Anti-NMDA receptor encephalitis in Japan: long-term outcome without tumor removal

Anti-NMDA receptor encephalitis associated with ovarian tumor: the gynecologist point of view

BACKGROUND

Anti-NMDA receptor antibody (anti-NMDAr) encephalitis, although still a rare condition, is well known to neurologists as it is the leading cause of non-infectious acute encephalitis in young women. However, this is less well known to gynecologists, who may have a decisive role in etiological management. Indeed, in 30-60% of cases in women of childbearing age, it is associated with the presence of an ovarian teratoma, whose removal is crucial in the resolution of symptomatology.

OBJECTIVES

Primary objective of our work was to present a review in a very schematic and practical way for gynecologists, about the data on anti-NMDAr encephalitis in terms of epidemiology, clinical symptomatology, treatment and prognosis. The second objective was to propose a decision tree for gynecologists to guide them, in collaboration with neurologists and anesthesiologists, after the diagnosis of NMDAr encephalitis associated with an ovarian mass.

METHOD

We conducted an exhaustive review of existing data using PubMed and The Cochrane Library. Then, we illustrated this topic by presenting two typical cases from our experience.

RESULTS

Anti-NMDA antibody encephalitis association with an ovarian teratoma is common, especially in women of reproductive age. Complementary examinations in search of an ovarian teratoma must therefore be systematic to envisage a possible surgical excision that may improve patient prognosis.

CONCLUSION

Anti-NMDA antibody encephalitis should not be ignored by gynecologists whose role in management is central.

Clinical and radiologic manifestation B-cell mediated autoimmune diseases of central nervous system

B-cell mediated autoimmune diseases of central nervous system (CNS) put a heavy burden on different aspects of society and economy. Taken together, there are different types of autoimmune diseases in which B-cells play an important role and affect CNS in a pattern of inflammation. These diseases have some similarities in clinical presentations and radiological findings and some similarities with other diseases in different aspects such as treatments with each disease having its own characteristics. In this review article, we had a survey on some different types of B-cell mediated autoimmune diseases of CNS and explained how they can be distinguished from each other and how distinct they are according to radiological findings. The aim of this study is to distinguish B-cell mediated autoimmune diseases of CNS from other non-B-cell diseases in order to choose the best anti-B-cell treatments. At the end of this article we briefly explain different types of treatments being utilized and the role of corticosteroids in acute phases of different diseases.

Sleep Disturbances in Patients with Autoimmune Encephalitis

PURPOSE OF REVIEW

To review sleep complaints reported in patients with autoimmune encephalitis, explore the relationship between sleep disturbances and subtypes of autoimmune encephalitis, and leverage knowledge concerning antibody-antigen specificity to inform the receptors, structures, and disseminated neural networks that contribute to sleep function in health and disease.

RECENT FINDINGS

Autoimmune encephalitis is an inflammatory brain disorder characterized by the subacute onset of psychiatric symptoms, cognitive impairment, and focal neurologic deficits or seizures. Sleep disturbances are detected in a majority of patients systematically screened for sleep complaints, may be the presenting symptom in patients with autoimmune encephalitis, and may compromise recovery in patients with autoimmune encephalitis. Early recognition of specific sleep disturbances in patients with subacute changes in behavior or cognition may support the diagnosis of autoimmune encephalitis. Similarly, recognition and treatment of sleep dysfunction in patients with known autoimmune encephalitis may speed recovery and improve long-term outcomes.

Clinical and Electroencephalographic Features of the Seizures in Neuronal Surface Antibody-Associated Autoimmune Encephalitis

Objectives: To investigate clinical and electroencephalographic features of the seizures in different types of neuronal surface antibody (NSAb)-associated autoimmune encephalitis (AE).

Methods: The clinical data of the seizures were analyzed in 18 patients with NSAb-associated AEs diagnosed in the First Affiliated Hospital of Dalian Medical University.

