Response of anti-NMDA receptor encephalitis without tumor to immunotherapy including rituximab

Colorectal Adenocarcinoma Derived From Mature Cystic Teratomas: A Case Report With Review of the Literature

Mature cystic teratomas (MCTs) are the most common benign ovarian germ cell neoplasms in women of reproductive age. Rarely, somatic malignancies arise from MCTs, the most common being squamous cell carcinoma. Adenocarcinomas are less common and colorectal adenocarcinomas are extremely rare. We present a case of somatic adenocarcinoma of colorectal type which may pose challenges in diagnosis and treatment. A middle-aged female presented to the Emergency Department with lower abdominal pain. CT scan revealed an 11 cm sharply demarcated left pelvic mass. Laparoscopy showed a left ovarian mass with torsion, a smooth external surface, and thick brownish contents. An intraoperative evaluation was consistent with an adenocarcinoma. Permanent histopathology revealed adenocarcinoma of colorectal phenotype with necrosis. Additional evaluation of the cyst showed benign colonic epithelial lining. The immunohistochemistry (IHC) profile of positive CDX2 and CK20 and negative PAX8, CK7, ER, and PR suggested a colorectal-type somatic adenocarcinoma arising from the MCT and was staged as IA, after negative endoscopic findings. Due to their rarity and atypical symptoms, distinguishing metastatic tumors from MCT-derived somatic malignancies is a challenging process. CT scan and serum tumor markers can be helpful but are not definite. Thorough clinical evaluation and proper staging are necessary after pathologic evaluation. Extensive sampling and IHC can further characterize the origin of the tumor. Diligent sampling and a high index of suspicion in this case clinched the correct diagnosis and clinical management. The patient is being treated for stage IA ovarian cancer as opposed to stage IV metastatic colorectal cancer.

Paraneoplastic motor disorders

Paraneoplastic neurological disorders (PNDs) are heterogeneous clinicopathologic syndromes that occur throughout the neuraxis resulting from damage to organs or tissues remote from the site of a malignant neoplasm or its metastases. The discordance between severe neurological disability and even an indolent malignancy suggests an underlying neuroimmunologic host immune response that inflicts nervous tissue damage while inhibiting malignant tumor growth. Motor system involvement, like other symptoms and signs, is associated with focal or diffuse involvement of the brain, spinal cord, peripheral nerve, neuromuscular junction or muscle, alone or in combination due to an underlying neuroimmune and neuroinflammatory process targeting neural-specific antigens. Unrecognized and therefore untreated, PNDs are often lethal making early detection and aggressive treatment of paramount importance. While the combination of clinical symptoms and signs, and analysis of detailed body and neuroimaging, clinical neurophysiology and electrodiagnostic studies, and tumor and nervous system tissue biopsies are all vitally important, the certain diagnosis of a PND rests with the discovery of a corresponding neural-specific paraneoplastic autoantibody in the blood and/or spinal cerebrospinal fluid.

Teenager with acute psychosis due to non-paraneoplastic anti-N-methyl-d-aspartate receptor encephalitis with a successful recovery: A case report

Introduction

Anti NMDAR encephalitis is a neuropsychiatric syndromic disease caused by an immunological response. Acute behavioral changes, psychosis, and catatonia are common clinical manifestations, are seizures, amnesia, speech difficulties, dyskinesia, and autonomic dysregulation.

Case presentation

We discuss the case of a 14-year-old girl who had psychotic symptoms and tested positive for anti-NMDAR antibodies.

Discussion

Patients present with psychiatric symptoms such as delusions, hallucinations, agitation, changes in speech mania, disorganized thinking, catatonia, insomnia, and often seizures. Anti-NMDAR encephalitis should be suspected in teenage patient with acute psychotic symptoms and seizure episodes. A multidisciplinary treatment strategy is required.

Conclusion

The delayed treatment can lead to complications and delayed recovery complicating the disease process so multidisciplinary approach of treatment is necessary.

•

Acute psychotic symptoms with seizure episodes in adolescent patient should have a suspicion of anti-NMDAR encephalitis.

•

The delayed treatment can lead to complications and delayed recovery complicating the disease process.

•

Multidisciplinary approach of treatment is necessary.

Efficacy and Safety of Low-Dose Rituximab in Anti-MuSK Myasthenia Gravis Patients: A Retrospective Study

PURPOSE

To evaluate the efficacy and safety of low dosages of rituximab (RTX) in the treatment of MuSK-antibody-positive MG patients.

PATIENTS AND METHODS

We retrospectively analyzed the data of MuSK-antibody-positive MG patients who were treated with low dosages of RTX from January 2018 to October 2021. The long-term treatment response to RTX was assessed by Myasthenia Gravis Foundation of America (MGFA) post-interventional status (PIS), Myasthenia Gravis Status and Treatment Intensity (MGSTI), dosage of steroid, MG-related activities of daily living (MG-ADL) and myasthenic muscle score (MMS) at the end of follow-up.

RESULTS

Clinical improvement was observed in all eight patients with follow-up for 8 to 29 months after treatment. At the last visit, complete stable remission had been achieved in one patient, pharmacologic remission in three patients, minimal manifestations status in three patients and improved in one patient based on the MGFA-PIS criteria. MGSTI level 2 or better had been reached in six (75%) patients at the last visit. The steroid dosage decreased from 60 mg at baseline to 15 mg at the last follow-up (p = 0.011). The average MG-ADL score decreased from 11 (range 7 to 15) to 0 (range 0 to 3; p = 0.011), and the MMS improved from 38.5 (range 24 to 60) to 100 (range 90 to 100; p = 0.012). These differences were all statistically significant. During RTX treatment and subsequent follow-up, 1 patient reported minor post-infusion malaise.

CONCLUSION

Low-dose RTX is effective and safe for treating anti-MuSK antibody positive MG patients. A long-term response is observed after treatment. Larger prospective studies are required to provide further evidence.

Psychiatric autoimmune conditions in children and adolescents: Is catatonia a severity marker?

OBJECTIVES

Patients with autoimmune encephalitis (AE) are likely to exhibit an acute onset of severe psychiatric features, including psychosis and/or catatonia. Based on the high prevalence of catatonia in AE and our clinical experience, we hypothesized that catatonia might be a marker of severity requiring more aggressive treatment approaches.

METHODS

To reach a sufficient number of cases with brain-autoimmune conditions, we pooled two samples (N = 58): the first from the French National Network of Rare Psychiatric diseases and the second from the largest Italian neuro-pediatrics center for encephalopathies. Autoimmune conditions were diagnosed using a multidisciplinary approach and numerous paraclinical investigations. We retrospectively compared patients with and without catatonia for psychiatric and non-psychiatric clinical features, biological and imaging assessments, type of immunotherapy used and outcomes.

