Clinical characteristics, treatments, and outcomes of patients with anti-N-methyl-d-aspartate receptor encephalitis: A systematic review of reported cases

Efficacy of steroid therapy in the acute stage of anti-NMDAR and anti-MOG antibody overlapping encephalitis: a case report and literature review

Background

Recently, cases of overlapping encephalitis caused by anti-N-methyl-D-aspartate receptor (anti-NMDAR) and anti-myelin oligodendrocyte glycoprotein (MOG) antibodies have been reported, and their clinical characteristics are gradually becoming clear. Acute-phase treatment typically involves the use of steroids, and although some studies have suggested that steroids can be effective, the extent of their efficacy has not yet been fully explored.

Case presentation

We present the case of a 25-year-old man with anti-NMDAR and anti-MOG antibody overlapping encephalitis who showed considerable improvement after steroid treatment. To gain a deeper understanding of the efficacy of steroids in managing this condition, we conducted a literature review of cases of anti-NMDAR and anti-MOG antibody double-positive encephalitis that were treated with steroids during the acute phase. Thirteen cases were analyzed, including a new case diagnosed at our hospital. All patients showed improvement after receiving steroid treatment in the acute phase. Ten patients did not have any sequelae, and nine of them showed a rapid or major response during the acute phase. In contrast, three patients experienced sequelae (mild cognitive decline, visual impairment, and memory impairment, respectively), with their response to steroids in the acute phase being slow or limited. Relapses occurred in five patients, in one patient during steroid tapering, and in another two patients after cessation of steroids.

Conclusion

Steroid therapy can be effective in the acute stage of anti-NMDAR and anti-MOG antibody overlapping encephalitis. A positive prognosis may be expected in patients who experience substantial improvement with steroid therapy during the acute phase.

Anti-N-methyl-D-aspartate receptor encephalitis in adults: a systematic review and analysis

PURPOSE

To analyze predictors of treatment outcome for anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis in adults.

METHODS

We performed a comprehensive literature search of PubMed, PsycInfo, and OVID. We included 424 patients from case reports and case series. Demographics, anti-NMDAR antibodies, prodromal and presenting symptoms, diagnostic workup, and treatment variables were recorded. Inferential analyses were performed in the subset (n = 299) of those with known treatment outcomes. Multivariate multinomial logistic regression analysis for treatment outcome compared full recovery versus partial recovery and full recovery versus death.

RESULTS

Treatment outcomes consisted of 34.67% full recovery (n = 147), 30.90% partial recovery (n = 131), 4.95% death (n = 21), and 29.48% unknown (n = 125). Speech/language abnormality and abnormal electroencephalogram (EEG) were each significantly associated with a higher relative risk for a full recovery. Treatment with intravenous immunoglobulin and plasmapheresis were each significantly associated with a higher relative risk for partial recovery. The analysis comparing death to full recovery found that catatonia was significantly associated with a lower relative risk for death. Increased age, orofacial dyskinesia, and no tumor removal were each significantly associated with a higher relative risk for death.

CONCLUSION

Increased age, orofacial dyskinesia, and no tumor removal were associated with a higher relative risk for death in anti-NMDAR encephalitis in adults. Clinicians should monitor and appropriately treat anti-NMDAR encephalitis with these findings to minimize the risk of death.

Systematic review: clinical characteristics of anti-N-methyl-D-aspartate receptor encephalitis

Background

The number of reported cases of anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis has gradually increased since its discovery in 2007, while there are no uniform treatment guidelines.

Objective

To summarize the clinical characteristics of patients with anti-NMDAR encephalitis and to analyze the factors affecting the disease prognosis.

Methods

A systematic analysis of medical records was conducted, and PubMed, Embase, and Cochrane Library were searched from January 1, 2011, to December 31, 2021. Data were extracted, analyzed, and recorded in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines.

Results

This study included 472 case reports. Most patients had prodromal symptoms of about 2 weeks, including psychiatric symptoms (53.2%), flu-like symptoms (51.5%), and seizures (23.9%), among others. Poor prognoses were associated with patients who had autonomic instability (p = 0.010), central hypoventilation (p = 0.014), and ICU support (p = 0.002). Patients with a higher age of onset were more likely to develop central hypoventilation (OR 1.024, CI 1.006-1.042, p = 0.009), cognitive impairment (OR 1.023, CI 1.009-1.037, p = 0.001), and memory impairment (OR 1.034, CI 1.017-1.050, p < 0.001), whereas patients with a lower age were more likely to have seizures (OR 0.979, CI 0.965-0.993, p = 0.003). In this study, 97.0% of patients received immunotherapy, with the most commonly used treatment regimen being intravenous methylprednisolone (IVGC) and intravenous immunoglobulin (IVIG). When compared with other treatment regimens, the IVGC+IVIG regimen (p < 0.001) resulted in better prognoses.

Conclusion

When encountering patients with fever, headache, and initial psychiatric symptoms of unknown etiology, clinicians should test their CSF for antibodies to distinguish autoimmune encephalitis. Patients with autonomic instability, central hypoventilation, and ICU support had poorer prognoses. Clinicians should be aware that older patients are more likely to develop central hypoventilation, cognitive impairment, and memory impairment, while younger patients are more likely to develop seizures. The IVGC+IVIG treatment regimen has better prognoses than others. This study includes case reports, which have obvious selection bias, and there are no unified standards to measure the severity of the disease. Therefore, in the future, larger samples and randomized controlled trials are needed to evaluate the efficacy of different treatment regimens.

Clinical Reasoning: A Young Adult With New Seizures and Chapeau de Gendarme

The evaluation of new seizures is a common clinical query for neurologists. It can be challenging to delineate between the numerous etiologies of new focal or generalized seizures and, if focal, to localize their onset. In this case report, we present a 26-year-old patient with a new onset of stereotyped events concerning for seizures featuring facial grimacing, dystonic left-hand posturing, and convulsions with immediate return to baseline. Throughout the case, we highlight a stepwise diagnostic approach to the evaluation of new-onset seizures, discuss clues that seizure semiology can provide for localization of ictal onset, and review a novel and atypical presentation of a disease entity frequently encountered by neurologists.

Neuropsychiatric phenotypes of anti-NMDAR encephalitis: a prospective study

BACKGROUND

Patients with anti-N-methyl-d-aspartate (NMDA) receptor encephalitis (ANMDARE) show a wide range of behavioral abnormalities and are often mistaken for primary psychiatric presentations. We aimed to determine the behavioral hallmarks of ANMDARE with the use of systematic neuropsychiatric and cognitive assessments.

METHODS

A prospective study was conducted, with 160 patients admitted to the National Institute of Neurology and Neurosurgery of Mexico, who fulfilled criteria for possible autoimmune encephalitis and/or red flags along a time window of seven years. Cerebrospinal fluid (CSF) antibodies against the NR1 subunit of the NMDAR were processed with rat brain immunohistochemistry and cell-based assays with NMDA expressing cells. Systematic cognitive, neuropsychiatric, and functional assessments were conducted before knowing NMDAR antibodies results. A multivariate analysis was used to compare patients with and without definite ANMDARE according to antibodies in CSF.

RESULTS

After obtaining the CSF antibodies results in 160 consecutive cases, 100 patients were positive and classified as having definite ANMDARE. The most frequent neuropsychiatric patterns were psychosis (81%), delirium (75%), catatonia (69%), anxiety-depression (65%), and mania (27%). Cognition was significantly impaired. A total of 34% of the patients had a predominantly neuropsychiatric presentation without seizures. After multivariate analysis, the clinical hallmarks of ANMDARE consisted of a catatonia-delirium comorbidity, tonic-clonic seizures, and orolingual dyskinesia.

CONCLUSIONS

Our study supports the notion of a neurobehavioral phenotype of ANMDARE characterized by a fluctuating course with psychotic and affective symptoms, catatonic signs, and global cognitive dysfunction, often accompanied by seizures and dyskinesia. The catatonia-delirium comorbidity could be a distinctive neurobehavioral phenotype of ANMDARE.

Clinical spectrum of contactin-associated protein 2 autoimmune encephalitis in children

Objective

Anti-contactin-associated protein 2 (CASPR2)-related autoimmune encephalitis (AE) is more common in adults than in children. Clinical understanding of anti-CASPR2-antibody (Ab)-related AE, diagnosis and treatment standards are lacking in children. Therefore, this retrospective study on clinical symptoms and treatment outcomes in children with anti-CASPR2-Ab-related AE was conducted, to improve the clinical understanding of the disease, its diagnosis and treatment.