Results: From May 2013 to April 2019, a total of 18 cases of NSAb-associated AE were diagnosed, including 9 cases of leucine-rich glioma-inactivated 1 protein (LGI1) antibody-associated encephalitis, 7 cases of anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis, and 2 cases of anti-γ-aminobutyric acid B receptor (GABA_BR) encephalitis. All nine cases (100%) with LGI1 AE had seizures manifesting in three types: faciobranchial dystonia seizure (FBDS) (44.4%), mesial temporal lobe epilepsy (MTLE)-like seizure (66.7%), and focal to bilateral tonic–clonic seizure (FBTCS) (77.8%). Six of nine (66.7%) showed abnormal signal on hippocampus or basal ganglia in brain MRI. Five of seven cases (71%) with anti-NMDAR encephalitis had seizures manifesting in three types: focal aware seizure (40%), focal-impaired awareness seizure (20%), generalized tonic–clonic seizure (GTCS) (100%), and status epilepticus (SE) (40%). Three of seven (42.8%) showed abnormalities in brain MRI. Both patients with anti-GABA_BR encephalitis had seizures manifesting in two types: GTCS and MTLE-like seizure, one with SE. One showed abnormal signal on left hippocampus in brain MRI. All patients (100%) with three types of AE had abnormalities in electroencephalogram (EEG), showing diffuse (4/18) or focal slow waves (14/18) in background, interictal (10/18), or ictal (6/18) epileptic discharges in the temporal or other regions; two patients with anti-NMDAR encephalitis showed delta activity or rhythm in frontotemporal region. All patients with seizures showed good response to immunotherapy except one with LGI1 AE.

Conclusions: Most patients with NSAb-associated AE had seizures; seizure types varied between different types of AE. In LGI1 AE, the hippocampus and basal ganglia were two main targets; the corresponding seizure type was MTLE-like seizure and FBDS, respectively. Anti-NMDAR encephalitis had more generalized than focal seizures. Delta activity or rhythm in the frontotemporal region in EEG was helpful for diagnosis. Anti-GABA_BR encephalitis was characterized by refractory seizures as initial symptom, mainly GTCS or MTLE-like seizure. Most seizures in NSAb-associated AE showed good response to immunotherapy, and antiepileptic drugs should be considered as an add-on symptomatic treatment.

Neurocritical care for Anti-NMDA receptor encephalitis

In this review, we summarize the clinical presentations of the acute stage of anti-N-methyl-d-aspartate (NMDA) receptor encephalitis and the neurocritical care strategy in intensive care units. Anti-NMDA receptor encephalitis has characteristic clinical features and is predominantly seen in young adults and children. Most patients have five stages of clinical presentation, including a prodromal phase, psychotic and/or seizure phase, unresponsive and/or catatonic phase, hyperkinetic phase, and gradual recovery phase. The clinical course usually begins with viral infection-like symptoms that last for up to 2 weeks (prodromal phase), followed by the rapid development of schizophrenia-like psychiatric symptoms and seizures (psychotic and seizure phase). Patients may have a decreased level of consciousness with central hypoventilation, frequently requiring mechanical ventilation. In the subsequent hyperkinetic phase, patients present with orofacial-limb dyskinesia and autonomic instability. Children with significant neurological symptoms of anti-NMDA receptor encephalitis should initially be managed in a pediatric intensive care unit. The acute critical presentations are, refractory seizures, autonomic dysfunction, hypoventilation, cardiac arrhythmia, and hyperkinetic crisis. Symptom-guided therapies and critical care are necessary in the acute stage to improve the prognosis.

Battey's operation as a treatment for hysteria: a review of a series of cases in the nineteenth century

Ovarian resection as a treatment for hysteria, called 'Battey's operation' or 'normal ovariotomy', was performed in the nineteenth century. Battey later reported that the resected ovaries appeared to have 'cystic degeneration'. Currently, patients with acute neuropsychiatric symptoms are screened for teratomas for the differential diagnosis of anti-NMDA receptor encephalitis. There is now a hypothesis that ovarian lesions resulting in paraneoplastic encephalitis were among the patients who underwent Battey's operation. We identified 94 published cases of Battey's operation for neuropsychiatric symptoms in the late nineteenth century. Among 36 cases with detailed descriptions, we found 3 patients who showed acute onset neuropsychiatric symptoms with macropathological ovarian findings that were compatible with teratoma. They showed favourable prognoses after surgery and might have motivated the surgeons to perform the operation.

