[Paraneoplastic Anti-N-methyl-D-aspartate Receptor Encephalitis Associated with Anterior Mediastinal Mature Teratoma]

We report a 27 years-old previously healthy male admitted to a psychiatric hospital because of abnormal behavior. He was suspected meningoencephalitis with fever, abnormal sweating, muscle tone, confusion, and introduced to the neurology department of our hospital. After admission, increasing convulsions and apnea attack required mechanical ventilation therapy. Anti-N-methyl-D-aspartate( NMDA) - receptor encephalitis was diagnosed based on positive (20-fold) anti-NMDA antibody in cerebrospinal fluid examination. An enhanced chest computed tomography (CT) showed a 43 mm cystic mass with calcification of the anterior mediastinum. He underwent the tumor resection under median sternotomy on the 18th hospital day. The plasmapheresis and steroid therapies were treated after the operation. The consciousness level gradually improved, the patient was withdrawn from the respirator on the post operative day( POD) 35, and transferred to a rehabilitation hospital on POD 60. The pathological result was mature teratoma. However, no specific findings such as inflammatory cell infiltration into nerve components were observed. Anti-NMDA receptor encephalitis was established by Dalmau in 2007 as encephalitis associated with ovarian teratoma. It presents mainly in young adult women with psychiatric symptoms, and requires mechanical ventilation management due to disturbance of consciousness, convulsions, and central hypoventilation in a short period of time. It presents severe symptoms in the acute phase and shows a unique clinical finding with a good prognosis even though it shows a protracted course. Treatment requires prompt tumor detection and early resection, as well as methylprednisolone (mPSL) pulse, plasmapheresis, and high-dose gamma globulin therapy. It is a neurological disease that requires emergency response, and the understanding and prompt response of related departments is important.

Electroconvulsive therapy for catatonia in anti-NMDA receptor encephalitis: A case series

BACKGROUND

Anti-NMDAR encephalitis is the most common cause of immune-mediated catatonia.

CASE SERIES

Three females presented with neuropsychiatric symptoms and were empirically treated with first-line immunotherapy and ovarian teratoma resection for suspected autoimmune encephalitis, preceding diagnostic confirmation via NMDAR antibody positivity. They required escalating large doses of benzodiazepines for refractory malignant catatonia resulting in ICU level care. ECT treatments were initiated, and patients were gradually noted to have clinical improvement as was measured by the Bush-Francis Catatonia Rating Scale.

CONCLUSIONS

Clinicians should recognize catatonia among patients with suspected anti-NMDAR encephalitis and consider the early implementation of ECT into treatment algorithms.

Myelin oligodendrocyte glycoprotein antibody and N-methyl-d-aspartate receptor antibody overlapping syndrome: insights from the recent case reports

The overlapping of two or more types of neural autoantibodies in one patient has increasingly been documented in recent years. The coexistence of myelin oligodendrocyte glycoprotein (MOG) and N-methyl-d-aspartate receptor (NMDAR) antibodies is most common, which leads to a unique condition known as the MOG antibody and NMDAR antibody overlapping syndrome (MNOS). Here, we have reviewed the pathogenesis, clinical manifestations, paraclinical features, and treatment of MNOS. Forty-nine patients with MNOS were included in this study. They were young males with a median onset age of 23 years. No tumors were observed in the patients, and 24 of them reported prodromal symptoms. The most common clinical presentations were psychiatric symptoms (35/49) and seizures (25/49). Abnormalities on magnetic resonance imaging involved the brainstem (11/49), cerebellum (9/49), and parietal lobe (9/49). Most patients mostly responded to immunotherapy and had a good long-term prognosis. However, the overall recurrence rate of MNOS was higher than that of mono antibody-positive diseases. The existence of concurrent NMDAR antibodies should be suspected in patients with MOG antibody-associated disease having psychiatric symptoms, seizures, movement disorders, or autonomic dysfunction. Similarly, serum MOG antibody testing should be performed when patients with anti-NMDAR encephalitis present with atypical clinical manifestations, such as visual impairment and limb weakness, and neuroradiological findings, such as optic nerve, spinal cord, or infratentorial involvement or meningeal enhancement. Early detection of the syndrome and prompt treatment can be beneficial for these patients, and maintenance immunosuppressive therapy is recommended due to the high overall recurrence rate of the syndrome.