Methods

This study retrospectively assessed children with anti-CASPR2-Ab-related AE from January 1, 2020, to June 30, 2022, in the Department of Neurology at Hunan Children's Hospital. Data regarding demographics, clinical symptoms, laboratory examinations, electroencephalography (EEG), imaging, and curative were collected.

Results

Thirteen patients were positive for serum anti-CASPR2-Ab (age at manifestation, 25 months to 13 years old; median, 8.1 years old; male-to-female ratio, 8/5). One patient (P1) had dual Abs, including anti-CASPR2 and anti-N-methyl-D-aspartate receptor Abs; his symptoms were more severe than those of children with anti-CASPR2 Abs alone. The clinical symptoms of the 13 patients with anti-CASPR2 Ab were movement disorders (9/13), consciousness disorders (9/13), abnormal demeanor (8/13), seizures (7/13), language disorders (6/13), fever (6/13), pain (4/13), involuntary exercise (4/13), poor diet (4/13), vomiting (3/13), sleep disorders (3/13), mood disorders (3/13), eczema/itching/redness (2/13), sweating (P8), urinary disorders (P13), and cognitive disorders (P9). No tumors were found in any patient. Additionally, EEG results of six patients were abnormal and imaging findings such as abnormal signals were found in 10 patients. Moreover, all except one patient recovered well after treatment; P1 with overlapping syndrome underwent recovery for more than 2 years. None of the patients who recovered have had a relapse.

Discussion and conclusion

Anti-CASPR2-Ab-related AE has several clinical manifestations. Anti-CASPR2-Ab levels were higher in male patients than in female patients. Moreover, related tumors are relatively rare. Most patients benefit from immunotherapy and have a lower chance of recurrence in the short term. Furthermore, different from patients who had anti-CASPR2-Ab AE alone, those with overlapping syndrome had a severe and complex condition requiring lengthy treatment and rehabilitation. Additional studies are needed to evaluate the long-term prognosis of these patients.

Seizure Evolution and Outcome in Pediatric Autoimmune Encephalitis

BACKGROUND

Our study aimed to characterize seizure incidence and seizure outcome of pediatric autoimmune encephalitis (AE) focusing on subgroup analysis based on antibody (Ab).

METHODS

Among 110 pediatric patients with AE, we compared seizure characteristics and outcomes in 68 patients with seizure, who satisfied the proposed criteria of pediatric AE. Accordingly, patients were classified into three groups, anti-myelin oligodendrocyte glycoprotein (anti-MOG) AE, anti-N-methyl-D-aspartic acid receptor (anti-NMDAR) AE, and Ab-negative AE. Univariate and multivariate analyses were performed to evaluate the risk factors for postencephalitic seizures, defined as persisting seizures six months after onset.

RESULTS

Seizure incidence in the anti-NMDAR (88.9%) and Ab-negative (71.1%) groups differed from anti-MOG group (37.8%). Median seizure frequency within six months was higher in the Ab-negative group (6.0, interquartile range [IQR] 3.0 to 13.0) than in the anti-NMDAR group (3.0, IQR 2.0 to 4.5) and anti-MOG group (2.0, IQR 1.0 to 5.0). Patients in the Ab-negative group tended to develop postencephalitic seizures more frequently and have a lower seizure freedom rate than those in the anti-NMDAR and anti-MOG groups. Ab-negative status, high seizure frequency within six months, and the presence of status epilepticus were associated with the development of postencephalitic seizures on univariate analysis. On multivariate analysis, Ab-negative status remained the only significant variable linked with postencephalitic seizure (odds ratio, 4.17; 95% confidence interval, 1.02 to 18.05).

CONCLUSIONS

We delineated the seizure incidence, evolution, and outcome of pediatric patients with Ab-positive and Ab-negative AE. Ab-negative status is predictive of higher seizure burden, more frequent development of postencephalitic seizures, and less favorable seizure outcome than anti-NMDAR and anti-MOG Ab-positive status.

Outcome of Pediatric Anti-N-Methyl-D-Aspartate (NMDA) Receptor Encephalitis in Rural Area of Thailand

Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis has a very good outcome; however, there are few reports in developing countries regarding the outcome of pediatric anti-NMDAR encephalitis. We aimed to report the clinical outcome of pediatric anti-NMDAR encephalitis in the rural area of Thailand. This retrospective cohort study recruited children between the age of 1 month and 15 years with the diagnosis of anti-NMDAR encephalitis admitted at Maharat Nakhon Ratchasima Hospital from 1st May 2015 to 31th March 2020. Baseline characteristics and investigation were recorded. The first-line treatment was intravenous pulse methylprednisolone alone, pulse methylprednisolone plus intravenous immune globulin (IVIG), or IVIG alone. The second-line treatment was monthly intravenous cyclophosphamide or azathioprine. The modified Rankin Scale (MRS) was used for evaluation at 1, 3, 6, 12, 18, and 24 months after receiving first-line treatment to determine clinical outcomes. The factors that may affect the outcomes were evaluated. In total, 17 patients were recruited, with the mean age of 8 years, and 76.46% were female. 82.35% of patients developed seizures, and 52.94% turned to status epilepticus. 70.59% received first-line treatment as pulse methylprednisolone plus IVIG. 82.35% received complete follow-up at 12 months. According to MRS score, at first diagnosis 94.12% reported severe disability, at 1 month after receiving treatment, 47.06% improved to moderate–mild disability, and at 6 and 12 months, 40% and 78.57% had complete recovery, respectively. Different types of first-line and second-line treatments did not affect the clinical outcome. Comorbidity of status epilepticus affected MRS. Anti-NMDAR encephalitis has a very good prognosis; prompt diagnosis is necessary. Comorbidity as status epilepticus may affect the clinical outcome.

Isolated Leptomeningeal Enhancement in Anti-N-Methyl D-Aspartate Receptor Encephalitis: The Diagnostic Value of Contrast-Enhanced Fluid-Attenuated Inversion Recovery Imaging

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a common autoimmune encephalitis that is noted to be a severe but treatable disease entity. Patients with anti-NMDAR encephalitis often develop psychotic symptoms, including delusions, hallucinations, and paranoia, as well as memory impairment and persistent loss of attention. However, MRI findings in such patients show no abnormalities in most cases. Although typical brain abnormality features, known as T2 hyperintensities, involve the brain parenchyma and contrast enhancement at the cerebral cortex or overlying meninges, isolated leptomeningeal enhancement has been rarely reported in anti-NMDAR encephalitis. Herein, we report a patient with anti-NMDAR encephalitis who presented with isolated leptomeningeal enhancement, additionally showing the diagnostic value of contrast-enhanced fluid-attenuated inversion recovery imaging.

A systematic review and quantitative synthesis of the long-term psychiatric sequelae of pediatric autoimmune encephalitis

BACKGROUND

Long-term neuropsychiatric sequelae of autoimmune encephalitis (AE) remain understudied, particularly in pediatric-onset AE. We aimed to synthesize the published data on ongoing psychiatric symptoms in pediatric-onset AE.

METHODS

The Pubmed, PyscINFO, Web of Science databases were searched from their inception years to August 23, 2021, and 29 studies were identified and analyzed. We also performed a quantitative synthesis of available patient data from the 29 studies combined with a cohort of anti-NMDA receptor (NMDAR) AE from our institution to examine the associations between acute treatment course and long-term psychiatric outcome.

RESULTS

At long-term follow up, 52.4% of the cases with pediatric-onset AE had any persistent symptom and 36.0% had at least one psychiatric symptom. Pooled data found that 36.3% of pediatric-onset anti-NMDAR AE had ongoing psychiatric symptoms. Using a univariate logistic regression analysis, we found that abnormal initial EEG, use of certain immunotherapies, and persistent cognitive impairments were associated with ongoing psychiatric symptoms.

LIMITATIONS

Limitations of the existing literature included a significant paucity of outcomes measured using consistent, objective methods. Limitations of the systematic review included the wide variability among the studies reviewed, which rendered a meta-analysis impossible and beyond the scope of the paper.

CONCLUSION

Chronic psychiatric and behavioral problems remain present in one-third of children months to years after onset of AE. Larger scaled prospective observational studies with a consistent standardized battery of testing are needed to examine impact of specific clinical features and immunotherapies on long-term mental health outcomes.

Ovarian teratoma related anti-N-methyl-D-aspartate receptor encephalitis: A case series and review of the literature

BACKGROUND

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a rare but important complication of ovarian teratoma. Between July 2012 and December 2019, six patients with ovarian teratoma-associated anti-NMDAR encephalitis were enrolled in our hospital and their clinical characteristics, treatment, and follow-up were reviewed. We also conducted a systematic literature review of ovarian teratoma related anti-NMDAR encephalitis reports between January 2014 and December 2019.