[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.

Clinical Characterization of Definite Autoimmune Limbic Encephalitis: A 30-case Series

Objective Limbic encephalitis (LE) is an inflammatory condition of the limbic system that has an acute or subacute onset. Several types of antibodies are related to the onset of LE, including anti-N-methyl D-aspartate receptor (NMDAR) antibodies and voltage-gated potassium channel (VGKC)-complex antibodies. However, the characteristics and prevalence of LE remain unclear, especially in Asian cohorts, due to the rarity. We aimed to survey their characteristics. Materials and Methods Data of 30 cases clinically defined as "definite autoimmune LE" (based on the standard criteria) were retrospectively collected. These patients were categorized into four subtypes: NMDAR (+) (n=8), VGKC (+) (n=2), antibodies related to paraneoplastic syndrome (n=2), and an antibody-negative group (uncategorized) (n=18). Results LE is rare in Japan, and affected only 30 of 16,759 hospital patients (0.2%) over a ten-year period. The NMDAR (+) group showed distinctive symptoms, while the other three groups had similar indications. Brain MRI indicated significant medial temporal lobe atrophy at one year follow up after discharge. The prevalence of cognitive dysfunction as a complication was 64% (9/14). First-line immunotherapy resulted in a good outcome. A drastic improvement was seen from 4.0±1.1 to 1.1+ on the modified Rankin Scale. A good treatment outcome was observed in all groups (NMDAR, VGKC, and uncategorized), suggesting the importance of an early clinical diagnosis and the early initiation of treatment. Furthermore, we reviewed 26 cases that were clinically diagnosed as definitive autoimmune LE in previous case reports. Conclusion Our findings show that the establishment of a clinical diagnosis based on the clinical criteria of definitive autoimmune LE is important for the initiation of immunotherapy.

Differential expression of antibodies to NMDA receptor in anti-NMDA receptor encephalitis and in neuropsychiatric systemic lupus erythematosus

Objective

Anti-NMDA receptor encephalitis is the most prevalent autoimmune encephalitis having characteristic clinical features with autoantibodies against tetrameric transmembrane channels composed of combinations of NR1 subunits of NMDA receptors with NR2 subunits, which are detected by cell-based assay (anti-NR1/NR2). On the other hand, antibodies against the linear epitope in NR2 subunit (anti-NR2) have been shown to be expressed in patients with diffuse psychiatric/neuropsychological syndromes of neuropsychiatric SLE (diffuse NPSLE). However, it has not been explored whether anti-NR1/NR2 might be detected in NPSLE, nor has it been clear whether anti-NR2 might have cross-reactivity with anti-NR1/NR2. The current study was therefore performed to explore the prevalence of anti-NR1/NR2 in NPSLE.

Methods

Serum specimens were obtained from 31 patients with NPSLE (22 with diffuse NPSLE and 9 with neurological syndromes or polyneuropathy) and from 18 normal healthy subjects. Anti-NR2 and anti-NR1/NR2 were measured by ELISA and cell-based assay, respectively. The positivity for anti-NR2 was defined by a value exceeding mean+2 SD of normal healthy subjects.

Results

Anti-NR2 was positive in the sera of 19 of 31 patients with NPSLE (in 15 of 22 patients with diffuse NPSLE). By contrast, anti-NR1/NR2 was positive only in 2 of 31 patients with NPSLE (in 2 of 22 patients with diffuse SLE). The positivity for anti-NR1/NR2 was not correlated with anti-NR2 values.

