Diagnosis Of anti-NMDAR Encephalitis Research Articles

Rapid deterioration of a case of anti–N-methyl-D-aspartate receptor encephalitis with an ovarian teratoma, mimicking viral encephalitis

Anti–N-methyl-D-aspartate receptor (NMDAR) encephalitis has recently emerged as an autoimmune encephalitis syndrome. Younger females are more likely to develop this condition which usually presents as a multistage illness with predominant neuropsychiatric manifestations. It is associated with the neuroglial surface antibodies developing against NMDAR. The association of ovarian teratoma has been well recognised in this condition and tumour resection will intensify the recovery of the illness along with immunotherapy. We present a case of 19-year-old female who presented with acute onset of fever, encephalopathy and facial myorhythmia mimicking acute viral encephalitis. Her clinical status deteriorated within a short period. Later, her CSF became positive for NMDAR antibody and a right ovarian teratoma was detected. Her clinical status markedly improved with immunotherapy and excision of the teratoma following a diagnosis of Anti-NMDAR encephalitis. As a potentially treatable neurological condition, clinicians should be aware of this autoimmune encephalitis syndrome causing encephalitis.

Persistent meningitis followed by anti-NMDAR encephalitis: case series and literature review (P5-5.002)

<h3>Objective:</h3> To report the cases of two patients with persistent meningitis followed by anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis and discuss the pathogenesis of the disease in conjunction with previous reports. <h3>Background:</h3> Although meningeal involvement has been reported in anti-NMDAR encephalitis, reports of persistent meningitis prior to the onset of encephalitis are rare. <h3>Design/Methods:</h3> Case series and literature review. <h3>Results:</h3> We experienced two patients with anti-NMDAR encephalitis preceded by persistent meningitis. Patient 1 presented with protracted fever, and a brain MRI revealed leptomeningitis. Although cerebrospinal fluid (CSF) cell counts spontaneously decreased from 87 to 16 cells/mm³ over 2 weeks without treatment, the symptoms and signs associated with meningitis lasted 60 days. Despite the administration of oral prednisolone, abnormal behavior and speech dysfunction occurred, leading to the diagnosis of encephalitis. After the detection of anti-NMDAR antibodies in CSF, the diagnosis of anti-NMDAR encephalitis was made, which improved after administration of intravenous methylprednisolone and plasmapheresis. Patient 2 had headache and fever for 22 days, and the CSF cell counts declined from 112 to 14 cells/mm³ over 2 weeks without treatment. The emergence of delusion, involuntary movement (tongue protrusion), and decreased level of consciousness prompted the diagnosis of encephalitis. Anti-NMDAR encephalitis was identified after the positive result of anti-NMDAR antibodies in CSF; it was successfully treated with intravenous methylprednisolone and plasmapheresis. In both cases, infectious meningitis was ruled out, suggesting a possible autoimmune mechanism. No tumors, including ovarian teratoma, were found during systemic evaluation. In previous cases, we found two patients with persistent meningitis followed by anti-NMDAR encephalitis. The findings in the four meningitis patients showed prolonged meningitis lasting from 5 to 60 days, and infectious or paraneoplastic meningitis was ruled out. <h3>Conclusions:</h3> Anti-NMDAR encephalitis should be considered a differential diagnosis of long-term persistent nonviral meningitis. <b>Disclosure:</b> Dr. Yamahara has nothing to disclose. Dr. Yoshikura has nothing to disclose. Dr. Kimura has nothing to disclose. Dr. Shimohata has nothing to disclose.

Post-Abortum NMDA Encephalitis (P5-5.010)