[A case report of anti-NMDA receptor encephalitis with mental disturbances manifestation]

Presented clinical observation of anti-NMDA-receptor encephalitis, which was first described in 2007, is rare and to date has not been sufficiently studied. The disease often manifests with psychopathological symptoms and catatonia, so patients are transferred into a mental healthcare institution and often require intensive care and resuscitation, due to the development of life-threatening respiratory and hemodynamic disorders. Diagnosis is based on detection of autoantibodies to the NR1- and NR2 subunits of the glutamate NMDA receptor in blood serum and cerebrospinal fluid. Pathogenesis-based therapy includes the administration of glucocorticoids and intravenous immunoglobulins, plasmapheresis, as well as the introduction of monoclonal antibodies in also used, and in severe cases, cytostatics are prescribed. The widespread comorbidity of anti-NMDA receptor encephalitis with ovarian neoplasms in women (up to 60%) requires appropriate diagnosis and early removal of ovarian neoplasms when they are detected. With timely diagnosis and adequate treatment strategies, the outcome of this rare disorder is usually positive.

Teratoma pathology and genomics in anti-NMDA receptor encephalitis

INTRODUCTION

Ovarian teratoma is a common occurrence in patients with anti-NMDA receptor encephalitis (NMDARe), and its removal is crucial for a favorable prognosis. However, the initial pathogenesis of autoimmunity in the encephalitic teratoma remains unclear. In this study, we aimed to investigate the genomic landscape and microscopic findings by comparing NMDARe-associated teratomas and non-encephalitic control teratomas.

MATERIALS AND METHODS

A prospective consecutive cohort of 84 patients with NMDARe was recruited from January 2014 to April 2020, and among them, patients who received teratoma removal surgery at Seoul National University Hospital were enrolled. We conducted a comparison of whole-exome sequencing data and pathologic findings between NMDARe-associated teratomas and control teratomas.

RESULTS

We found 18 NMDARe-associated teratomas from 15 patients and compared them with 17 non-encephalitic control teratomas. Interestingly, the genomic analysis revealed no significant differences in mutations between encephalitic and non-encephalitic teratomas. Pathologic analysis showed no discrepancies in terms of the presence of neuronal tissue and lymphocytic infiltration between the encephalitic teratomas (n = 14) and non-encephalitic teratomas (n = 18). However, rituximab-naïve encephalitic teratomas exhibited a higher frequency of germinal center formation compared to non-encephalitic teratomas (80% vs. 16.7%, P = 0.017). Additionally, rituximab-treated encephalitic teratomas demonstrated a reduced number of CD20+ cells and germinal centers in comparison to rituximab-naïve encephalitic teratomas (P = 0.048 and 0.023, respectively).

DISCUSSION

These results suggest that the initiation of immunopathogenesis in NMDARe-associated teratoma is not primarily attributed to intrinsic tumor mutations, but rather to immune factors present in the encephalitic patient group, ultimately leading to germinal center formation within the teratoma.

Glucocorticoid-dependent multiple sclerosis overlapping anti-NMDA receptor encephalitis: a case report and literature review update

BACKGROUND

Previous studies suggest a relationship between central nervous system inflammatory demyelinating diseases and anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis. Also, the overlap between anti-NMDAR encephalitis and multiple sclerosis (MS) has been reported. However, the pathogenesis and clinical characteristics are still obscure.

CASE PRESENTATION

A 33-year-old woman presented with diplopia and sensory ataxia at the onset. The cerebrospinal fluid (CSF) anti-NMDAR antibodies were positive (1:3.2), and nuclear magnetic resonance imaging (MRI) showed bilateral centrum ovale and lateral ventricle demyelinating lesions. Therefore, she was diagnosed with anti-NMDAR encephalitis. After administering intravenous immunoglobulin and oral prednisone, her lesions disappeared, and symptoms were relieved. The condition was maintained with a low dose of prednisone, but her lesions reappeared on MRI. Consequently, immunomodulatory therapy of mycophenolate mofetil was initiated. However, she developed dysarthria and right limb ataxia after 10 months with a positive CSF anti-NMDAR antibody (1:1) and positive oligoclonal band. The MRI showed symmetrical multiple demyelinating lesions. Considering the MS diagnosis, her neurological dysfunction again improved significantly after intravenous methylprednisolone. Unfortunately, her symptoms aggravated for the second time when teriflunomide was started. Finally, her condition was controlled again with oral prednisone.

