Case of autoimmune polyendocrine syndrome type 3 complicated with anti-N-methyl-D-aspartic acid-receptor encephalitis

Anti-N-methyl-D-aspartate receptor (NMDA-R) encephalitis is an autoimmune disorder in which autoantibodies in the limbic system bind to GluN1 subunits of NMDA-Rs in the brain. We report a rare case of autoimmune polyendocrine syndrome type 3 complicated by anti-NMDA-R encephalitis. After hospitalization for type 1 diabetes, the 39-year-old patient developed various schizophreniform symptoms and seizures after cold-like symptoms. These findings are consistent with the diagnosis of anti-NMDA-R encephalitis. Immune-related encephalitis was suspected at the early phase of the disease, and cerebrospinal fluid was positive for anti-NMDA-R antibody. Early steroid pulse therapy was initiated during the disease course. The condition improved gradually to full recovery. Early detection and treatment of anti-NMDA-R encephalitis should enhance a positive outcome, considering that besides thyroid diseases and type 1 diabetes, various autoimmune diseases are associated with autoimmune polyendocrine syndrome type 3.

[ECT in autoimmune encephalitis]

In this case report, a 27-year-old male presented at a department of neurology with postherpetic anti-N-methyl-d-aspartate (NMDA) receptor autoimmune encephalitis. The patient was psychotic and exhibited symptoms of akinetic and excited catatonia. He was mechanical restrained for a total of 46 days due to violent behaviour. He was treated with olanzapine and lorazepam up to 15 mg/day without effect on catatonic and behavioural symptoms. ECT was initiated, and the patient received a total of 16 treatments. He responded well to the treatment, and the violent behaviour resolved completely after the first treatment. ECT should be considered for catatonia in anti-NMDA-receptor autoimmune encephalitis.

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.

HSV encephalitis triggered anti-NMDAR encephalitis: a case report

BACKGROUND

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis (AE) is a common cause of nonviral infectious encephalitis, which can be triggered by herpes simplex virus infection. Previous studies have shown that approximately 27% of herpes simplex encephalitis (HSE) patients produce anti-NMDAR antibodies within 3 months. Immunotherapy is recommended in this situation, but some symptoms usually remain in the 1-year follow-up.

CASE PRESENTATION

A previously healthy 23-year-old Chinese young woman developed epileptic attack followed by psychiatric symptoms of confusion and irritation as well as cognitive deficits. Brain MRI showed hyperintense lesions of the right temporal lobe on DWI and T2 without contrast enhancement effects. Twenty-one days of acyclovir was administered based on the primary diagnosis of HSE. The anti-NMDAR antibody (IgG) was detected positively on day 11 after disease onset. She had improved cognitive function but suffered another grand mal epilepsy after the first course of intravenous immunoglobulin (IVIG) therapy combined with 1000 mg intravenous methylprednisolone. After discussion, another course of IVIG was started for 5 days. Her symptoms were well controlled with only mild cognitive deficits at the 1-year follow-up (mRS = 1).

CONCLUSIONS

Our case indicated that anti-NMDAR antibodies could develop earlier after HSE compared with previous data from adults. We suggested detecting AE antibodies simultaneously with each CSF analysis. Meanwhile, the second course of IVIG therapy was reasonable when symptoms were not controlled after the first course of IVIG combined with IV steroid treatment.

Clinical analysis of a patient simultaneously positive for antibodies of myelin oligodendrocyte glycoprotein and anti-N-methyl-D-aspartate receptor: A case report

RATIONALE

Myelin oligodendrocyte glycoprotein (MOG) antibody (MOG-Ab) disease (MOG-AD) is a type of demyelinating disease of the central nervous system characterized by a high frequency of optic neuritis (ON) attacks. anti-Nmethyl-D-aspartate receptor (NMDAR) encephalitis (anti-NMDARe) is an autoimmune disorder characterized by memory deficits, conscious disturbance, and seizures. Cases of simultaneous occurrence of MOG-Ab and anti-NMDARe antibody (anti-NMDARe-Ab) are rarely reported and could be mistaken for overlapping MOG-antibody disease (MOG-AD) and NMDARe. The diagnosis of such patients is challenging.