<h3>Objective:</h3> To present a case series of two patients who developed NMDAR encephalitis after elective abortion. <h3>Background:</h3> Anti-NMDAR encephalitis has been associated with several preceding triggers, most commonly tumors and HSV encephalitis. Recognizing other triggers is important to elevate clinical suspicion when evaluating patients with acute encephalitis symptoms. Although cases have been reported of NMDA encephalitis during pregnancy, to our knowledge only one other case preceded by an abortive procedure was published. <h3>Design/Methods:</h3> N/A <h3>Results:</h3> Two patients, aged 20 and 27 years old, with no previous neurological history developed anti-NMDAR encephalitis after undergoing an elective abortion. Symptoms started 2 weeks after the procedure and was described as an acute psychosis. Diagnosis of anti-NMDAR encephalitis was confirmed with antibody titer testing in the CSF and serum. Both patients had positive Anti-NMDAR antibody titer in CSF; one patient also had positive antibody testing in the serum. Hospital stay of both patients was complicated by catatonia, with one patient requiring prolonged ICU stay due to severe dysautonomia. Patients were treated with a 5-day course of IVIG and made a full recovery. Cancer workup was done with transvaginal ultrasound, and CT chest, abdomen and pelvis on initial presentation and was negative at the time of presentation. In serial CT scans, one of the patients developed a thymoma six months after the onset and underwent surgical removal of the lesion with complete resolution of the symptoms. <h3>Conclusions:</h3> These cases suggests that anti-NMDAR autoimmune encephalitis may be correlated with recent abortion. Recognizing this possible relation might indicate that termination of pregnancy in these patients may not lead to improvement of the neurological condition. It is important to note that this association should not preclude investigations for underlying malignancy. Further population studies need to be performed to confirm abortion as a possible trigger and underlying pathophysiology of this neurological condition. <b>Disclosure:</b> Dr. Aleyadeh has nothing to disclose. Dr. Nascimento Andrade has nothing to disclose. Dr. Shaikh has nothing to disclose. Dr. Bose has nothing to disclose. Dr. Umeton has nothing to disclose.

HIDING IN PLAIN SIGHT: ANTI-NMDAR- ENCEPHALITIS IN A 30-YEAR-OLD MALE- A CASE REPORT

The most common type of autoimmune encephalitis is anti-NMDAR-encephalitis. It is characterized by IgG an­tibodies against the GluN1 subunit of the NMDA receptor, leading to marked neuropsychiatric and behavioural symptoms that progress in a subacute manner to seizures, speech abnormalities, and a depressed level of con­sciousness. In this case report, the clinical course of a 30-year-old man who first received treatment for viral encephalitis after exhibiting normal symptoms is described. CSF showed lymphocytic pleocytosis with normal brain imaging. The EEG demonstrated diffuse slowing and encephalopathy. An autoimmunity encephalitis workup was done after exhaustive investigations for metabolic and infectious causes came back negative. A diagnosis of anti-NMDAR encephalitis was made after antibodies were found in the CSF.

Pediatric Anti-NMDA Receptor Autoimmune Encephalitis Masquerading as Depression: A Case Report From a Tertiary Care Center in South India

Abstract Autoimmune disorders are now widely recognized as playing a larger role in encephalitis than previously thought. The most common disorder appears to be anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis. Psychological symptoms, memory difficulties, and autonomic instability are all part of the complicated presentation and are being considered an important differential diagnosis for children presenting with acute behavioral disturbances. We present the case of a 17-year-old girl, who presented with a 1.5-year history of psychiatric symptoms such as pervasive low mood, decreased ability to concentrate on her studies, academic decline, memory disturbances along with poor social interaction, decreased self-esteem, and ideas of guilt. This was accompanied by altered biological functions. Within a week, the symptoms changed dramatically, with labile mood, over familiarity, over identification, déjà vu, auditory hallucinations and anxiety symptoms, nonspecific somatic symptoms such as fever, vomiting, and neurological symptoms including seizures and dyskinesia. Diagnosis of anti-NMDAR encephalitis was made by electroencephalography and serum antibody testing. Symptom improvement was noted with five cycles of plasmapheresis and injection of rituximab. Psychiatric manifestations are common, and child and adolescent psychiatrists are frequently the first to be contacted for patients with anti-NMDAR encephalitis. There is, therefore, an increasing need for them to become aware of the disorder and consider it in their differential diagnosis. A better prognosis can be achieved with appropriate evaluation by a multi-disciplinary team.

Anti-NMDAR Encephalitis with Relapsing Optic Neuritis

Autoimmune encephalitis with antibodies to NMDA receptors (anti-NMDAR encephalitis) is a frequent form of autoimmune encephalitis. The disease is curable, though the lack of timely treatment can lead to disability in patients or death. Difficulties in the diagnosis of anti-NMDAR encephalitis arise from its heterogenous manifestations, its possible combination with other autoimmune diseases, and lack of doctors’ awareness of this type of encephalitis. This article reviews published data and describes a case of anti-NMDAR encephalitis with atypical features in the form of relapsing optic neuritis; it was difficult to link optic nerve lesions with comorbidity with multiple sclerosis or optic neuromyelitis spectrum disorders.