Conclusions

These results demonstrate that the prevalence of anti-NR1/NR2 is extremely low in NPSLE. Moreover, the data also confirm that anti-NR2 antibodies do not have cross-reactivity with anti-NR1/NR2.

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.

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

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

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

RATIONALE

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

PATIENT CONCERNS

A 23-year-old woman presented with seizures.

DIAGNOSES

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

INTERVENTIONS

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

OUTCOMES

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

LESSONS

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

Anti-NMDAR encephalitis: A single-center, longitudinal study in China

OBJECTIVE

To describe the detailed clinical characteristics, immunotherapy, and long-term outcomes of patients with anti-NMDA receptor (NMDAR) encephalitis in China.

METHODS

A single-center, prospective study. Patients who met the diagnostic criteria were enrolled from 2011 to 2017 and followed up. The clinical features, treatment, and long-term outcomes were collected prospectively. Factors affecting the long-term prognosis were analyzed.

RESULTS

The study included 220 patients. The most common clinical presentations were psychosis (82.7%) and seizures (80.9%). Of the patients, 19.5% had an underlying neoplasm; of which ovarian teratoma was 100% of tumors in females and only one male had lung cancer. Most patients (99.5%) received first-line therapy (glucocorticoids, IV immunoglobulin, or plasmapheresis alone or combined), and only 7.3% received second-line immunotherapy (rituximab, cyclophosphamide alone, or combined). Long-term immunotherapy (mycophenolate mofetil or azathioprine >1 year) was administered to 53.2% of patients. During the first 12 months, 207 (94.1%) patients experienced improvement, and 5 (2.3%) died, whereas 38 (17.3%) experienced relapses. At 12-month follow-up, 92.7% had favorable clinical outcomes (modified Rankin Scale score ≤2).

CONCLUSIONS

Patients in China present with psychosis and seizure frequently but have a low percentage of underlying neoplasms. Re-enforced first-line immunotherapy is effective in managing anti-NMDAR encephalitis in the acute phase. Although relapse is relatively common, with combined first-line and long-term immunotherapy, most patients reached favorable outcomes.

Phylogenetic Analysis to Explore the Association Between Anti-NMDA Receptor Encephalitis and Tumors Based on microRNA Biomarkers

MicroRNA (miRNA) is a small non-coding RNA that functions in the epigenetics control of gene expression, which can be used as a useful biomarker for diseases. Anti-NMDA receptor (anti-NMDAR) encephalitis is an acute autoimmune disorder. Some patients have been found to have tumors, specifically teratomas. This disease occurs more often in females than in males. Most of them have a significant recovery after tumor resection, which shows that the tumor may induce anti-NMDAR encephalitis. In this study, I review microRNA (miRNA) biomarkers that are associated with anti-NMDAR encephalitis and related tumors, respectively. To the best of my knowledge, there has not been any research in the literature investigating the relationship between anti-NMDAR encephalitis and tumors through their miRNA biomarkers. I adopt a phylogenetic analysis to plot the phylogenetic trees of their miRNA biomarkers. From the analyzed results, it may be concluded that (i) there is a relationship between these tumors and anti-NMDAR encephalitis, and (ii) this disease occurs more often in females than in males. This sheds light on this issue through miRNA intervention.

A critical reflection on our first patient presenting with Anti-Nmethyl- D-aspartate receptor encephalitis

One of the best characterized autoimmune encephalitis is the Anti-Nmethyl- D-aspartate receptor (NMDAR) encephalitis, which may occur in the presence of cancer. First- and second-line immunotherapy and oncological investigations are suggested. We present here a case of an 18-year-old female who was our first patient suffering from Anti- NMDAR encephalitis more than 9 years ago. She was satisfactorily treated with intravenous immunoglobulins and high dose steroid therapy. After more than one year the patient had a relapse. First-line immunotherapy was repeated; however, a complete recovery was achieved only after plasmapheresis. Afterwards, she continued maintenance immunotherapy with steroids for two years and with Azathioprine for about five years associated to regular oncological assessment. In the last years our therapeutical approach of Anti-NMDARencephalitis has significantly changed. Nevertheless, established treatment guidelines are still missing and the role of long-term maintenance immunotherapy is largely unexplored. In addition, oncological revaluation might be indicated in selected patients.