CONCLUSIONS

Consistent with previous cases of overlapping anti-NMDAR encephalitis and MS, patients often show atypical symptoms on MRIs and immunological tests. The overlap cannot be arbitrarily treated because of the recurrence of previous diseases. Long-term follow-up, dynamic antibody monitoring, and MRI examination are crucial for these patients. The special dependency of the patient on glucocorticoids in this study has been rarely reported, which may guide the treatment of insensitivity to disease-modifying therapy in recurrent overlapping anti-NMDAR encephalitis and MS.

Movement disorders associated with pediatric encephalitis

New onset movement disorders are a common clinical problem in pediatric neurology and can be infectious, inflammatory, metabolic, or functional in origin. Encephalitis is one of the more important causes of new onset movement disorders, and movement disorders are a common feature (~25%) of all encephalitis. However, all encephalitides are not the same, and movement disorders are a key diagnostic feature that can help the clinician identify the etiology of the encephalitis, and therefore appropriate treatment is required. Movement disorders are a characteristic feature of autoimmune encephalitis such as anti-NMDAR encephalitis, herpes simplex virus encephalitis-induced autoimmune encephalitis, and basal ganglia encephalitis. Other rarer autoantibody-associated encephalitis syndromes with movement disorder associations include encephalitis associated with glycine receptor, DPPX, and neurexin-3 alpha autoantibodies. In addition, movement disorders can accompany acute disseminated encephalomyelitis with and without myelin oligodendrocyte glycoprotein antibodies. Extremely important infectious encephalitides that have characteristic movement disorder associations include Japanese encephalitis, dengue fever, West Nile virus, subacute sclerosing panencephalitis (SSPE), and SARS-CoV-2 (COVID-19). This chapter discusses how specific movement disorder phenomenology can aid clinician diagnostic suspicion, such as stereotypy, perseveration, and catatonia in anti-NMDAR encephalitis, dystonia-Parkinsonism in basal ganglia encephalitis, and myoclonus in SSPE. In addition, the chapter discusses how the age of the patients can influence the movement disorder phenomenology, such as in anti-NMDAR encephalitis where chorea is typical in young children, even though catatonia and akinesia is more common in adolescents and adults.

Clinical and radiological features, treatment responses and prognosis in pediatric patients with co-existing anti-N-methyl-D-aspartate receptor and myelin oligodendrocyte glycoprotein antibody-associated encephalitis: A single center study

OBJECTIVES

To characterize the clinical and radiological features, treatment responses and outcomes of children with co-existing anti-N-methyl-D-aspartate receptor(NMDAR) and myelin oligodendrocyte glycoprotein(MOG) antibody-associated encephalitis.

METHODS

Clinical manifestations, imaging features, effectiveness of treatment and outcomes of patients who were cerebral spinal fluid(CSF)-positive for NMDAR-antibody(NMDAR-ab) and seropositive for MOG-antibody(MOG-ab) were analyzed.

RESULTS

Twelve patients including 8 females and 4 males were enrolled. The median onset age was 9 years, ranging from 2.2 to 12.8 years. Behavioral changes and/or psychiatric symptoms (n = 8/12), seizures (n = 8/12), encephalopathy (n = 7/12) were 3 of the most common symptoms. Brain magnetic resonance imaging(MRI) of all the patients showed T2/fluid attenuation inversion recovery(FLAIR) abnormal signal in the cerebral white matter at least once in the courses of disease, 2 of whom developed new brain lesions which were asymptomatic. All of the patients had supratentorial lesions. Spinal cord MRI was performed in 7 patients. Only 1 patient showed related abnormalities with increased T2 signal in the spinal cord C1-5. Nine patients underwent optic nerve MRI; 5 patients demonstrated abnormal results, among whom 4 exhibited T2 abnormal signal (2 were symptom-free) and 1 showed a little effusion in bilateral optic nerve sheats. Intravenous immunoglobulin (IVIG) and intravenous methylprednisolone (IVMP) were the most common used therapies in those patients. Nine patients were treated with second-line therapy to prevent relapses. For total 29 clinical attacks, the median modified Rankin Scale (mRS) before treatment and after therapy of acute stage was 1 and 0, respectively. Seven of 12 patients(58.3 %) experienced clinical relapses. In terms of outcome, all of the patients' mRS of last follow-up (≥6 months) was ≤2.