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.

Anti-N-Methy-D-Aspartate receptor encephalitis in pediatric age

Introduction: Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an immune-mediated syndrome characterized by psychiatric symptoms, movement disorders, insomnia, seizures, altered level of consciousness and autonomic dysfunction. The aim of this study was described the cases of anti-NMDAR encephalitis admitted to a Neuropediatrics Department, in order to alert for the importance of early recognition of this clinical entity due to its implications in prognosis. Material and Methods: A retrospective review of the clinical processes of patients with anti-NMDAR encephalitis admitted to the Neuropediatrics Department of a University Hospital in the period between May 2009 and May 2016 was conducted. Results: Diagnosis of anti-NMDAR encephalitis was established in nine patients. Mean age at diagnosis was 9.4 years and five patients were male. Most cases (88.9%) presented with neuropsychiatric symptomatology. Movement disorders were another frequent finding (88.9%) and include chorea, dystonia and dyskinesias. Altered level of consciousness occurred in 77.8% of cases, insomnia and speech disturbance in 66.7%, seizures in 55.6% and autonomic dysfunction in 22.2%. Anti-NMDAR antibodies were identified in the cerebrospinal fluid of all patients. One patient had an underlying neoplasm. All patients underwent immunosuppressive therapy and seven patients fully recovered. In the remaining patients, sequelae included refractory epilepsy and cognitive impairment. Discussion: The diagnosis of anti-NMDAR encephalitis should be considered in children and adolescents presenting with psychiatric symptoms associated and movement disorders. In this sample, although most patients responded very favorably to treatment, severe sequelae were also observed. This highlights the importance of an early diagnosis to initiate treatment as soon as possible.

A Case of Teratoma-Associated Anti-NMDAR Encephalitis

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is an autoimmune encephalitis that is associated with the NMDA receptor and has a good response to treatment. However, only a small number of cases related teratoma has been reported in literature. Here we report a case of teratoma-associated anti-NMDAR encephalitis. A 25-year-old woman with the presentation of fever for 20 days and psychiatric symptoms for 9 days was admitted to the hospital. This patient progressed to a minimally conscious state consistent with encephalitis. Considering the possibility of autoantibody-mediated encephalitis, laboratory tests were undertaken to observe the anti-NMDAR antibodies in cerebrospinal fluid (CSF) and serum, which confirmed the diagnosis of anti-NMDAR encephalitis. Furthermore, gynecological ultrasound investigation detected teratoma in the left ovary. After resection of the teratoma with Laparoscopic adnexectom and treatment with immunosuppressive therapy, the patient recovered gradually and was discharged one month after the operation. Due to the lack of clinical practice guidelines for the prevention and treatment of anti-NMDAR encephalitis, the disease is still difficult to diagnose because of its vague manifestations. For the further study, the clinic data of one case of teratoma-related anti-NMDAR encephalitis was analyzed and the relevant literatures were reviewed.

Anti-N-methyl-d-aspartate receptor encephalitis in children: Incidence and experience in Hong Kong

AimThe study aims to analyze the incidence, clinical features, investigation findings and treatment outcomes of anti-N-methyl-d-aspartate receptor encephalitis in children from Hong Kong. MethodA retrospective study was carried out on paediatric patients diagnosed with anti-NMDAR encephalitis in Hong Kong from January 2009 to December 2015. ResultsFifteen patients (67% female, 93% Chinese) were identified over seven years and the estimated incidence in Hong Kong was 2.2/million children per year (95% CI 1.2–3.6). The median age of presentation was 12 years (range 1–17 years). The most common symptom groups observed were abnormal psychiatric behavior or cognitive dysfunction (14/15, 93%) and seizures (14/15, 93%), followed by speech dysfunction (13/15, 87%), movement disorders (12/15, 80%), decreased level of consciousness (10/15, 67%) and autonomic dysfunction or central hypoventilation (5/15, 33%). The median number of symptom groups developed in each patient was 5 (range 3–6). All patients were treated with intravenous immunoglobulin and/or steroids. Three patients (20%) with more severe presentation required additional plasmapheresis and rituximab. Outcome was assessable in 14 patients. Among those eleven patients who had only received intravenous immunoglobulin and/or steroids, nine patients (82%) achieved full recovery. One patient (9%) had residual behavioral problem, while another one (9%) who developed anti-NMDAR encephalitis after herpes simplex virus encephalitis was complicated with dyskinetic cerebral palsy and epilepsy. Among those three patients who required plasmapheresis and rituximab, one (33%) had full recovery and two (66%) had substantial recovery. The median duration of follow up was 20.5 months (range 3–84 months). ConclusionAnti-NMDAR encephalitis is an acquired, severe, but potentially treatable disorder. Ethnicity may play a role in the incidence of anti-NMDAR encephalitis and we have provided a local incidence with the majority of patients being Chinese. The diagnosis of anti-NMDAR encephalitis should be considered in children presenting with a constellation of symptoms including psychiatric and neurological manifestations. Patients may respond to first line immunotherapy. For those who do not, second line therapy is indicated in order to achieve a better outcome.