PATIENT CONCERNS

We report the case of a 37-year-old man who presented with recurrent headaches for 3 months and worsening symptoms over 2 weeks. He had a history of ON. He had a generalized seizure after 7 days in the hospital.

DIAGNOSIS

Brain magnetic resonance imaging (MRI) and cerebrospinal fluid tests showed no apparent abnormalities. Repeat MRI showed slight lesions 7 days later, and cerebrospinal fluid tests showed the simultaneous occurrence of MOG-Ab and anti-NMDARe-Ab.

INTERVENTIONS

He completely recovered after treatment with low doses of oral corticosteroids.

OUTCOMES

Two months and 2 years follow-up showed that his condition was stable.

LESSONS

The co-occurrence of MOG-Ab and anti-NMDAR-Ab does not indicate the co-occurrence of MOG-AD and anti-NMDARe. Laboratory findings should be combined with the clinical features to achieve an accurate and suitable diagnosis.

Clinical features and management of coexisting anti-N-methyl-D-aspartate receptor encephalitis and myelin oligodendrocyte glycoprotein antibody-associated encephalomyelitis: a case report and review of the literature

BACKGROUND

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis is an autoimmune encephalitis caused by antibodies targeting the GluN1 subunit of NMDA receptors. Myelin oligodendrocyte glycoprotein (MOG) antibody disorders are now widely accepted as peculiar neuroimmunological diseases with specific clinical and pathological features. Some rare cases of overlapping anti-NMDA receptor encephalitis and MOG antibody-associated diseases have been reported, presenting complex clinical symptoms that make the disease more difficult to recognize.

METHOD

In accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, the terms "NMDAR" and "MOG," "NMDAR" and "demyelination," and "MOG" and "encephalitis" were searched in PubMed. Clinical cases with dual-positive anti-NMDA cerebrospinal fluid receptors and MOG serum antibodies during the disease course were included in this study.

RESULTS

A total of 25 patients were analyzed in this study. The age at onset ranged from 3 to 54 years. The median number of relapses was 2.8. Administration of intravenous methylprednisolone and immunoglobulin was the most widely used treatment strategy (19/25 patients). Second-line treatments such as administration of mycophenolate mofetil, rituximab, interferon-β, azathioprine, cyclophosphamide, and temozolomide were also reported, followed by good outcomes.

CONCLUSIONS

The rates of coexisting anti-NMDA receptor encephalitis and MOG antibody-associated encephalomyelitis may be underestimated. Clinical symptoms such as seizures and cognitive decline accompanied by atypical central nervous system demyelination serve as warning signs of possible coexisting anti-NMDA receptor encephalitis and MOG antibody-associated encephalomyelitis. These patients could achieve good outcomes under proper immunotherapies.

Pediatric anti-NMDA receptor encephalitis associated with COVID-19

Anti-N-methyl-D-aspartate receptor encephalitis is a clinical condition characterized by acute behavioral and mood changes, abnormal movements, autonomic instability, seizures, and encephalopathy. We describe a 7-year-old boy diagnosed with autoimmune encephalitis due to NMDAR antibody in association with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (coronavirus disease 2019) (COVID-19), without pulmonary involvement or fever. The patient presented with acute ataxia, rapidly developed encephalopathy, and autoimmune encephalitis was suspected. Steroid treatment was withheld because of lymphopenia and intravenous immunoglobulin was started. The absence of clinical response prompted plasmapheresis and, when lymphocyte counts improved, pulse steroid treatment was applied. The latter was followed by significant improvement and the patient was discharged in a conscious and ambulatory state. Autoimmune encephalitis should be considered in the presence of neurological symptoms accompanying SARS-CoV-2 infection and steroid treatment should be preferred unless limited by contraindications.