CONCLUSIONS

Behavioral changes and/or psychiatric symptoms, seizures and encephalopathy were common in children with co-existing anti-NMDAR and MOG antibody-associated encephalitis. A minority of subjects may develop asymptomatic lesions on brain and optic nerve MRI. The relapse rate of this disease is relatively high. The majority of patients responded well to the immunotherapies and had a good outcome(mRS of last follow-up≤2).

Controversies in immunotherapy for anti-NMDA receptor encephalitis: a scoping review with a proposal of operational definitions

Anti-NMDA receptor encephalitis (NMDARE), an autoimmune encephalitis associated with autoantibodies against the N-methyl-D-aspartate (NMDA) receptor, affects predominantly young women and is associated with psychiatric symptoms, seizures, movement disorders, and autonomic instability. Traditional treatments of anti-NMDA receptor encephalitis involve corticosteroids, intravenous immunoglobulin, plasmapheresis, cyclophosphamide, and rituximab. However, many controversies remain in the treatment for NMDA receptor encephalitis, such as optimal timing and combination of different immunotherapies, the role of newer strategies (e.g., bortezomib or tocilizumab) for severe and refractory patients, and the need or not for long-term immunosuppression. Our goal was to perform a scoping review to discuss the controversial topics of immunotherapy for NMDA receptor encephalitis and propose operational definitions to guide clinical practice and future research in the field.

Pediatric anti-NMDAR encephalitis with demyelination on brain MRI: A single center study

OBJECTIVE

To explore the clinical characteristics, immunotherapy response, and prognosis of pediatric anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis associated with demyelination on brain magnetic resonance (MRI).

METHODS

We retrospectively reviewed the medical records of children diagnosed with anti-NMDAR encephalitis in our hospital between January 2016 and December 2021. All children with evidence of demyelination on brain MRI were included.

RESULTS

A total of 183 anti-NMDAR encephalitis children were included; 8.7 % (16/183) of them had demyelination on brain MRI. Nine were positive for myelin oligodendrocyte glycoprotein (MOG)-IgG, while two were positive for both MOG-IgG and glial fibrillary acidic protein (GFAP)-IgG. Four patients had a history of acquired demyelinating syndromes and encephalitis, respectively, while nine (56.3 %) had atypical symptoms of anti-NMDAR encephalitis. All children had supratentorial demyelination on brain MRI; four of them had additional infratentorial lesions. All children received first-line immunotherapy; four were administered repeated first-line immunotherapy and/or rituximab because of poor initial response. During the follow-up, 37.5 % (6/16) of the children relapsed, but all responded well to immunotherapy. There were no significant differences in mRS score before immunotherapy, response to first-line immunotherapy, and long-term prognosis between anti-NMDAR encephalitis children with and without demyelination. However, patients with demyelination were more likely to have a history of acquired demyelinating syndromes or unexplained cortical encephalitis and to relapse.

CONCLUSION

Pediatric anti-NMDAR encephalitis can co-occur with demyelination and has a high rate of MOG-IgG positivity. A history of acquired demyelinating syndromes or unexplained cortical encephalitis and atypical symptoms may indicate demyelination in children with anti-NMDAR encephalitis. Pediatric anti-NMDAR encephalitis with demyelination is more likely to relapse and needs a closer follow-up. However, it remains unknown whether more intensive immunotherapy is required in these patients.