Relevance of Surface Neuronal Protein Autoantibodies as Biomarkers in Seizure-Associated Disorders

The detection of neuronal surface protein autoantibody-related disorders has contributed to several changes in our understanding of central nervous system autoimmunity. The clinical presentation of these disorders may be associated (or not) with tumors, and often patients develop an inexplicable onset of epilepsy, catatonic or autistic features, or memory and cognitive dysfunctions. The autoantigens in such cases have critical roles in synaptic transmission and plasticity, memory function, and process learning. For months, patients with such antibodies may be comatose or encephalopathic and yet completely recover with palliative care and immunotherapies. This paper reviews several targets of neuronal antibodies as biomarkers in seizure disorders, focusing mainly on autoantibodies, which target the extracellular domains of membrane proteins, namely leucine-rich glioma-inactivated-1 (LGI1), contactin-associated protein-like 2 (CASPR2), the N-methyl-D-aspartate receptor (NMDAR), γ-aminobutyric acid receptor-B (GABA_BR), the glycine receptor (GlyR), and a-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs). In order to restore health status, limit hospitalization, and optimize results, testing these antibodies should be done locally, using internationally certified procedures for a precise and rapid diagnosis, with the possibility of initiating therapy as soon as possible.

A Metabolic Brain Pattern Associated With Anti-N-Methyl-D-Aspartate Receptor Encephalitis

BACKGROUND

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis causes substantial neurological disability. Autoantibodies causing encephalitis directed against the neuronal cell surface or synapse are of diagnostic importance giving the possibility of successful immunotherapy.

OBJECTIVE

In this study, we aim to provide supporting evidence that brain 18F-FDG-PET may be helpful in identifying likely patterns of regional brain glucose metabolism.

METHODS

Thirty-three patients (18 men and 15 women; age range of 17-55 y) with positive NMDA receptor antibody encephalitis that underwent an 18F-FDG-PET imaging examination were prospectively selected and compared with a reference group of 14 brain 18F-FDG-PET scans from healthy volunteers using voxel-based statistical analysis. Clusters of hyper- and hypo-metabolism were reported for the whole sample of patients (FWE-corrected P < 0.05), and uncorrected at P < 0.005 for a group of relapsed patients.

RESULTS

Mixed metabolic patterns (focal/bilateral hypermetabolism in the temporal lobe, insula, and cerebellum; associated with severe bilateral hypometabolism in the occipital and parietal lobes) were found.

CONCLUSIONS

Our findings suggest that 18F-FDG-PET should be included as an imaging tool when assessing affected patients in the clinical workup to rule out anti-NMDA encephalitis and help determine the most effective treatment.

Anti-NMDA-receptor antibody in initial diagnosis of mood disorder

Anti-NMDAR encephalitis is increasingly recognized as one etiology of psychiatric symptoms, but there is not enough evidence on patients with mood disorder. We assayed anti-NR1/NR2B IgG antibodies in serum and/or cerebrospinal fluid of 62 patients initially diagnosed with mood disorder by a cell-based assay. We also investigated the specific patient characteristics and psychotic symptoms. At first admission, the patients showed only psychiatric symptoms without typical neurological signs or abnormal examination findings. Four of the 62 patients had anti-NR1/NR2B IgG antibodies. The anti-NR1/NR2B IgG antibody-positive patients showed more super- or abnormal sensitivity (P = 0.00088), catatonia (P = 0.049), and more conceptual disorganization (P < 0.0001), hostility (P = 0.0010), suspiciousness (P < 0.0001), and less emotional withdrawal (P < 0.0001) and motor retardation (P < 0.0001) on the Brief Psychiatric Rating Scale than the antibody-negative patients. During the clinical course, anti-NR1/NR2B IgG antibody-positive patients showed more catatonia (P = 0.0042) and met Graus's criteria for diagnosis of anti-NMDAR encephalitis, but negative patients did not. Immunotherapy was effective for anti-NR1/NR2B IgG antibody-positive patients, and there was the weak relationship (R² = 0.318) between the anti-NR1/NR2B IgG antibody titer in the cerebrospinal fluid and the Brief Psychiatric Rating Scale score.