Bilateral thalamic changes in anti-NMDAR encephalitis presenting with hemichorea and dystonia and acute transient psychotic disorder

Anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis is one of the most common causes of autoimmune encephalitis. Both movement disorders and neuropsychiatric manifestations are considered core features of anti-NMDAR encephalitis. Strong clinical suspicion, along with NMDAR antibody positivity in paired sample of serum and cerebrospinal fluid, with supportive MRI changes clinch diagnosis in majority. We herein report a case of a middle-aged woman with subacute behavioral abnormalities, which were so severe that forced her to attempt suicide. Hemichorea and dystonia, which appeared later in course, are not previously reported movement disorders in combination in anti-NMDAR encephalitis. Further, magnetic resonance imaging showed bilateral thalamic hyperintensities with diffusion restriction, which are in turn not described in this entity. After amalgamation of history, especially the presence of neuropsychiatric symptoms, clinical features, physical examination, and investigations, the diagnosis of anti-NMDAR encephalitis could be established. Our case not only highlights that the combination of hemichorea and dystonia can be features of anti-NMDAR encephalitis, but adds novelty by bilateral symmetric thalamic changes.

An Elderly Case of Paraneoplastic Anti-NMDA Receptor Encephalitis Associated with Small-cell Lung Cancer Expressing NR1 Subunits

A 61-year-old Japanese man presented with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. NR1 antibodies were detected in his cerebrospinal fluid. Chest computed tomography revealed lung tumor. The patient was diagnosed with paraneoplastic anti-NMDAR encephalitis associated with lung cancer and treated with two cycles of intravenous high-dose methylprednisolone and one cycle of intravenous immunoglobulin. However, he died one year later without improvement. An autopsy confirmed small-cell lung cancer (SCLC). Immunohistochemistry revealed the expression of NR1 subunits in the tumor cells, suggesting that SCLC may trigger NR1 autoimmunity though the expression of NR1 subunits as onconeural antigens, expanding the phenotypic spectrum of paraneoplastic neurological syndrome associated with SCLC.

Cryptococcus Meningitis Can Co-occur with Anti-NMDA Receptor Encephalitis

We herein report a 50-year-old man with alcoholic cirrhosis who developed loss of consciousness and tremor of the upper limbs. Magnetic resonance imaging findings were suggestive of limbic encephalitis with bilateral hippocampal damage, and a cerebrospinal fluid (CSF) examination confirmed anti-N-methyl-D-aspartate (NMDA) and anti-glutamate receptor antibodies. Despite initial corticosteroid therapy, meningeal irritation symptoms appeared, owing to the development of cryptococcal meningitis (CM), diagnosed by the detection of cryptococcal capsular polysaccharide antigen in the follow-up CSF analysis. Cerebral infarction with reversible stenosis of major cerebral arteries during the clinical course was also observed. Following administration of antifungals and corticosteroids, the number of cells in the CSF gradually declined, and NMDA receptor antibodies disappeared. Our study demonstrates the unique coexistence of CM with anti-NMDA receptor encephalitis in adults.

Anti-NMDA receptor encephalitis concomitant with myelin oligodendrocyte glycoprotein antibody diseases: A retrospective observational study

Anti-N-methyl-D-aspartate receptor encephalitis (NMDARe) can coexist with myelin oligodendrocyte glycoprotein antibody (MOG-ab) disease.To characterize MOG-ab disease during NMDARe, we analyzed all the patients with MOG-ab disease and NMDARe from our hospital from December 2018 to December 2019 and data from a systematical review of previously published reports. Details of the patients identified were summarized and literature was reviewed.Four of thirty (14.2%) patients with anti-NMDARe had overlapping MOG-ab disease in our department. Analyze together with previously reported cases. Thirty-two NMDARe patients had overlapping MOG-ab disease. The onset age ranged from 3 to 48 years. Twenty-four patients (74%) developed abnormal behavior or cognitive dysfunction during the episodes of anti-NMDARe. None of these patients had tumors. 84% (27/32) patients received high doses of steroids as first-line immunotherapy and 28% (9/32) received mycophenolate mofetil (MMF) to prevent relapse. Twenty-six of twenty-seven (96%) had a good outcome.Steroids are the most common first-line immunotherapies in NMDARe overlapping MOG-ab disease. Most of the NMDARe patients overlapping MOG-ab disease have a good prognosis.