FLAIR-hyperintense lesions in anti-MOG-associated encephalitis with seizures overlaying anti-N-methyl-D-aspartate receptor encephalitis: A case report

RATIONALE

FLAIR-hyperintense lesions in anti-myelin oligodendrocyte glycoprotein (MOG)-associated encephalitis with seizures (FLAMES) is a rare clinical phenotype of anti-MOG; immunoglobulin G-associated disease is often misdiagnosed as viral encephalitis in the early stages. Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune encephalitis caused by antibodies targeting the GluN1 subunit of the NMDAR. The coexistence of anti-NMDAR encephalitis and FLAMES is very rare.

PATIENT CONCERNS

A 20-year-old female patient initially presented with seizures accompanied by daytime sleepiness.

DIAGNOSES

Magnetic resonance imaging revealed FLAIR-hyperintense lesions in unilateral cerebral cortex. NMDAR antibodies was positive in the cerebrospinal fluid and MOG antibodies in the serum.

INTERVENTIONS

Steroid therapy was administrated.

OUTCOMES

The symptoms completely relieved. At 6-month follow-up, the patient's condition remained stable. Magnetic resonance imaging showed no abnormalities in the unilateral cerebral cortex.

CONCLUSION

When a patient with anti-NMDAR encephalitis or FLAMES is encountered in clinical practice, the coexistence of these diseases with double-positive anti-NMDAR and MOG antibodies should be considered and adopt appropriate evaluation and treatment.

Analysis of the relation between cerebrospinal fluid antibody titers and clinical characteristics in pediatric patients with anti-N-methyl-D-aspartate receptor encephalitis

OBJECTIVE

This retrospective study aimed to investigate the relationship between cerebrospinal fluid (CSF) antibody titers of N-methyl-d-aspartate receptor (NMDAR), and clinical characteristics in pediatric patients with anti-NMDAR encephalitis.

METHODS

The clinical and laboratory characteristics of hospitalized patients with anti-NMDAR encephalitis, stratified by antibody titers in CSF and disease severity, were retrospectively studied. The demographics, clinical characteristics, main accessory examinations, immunotherapy, and prognosis of patients were recorded, and each observed indicator was statistically analyzed.

RESULTS

A total of 103 pediatric anti-NMDAR encephalitis patients were enrolled in the study, including 41 males (39.8%) and 62 females (60.2%) with a mean age of 8.0 ± 4.0 years. The proportion of patients with cognitive dysfunction and the positive pathogen was higher in the high-titer group than in the low-titer group (p = 0.023, p = 0.042). Consciousness disturbance that occurred as an initial symptom or during the course in the severe group was higher than in the non-severe group (p = 0.002, p < 0.001). More patients in the high-titer group received plasma exchange (PE) than in the low-titer group (p = 0.022). The cure rate of patients was higher with PE (65.2%) than with Corticosteroids and (or) intravenous immunoglobulin (58.1%).

CONCLUSIONS

Patients with symptoms of disturbance of consciousness may be severer. The severity in pediatric anti-NMDAR encephalitis patients was not correlated with anti-NMDAR antibody titers. Patients with high CSF antibody titers had a better prognosis after early PE therapy.

Patient with concurrent anti-NMDAR autoimmune encephalitis and immature teratoma of the ovary

In young women with anti-N-methyl-D-aspartate receptor (anti-NMDAR) autoimmune encephalitis (AE), co-occurrence with ovarian teratoma is common. While the management of mature teratoma with AE is well documented, literature on managing immature teratoma (IT) in tandem with AE is relatively scarce. Here, we report a case of a female patient in her early adolescence who presented with abdominal pain and was diagnosed with grade 3 IT combined with anti-NMDAR AE after an ovarian tumour was discovered and resected. Postsurgery, the patient received immunotherapy, chemotherapy and antiepileptic therapy, and two follow-up evaluations showed no signs of recurrence or sequelae. This case highlights the importance of a high index of suspicion for concurrent AE in the presence of ovarian teratoma, particularly IT, and the crucial role of concurrent administration of immunotherapy and chemotherapy following tumour resection in impacting prognosis.