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.

Resection of melanocytic nevi as a potential treatment of anti-NMDAR encephalitis patients without tumor: report of three cases

The most common underlying tumor associated with anti-N-methyl D-aspartate-receptor (NMDAR) encephalitis is ovarian teratoma. Resection of the underlying tumor may decrease exposure of autoantigen and make for faster response of immunotherapy and less relapse frequency. Similar to teratoma, expression of NMDAR in human epidermal melanocytes was suspected recently. The dense melanocytes in melanocytic nevus may serve as potential autoantigens and are prone to increase relapse frequency in the tumor-negative patients. Three patients with confirmed diagnosis of anti-NMDAR encephalitis were described here. They shared common features that the screening tests for an ovarian teratoma or other tumors were all negative, while they were found to have prominent melanocytic nevi on the skin and resection of the nevi likely played a positive effect on their persistent recovery. This is a report on treatment of anti-NMDAR encephalitis patients without underlying tumor through resection of melanocytic nevi. More clinical and experimental investigations are needed to prove its validity.

A case of reversible anti-NMDA-receptor encephalitis: neuropsychological and neuroradiological features

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is an autoimmune encephalitis mainly affecting young women. We report a case of a mild paraneoplastic anti-NMDAR encephalitis in a 31-year-old female with an ovarian immature teratoma. The patient exhibited a severe short-term episodic memory impairment and psychiatric symptoms. A detailed diagnostic work-up including complete clinical and laboratory examinations, neuropsychological assessments, and neuroradiological investigations has been done at the onset and during follow-up. The amnestic syndrome and MRI medial-temporal abnormalities reversed after medical and surgical treatment. The present report indicates that the disease can be rapidly reversible if promptly diagnosed and treated. While the disease has already been described elsewhere, the course of neurospychological deficits in adults is not as much known. Usually, when the diagnosis of anti-NMDAR encephalitis is made, the severity of the disease makes the assessment of the neuropsycological profile particulary challenging. The present report is of interest because it describes the complete neuropsychological profile of a mild form of anti-NMDAR encephalitis.

121. Differences Between Auto-Antibody Titres in Cerebrospinal Fluids and Sera of Patients With Anti-N-methyl-D Receptor Encephalitis

Abstract Anti--methyl-D-aspartate receptor (NMDAR) encephalitis is one of autoimmune limbic encephalitis which receives the most attention in the psychiatric field. Patients with anti-NMDAR encephalitis typically exhibit psychiatric symptoms such as hallucination, delusion, aggression, manic episodes, and abnormal behaviors. With the given psychiatric symptoms, those patients are often diagnosed as atypical psychosis or schizophrenia and medicated with antipsychotic drugs. The definite diagnosis of anti-NMDAR encephalitis still remains to be established, however. The subjects were the patients whose cerebrospinal fluids (CSF) were verified to contain anti-NMDAR1 receptor (GRIN1) auto-antibodies and thus were diagnosed as anti-NMDAR encephalitis. These subjects exhibited chronic or subacute symptoms which were classified into typical psychosis (21 patients) and atypical psychosis (20 patients). We measured the immunoreactivity for NMDAR1 in the cell-based immunoassay in all CSF samples as well as in some of their serum samples (37 patients). This study was approved by the authorization of the Kanazawa Medical College Ethics Committee and Niigata University Medical Ethics Committee. All the patients provided written informed consent to allow the use of CSF and blood samples for this investigation. Although all the CSF samples were positive for the auto-antibodies, the positive frequency of their blood samples was lower in the subjects with atypical psychosis (23.5%; 4 patients) than in those with typical psychosis (65.0%; 13 patients) ( < .05). In addition, the auto-antibody titres were significantly lower in both CSF ( < .05) and serum ( < .01) of the subjects with atypical psychosis. These results suggest that the patients with anti-NMDAR encephalitis, but not with typical psychotic symptoms, often exhibit lower or undetectable blood concentrations of anti-NMDAR1 auto-antibodies. Thus, the definite diagnosis of anti-NMDAR encephalitis requires CSF examination.