Anti-N-methyl-D-aspartate Receptor Encephalitis: a Rare Complication of Ovarian Teratoma

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a potentially life-threatening but reversible autoimmune disorder characterized by psychiatric symptoms, cognitive dysfunction, speech dysfunction, seizures, movement disorder, decreased level of consciousness, and autonomic dysfunction or central hypoventilation. It occurs predominantly in young women and approximately half of them have underlying tumors, mainly ovarian teratoma. A 24-year old woman was admitted because of fever, headache, abnormal movement and decreased mental status. Five cycles of plasmapheresis improved her neurological and mental status. Anti-NMDAR antibodies in her CSF and serum were positive, and computed tomography revealed a 1-cm sized mass suggestive of mature cystic teratoma arising from the right ovary. We promptly performed laparoscopic right ovarian cystectomy. She was discharged after 2 weeks with mild memory deficit. Prompt removal of ovarian teratoma and multidisciplinary care are particularly important for good outcome.

Screening for anti-NMDAR encephalitis in psychiatry

Anti-NMDAR encephalitis most commonly presents to psychiatric services, so early identification of this disorder is essential. We aim to validate the two screening criteria (Scott et al. and Herken and Pruss) which have been proposed to identify first episode psychosis patients who should have anti-NMDAR antibody testing. The performance of the screening criteria were assessed using anti-NMDAR encephalitis cases published in the literature, and antibody positive and negative cases from a state-wide cohort (Queensland, Australia). Sensitivity, specificity and area under receiver operator characteristic curve analysis was performed. There were 258 anti-NMDAR encephalitis cases and 103 control cases, which demonstrated high performance of both Scott et al. "screening recommended" criteria (sensitivity 97.3%, specificity 85.4%, AUC 0.914) and Herken and Pruss "yellow flags" criteria (sensitivity 91.5%, specificity 83.5%, AUC 0.875). These criteria remained accurate when neurological variables were excluded, and in cases without psychosis. The Scott et al. "screening not recommended", and Herken and Pruss "red flags" criteria did not demonstrate clinical utility for first episode psychosis case screening. The screening criteria with good performance identify an atypical picture of psychiatric presentation with increased risk of anti-NMDAR positivity prior to overt neurological symptoms or investigations and may be beneficial to include in the routine psychiatric assessment process.

Risk factors for pneumonia in patients with anti-NMDA receptor encephalitis: A single-center retrospective study

To identify the risk factors of pneumonia in patients with Anti-N-methyl-D-aspartate (Anti-NMDA) receptor encephalitis.This is a retrospective study.Department of Neurology in West China Hospital of Sichuan University.Patients with a definitive diagnosis of anti-NMDA receptor encephalitis.Risk factors associated with pneumonia were examined by bivariate analysis and multivariate logistic regression model.A total of 104 patients were included in this study, of which 41% patients (n = 43) were diagnosed with pneumonia at 7 days (range: 4-40 days) after admission. The occurrence of pneumonia was associated with prolonged hospital stays, a higher rate of poor outcome, and extra healthcare costs. Risk factors associated with pneumonia included Glasgow coma scale score (GCS), abnormal movements and hypokalemia.Pneumonia is a common complication in anti-NMDA receptor encephalitis. In the present study, we found that disorders of consciousness, abnormal movements, and hypokalemia were independent risk factors for pneumonia in inpatients with anti-NMDA receptor encephalitis. Pneumonia prolongs the patients' hospital stay, hospitalization expenditures, and affects the patients' prognosis.

[Acute neuropsychiatry: a confused patient and a puzzled doctor]

BACKGROUND

Anti-NMDA-receptor-encephalitis is a progressive autoimmune disease with significant mortality if left untreated.

CASE DESCRIPTION

A 58-year-old man without previous psychiatric or neurologic history presented at the emergency department after brief loss of consciousness at work. Within a few hours, the patient developed acute neuropsychiatric symptoms, including altered levels of consciousness, aggression, incoherence, change in behaviour, and psychomotor agitation. Initially, additional blood, cerebrospinal fluid and EEG tests showed no abnormalities. Over the course of the following days, catatonia, orofacial dyskinesia and autonomic-function disorder developed, eventually with respiratory insufficiency, necessitating transfer to the intensive-care unit. At this stage, the EEG did show abnormalities, and cerebrospinal fluid analysis showed marginal pleocytosis. The patient was treated with intravenous methylprednisolone and immunoglobins. Anti-NMDA-receptor antibodies were present in the blood and cerebrospinal fluid. Screening for malignancy identified small-cell lung carcinoma, for which the patient was treated with cytostatic agents.