[Recent progress in autoimmune encephalitis and its related disorders]

After the discovery of a series of autoantibodies against neuronal cell surface antigens (NSAs) of the CNS in the past 10 years, the concept of encephalitis has changed dramatically. Accordingly, a practical, syndrome-based diagnostic approach to autoimmune encephalitis was proposed in 2016. These autoantibodies have also been identified in a subset of overlapping encephalitis and demyelinating syndrome, epilepsy, first episode psychosis, movement disorders, post-herpes simplex encephalitis, progressive dementia, postpartum psychosis, stiff-person spectrum disorders, or non-REM/REM sleep behavior disorder. Although not all neuronal antibody tests are available in Japan, we have entered a new era that we have to make a correct diagnosis and start appropriate immunotherapy based on initial neurological assessment and conventional tests, without being constrained by conventional fixed ideas or normal-appearing brain MRIs while waiting for neuronal antibody test results. Although many issues need to be resolved in Japan in terms of diagnosis and treatment in autoimmune encephalitis, this review focusses on recent progress in autoimmune encephalitis and its related disorders closely related to clinical practice, including Hashimoto encephalopathy and new-onset refractory status epilepticus (NORSE).

Immunotherapy for anti-NMDA receptor encephalitis: Experience from a single center in Taiwan

BACKGROUND

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis is an anti-neuronal antibody-mediated inflammatory brain disease that causes severe psychiatric and neurological deficits in previously healthy patients. The aims of this study were to demonstrate the clinical characteristics of patients diagnosed with anti-NMDA receptor encephalitis and to compare the different treatment strategies among these patients.

METHODS

Patients presenting with newly acquired psychiatric and/or neurological deficits were studied retrospectively from 2009 to 2017. Patients with evidence of anti-NMDA receptor antibodies in serum and/or cerebrospinal fluid were enrolled. The modified Rankin scale was used to assess the initial status and outcomes of the enrolled patients. Details of the clinical presentations and results of investigations were analyzed.

RESULTS

All (n = 24) of the patients received first-line immunotherapy (steroids, and/or intravenous immunoglobulin, and/or plasma exchange), and 14 patients received second-line immunotherapy (rituximab and/or cyclophosphamide). The mean time between the first- and second-line treatment was 13 days. During the first 6 months, 20 patients (20/24, 83%) achieved a good outcome (modified Rankin Scale score ≤2) and 15 patients (15/24, 62.5%) completely recovered. Four patients (17.7%) relapsed, and three patients (12.5%) had associated tumors.

CONCLUSION

Immunotherapy is an effective treatment for anti-NMDA receptor encephalitis. Rituximab and/or cyclophosphamide are treatment options for those who cannot tolerate or do not respond to first-line immunotherapy. Prospective studies are necessary to investigate the role of rituximab and cyclophosphamide in anti-NMDA receptor encephalitis.

Neuronal NMDAR Currents of the Hippocampus and Learning Performance in Autoimmune Anti-NMDAR Encephalitis and Involvement of TNF-α and IL-6