Communicating Hydrocephalus Associated with Relapsing Anti-N-Methyl-DAspartate Receptor (NMDAR) Encephalitis in an Adolescent Girl

Anti–N-methyl-D-aspartate receptor (NMDAR) encephalitis is uncommon cause of immune mediated encephalopathy in children. It usually manifests as psychosis, seizures and dyskinesia. We describe an unusual association with the phenotype of this disease. An 11 year-old girl presented with psycho-behavioral disturbances, headache, fever and episodic disorientation few weeks after fever and upper respiratory tract infection. Her MRI showed communicating hydrocephalus. She was found to have positive anti-NMDAR antibodies. She underwent VP shunt followed by immunomodulatory therapy resulting in resolution of headache and substantial improvement of alertness and psycho-behavior. Several months later she relapsed and remission was induced by a repeated course of immunomodulatory therapy. This report illustrates the remarkable phenotypic variability in this condition. The diagnosis of anti-NMDAR encephalitis should be considered in patients who present with subacute or relapsing encephalopathy associated with communicating hydrocephalus.

A young child of anti-NMDA receptor encephalitis presenting with epilepsia partialis continua: the first pediatric case in Korea.

Anti-N-methyl D-aspartate receptor (anti-NMDAR) encephalitis, recently recognized as a form of paraneoplastic encephalitis, is characterized by a prodromal phase of unspecific illness with fever that resembles a viral disease. The prodromal phase is followed by seizures, disturbed consciousness, psychiatric features, prominent abnormal movements, and autonomic imbalance. Here, we report a case of anti-NMDAR encephalitis with initial symptoms of epilepsia partialis continua in the absence of tumor. Briefly, a 3-year-old girl was admitted to the hospital due to right-sided, complex partial seizures without preceding febrile illness. The seizures evolved into epilepsia partialis continua and were accompanied by epileptiform discharges from the left frontal area. Three weeks after admission, the patient's seizures were reduced with antiepileptic drugs; however, she developed sleep disturbances, cognitive decline, noticeable oro-lingual-facial dyskinesia, and choreoathetoid movements. Anti-NMDAR encephalitis was confirmed by positive detection of NMDAR antibodies in the patient's serum and cerebrospinal fluid, and her condition slowly improved with immunoglobulin, methylprednisolone, and rituximab. At present, the patient is no longer taking multiple antiepileptic or antihypertensive drugs. Moreover, the patient showed gradual improvement of motor and cognitive function. This case serves as an example that a diagnosis of anti-NMDAR encephalitis should be considered when children with uncontrolled seizures develop dyskinesias without evidence of malignant tumor. In these cases, aggressive immunotherapies are needed to improve the outcome of anti-NMDAR encephalitis.

PP08.1 – 2529: Cyclophosphamide in treatment resistant tumour negative pediatric NMDAR encephalitis

Objective Report 2 children with treatment resistant NMDAR encephalitis. Case reports and results: Case 1: A 4.5 year-old-girl presented with an 8 week history of acute onset agitation, insomnia, abnormal involuntary movements, and mutism. On examination, she had no visual fixation or auditory perception, no communication or understanding, had continuous dyskinetic movements. A diagnosis of anti NMDAR-encephalitis was concluded after the IgG antibodies to NR1 subunit of NMDA receptors was positive in both CSF and serum. She was given methylprednisolone and 4 weeks later IVIG, with no response. Cyclophosphamide pulse therapy (3 doses monthly cycles) was initiated 8 months into the illness with the child still in vegetative state. There was remarkable improvement with cyclophosphamide therapy. At the last follow up, 21 months after onset she has started attending regular school. Case 2: A 8-year-old boy presented with acute onset seizures, impaired speech, lack of sleep, and abnormal behaviour. On examination he was delirious, mute and had abnormal movements. CSF and serum IgG antibodies to NR1 subunit of NMDA receptor were positive. He was treated with pulse methylprednisolone and IVIG. Two weeks later, the child was given Rituximab (4 doses every 4 weeks) with no improvement. Cyclophosphamide pulse therapy (3, monthly cycles) was initiated after 6 months of his disease onset. At last follow up, 12 months after disease onset he continues to be normal and attends regular school. Conclusion Use of cyclophosphamide resulted in near complete recovery in two children with tumor negative NMDAR encephalitis resistant to steroids, IVIG and Rituximab (case 2). This despite the fact that the illness was severe and the symptoms had persisted for more than 6 months. This suggests that cyclophosphamide is an effective immunomodulator in children with Anti NMDAR encephalitis. Its use should be considered in children with incomplete or no response to first line agents.