CONCLUSION

Acute neuropsychiatric symptoms in a middle-aged patient with no psychiatric medical history are suggestive of an underlying somatic cause. Timely recognition and treatment of anti-NMDA-receptor encephalitis is essential to improve the prognosis.

Nursing care in anti-N-methyl-D-aspartate receptor encephalitis: A case series

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a paraneoplastic limbic encephalitis, recently identified.To summarize our experience in the nursing care of patients with anti-NMDAR encephalitis managed with surgery and pharmacotherapy.This study included 45 patients treated between July 2015 and November 2016. Laparoscopic oophorocystectomy was performed in 11 female patients with teratomas. Eleven patients required tracheal intubation or tracheotomy and ventilation.The patients were hospitalized for an average of 25.2 days. The mental and neurological symptoms were significantly relieved 23.6 ± 4.8 days after surgery or immunotherapy. Near-normal function was restored in 11 patients, while 34 patients had varying degrees of dysfunction at discharge. After follow-up of 1 to 18 months, 24 patients were found to have permanent impairments.Appropriate symptomatic nursing care is required to ensure the safety of patients with anti-NMDAR encephalitis.

A Unique Shape of Brainstem Lesion that Caused Orthostatic Hypotension in Anti-NMDAR Encephalitis

After experiencing upper respiratory-tract symptoms, a 41-year-old woman developed encephalitis with consciousness disturbance and respiratory failure. She had external ophthalmoplegia and facial diplegia. Magnetic resonance imaging revealed a brainstem lesion with spared longitudinal pontine bundles. Abnormal findings of the brainstem auditory-evoked potentials and blink reflex supported brainstem damage. The patient was positive for anti-N-methyl-D-aspartate receptor (NMDAR) antibodies. Repeated immunological treatments improved her symptoms, but severe orthostatic hypotension emerged. A head-up tilt test revealed no arginine vasopressin response to hypotension. The atypical symptoms of this case highlighted that the brainstem is one of the pivotal regions in anti-NMDAR encephalitis.

Clinical characteristics of autoimmune disorders in the central nervous system associated with myasthenia gravis

Myasthenia gravis (MG) is occasionally associated with autoimmune diseases in the central nervous system (CNS), such as neuromyelitis optica spectrum disorder (NMOSD), multiple sclerosis (MS), Morvan syndrome, and anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. Here, we report five original cases associated with autoimmune disorders in the CNS among 42 patients with MG in a single tertiary hospital in Japan (11.9%). In four of these five cases, the second disease developed when the preceding disease was unstable. Accurate diagnosis of the newly developing disease may be difficult in such cases, because some neurological symptoms can be seen in both disorders. This implies the great importance of recognizing the possible co-occurrence of MG and disorders in the CNS. In addition, a comprehensive review of the literature revealed distinct clinical characteristics depending on the associated disease in the CNS, including thymic pathology and temporal relationship between MG and associated CNS disorders. Notably, NMOSD usually develops after the onset of MG and thymectomy, in clear contrast to MS. Thymoma is highly prevalent among patients with Morvan syndrome, in contract to cases with NMOSD and MS. The analysis of clinical characteristics, representing the first such investigation to the best of our knowledge, suggests different pathogeneses of these autoimmune diseases in the CNS, and provides significant implications for clinical practice.

Association of Anti N-methyl-D-aspartate (NMDA) Receptor Encephalitis with Chediak-Higashi Syndrome

BACKGROUND

Neurological manifestations of Chediak-Higashi syndrome mainly include peripheral neuropathy, ataxia, tremors, cranial nerve palsies, intellectual decline and seizures.

CASE CHARACTERISTICS

A 2 years 10 month old girl with silvery hair syndrome presented with sub-acute onset behavioral issues, ataxia and multiple type abnormal movements. Cerebrospinal fluid examination was positive for Anti NMDA receptor antibodies. Hair shaft examination and peripheral blood film findings were suggestive of Chediak Higashi syndrome.