RESULTS

The sample included 25 patients (43%) with catatonia and 33 (57%) without catatonia. Forty-two patients (72.4%) had a definite AE (including 27 anti-NMDA receptor encephalitis) and 16 (27.6%) suspected autoimmune encephalitis. Patients with catatonia showed significantly more psychotic features [18 (72%) vs 9 (27.3%), p < 0.001)] and more movement disorders [25 (100%) vs 20 (60.6%), p < 0.001] than patients without catatonia. First line (corticoids, immunoglobulin and plasma exchanges) and second line (e.g., rituximab) therapies were more effective in patients with catatonia, with 24 (96%) vs 22 (66.7%) (p = 0.006) and 17 (68%) vs 9 (27.3%) (p = 0.002), respectively. However, those with catatonia received more combinations of first and second line treatments and had more relapses during outcomes.

CONCLUSION

Despite its exploratory design, the study supports the idea that autoimmune catatonia may be a marker of severity and morbidity in terms of initial presentation and relapses, requiring the need for early and aggressive treatment.

Ovarian teratoma-associated anti-NMDAR encephalitis: a single-institute series of six patients from China

Purpose

Ovarian teratoma-associated anti-N-methyl-d-aspartate receptor encephalitis is a rare disease with uncertain etiology and pathogenesis. The disorder is severe and rare with a great impact on young adults. This study aimed to improve the awareness of the disease from experience in our single center.

Methods

Between July 2012 and December 2019, six patients with ovarian teratoma-associated anti-N-methyl-d-aspartate receptor encephalitis were enrolled in Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University. All patients’ data like manifestations, laboratory and radiological data, treatment, and follow-up were reviewed.

Results

Typical psychotic symptoms, memory, and consciousness disorders accompanied by seizures were observed in all patients from this study. All six patients showed positive signals in serum and cerebrospinal fluid samples for N-methyl-d-aspartate receptor and received immunotherapy. Three patients underwent unilateral oophorocystectomy and the other three underwent unilateral oophorectomy through minimally invasive surgeries, including laparoscopic and single-port laparoscopic surgeries. The median follow-up time 24.5 months (range from 6 to 93 months). No death occurred. Two patients had recurrent psychotic symptoms while the left four patients had no mental symptoms or tumor recurrence during postoperative follow-up.

Conclusions

For patients with clinical manifestations of unexplained acute psychiatric symptoms accompanied by seizures, memory, and consciousness disorders, the possibility of anti-N-methyl-d-aspartate receptor encephalitis should be considered. To confirm the diagnosis, examinations of anti-N-methyl-d-aspartate receptor antibodies need to be completed as early as possible. Immunotherapy and tumor location should be given in time once the diagnosis is defined. We recommended removing the tumor as soon as possible without concerning whether the patient is in the acute phase or not. The surgical procedure should be decided based on pathology, age, fertility desire, and patients’ requirements and it should be ensured that tumors are completely removed during operation. Postoperative follow-up is particularly important.

Pulmonary embolism complicated the course of anti-N-methyl-D aspartate receptor encephalitis in a pediatric intensive care unit setting: a case report

INTRODUCTION

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis, an autoimmune neurological disorder resultant from the autoantibodies directed to the NR1 subunit of the NMDAR, is mainly characterized by neuropsychiatric symptoms, including behavior changes, paranoia, delusions, epileptic seizures, movement disorders, aphasia, insomnia, dysautonomia, and altered consciousness. Pulmonary embolism (PE) presents with pleuritic chest pain, hemoptysis, and respiratory distress by obstruction of the pulmonary circulation. Unlike adults, pediatric PE usually related to obvious risk factors, including central venous line, malignancy, lupus erythematosus, renal disease, congenital thrombophilia, surgery, and major trauma. Besides, PE has rarely been encountered in adult patients with anti-NMDAR encephalitis even in the absence of these risk factors.

CASE PRESENTATION

A 16-year-old male patient, with acute psychosis, epileptic seizure, and altered consciousness, was diagnosed as having anti-NMDAR encephalitis and treated by intravenous immunoglobulin and high-dose pulse intravenous methylprednisolone. During follow-up, on the 11^th day of hospitalization, the disease course was complicated by the occurrence of pulmonary embolism, presenting with acute onset respiratory distress and the need for supplementary oxygen treatment. PE improved with low-molecular-weight heparin treatment.

CONCLUSION

Pulmonary embolism should be kept in mind as a possible cause of respiratory insufficiency in pediatric anti-NMDAR encephalitis patients along with altered consciousness, breathing instability, hypersalivation, status epilepticus or dystonia, and their treatment.

Diagnosis and treatment of limbic encephalitis in the cancer patient

Limbic encephalitis is an inflammatory process involving the limbic structures of the brain, manifested with short-term memory deficits, confusion, depression and seizures. It is usually a paraneoplastic condition but it may also appear as a nonparaneoplastic syndrome. Patients with this condition may exhibit a variety of antibodies in their serum or/and cerebrospinal fluid targeting basement membrane components that bind to a variety of neurotransmitter receptors such as α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid and GABA B and proteins associated to the ion channels such as LGI1, Caspr2 or intracellular components. Flurodeoxyglucose PET/computed tomography usually demonstrates increased uptake in the limbic structures, and it may reveal the site of the primary tumor. Treatment consists of tumor removal if possible. Symptomatic treatment includes steroids, gamma immune globulin, plasma exchange, immunosuppressive therapies and anti-epileptic drugs. Prognosis is better when it is associated with antibodies against basement membrane rather than intracellular antibodies.

[Anti-NMDAR encephalitis associated with relapsing optic neuritis]

Autoimmune encephalitis with antibodies to NMDA receptors (anti-NMDAR encephalitis), is the most common form of autoimmune encephalitis. The disease is curable, however, the lack of timely therapy can lead to the disability of patients or to the death. Difficulties in the diagnosis of anti-NMDAR encephalitis are caused by the heterogeneity of its manifestations, a possible overlapping with other autoimmune diseases and insufficient awareness about this form of encephalitis. This article describes the case of anti-NMDAR encephalitis associated with recurrent optic neuritis which might be an atypical manifestation for this disease. Optic neuritis could not be explained by overlapping with multiple sclerosis or neuromyelitis optica spectrum disorders.

[Anti-NMDAR encephalitis associated with relapsing optic neuritis: a case report and differential diagnosis]

Autoimmune encephalitis with antibodies to NMDA receptors, or anti-NMDAR encephalitis, is the most common form of autoimmune encephalitis. The disease is curable, however, the lack of timely therapy can lead to the disability of patients or to the death. Difficulties in the diagnosis of anti-NMDAR encephalitis are caused by the heterogeneity of its manifestations, a possible overlapping with other autoimmune diseases and insufficient awareness about this form of encephalitis. This article presents the literature review and describes the case of anti-NMDAR encephalitis associated with recurrent optic neuritis, which might be an atypical manifestation for this disease. Optic neuritis could not be explained by overlapping with multiple sclerosis or neuromyelitis optica spectrum disorders.

