landscape and trends of autoimmune encephalitis: A bibliometric analysis.

Background: Autoimmune encephalitis (AE) is a neuroautoimmune disease featured by the presence of antibodies targeting neuronal surface, synaptic, or intracellular antigens. An increasing number of articles on its clinical manifestations, treatments, and prognosis have appeared in recent years. The objectives of this study were to summarize this growing body of literature and provide an overview of hotspots and trends in AE research using bibliometric analysis. Methods: We retrieved AE-related articles published between 1999 and 2022 from the Web of Science Core Collection. Using bibliometric websites and software, we analyzed the data of AE research, including details about countries, institutions, authors, references, journals, and keywords. Results: We analyzed 3348 articles, with an average of 32.83 citations per article and an H-index of 141. The USA (1091, 32.587%), China (531, 15.860%), Germany (447, 13.351%), England (266, 7.945%), and Japan (213, 6.362%) had the greatest numbers of publications. The top five institutions by numbers of publications were Oxford (143, 4.271%), the Udice French Research Universities (135, 4.032%), the University of Pennsylvania (135, 4.032%), l'Institut National de la Sante de la Recherche Medicale Inserm (113, 3.375%), and the University of Barcelona (110, 3.286%). The most productive authors were J. Dalmau (98, 2.927%), A. Vincent (65, 2.479%), H. Pruess (64, 1.912%), C. G. Bien (43, 1.284%), and F. Graus (43, 1.284%). "autoimmune encephalitis" was the most frequently used keyword (430), followed by "antibodies" (420), "NMDA receptor encephalitis" (383), and "limbic encephalitis" (368). In recent years, research hotspots have focused on the diagnosis and immunotherapy of NMDAR encephalitis and on limbic encephalitis. Conclusion: Developed Western countries have made significant contributions to this field. China has shown a steady increase in the number of publications in recent years, but the quality and influence of these articles warrant efforts at improvement. Future directions in AE research lie in two key areas: (i) the clinical manifestations, prevalence, and prognosis of AE (enabled by advances in diagnosis); and (ii) the efficacy and safety of targeted, individualized immunotherapy.