MESSAGE

Anti NMDA receptor encephalitis may be associated with Chediak Higashi Syndrome.

Teratoma-associated anti-N-methyl-D-aspartate receptor encephalitis: A case report and literature review

RATIONALE

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is an autoimmune disease associated with the NMDA receptor and has a good response to treatment. However, only few cases related to teratoma have been reported. Here, we report a case of teratoma-associated anti-NMDAR encephalitis.

PATIENT CONCERNS

A 25-year-old woman presenting with fever for 20 days and psychiatric symptoms for 9 days was admitted to the hospital. The patient progressed to a minimally conscious state consistent with encephalitis.

DIAGNOSIS

Considering the possibility of autoantibody-mediated encephalitis, laboratory tests were conducted to detect anti-NMDAR antibodies in cerebrospinal fluid and serum. Results confirmed the diagnosis of anti-NMDAR encephalitis. Furthermore, gynecological ultrasound investigation detected teratoma in the left ovary.

INTERVENTIONS

After resection of the teratoma with laparoscopic adnexectom, the patient was treatment with immunosuppressive therapy.

OUTCOMES

The patient recovered gradually and was discharged 2 months after the operation.

LESSONS

Anti-NMDAR encephalitis remains difficult to diagnose because of its vague manifestations, and no clinical practice guidelines for prevention and treatment of the disease have been established yet. The clinical data of a case of teratoma-related anti-NMDAR encephalitis were analyzed, and relevant studies were reviewed.

NMDAR encephalitis presenting as akinesia in a patient with Parkinson disease

We describe the case of a woman with Parkinson disease who developed an N-methyl-d-aspartate receptor antibody-mediated encephalitis. As a novelty, the encephalitis presentation mimicked a worsening of the pre-existing extrapyramidal syndrome, manifesting mainly as severe bradykinesia and, eventually, akinesia. Brain MRI was normal, whereas cerebrospinal fluid (CSF) analysis disclosed unique-to-CSF oligoclonal bands. Prompt identification and timely immunotherapy led to a complete recovery.

Clinical Profile and Neuropsychiatric Outcome in Children with Anti-NMDAR Encephalitis

Six children with anti-NMDAR encephalitis were followed-up for 6 to 24 months. They presented with seizures, neuropsychiatric symptoms and movement disorder, particularly orofacial dyskinesia and choreoathetosis. Immunosuppressive therapy resulted in varying degrees of improvement; none relapsed. Expressive aphasia was the last symptom to regress.

A mouse model of seizures in anti-N-methyl-d-aspartate receptor encephalitis

OBJECTIVE

Seizures develop in 80% of patients with anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis, and these represent a major cause of morbidity and mortality. Anti-NMDAR antibodies have been linked to memory loss in encephalitis; however, their role in seizures has not been established. We determined whether anti-NMDAR antibodies from autoimmune encephalitis patients are pathogenic for seizures.

METHODS

We performed continuous intracerebroventricular infusion of cerebrospinal fluid (CSF) or purified immunoglobulin (IgG) from the CSF of patients with anti-NMDAR encephalitis or polyclonal rabbit anti-NMDAR IgG, in male C57BL/6 mice. Seizure status during a 2-week treatment was assessed with video-electroencephalography. We assessed memory, anxiety-related behavior, and motor function at the end of treatment and assessed the extent of neuronal damage and gliosis in the CA1 region of hippocampus. We also performed whole-cell patch recordings from the CA1 pyramidal neurons in hippocampal slices of mice with seizures.

RESULTS

Prolonged exposure to rabbit anti-NMDAR IgG, patient CSF, or human IgG purified from the CSF of patients with encephalitis induced seizures in 33 of 36 mice. The median number of seizures recorded in 2 weeks was 13, 39, and 35 per mouse in these groups, respectively. We observed only 18 brief nonconvulsive seizures in 11 of 29 control mice (median seizure count of 0) infused with vehicle (n = 4), normal CSF obtained from patients with noninflammatory central nervous system (CNS) conditions (n = 12), polyclonal rabbit IgG (n = 7), albumin (n = 3), and normal human IgG (n = 3). We did not observe memory deficits, anxiety-related behavior, or motor impairment measured at 2 weeks in animals treated with CSF from affected patients or rabbit IgG. Furthermore, there was no evidence of hippocampal cell loss or astrocyte proliferation in the same mice.