Anti-N-methyl-d-aspartate Receptor Encephalitis: A Case Series and Review of the Literature

Anti-NMDAR (N-methyl-d-aspartate receptor) encephalitis is a potentially severe form of encephalitis associated with antibodies against NR1 and NR2 subunits of the NMDAR. Anti-NMDAR encephalitis is a treatable cause of encephalitis. An underlying tumor should be actively looked for as this is also considered to be a paraneoplastic syndrome. We report two children with anti-NMDAR encephalitis with a literature review of current evidence in diagnosing and managing this rare condition. Resection of the tumor, glucocorticoids, intravenous immunoglobulin, and plasma exchange often result in improvement, usually within four weeks. Outcome corresponds with the rapidity of commencing appropriate treatment.

Anti-N-methyl-D-aspartate receptor encephalitis: A review of pathogenic mechanisms, treatment, prognosis

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a treatable autoimmune disorder characterized by prominent neuropsychiatric symptoms that predominantly affects children and young adults. In this review, we discuss the pathogenic mechanisms and immunologic triggers of anti-NMDAR encephalitis, and provide an overview of treatment and prognosis of this disorder, with specific focus on the management of common symptoms, complications, and patients during pregnancy. Most patients respond well to first-line treatment and surgical resection of tumors. When first-line immunotherapy fails, second-line immunotherapy can often improve outcomes. In addition, treatment with immunomodulators and tumor resection are effective treatment strategies for pregnant patients. Benzodiazepines are the preferred treatment for patients with catatonia, and electroconvulsive therapy (ECT) may be considered when pharmacological treatment is ineffective. Age, antibody titer, cerebellar atrophy, levels of biomarkers such as C-X-C motif chemokine 13 (CXCL13), cell-free mitochondrial (mt)DNA in cerebral serum fluid (CSF), and timing from symptom onset to treatment are the main prognostic factors. Patients without tumors or those who receive insufficient immunotherapy during the first episode are more likely to relapse.

Childhood Onset of Anti-N-Methyl-D-Aspartate Receptor Encephalitis Without Teratoma Masquerading as a Psychotic Disorder

Many neurologic disorders manifest as psychiatric symptoms. Anti-N-Methyl-D-Aspartate (NMDA) receptor encephalitis is an autoimmune disease of the brain characterized by numerous neurological and psychiatric features. Despite being rare, its prevalence is rapidly increasing and early management is critical in ensuring successful and sustainable recovery. Therefore, the illness should be considered as a differential diagnosis when clinically assessing patients. This report presents a case of a female child who was hospitalized for acute psychiatric manifestations, which was later confirmed as anti-NMDA receptor encephalitis. She recovered relatively successfully after combined neurological and psychiatric treatment. This report provides information on the clinical course of early onset anti-NMDA receptor encephalitis, including treatment strategy and prognosis.

Clinical variants of limbic encephalitis

The clinical picture of immunomediator disorders of the central nervous system resulting from autoimmune or paraneoplastic processes is often represented by the limbic symptom complex or limbic encephalitis. The article gives a brief description of these conditions, allocated to a separate nosological group in 2007. The symptoms of limbic encephalitis include mental disorders and epileptic seizures of both convulsive and non-convulsive spectrum, up to epileptic status. Four clinical cases representative of different variants of limbic encephalitis are presented in this study, along with the discussion of epidemiology, differential diagnostics, and generally accepted patient management strategies. The diagnosis of limbic encephalitis was made on clinical grounds alone in three cases and on the presence of antibodies to N-Methyl-d-aspartic acid receptors in one case. A combination of glucocorticoid pulse therapy with prolonged use of valproic acid was successfully applied for the treatment of limbic encephalitis with non-convulsive epileptic status. Plasmapheresis was used for the treatment of limbic encephalitis with recurrent focal non-motor attacks with and without loss of consciousness, as well as for limbic encephalitis with focal motor attacks. Presented cases emphasize the need to increase the awareness of physicians of various specialties to autoimmune disorders of the nervous system. In addition, it highlights the necessity of complete diagnostic workup for a patient with impaired consciousness of unclear etiology.

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.

Clinical characteristics and factors associated with short-term prognosis in adult patients with autoimmune encephalitis of non-neoplastic etiology

BACKGROUND

Reports that autoimmune encephalitis (AE) is associated with antibodies have increased; however, little is known about the distribution of clinical symptoms, imaging changes, and prognostic factors in patients with AE of non-neoplastic etiology. Accordingly, we evaluated the clinical characteristics and factors associated with short-term prognosis.

METHODS

From January 2016 to June 2018, 31 adult patients were diagnosed with AE of non-neoplastic etiology at Shengjing Hospital of China Medical University and their demographic and clinical characteristics were abstracted. Factors affecting disease severity and predictors of prognosis were analyzed.

RESULTS

Among 31 patients, 19 had anti-NMDAR, 5 had anti-GABABR, and 7 had anti-LGI1 antibody encephalitis. Status epilepticus, ataxia, and cognitive dysfunction were the most common neurological symptoms. Deep white matter (DWM) abnormalities were the most common changes observed on MRI. Logistic regression analysis indicated that conscious disturbance (odds ratio = 11.67, 95%, confidence interval 2.13-64.04; p = 0.005) is an independent factor associated with poor prognosis in AE.

CONCLUSION

The clinical manifestations of AE are diverse; status epilepticus, ataxia, and cognitive dysfunction are most common. The DWM of the brain, rather than the limbic lobe system, was most prone to MR signal abnormalities. Conscious disturbance may be an important predictor of poor short-term prognosis in patients with AE of non-neoplastic etiology.

A causality algorithm to guide diagnosis and treatment of catatonia due to autoimmune conditions in children and adolescents

OBJECTIVES

Pediatric catatonia is a rare and life-threatening syndrome. Around 20% of juvenile catatonia is associated with organic condition (Consoli et al., 2012). Autoimmune conditions represent a diagnostic and therapeutic challenge since specific antibodies can be missed. To facilitate decision making, we recently formulated a causality assessment score (CAUS) using a stepwise approach and an immunosuppressive therapeutic challenge (Ferrafiat et al., 2016). Our objectives were to validate retrospectively CAUS and to define its threshold for an accurate distinction between organic catatonia and non-organic catatonia, and specifically between autoimmune catatonia and non-organic catatonia.

METHOD

To obtain a sufficient number of cases with organic catatonia, we pooled two samples (N=104) - one from a child psychiatry center, the other from neuro-pediatrics center - expert in catatonia and autoimmune conditions. Organic conditions were diagnosed using a multidisciplinary approach and numerous paraclinical investigations. Given the binary classification needs, we used receiver operating characteristic (ROC) analysis (Peacock and Peacock, 2010) to calculate the best classification threshold.