H - 35 Anti-N-Methyl D-Aspartate Receptor (Anti-NMDAR) Encephalitis in a Spanish Monolingual Immigrant Adjudicated Incompetent to Stand Trial

OBJECTIVE

Anti-N-methyl D-aspartate receptor (anti-NMDAR) encephalitis is a rare, recently discovered condition that typically presents initially with psychiatric disturbances followed by neurological and neuropsychological symptoms. Little is known about neuropsychological outcomes with this condition. This poster will expand our knowledge by presenting a monolingual Spanish male who emigrated to the US from Latin America and was arrested on multiple offenses during psychiatric symptom onset of anti-NMDAR encephalitis.

METHODS

He was diagnosed with anti-NMDAR encephalitis while incarcerated and experienced severe medical complications while hospitalized during the acute phase. He was subsequently adjudicated incompetent to stand trial (ICST) and sent to a state hospital for competency restoration. During the patient's sub-acute recovery phase in the state hospital, he was administered a limited neuropsychological battery in Spanish to characterize his cognitive functioning and assist in the competency restoration process.

RESULTS

Most cognitive scores were in the below average range, consistent with neuropsychological profiles of anti-NMDAR encephalitis. Virtually all scores on measures of executive functioning were in the exceptionally low range. While immediate and delayed memory were low to below average, recognition memory was qualitatively better. He was diagnosed with major neurocognitive disorder due to anti-NMDAR encephalitis.

CONCLUSIONS

This case study highlights a case of anti-NMDAR encephalitis with multiple intersecting factors (i.e., immigrant status, monolingual Spanish speaking, < 12 years of education, adjudicated ICST, etc.) that made it difficult to judge the true etiology of the patient's deficits, or even whether some of the weaknesses found actually represent normal cognition given his background and limited availability of appropriate norms.

Anti-NMDAR encephalitis secondary to acute necrotizing encephalopathy caused by herpes simplex virus infection in infants: Case series

BACKGROUND

To describe the clinical characteristics of anti-NMDAR encephalitis secondary to acute necrotizing encephalopathy caused by herpes simplex virus encephalitis in infants, and aid in its early recognition, diagnosis and treatment.

CASE PRESENTATION

A total of 4 infants were included; all presented with fever, seizures, and progressive disturbances of consciousness and were diagnosed with herpes simplex virus (HSV-1) encephalitis. Cerebrospinal fluid (CSF) protein levels progressively increased, and the head MRI showed necrotizing encephalopathy. There was no significant improvement or recurrence after treatment with acyclovir, dexamethasone, or immunoglobulins. CSF reexamination at 3 weeks to 3 months showed positive anti-NMDAR IgG antibodies and gradual improvement after high-dose methylprednisolone therapy.

CONCLUSION

Infants with ANE associated with HSV can develop secondary anti-NMDAR encephalitis, recognition of which is critical to ensure the appropriate institution of immunotherapy after active CNS infection has been ruled out.

Lymphomatosis cerebri with coexistent anti-N-methyl-D-aspartate receptor antibody: A case report

Diagnosis of lymphomatosis cerebri (LC) is usually delayed because of its rarity and the need for pathological confirmation. The association of LC with humoral immunity has scarcely been reported. Herein, we present a woman with a 2-week history of dizziness and gait ataxia, followed by diplopia, altered mental status, and spasticity of all limbs. Magnetic resonance imaging (MRI) of the brain showed multifocal lesions involving bilateral subcortical white matter, deep gray structures, and brainstem. Oligoclonal bands and anti-N-methyl-D-aspartate receptor (NMDAR) antibodies were present in cerebrospinal fluid (CSF) twice. She was initially treated with methylprednisolone but still worsening. A stereotactic brain biopsy confirmed the diagnosis of LC. This is a report on the distinctive coexistence of the rare CNS lymphoma variant and the anti-NMDAR antibody.

Anti-N-methyl-d-aspartate receptor encephalitis preceded by meningitis lasting up to 60 days

Long-lasting meningitis complicated by N-methyl-d-aspartate receptor (NMDAR) encephalitis has not been discussed widely in the literature. Herein, we present two cases of anti-NMDAR encephalitis preceded by meningitis. The patients had 60- and 22-day periods of preceding meningitis, which improved with intravenous methylprednisolone and plasmapheresis. No tumors were detected in either of the patients. Although meningitis preceding anti-NMDAR encephalitis is not rare, our patients, especially those who had it for a duration of 60 days, had longer durations of meningitis. This manuscript foregrounds that anti-NMDAR encephalitis might be included in the differential diagnosis of long-lasting meningitis.