AIM

To better understand anti-NMDAR encephalitis through literature review and patients enrolled in our hospital.

METHODS

The six patients enrolled in the study were those diagnosed with anti-NMDAR encephalitis. Their history, clinical manifestations, and medications were recorded and optimum treatment provided in addition to maintaining a record of the follow-ups. In addition, we also extensively surveyed the literature and provide summarized data from 155 published cases of anti-NMDAR encephalitis from 130 case reports. PubMed and Scopus were the sources of these publications and the time period covered was 6 years ranging from January 2014 through December 2019.

RESULTS

The six patients enrolled for this study presented with typical symptoms resulting in a diagnosis of ovarian teratoma induced anti-NMDAR encephalitis. Appropriate interventions led to a positive outcome in all the patients, with five of six patients reporting full recovery and the sixth patient recovering with a few deficits. No death was recorded. The literature survey comprising of 155 patients cases across 130 case reports of anti-NMDAR encephalitis clearly indicated an upward trend in the reports/diagnosis in China, particularly in the surveyed time from 2014 through 2019. The majority of patients (150/155) underwent surgical intervention resulting in positive outcome. No treatment intervention was mentioned for one case while the four patients who were not surgically operated succumbed to the disease.

CONCLUSION

Suspected anti-NMDAR encephalitis should be quickly evaluated for anti-NMDAR antibodies since early diagnosis is important. In case of a tumor, its earliest and complete removal is recommended. Finally, early use of corticosteroids and IgG-depleting strategies (intravenous immunoglobulin or plasma exchange) may improve outcome.

Abnormal Brain MRI Findings in Anti-N-Methyl-D-Aspartate Receptor Encephalitis and Correlation With Outcomes

Purpose

The reported prevalence of abnormal findings by brain MRI varies from 11 to 83% among patients with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. Here, we investigated the prevalence of abnormal MRI findings in Chinese patients and explored whether such findings are correlated with clinical outcomes.

Methods

This retrospective study analyzed a consecutive series of 52 patients with anti-NMDAR encephalitis admitted to our hospital. The patients were assigned to the “MRI-normal” or the “MRI-abnormal” group based on brain MRI after admission. The groups were compared in terms of clinicodemographic characteristics and scores on the Mini-Mental State Examination (MMSE) and modified Rankin Scale (mRS) 3 and 12 months after admission.

Results

Thirty-seven (71.15%) of the patients showed abnormalities on brain MRI; these patients were more likely to be men and showed abnormalities on electroencephalography. Patients who showed normal or abnormal MRI findings did not differ significantly in terms of clinical symptoms, rates of mortality or relapse, or mRS scores after 3 and 12 months. However, patients with abnormal MRI showed significantly lower MMSE scores than those with normal MRI after 3 and 12 months.

Conclusions

We found high prevalence of abnormal MRI findings in our sample of Chinese patients with anti-NMDAR encephalitis. We also found that the abnormal findings were associated with cognitive decline but not necessarily with mortality or functional outcomes in the short or long term.

Mature Ovarian Teratoma: Neurological Implications in a Young Woman

Anti-NMDAR encephalitis is an autoimmune syndrome associated with antibodies against NMDA receptors. In some cases, it is associated with various tumors; one of them is ovarian teratoma, which mostly affects women below the age of 30 years. Here, we report a case of ovarian teratoma associated with anti-NMDAR encephalitis treated with both laparoscopic surgery and immunotherapy. Multidisciplinary approach is the cornerstone for the management of this syndrome.

Anti-N-Methyl-D-Aspartate Receptor (NMDAR) Encephalitis in Children and Adolescents: A Systematic Review and Quantitative Analysis of Reported Cases

OBJECTIVE

This pooled analysis, from a systematic review, examines anti-N-Methyl D-Aspartate Receptor (NMDAR) encephalitis presentation in children and adolescents.

METHOD

A comprehensive literature search from database inception through December 31, 2019, using PubMed, PsycInfo, and OVID was performed. Case reports and case series were included. Sample characteristics are described. Prodromal and presenting symptoms between partial recovery and full recovery are compared. The association between presenting symptoms and abnormal MRI, abnormal EEG, and tumor presence are determined.

RESULTS

The sample (n=283) had a mean age of 10.8 years with 75.3% females. The most common prodromal and presenting symptom was seizure (29.7% and 63.3%, respectively). Partial and full recovery did not differ for prodromal and presenting symptoms. Multivariate logistic regression analysis found that (1) delusion were significantly associated with higher odds and aggressive behavior was associated with lower odds for abnormal findings on magnetic resonance imaging (MRI); (2) waxing and waning of symptoms were significantly associated with higher odds for abnormal electroencephalograms (EEG), and (3) increased age and psychosis were each significantly associated with increased odds, and sleep disturbance and orofacial dyskinesia with lower odds for tumor presence.

CONCLUSION

Given the pattern of findings, routinely obtaining MRI and EEG should be considered for anti-NMDAR encephalitis in children and adolescents presenting with delusion and waxing and waning of symptoms, respectively. Investigation of tumors should be considered in patients with anti-NMDAR encephalitis especially when psychosis is present.

Use and Safety of Immunotherapeutic Management of N-Methyl-d-Aspartate Receptor Antibody Encephalitis: A Meta-analysis

Question

What are the most effective treatments for N-methyl-d-aspartate receptor (NMDAR) antibody encephalitis?

Findings

In this meta-analysis of individual patient data including 1550 cases, treatment factors at first event that were significantly associated with good functional outcome 12 months from disease onset included first-line treatment with therapeutic apheresis alone, corticosteroids in combination with intravenous immunoglobulin (IVIG), or corticosteroids in combination with IVIG and therapeutic apheresis, while lack of immunotherapy within 30 days of disease onset was significantly associated with poor outcome. Rituximab and long-term IVIG use were significantly associated with nonrelapsing disease course.

Meaning

Separate treatment factors are associated with functional outcomes and relapsing disease biology in those with NMDAR antibody encephalitis.

Importance

Overall, immunotherapy has been shown to improve outcomes and reduce relapses in individuals with N-methyl-d-aspartate receptor (NMDAR) antibody encephalitis (NMDARE); however, the superiority of specific treatments and combinations remains unclear.

Objective

To map the use and safety of immunotherapies in individuals with NMDARE, identify early predictors of poor functional outcome and relapse, evaluate changes in immunotherapy use and disease outcome over the 14 years since first reports of NMDARE, and assess the Anti-NMDAR Encephalitis One-Year Functional Status (NEOS) score.

Data Sources

Systematic search in PubMed from inception to January 1, 2019.

Study Selection

Published articles including patients with NMDARE with positive NMDAR antibodies and available individual immunotherapy data.

Data Extraction and Synthesis

Individual patient data on immunotherapies, clinical characteristics at presentation, disease course, and final functional outcome (modified Rankin Scale [mRS] score) were entered into multivariable logistic regression models.

Main Outcomes and Measures

The planned study outcomes were functional outcome at 12 months from disease onset (good, mRS score of 0 to 2; poor, mRS score greater than 2) and monophasic course (absence of relapse at 24 months or later from onset).

Results

Data from 1550 patients from 652 articles were evaluated. Of these, 1105 of 1508 (73.3%) were female and 707 of 1526 (46.3%) were 18 years or younger at disease onset. Factors at first event that were significantly associated with good functional outcome included adolescent age and first-line treatment with therapeutic apheresis, corticosteroids plus intravenous immunoglobulin (IVIG), or corticosteroids plus IVIG plus therapeutic apheresis. Factors significantly associated with poor functional outcome were age younger than 2 years or age of 65 years or older at onset, intensive care unit admission, extreme delta brush pattern on electroencephalography, lack of immunotherapy within the first 30 days of onset, and maintenance IVIG use for 6 months or more. Factors significantly associated with nonrelapsing disease were rituximab use or maintenance IVIG use for 6 months or more. Adolescent age at onset was significantly associated with relapsing disease. Rituximab use increased from 13.5% (52 of 384; 2007 to 2013) to 28.3% (311 of 1100; 2013 to 2019) (P < .001), concurrent with a falling relapse rate over the same period (22% [12 of 55] in 2008 and earlier; 10.9% [35 of 322] in 2017 and later; P = .006). Modified NEOS score (including 4 of 5 original NEOS items) was associated with probability of poor functional status at 1 year (20.1% [40 of 199] for a score of 0 to 1 points; 43.8% [77 of 176] for a score of 3 to 4 points; P = .05).

Conclusions and Relevance

Factors influencing functional outcomes and relapse are different and need to be considered independently in development of evidence-based optimal management guidelines of patients with NMDARE.