RESULTS

The cohort included 67 cases of non-organic catatonia and 37 cases of organic catatonia. ROC analysis showed that the CAUS performance in discriminating both organic catatonia vs. non-organic catatonia, and autoimmune catatonia vs. non-organic catatonia was excellent (Area Under the Curve=0.99). In both analyses, for a CAUS threshold≥5, accuracy equaled to 0.96.

CONCLUSION

Regarding juvenile catatonia, the use of the CAUS score algorithm combining a therapeutic challenge and a threshold≥5 may help to diagnose and treat autoimmune conditions even without formal identification of auto-antibodies.

Ovarian teratoma associated Anti-N-methyl-D-aspartate receptor encephalitis: a difficult diagnosis with a favorable prognosis

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a recently described auto-immune and paraneoplastic encephalitis with prominent neuropsychiatric manifestations affecting young adults with ovarian teratoma. The availability of a novel assay to measure these antibodies might suggest an etiology for this potentially life-threatening disease, which if early recognized can be treated promptly with surgery with chances of a good clinical outcome. Reported prognostic indicators for a good outcome depend on the presence of a tumor, prompt treatment and no admission to an intensive care unit. However, due to the rarity and unawareness of this disease, the diagnosis may be delayed as primary psychiatric disorders, and infective encephalitis is taken more into consideration and ruled out first. Here we report a case of anti-NMDAR encephalitis in a 22-year-old female prompted by an ovarian teratoma with a gradual and complete resolution of symptoms after surgical excision of the teratoma and immunomodulating therapies.

Anti-NMDA Receptor Encephalitis: Clinical Features and Basic Mechanisms

In slightly more than 10 years, anti-NMDA receptor (NMDAR) encephalitis has changed from a rare paraneoplastic syndrome to the most common cause of nonviral encephalitis. It presents fulminantly with progressive psychosis, seizures, and autonomic dysfunction, leading to death if untreated. However, rapid recognition and treatment can lead to survival and a return to baseline levels of functioning in many patients. While initially associated with ovarian teratomas, it is now associated with other tumors and can reflect a postviral event. The antibodies to the NMDAR made in this syndrome are pathogenic and are directed at the extracellular domain of the GluN1 subunit. Such antibodies lead to internalization of NMDARs in model systems, leading to a physiological state characterized by NMDAR hypofunction. Analogous disorders, characterized by antibodies to other synaptic receptors, present with neurological and psychiatric dysfunction and also appear to reflect antibody-induced internalization of receptors. However, this simple pathophysiology may be too simplistic to reflect the complexity of events in anti-NMDAR encephalitis. Future scientific investigations may allow a more complete understanding of this disorder and improve treatment of anti-NMDAR encephalitis.

Status epilepticus and anti-NMDA receptor encephalitis after resection of an ovarian teratoma

Anti-N-methyl-D-aspartate receptor encephalitis is a recently recognised autoimmune, paraneoplastic syndrome that typically presents with psychiatric disturbance, reduced conscious level and seizures. The disorder has been previously associated with ovarian teratomas. We present the case of a 35-year-old female, with a previous surgical history for resection of an ovarian teratoma, who later developed status epilepticus and anti-N-methyl-D-aspartate receptor encephalitis requiring intensive care management. Her presentation, treatment and early follow-up are described, alongside an overview of anti-N-methyl-D-aspartate receptor encephalitis pathophysiology and intensive care management.

Extended Clinical Spectrum of Anti-N-Methyl-d-Aspartate Receptor Encephalitis in Children: A Case Series

OBJECTIVE

There is a wide spectrum of clinical manifestations in children with anti-N-methyl-d-aspartate (NMDA) receptor antibody encephalitis from two different health care settings.

METHODS

We describe our experience with 13 patients (median age, 7 years; range, 5 months to 19 years) presenting to tertiary referral centers in India and the United States.

RESULTS

Initial manifestations were neurological (seizures or movement disorders) in eight patients, and psychiatric (e.g., emotional lability and hallucination) in five patients. Symptoms during the clinical course included seizures in ten patients, movement disorders (dyskinesia and choreiform movements) in 11 patients, and behavioral changes (aggressiveness and insomnia) in ten patients. Concomitant infections (herpes simplex virus 1, tuberculous meningitis, and influenza A) were present in three patients. Analysis of the cerebrospinal fluid in all except two cases preceded by infection (herpes simplex virus encephalitis and tuberculous meningitis) was unremarkable. Treatment included intravenous immunoglobulin/methylprednisolone (11 patients), rituximab (eight patients), plasmapheresis (two patients), and cyclophosphamide (two patients). Six patients recovered completely. Two patients had mild residual neurological deficits, whereas four had severe residual neurological deficits. Two patients had profound autonomic instability, which was the cause of death for one of them. Two patients relapsed at two and six months after the initial recovery.

CONCLUSIONS

We describe the differences and similarities of clinical presentation, test results, and response to treatment of children with anti-N-methyl-d-aspartate receptor encephalitis from India and the United States. Included is a description of one of the youngest patients with anti-N-methyl-d-aspartate receptor encephalitis (five months) and the first patient to be reported in association with tuberculous meningitis.

Anti-N-Methyl-D-aspartate Receptor Encephalitis: A Severe, Potentially Reversible Autoimmune Encephalitis

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is potentially lethal, but it is also a treatable autoimmune disorder characterized by prominent psychiatric and neurologic symptoms. It is often accompanied with teratoma or other neoplasm, especially in female patients. Anti-NMDAR antibodies in cerebrospinal fluid (CSF) and serum are characteristic features of the disease, thereby suggesting a pathogenic role in the disease. Here, we summarize recent studies that have clearly documented that both clinical manifestations and the antibodies may contribute to early diagnosis and multidisciplinary care. The clinical course of the disorder is reversible and the relapse could occur in some patients. Anti-NMDAR encephalitis coexisting with demyelinating disorders makes the diagnosis more complex; thus, clinicians should be aware of the overlapping diseases.

Association of Progressive Cerebellar Atrophy With Long-term Outcome in Patients With Anti-N-Methyl-d-Aspartate Receptor Encephalitis

IMPORTANCE

Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis is an immune-mediated disorder that occurs with IgG antibodies against the GluN1 subunit of NMDAR. Some patients develop reversible diffuse cerebral atrophy (DCA), but the long-term clinical significance of progressive brain and cerebellar atrophy is unknown.

OBJECTIVE

To report the long-term clinical implications of DCA and cerebellar atrophy in anti-NMDAR encephalitis.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective observational study and long-term imaging investigation was conducted in the Department of Neurology at Kitasato University. Fifteen patients with anti-NMDAR encephalitis admitted to Kitasato University Hospital between January 1, 1999, and December 31, 2014, were included; data analysis was conducted between July 15, 2015, and January 18, 2016.