Effect and timing of operative treatment for teratoma associated N-Methyl-d-Aspartate receptor-antibody encephalitis: A systematic review with meta-analysis

Resection of an underlying ovarian teratoma in patients with N-Methyl-d-Aspartate receptor (NMDAR)-antibody encephalitis is supported by pathophysiological studies demonstrating the production of NMDAR antibodies within the teratoma. This systematic review assesses the clinical effect of teratoma resection and compares early versus late resection. Literature search was performed on the first of October 2022 (MEDLINE, Embase, CENTRAL, Web of Science). Original studies including more than three patients with NDMAR encephalitis and associated ovarian teratoma were included and evaluated with the Study Quality Assessment Tool for risk of bias. Fourteen studies referring to 1499 patients were included and analyzed in four syntheses using the fixed Mantel-Haenszel method. The rate of relapse in patients with ovarian teratoma resection was lower than in patients without resection (risk ratio for relapse 0.30, 95% CI 0.17-0.51), however the certainty level of evidence is very low. Despite some evidence pointing to a beneficial effect of early teratoma resection in patients with NMDAR-antibody encephalitis, systematically accessible data are insufficient to provide recommendations for or against resection, as well as for timing of surgery. The authors received no financial support for the research, authorship, or publication of this article. For the systematic review no clinical-trial database registration had been done.

A small mature cystic ovarian teratoma associated with anti-NMDA receptor encephalitis and acute respiratory failure: A case report

OBJECTIVE

To report a rare case of anti-N-Methyl-d-aspartate receptor encephalitis (anti-NMDARE) presented by mental and behavioral changes and seizures accompanied with respiratory failure.

CASE REPORT

A 37-year-old multiparous woman was initially presented with abnormal mental behavior and the diagnosis of schizophrenia was made, but the disease progressed rapidly to general convulsion and acute respiratory failure. Although active treatment, including steroids, intravenous immunoglobulins (IVIGs) and plasma exchange was applied, no significant improvement was obtained. Transvaginal ultrasound and pelvic magnetic resonance image (MRI) were arranged and the results showed a suspicious cystic lesion (3 × 2.3 cm) at the right ovary. Laparoscopic unilateral salpingo-oophorectomy was performed and final pathology reported a matured cystic teratoma, suggesting that this patient had anti-NMDARE secondary to ovarian mature teratoma. After surgery, the clinical condition was dramatically improved and she recovered completely without sequelae.

CONCLUSION

Although it is well-known about the relation between anti-NMDARE and ovarian mature teratoma, this small tumor may result in the missing diagnosis. Remind us to consider the possibility of any small ovarian cystic lesion-related anti-NMDARE in women with autoimmune encephalitis.

HSV-1 Encephalitis Presenting with Diplopia: Effects of Infection or Autoimmunity?

This report describes a case in which diplopia was developed as a finding of postinfectious anti- N -methyl- d -aspartate receptor encephalitis. Infectious encephalitis, especially herpes simplex virus, is essential as it is one of the triggers of autoimmune encephalitis. Even if the cases present unexpected clinical findings, we should be vigilant in terms of autoimmune processes, such as diplopia seen in our case.

Autoimmune encephalitis as a possible reason for psychiatric hospitalisation in the teenage population

Autoimmune encephalitis (AE) is a rare disease manifested by rapidly progressive short-term memory loss and other cognitive impairment accompanied by multiple disorders related to the limbic system involvement. The initial symptoms of autoimmune encephalitis may imitate other psychiatric disorders and delay the implementation of an appropriate treatment. The case description of a 15-year-old patient with an initial diagnosis of psychotic disorder has been presented. Because of atypical course of an illness and an ineffective treatment with psychotropic drugs, additional tests were made including serological tests, a cerebrospinal fluid (CSF) analysis and magnetic resonance imaging. Due to the entire clinical picture an autoimmune encephalitis was suspected. The implemented treatment included steroid therapy, intravenous immunoglobulins (IVIG) and plasmapheresis. The treatment regimen was repeated until remission was achieved.