Clinical Features of Coexisting Anti-NMDAR and MOG Antibody-Associated Encephalitis: A Systematic Review and Meta-Analysis

Coexisting anti-NMDAR and MOG antibody (anti-NMDAR-IgG⁺/MOG-IgG⁺)-associated encephalitis have garnered great attention. This study aimed to perform a secondary analysis to determine the clinical features of this disease. We searched several databases for related publications published prior to April 2021. A pooled analysis was conducted with the fixed-effects model using the Mante-Haenszel method (I ² ≤ 50%), or the random-effects model computed by the DerSimonian-Laird method (I ² > 50%). Stata software (version 15.0 SE) was used for the analyses. Nine observational studies and 16 case reports (58 cases with anti-NMDAR-IgG⁺/MOG-IgG⁺, 21.0 [8.5, 29.0] years, male 58.6%) were included. The incidences (95%CI) of anti-NMDAR-IgG⁺/MOG-IgG⁺ in the patients with serum MOG-IgG⁺ and CSF anti-NMDAR-IgG⁺ were 0.09 (0.02-0.19) and 0.07 (0.01-0.19), respectively. The median [IQR] of CSF anti-NMDAR antibody titer was 32 [10, 100], and the serum anti-MOG antibody titer was 100 [32, 320]. The prominent clinical symptoms were encephalitic manifestations, including seizures (56.9%) and abnormal behavior (51.7%), rather than demyelinating manifestations, such as speech disorder (34.5%) and optic neuritis (27.6%). Relapse occurred in 63.4% of anti-NMDAR-IgG⁺/MOG-IgG⁺ patients, in whom 50.0% of cases relapsed with encephalitic manifestations, and 53.8% relapsed with demyelinating manifestations. The common MRI changes were in the cortex or subcortex (70.7%) and brainstem (31.0%). 31.3% of patients presented with unilateral cerebral cortical encephalitis with epilepsy and 12.5% displayed bilateral frontal cerebral cortex encephalitis. Anti-NMDAR-IgG⁺/MOG-IgG⁺ patients showed more frequent mental behavior (OR, 95%CI, 68.38, 1.36-3,434.37), involuntary movement (57.86, 2.53-1,325.11), sleep disorders (195.00, 7.07-5,380.15), and leptomeninge lesions (7.32, 1.81-29.58), and less frequent optic neuritis (0.27, 0.09-0.83) compared to anti-NMDAR-IgG^-/MOG-IgG⁺ patients and presented more common relapse (5.63, 1.75-18.09), preceding infection (2.69, 1.03-7.02), subcortical lesions (116.60, 4.89-2,782.09), basal ganglia lesions (68.14, 2.99-1,554.27), brainstem lesions (24.09, 1.01-574.81), and spinal cord lesions (24.09, 1.01-574.81) compared to anti-NMDAR-IgG⁺/MOG-IgG^-. In conclusion, anti-NMDAR-IgG⁺/MOG-IgG⁺ was rarely observed, but the incidence rate of relapse was very high. The overall symptoms seemed to be similar to those of NMDAR encephalitis.

Spectrum of Anti-NMDA Receptor Antibody Encephalitis: Clinical Profile, Management and Outcomes

Background:

Anti-N-methyl D-aspartate receptor (anti NMDAR) antibody encephalitis is an immune-mediated entity characterised by a constellation of neuro-psychiatric symptoms.

Objective:

To describe clinical profile and treatment outcomes of patients with anti NMDAR antibody encephalitis.

Settings and Design:

Subjects were selected by screening for all patients satisfying Graus et al.'s criteria for probable anti NMDAR antibody encephalitis, admitted in neurology department of a tertiary care centre in Eastern India.

Materials and Methods:

A prospective, longitudinal study was conducted by identifying 25 patients with anti NMDAR antibodies in CSF and or serum, between September 2018 to February 2020.

Statistical Analysis:

Chi square test was used to compare variables.

Results:

Out of 98 patients screened, 25 subjects (14 females: 11 male) were positive for anti NMDAR autoantibodies, with a mean age of 17 years. 13 subjects belonged to paediatric age group. Most common presenting feature was memory/learning deficit (88%) followed by behavioural abnormalities (84%) and seizures (68%). 11 patients (44%) patients needed escalation to second line therapy, rituximab. Seven (28%) and twelve (48%) patients underwent complete (mRS 0-1) and partial recovery (mRS 2-3) respectively, while 4 (16%) became disabled (mRS 4-5). Mortality was 8%. Paediatric population had a better outcome in terms of disability (p = 0.043).

Conclusion:

Anti NMDAR-Ab encephalitis is the most common cause of antibody positive autoimmune encephalitis worldwide. There are important clinical markers and investigational profiles which carry prognostic significance.

Encephalitis in Previously Healthy Children

Encephalitis is defined as altered mental status for more than 24 hours accompanied by 2 or more findings concerning for inflammation of the brain parenchyma: fever, seizures or other focal neurologic disorders, cerebrospinal fluid pleocytosis, and abnormal neuroimaging and electroencephalographic findings. Herpes simplex virus causes the most severe form of virus-induced encephalitis; the early administration of acyclovir can improve the prognosis of this disease. The rising interest in autoimmune causes of encephalitis, most notably anti-N-methyl-d-aspartate receptor, should prompt the clinician to consider immunomodulatory treatments, which may improve outcomes. A broad testing panel may be necessary to detect the etiologic agent; a few published pediatric cases suggest that infectious and autoimmune causes may occur concurrently in the same patient with encephalitis. More than 40% of children diagnosed as having encephalitis will not return to their previous level of neurologic function after resolution of their disease, although outcomes are highly variable depending on the etiologic agent.

Pediatric anti-N-methyl-d-aspartate receptor encephalitis in southern China: Analysis of 111 cases

OBJECTIVE

To study the clinical features of children diagnosed with anti-NMDAR encephalitis in southern China.

METHODS

Clinical data of children diagnosed with anti-NMDAR encephalitis from October 2014 to June 2020 from one national regional medical center were analyzed. Neurological disability was assessed by modified Rankin Scale (mRS) throughout the course of disease.

RESULTS

111 children (M/F = 49/62; mean onset age = 6.8 y) with anti-NMDAR encephalitis were involved. Prodromal events occurred in 34.2% of patients with infectious events being the most common. Seizure was the most common initial symptom, though movement disorder served as the most common event throughout the course of disease. 9.9% of patients had overlapped with other neuronal autoantibodies. Electroencephalogram showed abnormalities with slow wave (100.0%), epileptic discharge (31.5%) and delta brush (8.1%) respectively. 41.4% of patients had abnormal brain MRI, with focal lesions being the most common. None patients had tumor. 80.9% of patients had good response to first line therapy (steroid plus immunoglobulin), while 14 patients accepted second-line therapy (Rituximab) and all had a good response. Boys were significantly more likely to need more course of steroid. 13.8% of patients relapsed. 2 male patients died. mRS score was significantly improved after treatment. 51.4% of patients had a full recovery and 81.7% had mRS score ≤ 2. The median mRS score of boys after treatment was higher than that of girls. Non-infectious prodromal event, past medical history, perivascular lesions in brain MRI, hospital stay, initial mRS score higher than 3, and RTX treatment were independent risk factors associated with poor prognosis, defined as mRS score > 2.

CONCLUSION

Of pediatric anti-NMDAR encephalitis in southern China: median onset age around 7 years; girls more common; boys might have poor outcome than girls; seizure or movement disorder respectively being most common onset or course symptom; a few overlapped with other neuronal autoantibodies; rare combined with tumor; most had a good response to immunotherapy and a good prognosis; relapse rate relatively high; fatality rate relatively low; some risk factors associated with poor prognosis.