EXPOSURES

Neurologic examination, immunotherapy, and magnetic resonance imaging (MRI) studies were performed.

MAIN OUTCOMES AND MEASURES

Long-term MRI changes in association with disease severity, serious complications (eg, pulmonary embolism, septic shock, and rhabdomyolysis), treatment, and outcome.

RESULTS

The clinical outcome of 15 patients (median age, 21 years, [range, 14-46 years]; 10 [67%] female) was evaluated after a median follow-up of 68 months (range, 10-179 months). Thirteen patients (87%) received first-line immunotherapy (intravenous high-dose methylprednisolone, intravenous immunoglobulin, and plasma exchange alone or combined), and 4 individuals (27%) also received cyclophosphamide; 2 patients (13%) did not receive immunotherapy. In 5 patients (33%), ovarian teratoma was found and removed. Serious complications developed in 4 patients (27%). Follow-up MRI revealed DCA in 5 patients (33%) that, in 2 individuals (13%), was associated with progressive cerebellar atrophy. Long-term outcome was good in 13 patients (87%) and poor in the other 2 individuals (13%). Although cerebellar atrophy was associated with poor long-term outcome (2 of 2 vs 0 of 13 patients; P = .01), other features, such as DCA without cerebellar atrophy, serious complications, ventilatory support, or prolonged hospitalization, were not associated with a poor outcome. Five patients with DCA had longer hospitalizations (11.1 vs 2.4 months; P = .002), required ventilatory support more frequently (5 of 5 vs 4 of 10 patients; P = .04), and developed more serious complications (4 of 5 vs 0 of 10 patients; P = .004) compared with those without DCA. Although DCA was reversible, cerebellar atrophy was irreversible.

CONCLUSIONS AND RELEVANCE

In anti-NMDAR encephalitis, DCA can be reversible and does not imply a poor clinical outcome. In contrast, cerebellar atrophy was irreversible and associated with a poor outcome. This observation deserves further study to confirm progressive cerebellar atrophy as a prognostic marker of poor outcome.

"Autoimmune Epilepsy": Encephalitis With Autoantibodies for Epileptologists

Autoimmune encephalitides may account for epilepsies of so far unknown cause. These "autoimmune epilepsies" may respond well to immunotherapy. More than a dozen autoantibodies have been found with this constellation; therefore, broad autoantibody testing of serum-CSF pairs offers the best diagnostic yield. Several particular features raise the suspicion of an autoimmune cause in otherwise unexplained seizure disorders.

Lower dosages of rituximab used successfully in the treatment of anti-NMDA receptor encephalitis without tumour

OBJECTIVE

The aim of this study was to evaluate the use and efficacy of lower dosages of rituximab for treating anti N-methyl-d-aspartate receptor (NMDAR) encephalitis without tumour.

METHODS

We performed a prospective study of 10 patients with anti-NMDAR encephalitis who did not respond to 10 to 14days first-line immunotherapy and received rituximab administered intravenously (IV) at a dosage of 100mg once per week for 4 consecutive weeks. Reinfusion of rituximab was given when CD19⁺ B-cell counts of total lymphocytes in peripheral blood >1%. The annualized relapse rate (ARR), modified Rankin scale (mRS) and CD19⁺ B-cell counts were measured every 4 to 10weeks after initial rituximab treatment in order to assess the clinical outcome and efficacy of rituximab.

RESULTS

Lower dosages of rituximab led to a significant reduction of mRS and CD19⁺ B-cells when compared with before the rituximab infusion (P<0.05) and allowed 9 (90%) patients to maintain a stabilised neurological status. One patient experienced a relapse at 19weeks after initial rituximab infusion. Although ARR reduction of all 10 patients did not achieve statistical significance (P>0.05), in the 4 patients who had relapses before rituximab treatment there was an apparent reduction in ARR over 56weeks. At the last follow up, 9 patients (90%) had a good outcome (mRS≤2) including 3 patients (30%) who recovered completely (mRS=0). Transient infusion adverse events occurred in 2 patients. We observed no serious delayed adverse events during the 56weeks follow-up.

CONCLUSIONS

In patients with anti-NMDAR encephalitis who did not respond to first-line immunotherapy, early application of lower dosages of rituximab could efficiently reduce CD19⁺ B-cell counts of peripheral blood and improve the prognosis of anti-NMDAR encephalitis.

Rituximab for Treatment of Refractory Anti-NMDA Receptor Encephalitis in a Pediatric Patient

Anti-N-methyl d-aspartate receptor (anti-NMDAR) encephalitis is a devastating disease that is increasingly being identified in both children and adults with psychosis, language disturbances, behavioral changes, and motor deficits. Currently no consensus guidelines exist for the optimal management of patients with this disease, although intravenous immune globulin (IVIG) therapy is often considered first-line pharmacotherapy. We present a case of an otherwise healthy 4 year-old-child who presented with seizures, loss of age-appropriate language skills, and behavioral changes, in whom anti-NMDAR was subsequently diagnosed. After marked intolerance to corticosteroid therapy and inadequate clinical response to IVIG, immunotherapy with rituximab was initiated. The patient had rapid return of language skills and complete resolution of dyskinesia after a single rituximab infusion, with no residual deficits at her 6-month follow-up visit. Early intervention in patients with anti-NMDAR encephalitis is of paramount importance for successful outcomes and baseline recovery. Only approximately half of patients respond to first-line immunotherapy, necessitating further evaluation of alternative therapies and the development of a treatment algorithm for practitioners. This case report builds upon previous findings illustrating rapid symptom resolution after rituximab infusion and adds to the available body of evidence for management of pediatric patients with anti-NMDAR.

Adaptive Immunity Is the Key to the Understanding of Autoimmune and Paraneoplastic Inflammatory Central Nervous System Disorders

There are common aspects and mechanisms between different types of autoimmune diseases such as multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSDs), and autoimmune encephalitis (AE) as well as paraneoplastic inflammatory disorders of the central nervous system. To our present knowledge, depending on the disease, T and B cells as well as antibodies contribute to various aspects of the pathogenesis. Possibly the events leading to the breaking of tolerance between the different diseases are of great similarity and so far, only partially understood. Beside endogenous factors (genetics, genomics, epigenetics, malignancy) also exogenous factors (vitamin D, sun light exposure, smoking, gut microbiome, viral infections) contribute to susceptibility in such diseases. What differs between these disorders are the target molecules of the immune attack. For T cells, these target molecules are presented on major histocompatibility complex (MHC) molecules as MHC-bound ligands. B cells have an important role by amplifying the immune response of T cells by capturing antigen with their surface immunoglobulin and presenting it to T cells. Antibodies secreted by plasma cells that have differentiated from B cells are highly structure specific and can have important effector functions leading to functional impairment or/and lesion evolvement. In MS, the target molecules are mainly myelin- and neuron/axon-derived proteins; in NMOSD, mainly aquaporin-4 expressed on astrocytes; and in AE, various proteins that are expressed by neurons and axons.