Does MAP2 have a role in predicting the development of anti-NMDAR encephalitis associated with benign ovarian teratoma? A report of six new pediatric cases.

Anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis is a potentially fatal neurologic syndrome in which patients present with a spectrum of central nervous system deficits. Sixty percent of the cases can be attributed to the presence of tumors, most often ovarian teratomas. This report examines 6 pediatric patients who presented with neurologic deficits associated with the presence of such tumors. These cases illustrate a perplexing phenomenon, where benign teratomas could have a possible association with anti-NMDAR encephalitis. The purpose of this study was to compare the histology and immunohistochemistry of tumors associated with this syndrome to ovarian teratomas found in patients presenting with no neurologic symptoms. After obtaining institutional review board approval, 57 cases of ovarian teratomas were identified at our institution over 12 years. Six patients were identified with anti-NMDAR encephalitis. A panel of immunostains, including S100, GFAP, MAP2, and NeuN was applied to patients' tumor sections as well as the 6 controls from age-matched patients. No qualitative histologic or immunohistochemical differences were seen between the study cases and control group. Because no qualitative differences were identified between the study cases and the control group, testing of paired serum and cerebrospinal fluid remains the best method for diagnosis of anti-NMDAR encephalitis. Tumor banking with molecular analysis of ovarian teratomas, including whole-genome sequencing and comparative genomic hybridization between ovarian tissue saved from patients with and without anti-NMDAR encephalitis, is necessary to fully understand the etiopathogenesis of anti-NMDAR encephalitis.

Anti-NMDAR encephalitis misdiagnosed as Hashimoto's encephalopathy

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a well-defined autoimmune disorder. Hashimoto's encephalopathy (HE) is a still controversial entity, lacking definite diagnostic criteria.We described a 14-year-old-girl presenting with a clinical picture consistent with the diagnosis of anti-NMDAR encephalitis, confirmed by NMDAR antibody testing. Four years earlier, she had presented a similar episode of acute encephalopathy diagnosed as HE.Anti-NMDAR encephalitis and HE share similar clinical features so that the differential diagnosis can be difficult if specific antibodies are not tested. The correct diagnosis of anti-NMDAR encephalitis is crucial to plan the appropriate management and follow-up, namely in term of oncological screening, since it can be paraneoplastic in origin. We suggest to re-evaluate the clinical history of all subjects with previous HE diagnosis in order to evaluate the possible diagnosis of anti-NMDAR encephalitis and plan the appropriate management of these patients.

Anti-N-methyl D-aspartate receptor encephalitis in childhood

To discuss the differential diagnosis of encephalitis beyond that of infectious etiology and to inform pediatricians about the possibility of anti-N-methyl-D-aspartate receptor (NMDAr) encephalitis in children by highlighting its most important clinical features. Three patients presented with an initial neuropsychiatric syndrome followed by encephalopathy and movement disorder. The initial neuropsychiatric features which developed over days to weeks included a change in personality, anxiety, confusion, and speech regression. This was followed by a choreoathetoid or dystonic movement disorder affecting the orofacial region and the limbs. After the exclusion of the major causes of encephalitis, NMDAr antibodies were identified in serum and cerebrospinal fluid, and neoplasm screening did not detect any tumor. Patients were submitted to immunosuppression, and two of them had a full neurological recovery. One of them still presents a mild dystonic posture in a limb. Clinical signs of anti-NMDAr encephalitis in children are similar to those previously described in adults. Tumors are not usually detected by this age. The diagnosis of anti-NMDAr encephalitis must be addressed only after the exclusion of infectious and other recognizable causes of encephalitis. Pediatricians should be aware of this treatable autoimmune condition.