Immunotherapies for Anti-N-M-methyl-D-aspartate Receptor Encephalitis: Multicenter Retrospective Pediatric Cohort Study in China

Background: Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis has been discovered for more than a decade, but the establishment of standardized immunotherapy protocol for pediatric patients still needs more clinical evidence. Methods: A multicenter, retrospective study was conducted on pediatric patients diagnosed with anti-NMDAR encephalitis between November 2011 and December 2018. The clinical records including clinical manifestations, immunotherapy strategies, and outcomes were collected and analyzed. Results: A total of 386 patients were included in our study and the median onset age was 8.00 (IQR 4.83-10.90) years. All patients received first-line immunotherapy and the majority (341, 88.3%) used the standard combination of methylprednisolone pulses (MEP) and intravenous immunoglobulins (IVIG), but 211 patients did not show satisfactory improvement (mRS ≥ 3). Mainly three treatment strategies were applied after first-line immunotherapy: second-line immunotherapy, repetitive first-line immunotherapy, and maintaining oral prednisolone. For patients with mRS ≥ 4 after first-line immunotherapy, the incidence of poor outcome (mRS ≥ 3) in oral prednisolone group was higher than that in other treatment groups (p = 0.039). No difference in complete recovery rate (mRS = 0) was found between patients receiving second-line and repetitive first-line immunotherapy, or patients using long-term and short-term prednisolone. Out of 149 patients who received anti-myelin oligodendrocyte glycoprotein antibody (MOG-Ab) test, 27 (18.12%) were positive. Patients with concomitantly positive MOG-Ab showed milder conditions compared to patients with typical anti-NMDAR encephalitis and were more inclined to relapses. We also identified female, MOG-Ab positive, and not receiving second-line and/or repetitive first-line immunotherapy were risk factors for relapses. Conclusions: For patients with mRS ≥ 4 after first-line immunotherapy and patients with concomitantly positive MOG-Ab, second-line immunotherapy is recommended. When second-line immunotherapy is not applicable, repetitive first-line immunotherapy can be considered as an option. Both second-line and repetitive first-line immunotherapy are beneficial to reduce relapse rate. The duration of sequential oral prednisolone can be shortened after fully evaluating patients' conditions.

Clinical Features and Outcomes in Pediatric Autoimmune Encephalitis Associated With CASPR2 Antibody

Background: Contactin-associated protein-like 2 (CASPR2) neurological autoimmunity has been associated with various clinical syndromes involving central and peripheral nervous system. CASPR2 antibody-associated autoimmune encephalitis is mostly reported in adults. Analysis of the clinical presentation and prognostic data of CASPR2 antibody-associated autoimmune encephalitis in children remains important. Methods: A single-center retrospective review of children diagnosed with CASPR2 antibody-associated autoimmune encephalitis from June 1st, 2018 to October 31st, 2020. Results: Six patients were identified. The median age was 12 years (range 1.8-14), with an overall male predominance of 83% (5/6). Commonest clinical features were psychiatric symptoms (6/6), movement disorders (4/6), altered consciousness (3/6), sleep disorders (3/6), and headache (3/6). Four patients (4/6) received first-line therapy alone (steroids combined with intravenous immunoglobulins), and two patients (2/6) received second-line therapy (rituximab, mycophenolate mofetil, or cyclophosphamide). All patients showed no peripheral nervous system involvement. One patient had comorbidities with systemic lupus erythematosus. No evidence of neoplastic disease was found in the whole cohort. All patients had favorable outcomes (modified Rankin Score 0-2) with recurrence rate at 0%, respectively. Conclusion: CASPR2 antibody-associated autoimmune encephalitis is rare in children. Our findings suggest that this type of encephalitis seems to occur more frequently in older children. Patients respond well to immunotherapy and usually demonstrate a favorable clinical outcome. Associated tumors are extremely rare.

Finding the Cause of Psychosis: A Challenging Case of Anti-NMDAR Encephalitis

An autoimmune response causing inflammation in the brain tissue is called autoimmune encephalitis. Autoantibodies directed against N-methyl-D-aspartate (NMDA) receptors cause a type of autoimmune encephalitis resulting in memory loss, confusion, and psychosis. A 28-year-old male with a history of schizophrenia, seizure disorder, and stroke presented with a 2-day history of bizarre behavior, restlessness, insomnia, agitation, and hallucinations. He was initially managed for acute psychosis without any improvement. Further workup for organic causes revealed positive NMDAR antibodies in both the cerebrospinal fluid and serum, confirming a diagnosis of autoimmune encephalitis. His condition later improved with steroids and intravenous immunoglobulins. This case signifies the importance of ruling out organic causes in patients with unexplained neuropsychiatric symptoms. NMDA encephalitis is more common in young females with underlying malignancies, especially ovarian teratomas. This case is unique, given the extremely rare occurrence of NMDA encephalitis in male patients without any malignancies.

Anti-N-methyl-D-aspartate receptor encephalitis in a young female with subclinical hypothyroidism associated with anti-thyroid peroxidase and anti-thyroglobulin antibodies: A case report

Anti-N-methyl-D-aspartate receptor encephalitis is a life-threatening medical emergency that can be clinically misperceived as Hashimoto’s encephalopathy. We present a case of anti-N-methyl-D-aspartate receptor encephalitis in an otherwise healthy young female with subclinical hypothyroidism without an associated ovarian teratoma. She was first misdiagnosed as Hashimoto’s encephalopathy due to delirium and behavioral changes, seizures, psychosis, and increased amount of thyroid peroxidase and thyroglobulin antibodies in serum. Final diagnosis was established by third week following presentation with the detection of anti-N-methyl-D-aspartate receptor antibodies in her cerebrospinal fluid. After treatment with intravenous immunoglobulin, methylprednisolone, and amisulpride, she recovered significantly with minimal sequelae at 3-week follow-up.

Co-expression of NMDA-receptor subunits NR1, NR2A, and NR2B in dysplastic neurons of teratomas in patients with paraneoplastic NMDA-receptor-encephalitis: a retrospective clinico-pathology study of 159 patients

Objective

To comprehensively describe the pathological features of neurons in patients with ovarian teratomas and paraneoplastic anti-NMDAR encephalitis (anti-NMDARE), emphasizing on NMDA-receptor expression and infiltrating lymphocytes.

Methods

A retrospective study was performed in a large series of 159 patients from the West China Hospital. We retrospectively identified 12 patients with paraneoplastic anti-NMDARE (11 case with ovarian teratomas and 1 case with mixed germ cell tumor), which were compared to 35 patients with teratomas and no encephalitis and to 147 patients with anti-NMDARE and no evidence for tumors. Patient history and outcome were reviewed from the clinical charts and compared between all three groups. Histopathological examination, including double-immunofluorescence of NMDAR subunits and IgG was performed in all teratoma tissues. Magnetic Luminex Assay Human Premixed Multi-Analyte Kit was performed to investigate cytokines profile of CSF.

Results

Patients with paraneoplastic anti-NMDARE had a more severe clinical presentation, i.e. they required more mechanical ventilation and intensive care (p < 0.001). Though immunotherapy was initiated earlier in this group, repeated intravenous immunoglobulin administration (IVIG) was more common (p = 0.002) and with higher cerebrospinal fluid (CSF) antibody titres (p = 0.004). Following tumor resection, the outcome did not differ between groups. A peculiar population of floating-frog like dysplastic neurons were observed only in teratomas of patients with paraneoplastic anti-NMDARE, co-expressing NR1, NR2A, NR2B subunits and IgG. Also, CD20 positive B-cells were more common in anti-NMDARE teratomas. In CSF of paraneoplastic anti-NMDARE patients, TNF-α, IL-10 and GM-CSF concentrations were higher than in negative symptom control and VEGF-A and IL-1a were lower than in anti-NMDARE patients (0.25 < p < 0.05).

Conclusions

Patients with teratomas and paraneoplastic anti-NMDARE revealed a cellular population of dysplastic neurons co-expressing NMDAR subunits, which were the potential source of autoantigens triggering anti-NMDARE. Some inflammatory cytokines may be involved in pathogenesis of paraneoplastic anti-NMDARE.

Autoimmune encephalitis and epilepsy: evolving definition and clinical spectrum

Advances in autoimmune encephalitis studies in the past 10 years have led to the identification of new syndromes and biomarkers that have transformed the diagnostic approach to the disorder. The disorder or syndrome has been linked to a wide variety of pathologic processes associated with the neuron-specific autoantibodies targeting intracellular and plasma membrane antigens. However, current criteria for autoimmune encephalitis are quite dependent on antibody testing and responses to immunotherapy, which might delay the diagnosis. This form of encephalitis can involve the multifaceted presentation of seizures and unexpected behavioral changes. The spectrum of neuropsychiatric symptoms in children is less definitive than that in adults, and the incorporation of clinical, immunological, electrophysiological, and neuroradiological results is critical to the diagnostic approach. In this review, we document the clinical and immunologic characteristics of autoimmune encephalitis known to date, with the goal of helping clinicians in differential diagnosis and to provide prompt and effective treatment.