Catatonia and Autoimmune Conditions in Children and Adolescents: Should We Consider a Therapeutic Challenge?

OBJECTIVE

Catatonia as a result of autoimmune conditions offers new therapeutic opportunities for patients that child and adolescent psychiatrists should consider. However, the diagnosis is sometimes challenging when an autoimmune signature is not identified.

METHODS

In this study, we aim to summarize seven cases from a 20-year series of 84 youths with catatonia, including three cases that represented a diagnostic challenge because of the absence of positive autoimmune testing.

RESULTS

Immunosuppressive/modulatory treatment improved catatonic and psychotic features in all cases.

CONCLUSION

To facilitate treatment decision-making, we propose a causality assessment score and a treatment algorithm, which may help clinicians consider whether an autoimmune condition is associated with catatonia.

Serum uric acid and anti-N-methyl-d-aspartate receptor encephalitis

BACKGROUND

Uric acid (UA) levels are associated with autoimmune and neurodegenerative disorders, but their relationship with anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis is unknown.

METHODS

UA levels were evaluated in 58 patients with anti-NMDAR encephalitis, and 58 age- and sex-matched healthy controls (CTLs). Follow-up evaluations of 30 out of the 58 patients with anti-NMDAR encephalitis were conducted 3 months after admission. Modified Rankin scale (mRS) scores and clinical and cerebrospinal fluid parameters were evaluated in all anti-NMDAR encephalitis patients.

RESULTS

Serum UA levels were significantly lower in patients with anti-NMDAR encephalitis than those in CTLs (p < 0.001), and this was especially evident in patients with severe impairments (mRS ≥ 4 vs. <4, p = 0.004) or with limited response to treatment (vs. favourable outcome, p = 0.002). Follow-up evaluations revealed that serum UA levels normalized after treatment, with significantly increased serum UA levels (p < 0.001), and that mRS scores were significantly lower (p < 0.001) than those before treatment. In addition, serum UA levels were significantly associated with mRS scores (r = -0.463, p < 0.001).

CONCLUSION

Our results showed that serum UA levels in patients with anti-NMDAR encephalitis are reduced during attacks compared with those in CTLs, are normalized after treatment, and are associated with disease severity.

Low serum vitamin D levels and anti-N-methyl-d-aspartate receptor encephalitis: A case-control study

BACKGROUND

Low vitamin D levels are associated with autoimmunity, but the relationship with anti-N-Methyl-d-aspartate receptor (anti-NMDAR) encephalitis is unknown.

METHODS

25(OH) D levels and clinical and cerebrospinal fluid parameters were evaluated in 30 patients with anti-NMDAR encephalitis and compared with 90 age-, sex-, and season-matched healthy controls.

RESULTS

25(OH)D levels were lower in patients with anti-NMDAR encephalitis compared to controls (43.89 ± 17.91 vs 64.24 ± 24.38 nmol/L, p < 0.001), especially for females (vs males, p = 0.008), aged ≤30 years (vs > 30 years, p = 0.002), severe impairment (mRS ≥ 5) (vs mRS < 5, p = 0.018), and limited treatment responses (vs favorable treatment, p = 0.02). Serum 25(OH)D levels were associated with age (r = 0.393, p = 0.032), and mRS (r = -0.417, p = 0.022).

CONCLUSIONS

Our data showed that serum 25(OH)D levels were reduced in patients with anti-NMDAR encephalitis.

Clinical Characteristics and Follow-up of South Indian Children with Autoimmune Encephalopathy

OBJECTIVE

To describe the clinical characteristics of a cohort of south Indian children with probable autoimmune encephalopathy from a tertiary care academic hospital and to compare this data with the existing literature.

METHODS

Patients with encephalopathy plus one or more of neuropsychiatric symptoms, seizures, movement disorder or cognitive dysfunction were identified. Common infectious causes were excluded. Clinical characteristics, investigations, management and outcome were analyzed.

RESULTS

Thirteen patients were included in the study; 12 were females (92.3 %) and mean age was 9.6 y. Most common presentation was behavior change (13 patients) followed by seizures (11 patients). Three patients showed lymphocytic pleocytosis in CSF and one patient had oligoclonal bands. Initial MRI was normal in all patients except in one. Most common EEG abnormality was mild background slowing. Only one child had ovarian tumor. S.NMDA receptor antibody was positive in 10 patients (83 %), and all of them received immunotherapy. Six out of 13 children were followed up for more than 1 y (mean - 21 mo). Recurrence was noted in 4 out of 6 patients (66 %). On last follow-up, good recovery was seen in 2 children (33 %), moderate disability in 3 (50 %) and severe disability in 1 (16 %).

CONCLUSIONS

The clinical characteristics and outcome of one of the largest single center cohort of Indian children with autoimmune encephalopathy is reported. Autoimmune encephalopathy should be considered as a differential diagnosis in the acute and subacute encephalopathies of childhood and treating pediatrician should be aware of this entity.

Anti-NMDA receptor encephalitis: An emerging differential diagnosis in the psychiatric community

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis is a new diagnosis, as recent as 2007, that develops as a result of autoantibodies to the NMDA receptor. The clinical manifestations of the disorder include complex psychiatric symptoms, seizures, movement disorders, cognitive dysfunction, and autonomic instability. Tumor resection, if present, and immunotherapy are the mainstays of therapy. Treatment should be initiated early and aggressively as it has been associated with better patient outcomes. A significant proportion of patients with anti-NMDA receptor encephalitis initially seek the help of a psychiatrist, highlighting the importance of its recognition within the mental health community. In an effort to promote disease awareness, this article will review a patient case and the pathophysiology, clinical presentation, diagnosis, and management of anti-NMDA receptor encephalitis.

Utility of Plasmapheresis in Autoimmune-Mediated Encephalopathy in Children: Potentials and Challenges

Autoimmune-mediated encephalopathy in children continues to constitute a diagnostic and therapeutic challenge in pediatric population. Utility and usefulness in this clinical setting of plasmapheresis have seldom been evaluated in current pediatric literature. Children with immune-mediated encephalopathies represent a uniquely different group among patients presenting to intensive care units or neurological services worldwide. Arriving at a final diagnosis is not an easy task for treating physicians. It is very crucial to consider early use of first-line immunotherapy modalities, save those children's lives and improve outcomes. Plasmapheresis is an emerging, potentially beneficial first-line therapy in such patients. However, indications, value, logistics, and procedural difficulties are often faced. This study is mainly meant to review the current knowledge in regard to the clinical value of plasmapheresis in children with immune-mediated encephalopathy.