SIGNIFICANCE

Our findings indicate that autoantibodies can induce seizures in anti-NMDAR encephalitis and offer a model for testing novel therapies for refractory autoimmune seizures.

The psychopathology of NMDAR-antibody encephalitis in adults: a systematic review and phenotypic analysis of individual patient data

BACKGROUND

Early immunotherapy administration improves outcomes in patients with N-methyl-D-aspartate receptor (NMDAR)-antibody encephalitis. As most patients with NMDAR-antibody encephalitis present to psychiatrists, the psychopathology of NMDAR-antibody encephalitis needs to be clearly defined to encourage accurate clinical identification and prompt treatment.

METHODS

For this systematic review, we searched PubMed for all studies published in English between Jan 1, 2005, and Oct 7, 2017, to identify individually reported adult patients (≥18 years) who satisfied consensus criteria for definite NMDAR-antibody encephalitis. After generating a list of 50 fine-grained, lower-level features, we extracted psychopathological data in addition to demographic and aetiological data. The lower-level features were later ordered within higher-level categories. As a means of quality control, we filtered the data according to proxy markers of psychiatric involvement in their description. Subsequently, we compared lower-level features from individual patient data with operationalised psychiatric syndromes using a constrained combination approach and principal component analysis, and did a network analysis to explore the inter-relationships between multiple lower-level features. The review protocol was prospectively registered with PROSPERO, number CRD42017068981.

FINDINGS

Of 1096 records identified in PubMed, 333 satisfied inclusion criteria and described 1100 patients in total with NMDAR-antibody encephalitis. The psychopathology of 505 (46%) patients with reported psychiatric symptoms was described in more detailed terms than only psychiatric or behavioural. 464 (91%) of the 505 patients were from papers in which patient data were reported individually. The remainder of the analyses focused exclusively on these 464 patients. Median age was 27 years (IQR 22-34), 368 (79%) of 464 patients were female and in 147 (32%), NMDAR-antibody encephalitis was associated with ovarian teratoma. The five higher-level categories into which the 464 patients most frequently grouped were behaviour (316 [68%]), psychosis (310 [67%]), mood (219 [47%]), catatonia (137 [30%]), and sleep disturbance (97 [21%]). The overall pattern of lower-level features was statistically stable across subgroups classified by age, sex, pregnancy association, presence of ovarian teratoma, prior herpes simplex virus encephalitis, and isolated psychiatric presentations (two-way ANOVA p=0·6-0·9). Constrained combination and principal component analyses found that mixtures of mood and psychosis syndromes fit each patient better than any single diagnosis alone, particularly for the patients in the psychiatric-described subgroup (mean ΔAkaike information criterion -0·04 in non-psychiatric-described subgroup vs 0·61 in psychiatric-described subgroup). The overlapping nature of the higher-level features was also enriched upon analysis of the psychiatric-described data (221 [67%] of 329 overlaps in non-psychiatric-described subgroup vs 96 [81%] of 118 overlaps in psychiatric-described subgroup, p=0·0052). Network analysis confirmed that the features were closely related and consistent between individual patients; the psychiatric-described subgroup had a markedly high and narrow range of closeness centralities (92% above 0·93 in psychiatric-described subgroup vs 51% above 0·93 in the non-psychiatric group).

INTERPRETATION

The distinctive aspect of NMDAR-antibody encephalitis psychopathology is complexity; core aspects of mood and psychotic disorders consistently coexist within individual patients. Alongside the predominant young female demographic, these psychopathological features could help psychiatrists identify patients who would benefit from cerebrospinal fluid testing and immunotherapies. Well-controlled prospective studies with bespoke inventories are needed to advance this clinically grounded approach.

FUNDING

Wellcome Trust, NIHR Oxford Biomedical Research Centre, NIHR Oxford Health Biomedical Research Centre, British Medical Association Foundation for Medical Research.