Rituximab for Autoimmune Encephalitis with Epilepsy

Intractable epilepsy remains a significant medical challenge, resulting in recurrent and prolonged intensive care unit (ICU) admissions. Autoimmune encephalitis is emerging as a treatable cause of intractable epilepsy. It is characterized by antibodies against cerebral antigens, such as potassium channels such as leucine-rich, glioma inactivated 1 (LGI1) and contactin-associated protein 2 (CASPR2), calcium channels such as the voltage-gated calcium channel (VGCC), or neurotransmitter receptors such as the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR), gamma aminobutyric acid receptor (GABAR), and N-methyl-D-aspartate receptor (NMDAR). Diagnosis requires a syndrome consistent with an antibody identified in serum or cerebrospinal fluid (CSF) using methods that minimize risk of false-positives. Although there is no officially approved therapy for these disorders, typical approaches involve chronic high-dose steroids, intravenous immunoglobulin (IVIG), or plasma exchange. Rituximab is effective for antibody-associated disorders such as lupus, myasthenia gravis, and neuromyelitis optica. Here, we present three patients who were admitted with recalcitrant status epilepticus and demonstrated serum antibodies against NMDAR, LGI1, or VGCC using a cell-based assay. All patients demonstrated complete, long-term epilepsy control and improvement in symptoms with rituximab.

Characterisation and outcome of neuropsychiatric symptoms in patients with anti-NMDAR encephalitis

BACKGROUND

Encephalitis due to anti-N-methyl-D-aspartate receptor antibodies (ANMDARE) is the most frequent immune-mediated encephalitis. It is distinguished by the subacute onset of neuropsychiatric symptoms.

OBJECTIVE

To evaluate the characteristic neuropsychiatric symptoms and their outcome in patients diagnosed with ANMDARE.

METHODS

This was a prospective, longitudinal study in patients with a diagnostic suspicion of ANMDARE that presented to the National Institute of Neurology from March 2018 to February 2019. A comparative analysis of two groups (positive N-methyl-D-aspartate receptor [NMDAR] vs. negative NMDAR antibodies in cerebrospinal fluid [CSF]) was done on admission and at discharge. Neuropsychiatric systematic assessments included the Neuropsychiatric Inventory Questionnaire, the Bush Francis Catatonia Rating Scale, the Confusion Assessment Method Severity, the Montreal Cognitive Assessment, and the Overt Agitation Severity Scale.

RESULTS

24 individuals were analysed: 14 had positive NMDAR antibodies, and 10 had negative NMDAR antibodies in CSF. On admission, agitation/aggression, euphoria/exaltation, and disinhibition were more common in patients with positive antibodies. Excited catatonia and delirium were diagnosed more frequently in patients with positive antibodies. At discharge, there was an important decrease in neuropsychiatric symptoms, but substantial cognitive impairment remained. The mean hospitalisation length was 41.71 (SD 39.33) days for patients with definitive ANMDARE (p 0.259).

CONCLUSIONS

Neuropsychiatric symptoms profile in ANMDARE was associated with the early onset of euphoria/exaltation and disinhibition, accompanied by marked psychomotor agitation. When ANMDARE was suspected, the presence of excited-type catatonia and delirium showed a tendency to predict definitive ANMDARE. At discharged, most patients recovered from catatonia, delirium, and psychosis, but marked cognitive symptoms, anxiety, and depression persisted at discharge.

Extreme delta brush patterns guide the complex motor phenomenon of anti-NMDA receptor encephalitis: A case report

RATIONALE

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is an autoimmune disease that is associated with cell-surface NMDAR-targeting autoantibodies. Typical anti-NMDAR encephalitis symptoms include psychosis, seizure and extrapyramidal side effects. However, early diagnosis of anti-NMDAR encephalitis remains challenging due to the complexity of the motor phenomenon.

PATIENT CONCERNS

Here, we report a new diagnosis of anti-NMDAR encephalitis in a young woman with a history of epilepsy.

DIAGNOSES

Electroencephalography revealed a typical "extreme delta brush" pattern, which indicated anti-NMDAR encephalitis.

INTERVENTIONS

The clinical status of the patient markedly improved after immediate and aggressive immunosuppression therapies.

OUTCOMES

The patient was discharged with mild cognitive impairment. However, this was completely resolved 1 month postdischarge.

LESSONS

We conclude that subacute onset focal seizure with psychosis as well as compatible electroencephalography findings (i.e., extreme delta brush patterns) should be considered notable early indicators of anti-NMDAR encephalitis. This would ensure early and effective clinical interventions, which are essential for favorable outcomes.

Anti-NMDAR Encephalitis: Higher Suspicious Needed for Earlier Diagnosis (Case Report, Literature Review and Diagnostic Criteria)

Background

Auto-immune mediated anti-NMDA receptor encephalitis is a very common delayed diagnosed encephalitis which predominately affecting young population.

Objectives

This encephalitis is relatively unknown amongst emergency physicians and a majority of patients are admitted to psychiatric wards before their diagnosis is confirmed and appropriate treatments are commenced. We reported a case of a 22-year-old female presented to our emergency department with acute psychiatric symptoms. She was initially diagnosed with first presentation of acute psychosis and was hospitalised under mental health act. further assessment in the emergency department identified possible an organic cause for her acute psychosis and she was later admitted under medical team after her mental health assessment order was revoke. Several days later, her CSF result was positive with anti-NMDA receptor anti-bodies. Appropriate treatments were instituted leading to her full recovery.

Conclusion

This case was the first confirmed anti-NMDA receptor encephalitis in our emergency department. It highlights the importance of thorough assessment of psychiatric presentations to emergency departments and consideration of auto-immune medicated encephalitis as one of the differential diagnosis in young patients presenting with first acute psychotic episode.

Co-occurrence of Anti-N-Methyl-D-Aspartate Receptor Encephalitis and Anti-myelin Oligodendrocyte Glycoprotein Inflammatory Demyelinating Diseases: A Clinical Phenomenon to Be Taken Seriously

Background: Anti-N-methyl-D-aspartate receptor (NMDAR) immunoglobulin G antibodies which exist on myelin sheaths, composed of oligodendrocytes, especially target GluN1 subunits and are highly characteristic of anti-NMDAR encephalitis which is a newly recognized autoimmune encephalitis (AE) characterized by psychiatric symptoms, behavioral abnormalities, seizures, cognitive impairment and other clinical symptoms. Myelin oligodendrocyte glycoprotein (MOG) is a type of protein which is expressed on the surface of oligodendrocytes and myelin in the central nervous system. Anti-MOG antibodies cause demyelination. In some rare reported cases, these two types of antibodies have been found to co-exist, but the underlying mechanisms remain unknown.

Case presentation: Here we report cases of 4 inpatients (median age 31.5 years, age range 27–43 years) from The Second Xiangya Hospital of Central South University between March 2018 and April 2019. Two of the cases were first diagnosed as anti-NMDAR encephalitis and had developed visual impairments in the course of the dosage reduction during corticosteroid therapy. They were found at the time, to have anti-MOG antibody-positive CSF and/or serum. Another patient was diagnosed with anti-MOG inflammatory demyelinating diseases (IDDs) when he tested double positive for both anti-NMDAR and anti-MOG antibodies early in the course of his illness. Over the course of the dosage reduction during corticosteroid therapy, his symptoms deteriorated; however, anti-MOG antibody levels elevated while anti-NDMAR antibody levels remained low. The other patient had initially developed psychiatric symptoms and limb weakness. She was also double positive for anti-NMDAR and anti-MOG antibodies early in the course of her illness. However, over the course of the dosage reduction during corticosteroid therapy, her symptoms worsened and levels of both antibodies elevated.

Conclusion: Anti-NMDAR and anti-MOG antibodies may coexist in rare cases. In addition, anti-NMDAR encephalitis and anti-MOG inflammatory demyelinating diseases may occur either simultaneously or in succession. Thus, when a patient is diagnosed with either of these two diseases, but exhibits symptoms of the other disease, the possibility of co-occurrence with both these diseases should be considered and the appropriate antibodies should be accurately detected to enable prompt selection of appropriate treatments by the physicians.

Anti-N-methyl-D-aspartate receptor encephalitis induced by bilateral ovarian teratomas with distinct histopathologic types: A case report and brief literature review

RATIONALE

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune disorder that is most frequently induced by ovarian teratoma in young females. The condition can be controlled and reversed via ovarian tumor resection and immunotherapy. However, anti-NMDAR encephalitis induced by bilateral ovarian teratomas with distinct histopathologic types is rarely reported in the literature.

PATIENT CONCERNS

A 23-year-old woman presented with seizures.

DIAGNOSES

The diagnosis was anti-NMDAR encephalitis associated with ovarian teratomas based on positive anti-NMDAR antibody tests in both the cerebrospinal fluid and serum, and the detection of bilateral ovarian lesions on pelvic computed tomography. The postoperative histopathologic examination confirmed that the left lesion was an immature teratoma, and the right lesion was a mature teratoma.

INTERVENTIONS

We performed surgical resection of the ovarian teratomas and administered immunotherapy for the control of anti-NMDAR encephalitis. Chemotherapy was administered for the immature teratoma.

OUTCOMES

The patient recovered without any postoperative complications. She has been confirmed to be in complete clinical remission, and has not had a recurrence during 18 months of follow-up.