Anti N-methyl-D-aspartate receptor encephalitis: a game-changer?

INTRODUCTION

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an inflammatory disorder of the brain that has garnered significant interest within the medical and lay communities. There is a need for formal guidelines to assist physicians in identifying patients who should undergo testing for NMDAR encephalitis, recognizing the high potential for this potentially treatable disease to mimic more common disorders, and consequently remain undiagnosed.

AREAS COVERED

This review highlights the impact of the discovery of NMDAR encephalitis on the fields of neurology and psychiatry, and discusses the steps that are necessary to improve recognition and treatment of NMDAR encephalitis. Expert commentary: While much progress has been made in our understanding of NMDAR encephalitis, much work remains to be done to delineate the underlying disease mechanisms and their relevance to brain function.

Cerebral (18)FluoroDeoxy-Glucose Positron Emission Tomography in paediatric anti N-methyl-D-aspartate receptor encephalitis: A case series

BACKGROUND

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a frequent and severe cause of encephalitis in children with potential efficient treatment (immunotherapy). Suggestive clinical features are behavioural troubles, seizures and movement disorders. Prompt diagnosis and treatment initiation are needed to guarantee favourable outcome. Nevertheless, diagnosis may be challenging because of the classical ancillary test (magnetic resonance imaging (MRI), electroencephalogram, standard cerebro-spinal fluid analysis) have limited sensitivity. Currently, immunological analyses are needed for the diagnostic confirmation. In adult patients, some studies suggested a potential role of cerebral (18)FluoroDeoxy-Glucose Positron Emission Tomography (FDG-PET) in the evaluation of anti-NMDAR encephalitis. Nevertheless, almost no data exist in paediatric population.

METHOD

We report retrospectively clinical, ancillary tests and cerebral FDG-PET data in 6 young patients (median age=10.5 years, 4 girls) with immunologically confirmed anti-NMDAR encephalitis.

RESULTS

Our patients presented classical clinical features of anti-NMDAR encephalitis with severe course (notably four patients had normal MRI). Our series shows the feasibility and the good sensitivity of cerebral FDG-PET (6/6 patients with brain metabolism alteration) in paediatric population. We report some particular features in this population: extensive, symmetric cortical hypometabolism especially in posterior areas; asymmetric anterior focus of hypermetabolism; and basal ganglia hypermetabolism. We found also a good correlation between the clinical severity and the cerebral metabolism changes. Moreover, serial cerebral FDG-PET showed parallel brain metabolism and clinical improvement.

CONCLUSION

Our study reveals the existence of specific patterns of brain metabolism alteration in anti-NMDAR encephalitis in paediatric population.

Anti-leucine-rich glioma-inactivated 1 limbic encephalitis: A case report and literature review

This study describes the case of a 41-year-old woman admitted for anterograde memory loss, right facial grimacing and right arm posturing that had begun 1 month previously. Cranial magnetic resonance-diffusion weighted imaging and -fluid-attenuated inversion recovery imaging revealed a hyperintense signal in the left hippocampus and right basal ganglia, but no contrast enhancement. An electroencephalogram revealed rhythmic sharp and slow waves and rhythmic θ build-ups in the left temporal area. Single-photon emission computed tomography showed increased regional blood flow perfusion in the left cerebral frontal lobe and the right basal ganglia. The cerebrospinal fluid was normal, with the exception of the presence of leucine-rich glioma-inactivated 1 (LGI1) antibodies, and LGI1 antibodies were also found in the blood serum. The presence of the antibodies, the faciobrachial dystonic seizures (FBDSs) and the memory loss indicated limbic encephalitis. After 3 months of immunotherapy, the patient was free from epileptic seizures and had undergone a partial memory restoration. FBDSs alone justify the immediate initiation of immunotherapy, even prior to laboratory confirmation of the disease, as early treatment limits the duration of the illness.

Antibody-Mediated Autoimmune Encephalopathies and Immunotherapies

Over the last 15 years it has become clear that rare but highly recognizable diseases of the central nervous system (CNS), including newly identified forms of limbic encephalitis and other encephalopathies, are likely to be mediated by antibodies (Abs) to CNS proteins. The Abs are directed against membrane receptors and ion channel-associated proteins that are expressed on the surface of neurons in the CNS, such as N-methyl D-aspartate receptors and leucine-rich, glioma inactivated 1 protein and contactin-associated protein like 2, that are associated with voltage-gated potassium channels. The diseases are not invariably cancer-related and are therefore different from the classical paraneoplastic neurological diseases that are associated with, but not caused by, Abs to intracellular proteins. Most importantly, the new antibody-associated diseases almost invariably respond to immunotherapies with considerable and sometimes complete recovery, and there is convincing evidence of their pathogenicity in the relatively limited studies performed so far. Treatments include first-line steroids, intravenous immunoglobulins, and plasma exchange, and second-line rituximab and cyclophosphamide, followed in many cases by steroid-sparing agents in the long-term. This review focuses mainly on N-methyl D-aspartate receptor- and voltage-gated potassium channel complex-related Abs in adults, the clinical phenotypes, and treatment responses. Pediatric cases are referred to but not reviewed in detail. As there have been very few prospective studies, the conclusions regarding immunotherapies are based on retrospective studies.

A spectrum of inflammation and demyelination in acute disseminated encephalomyelitis (ADEM) of children

Acute disseminated encephalomyelitis (ADEM) is an inflammatory demyelinating disease of the central nervous system that involves multifocal areas of the white matter, rarely the gray matter and spinal cord, mainly affecting children and mostly occurring 1-2weeks after infections or more rarely after vaccinations. Though a specific etiologic agent is not constantly identified, to evaluate carefully patient's clinical history and obtain adequate samples for the search of a potential ADEM causal agent is crucial. In the case of a prompt diagnosis and adequate treatment, most children with ADEM have a favorable outcome with full recovery, but in the case of diagnostic delays or inappropriate treatment some patients might display neurological sequelae and persistent deficits or even show an evolution to multiple sclerosis. The suspicion of ADEM rises on a clinical basis and derives from systemic and neurologic signs combined with magnetic resonance imaging of the central nervous system. Other advanced imaging techniques may help an appropriate differential diagnosis and definition of exact disease extension. Although there is no standardized protocol or management for ADEM, corticosteroids, intravenous immunoglobulin, and plasmapheresis have been successfully used. There is no marker that permits to identify the subset of children with worse prognosis and future studies should try to detect any biological clue for prevision of neurologic damage as well as should optimize treatment strategies using an approach based on the effective risk of negative evolution.