LESSONS

Anti-NMDAR encephalitis induced by bilateral ovarian teratomas of differing histopathologic types (1 immature and 1 mature) is rare. Early diagnosis and treatment with tumor resection, immunotherapy, and chemotherapy are critical for a good prognosis.

Therapeutic plasma exchange in neurological disorders: Experience from a tertiary neuroscience centre

Therapeutic plasma exchange (TPE) involves the extracorporeal separation of plasma from the cellular components of blood with replacement fluid, such as human albumin or fresh frozen plasma. A number of studies across the world revealed that more than one third of TPE procedures were performed for neurological disorders. Myasthenia gravis (MG), Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyneuropathy (CIDP) were the most frequently cited indications for TPE, followed by multiple sclerosis (MS). However, treatments of these conditions have evolved over the years and it is likely that this has impacted on clinical practice. Here we present our experience of using TPE to treat neurological disorders. We reviewed the medical records of all 63 patients who received 349 procedures over 70 therapeutic cycles between 2012 and 2015 in a tertiary neurology centre. In total only 2 patients with GBS and MG were treated with TPE. The commonest indication was voltage gated potassium channel (VGKC) complex antibody associated disorders followed by CIDP and MS. There were 11 patients with limbic encephalitis. Nine of them had antibodies against VGKC complex and two had N-methyl-D-aspartate (NMDA) receptor antibodies. Sixty four percent of patients with limbic encephalitis and overall 78% of patients responded to TPE. The complication rate associated with this procedure was 8.6 per 100 therapeutic cycle. There was no treatment related mortality. We observed a change in indications of TPE compared to historical studies. It was less frequently used to treated GBS and MG. It was found to be safe and effective.

Catatonia in patients with anti-NMDA receptor encephalitis

AIM

There is a lack of studies related to the frequency, phenomenology, and associated features of catatonic syndrome in patients with anti-NMDA receptor encephalitis (ANMDARE). This study aimed to measure the frequency of catatonia in this condition and to delineate its particular symptoms.

METHODS

A prospective study was done with all inpatients who fulfilled the criteria of definite ANMDARE admitted to the National Institute of Neurology and Neurosurgery of Mexico from January 2014 to September 2018. The Bush-Francis Catatonia Rating Scale and Braünig Catatonia Rating Scale were administered at admission.

RESULTS

Fifty-eight patients were included and catatonia was diagnosed in 41 of these patients (70.6%). Immobility, staring, mutism, and posturing were the most frequent catatonic signs. Catatonia was associated with delirium, hallucinations, psychomotor agitation, generalized electroencephalography dysfunction, and previous use of antipsychotics. Mortality was present in 10% of the total sample; it was associated with status epilepticus, and was less frequent in the catatonia group. After immunotherapy, all cases showed a complete recovery from catatonic signs.

CONCLUSION

This systematic assessment of catatonic syndrome shows that it is a frequent feature in patients with ANMDARE as part of a clinical pattern that includes delirium, psychomotor agitation, and hallucinations. The lack of recognition of this pattern may be a source of diagnostic and therapeutic errors, as most physicians associate catatonia with schizophrenia and affective disorders.

Anti-NMDA receptor encephalitis: a case study and illness overview

Anti-N-methyl D-aspartate (NMDA) receptor (anti-NMDAR) encephalitis is among one of the most common autoimmune encephalitides. However, variations in clinical presentation and nonsequential multiphasic course often lead to delays in diagnosis. The mild encephalitis (ME) hypothesis suggests a pathogenetic mechanism of low-level neuroinflammation sharing symptom overlap between anti-NMDAR encephalitis and other psychiatric disorders including schizophrenia. Clinical symptoms of anti-NMDAR encephalitis may mimic schizophrenia and psychotic spectrum disorders or substance-induced psychosis. Although initially described in association with ovarian teratomas in women, anti-NMDAR encephalitis has been reported in individuals without paraneoplastic association, as well as in males. It can affect all age groups but is usually lower in prevalence in individuals greater than 50 years old, and it affects females more than males. Clinical evaluation is supported by laboratory workup, which includes cerebrospinal fluid (CSF) assays. The latter often reveals lymphocytic pleocytosis or oligoclonal bands with normal to elevated CSF protein. CSF testing for anti-NMDAR antibodies facilitates diagnostic confirmation. Serum anti-NMDAR antibody assays are not as sensitive as CSF assays. Management includes symptomatic treatment and immunotherapy.

Clinical Features, Treatment, and Outcomes Among Chinese Children With Anti-methyl-D-aspartate Receptor (Anti-NMDAR) Encephalitis

Objective: Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is the most common form of autoimmune encephalitis in pediatric patients. In this study, we aimed to investigate the clinical features and long-term outcomes of pediatric patients with anti-NMDAR encephalitis in China.

Methods: We conducted a retrospective study of children (age range: 0–18 years) with anti-NMDAR encephalitis treated at Children's Hospital of Fudan University between July 2015 and November 2018. Demographic characteristics, clinical features, treatment, and outcomes were reviewed.

Results: Thirty-four patients with anti-NMDAR encephalitis were enrolled (age range: 5 months to 14 years; median age: 7 years; female: 18). The median follow- up duration was 20 months (range: 6–39 months). Eighteen (52.9%) patients initially presented with seizures and 10 (29.4%) with abnormal (psychiatric) behaviors or cognitive dysfunction. Thirty (88.2%) patients exhibited more than two symptoms during the disease course. No neoplasms were detected. Twelve (35.2%) patients had abnormal cerebrospinal fluid (CSF) findings, including leukocytosis, and increased protein concentration. Eighteen (52.9%) patients exhibited normal brain MRI findings. Electroencephalography revealed abnormal background activity in 27 (79.4%) patients, and epileptiform discharges in 16 (47.0%) patients prior to immunotherapy. All patients received first-line immunotherapy, with 30 (88.2%) and four (11.8%) patients achieving good (Modified Rankin Scale [mRS] score of 0–2) and poor outcomes (mRS score of 3–5), respectively. Initial mRS scores differed significantly between the good and poor outcome groups. Fourteen out of 18 patients (77.7%) with seizures accepted anti-epileptic drug (AED) administration, and seizure freedom was achieved in 12 out of 14 (85.7%) patients at the last follow-up. Ten of these 12 (83.3%) patients withdrew from AED treatment within 1 year.

Conclusions: Most patients achieved seizure freedom, so long-term use of AEDs may not be necessary for pediatric patients with anti-NMDAR encephalitis. Among our patients, 83.3% were sensitive to first-line immunotherapy and achieved good outcomes. Higher mRS scores before immunotherapy predicted poor outcomes, highlighting the need for a comprehensive assessment of patients with anti-NMDAR encephalitis.

An evolving redefinition of autoimmune encephalitis

Autoimmune encephalitis encompasses a wide variety of protean pathologic processes associated with the presence of antibodies against neuronal intracellular proteins, synaptic receptors, ion channels and/or neuronal surface proteins. This type of encephalitis can also involve children with complex patterns of seizures and unexpected behavioural changes, which jeopardize their prompt recognition and treatment. Many epidemiological studies have shown that numerous immune-based forms of encephalitis can be encountered, almost surpassing the rate of postinfectious encephalitides. However, the overall exact prevalence of autoimmune encephalopathies remains underestimated, and the definition of diagnostic algorithms results muddled. The spectrum of neuropsychiatric manifestations in the pediatric population with autoimmune encephalitis is less clear than in adults, but the integration of clinical, immunological, electrophysiological and neuroradiological data is essential for a general approach to patients. In this review we report the most relevant data about both immunologic and clinical characteristics of the main autoimmune encephalitides recognized so far, with the aim of assisting clinicians in the differential diagnosis and favouring an early effective treatment. Correlations between phenotype and autoantibodies involved in the neurological damage of autoimmune encephalitis are largely unknown in the first years of life, because of the relatively small number of pediatric patients adequately studied. Future multicenter collaborative studies are needed to improve the diagnostic approach and tailor personalized therapies in the long-term.

Th17 cells were recruited and accumulated in the cerebrospinal fluid and correlated with the poor prognosis of anti-NMDAR encephalitis

Anti-N-methyl-D-aspartate-receptor (NMDAR) encephalitis is an autoimmune disorder characterized by memory deficits, psychiatric symptoms, and autonomic instability. The lack of suitable biomarkers targeting anti-NMDAR encephalitis makes the immunotherapy and prognosis challenging. In this study, we found that the Th17 cells were significantly accumulated in the cerebrospinal fluid (CSF) of anti-NMDAR encephalitis patients than that of control individuals. The concentration of the cytokines and chemokines including interleukin (IL)-1β, IL-17, IL-6, and CXCL-13 were significantly increased in the CSF of anti-NMDAR encephalitis patients. IL-6 and IL-17 were found to promote the differentiation of CD4+ T cells into Th17 lineage. The chemotaxis assay showed that CCL20 and CCL22 play essential roles in the migration of Th17 cells. Notably, the correlation between the expression of IL-17 and the outcome of anti-NMDAR encephalitis patients was analyzed. The data showed that high level of IL-17 was significantly correlated with the limited response to the treatment and relapse of anti-NMDAR encephalitis patients. Our results suggested the potential important involvement of IL-17 in anti-NMDAR encephalitis.

Paraneoplastic Teratoma-associated Anti-N-Methyl-D-Aspartate Receptor Encephalitis: The First Published Report from Saudi Arabia

Paraneoplastic teratoma-associated anti-N-methyl-D-aspartate (anti-NMDA) receptor encephalitis is a lately introduced disease that was first documented in 2007. In a recent systemic review in 2014, only a total of 174 cases of teratoma-associated anti-NMDA receptor encephalitis was reported. Herein, to the best of our knowledge, in Saudi Arabia, we report the first ever case of mature ovarian teratoma-associated anti-NMDA receptor encephalitis in a 21-year-old Saudi woman who presented to clinical attention with a nine-day history of neuropsychiatric symptoms preceded by a two-day flu-like illness. Central nervous system (CNS) examination was remarkable for confusion and an inability to move her lower limbs. Abdominal examination was remarkable for mild right lower quadrant tenderness without palpable organomegaly. Initial laboratory findings were remarkable for high CA-125 level of 205 units/ml (normal: 0 - 35 units/ml) and CA 19-9 level of 121 units/ml (normal: 0 - 37 units/ml). Cerebrospinal fluid (CSF) examination showed lymphocytic pleocytosis and oligoclonal bands. Computed tomography (CT) scan of the abdomen and pelvis showed a 7.2 x 6.3 x 5.5 cm mass of the right ovary that was highly suspicious for a mature teratoma with fat densities and calcified foci. Serum and CSF tested positive for anti-NMDA receptor antibodies. The patient underwent right oophorectomy and the final histopathological diagnosis was confirmed. Postoperatively, the patient had an uneventful postoperative course and did not receive adjuvant secondary immunotherapies. One day following the surgery, her neuropsychiatric symptoms improved dramatically. At a six-month follow-up at the outpatient clinic, the patient was symptom-free

Non-inflammatory cerebrospinal fluid delays the diagnosis and start of immunotherapy in anti-NMDAR encephalitis

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a form of autoimmune encephalopathy that presents with a wide variety of symptoms, including neuropsychiatric manifestations. The authors' aim for this study was to analyze the results of paraclinical studies of patients with a diagnosis of anti-NMDAR encephalitis and the association between symptom onset and diagnosis, and start of immunotherapy. Retrospective data of 29 patients with anti-NMDAR encephalitis were gathered and analyzed. Abnormal EEG was found in 27 patients (93.1%), whereas MRI was abnormal in 19 patients (65.5%). In contrast, an inflammatory pattern on CSF analysis was found in only 13 patients (44.8%). The absence of pleocytosis or increased proteins in the CSF was associated with a longer time from symptom onset to diagnosis and treatment (p = 0.003). The authors conclude that noninflammatory CSF may delay the correct diagnosis and start of immunotherapy in anti-NMDAR encephalitis. In the presence of suggestive clinical features, extensive studies including EEG are recommended.

Late-onset anti-N-methyl-d-aspartate receptor encephalitis in China

PURPOSE

This study aimed to summarize the clinical characteristics and outcome of late-onset anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis in China.

METHOD

All cases of people with a definitive diagnosis of anti-NMDAR encephalitis in West China Hospital between June 2012 and April 2017 were retrospectively reviewed. The demographics, clinical characteristics, and outcome of those patients (age≥45years old) were summarized. Comparisons were conducted between older (≥45years old) and younger (18-44years old) adults.

RESULT

Eighteen (12%) of 151 people were ≥45years old, 9 of whom (50%) were female. Psychiatric symptoms were the most common clinical manifestations of older adults and presented in all individuals. At the last follow-up, 14 (78%) of them had a good outcome (modified Rankin Scale: 0-2) and one (6%) died. Compared with 121 younger adults, older adults had a higher proportion of presenting memory deficit as the initial symptom (17% vs. 2%, p=0.023), longer interval from onset to admission (30 vs. 13days, p=0.013), and longer interval from onset to diagnosis (42.5 vs. 24days, p=0.045). No older adults' condition was accompanied with teratoma compared with 75% of younger adults with tumor (p=0.032). And older adults had a tendency to have a lower rate of positive NMDAR antibody (Ab) in serum (28% vs. 52%, p=0.053).

CONCLUSION

Delayed admission and diagnosis are more common in older adults than in younger adults. A comprehensive consideration of all symptoms and early screening of NMDAR Ab, especially in cerebrospinal fluid, is necessary and beneficial to differential diagnosis.

Updates in Refractory Status Epilepticus

Refractory status epilepticus is defined as persistent seizures despite appropriate use of two intravenous medications, one of which is a benzodiazepine. It can be seen in up to 40% of cases of status epilepticus with an acute symptomatic etiology as the most likely cause. New-onset refractory status epilepticus (NORSE) is a recently coined term for refractory status epilepticus where no apparent cause is found after initial testing. A large proportion of NORSE cases are eventually found to have an autoimmune etiology needing immunomodulatory treatment. Management of refractory status epilepticus involves treatment of an underlying etiology in addition to intravenous anesthetics and antiepileptic drugs. Alternative treatment options including diet therapies, electroconvulsive therapy, and surgical resection in case of a focal lesion should be considered. Short-term and long-term outcomes tend to be poor with significant morbidity and mortality with only one-third of patients reaching baseline neurological status.

Fulminant course in a patient with anti-N-methyl-D-aspartate receptor encephalitis with bilateral ovarian teratomas: A case report and literature review

RATIONALE

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis is an autoimmune disorder that can be controlled and reversed by immunotherapy. The presentation of NMDA receptor encephalitis varies, but NMDA receptor encephalitis is seldom reported in patients with both bilateral teratomas and preexisting brain injury.

PATIENT CONCERNS

A 28-year-old female with a history of traumatic intracranial hemorrhage presented acute psychosis, seizure, involuntary movement, and conscious disturbance with a fulminant course. Anti-NMDA receptor antibody was identified in both serum and cerebrospinal fluid, confirming the diagnosis of anti-NMDA receptor encephalitis. Bilateral teratomas were also identified during tumor survey. DIAGNOSES:: anti-N-methyl-D-aspartate receptor encephalitis.

INTERVENTIONS

Tumor resection and immunotherapy were performed early during the course.

OUTCOMES

The patient responded well to tumor resection and immunotherapy. Compared with other reports in the literature, her symptoms rapidly improved without further relapse.

LESSONS

This case report demonstrates that bilateral teratomas may be related to high anybody titers and that the preexisting head injury may be responsible for lowering the threshold of neurological deficits. Early diagnosis and therapy are crucial for a good prognosis in such patients.

Red flags for suspecting anti-NMDAr encephalitis in a first psychotic episode: report of two cases

Anti-N-methyl-D-Aspartate receptor (NMDAr) encephalitis is a recently described clinical entity with an increasing number of reported cases. Psychiatric symptoms in the early stages of the disease constitute a diagnostic challenge for the treating physician. We present two clinical cases: clinical case 1, a 26-year-old man, and clinical case 2, an 18-year-old man; both presented with a first episode of psychosis and were hospitalized as psychiatric disorders. Subsequently, both cases were diagnosed as anti-NMDAr encephalitis. The high prevalence of psychiatric symptoms in anti-NMDAr encephalitis forces psychiatrists and neurologists to have a high degree of suspicion in the presence of atypical symptoms in patients evaluated for the first episode of psychosis.

Anti-N-methyl-D-aspartate receptor encephalitis associated with mediastinal teratoma: a rare case report and literature review

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a recently identified neuroautoimmune disorder characterized by antibodies against the heteromeric NR1-NR2 receptor complex. To our best knowledge, anti-NMDAR encephalitis combined with mediastinal teratoma is extremely rare with only three cases been reported in literature worldwide. In this article, we present an 18 years old female diagnosed as anti-NMDAR encephalitis caused by a large mature mediastinal teratoma whose initial manifestations were acute headache and seizures. She was treated with intravenous immunoglobulin (IVIg) and surgical resection with a complete recovery. Our case shows that tumor resection along with prompt immunotherapy are effective treatment of the disease.