Complete recovery from paraneoplastic anti-NMDAR encephalitis associated with a small ovarian teratoma following a laparoscopic salpingo-oophorectomy: A case report

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a severe but treatment-responsive disorder, initially identified in young women with an ovarian teratoma. Symptoms include mood, behavior and personality irregularities that resemble acute psychosis. The present study reports the rare case of a patient with anti-NMDAR encephalitis and severe neurological symptoms, that exhibited a rapid recovery following a laparoscopic salpingo-oophorectomy. The 39-year-old woman was admitted to the Department of Obstetrics and Gynecology, Osaka City University Graduate School of Medicine (Osaka, Japan) with a 5-day history of fever and stomach ache. One week later, the patient developed hallucinations and emotional lability. Initially, a diagnosis of limbic or herpes encephalitis was considered; thus, the patient was administered acyclovir and received steroid pulse therapy. However, the patient subsequently developed apnea, and in response, a tracheal intubation, mechanical ventilation and plasmapheresis were performed. Anti-NMDAR encephalitis was subsequently considered as a diagnosis and mediastinal and pelvic computed tomography (CT) examinations were conducted to detect for the presence of a teratoma. A 24×24-mm cystic lesion was identified in the pelvis from an abdominal CT scan and the lesion appeared to be an ovarian teratoma. In addition, serum and cerebrospinal fluid samples were collected, and were found to test positive for anti-NMDAR antibodies. A laparoscopic salpingo-oophorectomy was performed, which resulted in rapid improvement of the patients mental symptoms, followed by a complete recovery.

Refractory status epilepticus caused by anti-NMDA receptor encephalitis that markedly improved following combination therapy with rituximab and cyclophosphamide

We herein describe the case of a 48-year-old woman who presented with nonconvulsive status epilepticus refractory to antiepileptic drugs caused by anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis without any tumors. She developed nausea and psychiatric symptoms, followed by fever and an acute progressive disturbance of consciousness. On admission to our hospital, she presented with involuntary orofacial movements and central hypoventilation, and an electroencephalogram showed a generalized slow activity consistent with nonconvulsive status epilepticus. The patient's drug-resistant status epilepticus markedly improved following second-line immunotherapy with rituximab and cyclophosphamide. Physicians should consider the early initiation of second-line therapy in certain cases of anti-NMDAR encephalitis.

Anti-glutamate ∊2 receptor antibody-positive and anti-N-methyl-d-aspartate receptor antibody-negative lobar encephalitis presenting as global aphasia and swallowing apraxia

Background

Little is known about the difference between anti-N-methyl-D-aspartate receptor (NMDAR) antibody-positive encephalitis and anti-glutamate receptor (GluR) antibody-positive encephalitis.

Objectives

To characterize anti-GluR antibody-positive encephalitis.

Methods

We report a 33-year-old man with nonparaneoplastic anti-GluR ∊2, ζ1 and δ2 antibody-positive and anti-NMDAR antibody-negative encephalitis, using neuropsychological tests and imaging studies including magnetic resonance imaging and single photon emission computed tomography (SPECT) with a ^99mTc-ethylcysteinate dimer.

Results

The patient exhibited global aphasia and swallowing apraxia (inability to transfer food to the pharyngeal cavity without sialorrhea). He was treated with 3 courses of corticosteroid pulse therapy and had recovered markedly 3 weeks after onset. Magnetic resonance diffusion-weighted images revealed hyperintensity in the bilateral frontal and left parietal cortices. Seven months later, a small area of hyperintensity in the left supramarginal gyrus remained. SPECT revealed hypoperfusion in extensive regions of the bilateral frontal lobes and left supramarginal gyrus. Thirteen months later, blood flow reduction was restricted to diffuse areas in the frontal lobes.

Conclusions

Frontal lobar encephalitis without medial temporal involvement, marked cognitive impairment with a relatively preserved level of consciousness, and a favorable response to corticosteroid therapy, with nearly reversible cortical damage, may characterize anti-GluR antibody-positive encephalitis.

Three phenotypes of anti-N-methyl-D-aspartate receptor antibody encephalitis in children: prevalence of symptoms and prognosis

BACKGROUND

Anti-N-methyl-d-aspartate (NMDA) receptor antibody encephalitis is becoming an increasingly recognized cause of encephalopathy in individuals previously presumed to have viral encephalitis. Various manifestations of this disease include altered mental status, behavioral changes, seizures, and movement disorders. We have noted three distinct subtypes of this disease which appear to have differential responses to immunotherapies and differences in prognosis.

METHODS AND PATIENTS

We report eight patients observed at our children's hospital from 2009 through 2013 who appear to clearly fall into one of our three clinical categories. To find comparable articles reflecting this classification, we then performed a MEDLINE search of all articles involving the subject heading "anti-NMDA receptor encephalitis" or just the keyword phrase "NMDA encephalitis," and we found 162 articles to review. Twenty-two articles were eliminated due to basic science, and we were able to review 105 of the remaining articles, most of which were case reports or case series, although a few were larger reviews. For the sake of our review, we defined type 1 or "classic" anti-NMDA receptor antibody encephalitis as having a duration of <60 days and being characterized predominantly by a catatonic or stuporous state, type 2 or psychiatric-predominant anti-NMDA receptor antibody encephalitis as having no noteworthy catatonic or stuporous state in addition to the presence of predominantly behavioral and psychiatric symptoms, and type 3 or catatonia-predominant anti-NMDA receptor antibody encephalitis as having a duration of ≥60 days in a predominantly catatonic or stuporous state.

RESULTS

We note that the poorest responders, even to aggressive immunotherapies, are the patients with catatonia-persistent type anti-NMDA receptor antibody encephalitis, which has, as its hallmark, prolonged periods of severe encephalopathy. Patients with predominantly psychiatric symptoms, which we call the psychiatric-predominant anti-NMDA receptor antibody encephalitis, have had excellent responses to plasma exchange or other immunotherapies and appear to have the least residual deficits at follow-up. Patients with fairly equal representations of periods of altered mental status, behavioral problems, and movement disorders appear to have an intermediate prognosis and likely require early aggressive immunotherapy.

CONCLUSIONS

In our series, we discuss representative examples of these clinical subtypes and their associated outcomes, and we suggest that tracking these subtypes in future cases of anti-NMDA receptor antibody encephalitis might lead to better understanding and better risk stratification with regard to immunotherapy decisions.

Anti-NMDA encephalitis: an uncommon, autoimmune mediated form of encephalitis

We report an interesting case of a 19 year old female with findings on MRI suggestive of viral encephalitis. An extensive workup was negative for infectious causes and she was subsequently diagnosed with anti-NMDA encephalitis. Anti-NMDA encephalitis is a highly lethal but treatable form of autoimmune encephalitis that has recently been characterized. It is frequently found in young women and associated with an underlying teratoma. Although rare, this diagnosis should be considered in young females for whom a rapid onset of encephalitis cannot be explained by more common causes.