Among autoimmune encephalitis, patients with anti-N-methyl D- aspartate receptor (NMDAR) encephalitis typically present epileptic seizures, memory deficits and psychiatric symptoms. However, the signal mechanisms leading to the functional disorders of autoantibodies are largely unclear. In this study, anti-NMDAR antibody was administered into dentate gyri against the NR1 subunit of the NMDAR. The purpose of the study examined the effects of pro-inflammatory tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) on neuronal NMDAR currents of the hippocampus in rats with anti-NMDAR encephalitis and we further determined the role played by TNF-α and IL-6 in modulating learning performance. In results, we observed a decrease in amplitude of the NMDAR-mediated excitatory postsynaptic currents (NMDAR-EPSCs) in the hippocampal neurons of animals treated with anti-NMDAR. In those rats with anti-NMDAR, we also observed impaired learning performance in the Morris water maze and spatial working memory test. Of note, cerebral infusion of TNF-α and IL-6 worsened NMDAR-EPSCs and this was accompanied with exaggeration of impaired learning performance. In conclusion, our findings suggest that the role played by neuroinflammation in exacerbating the memory impairment found in animals treated with anti-NMDAR. Anti-inflammation is a potential target in improving the memory impairment induced by anti-NMDA encephalitis.

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

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

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

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

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

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.

Temporal Changes on 123I-Iomazenil and Cerebral Blood Flow Single-photon Emission Computed Tomography in a Patient with Anti-N-methyl-D-aspartate Receptor Encephalitis

A 45-year-old man was admitted due to tonic seizures, aphasia, disturbance of consciousness, and abnormal behavior. Because cerebral magnetic resonance imaging findings were normal and mild cerebrospinal fluid (CSF) pleocytosis was observed, autoimmune encephalitis was suspected. The presence of anti-N-methyl-D-aspartate (NMDA) receptor antibodies in the CSF was subsequently confirmed. ¹²³I-Iomazenil and cerebral blood flow single photon emission computed tomography (SPECT) revealed an abnormal uptake in the left frontotemporal region. Multimodal immunotherapy was administered, which remarkably improved the level of consciousness. Progressive reversibility of SPECT findings with clinical improvement suggested that the disorder-related functional deficits had been caused by anti-NMDA receptor antibodies.

Longitudinal brain morphology in anti-NMDA receptor encephalitis: a case report with controls

BACKGROUND

Anti-N-methyl-D-aspartate-receptor (NMDAR) encephalitis is a severe autoimmune condition, which typically affects young females. The long-term clinical consequences and brain morphology changes after anti-NMDAR encephalitis are not well known.

CASE PRESENTATION

We present clinical and neuroimaging follow-up data on a 25-year female patient with typically presenting anti-NMDAR encephalitis. Longitudinal analyses of brain morphology were done using 3 T structural magnetic resonance imaging (sMRI) and Freesurfer analysis at the time of diagnosis and after symptomatic remission. The presented case attained good functional recovery after standard immunoglobulin-corticosteroid treatment but elevated serum NMDAR antibody levels persisted. The patient had no symptomatic relapses during a 3-year clinical follow-up. In the baseline brain sMRI scan there were no marked volume changes. However, a follow-up sMRI after 9 months indicated clear volume reductions in frontal cortical regions compared to matched controls with identical sMRI scans.

CONCLUSIONS

This case report of anti-NMDAR encephalitis suggests that despite clinical recovery long-term brain morphological changes can develop in the frontal cortex. Longer clinical and imaging follow-up studies are needed to see whether these frontocortical alterations are fully reversible and if not, can they result in trait vulnerabilities for e.g. neuropsychiatric disorders.

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.

Autoimmune Encephalitides

Autoimmune encephalitis is a severe inflammatory disorder of the brain with diverse causes and a complex differential diagnosis. Recent advances in the past decade have led to the identification of new syndromes and biological markers of limbic encephalitis, the commonest presentation of autoimmune encephalitis. The successful use of serum and intrathecal antibodies to diagnose affected patients has resulted in few biopsy and postmortem examinations. In those available, there can be variable infiltrating inflammatory T cells with cytotoxic granules in close apposition to neurons, consistent with an inflammatory autoimmune basis, but true vasculitis is rarely seen. The exception is Hashimoto encephalopathy.

Diagnosis and Management of Autoimmune Dementia

PURPOSE OF REVIEW

To describe the clinical, laboratory, and MRI features that characterize cognitive decline in the setting of central nervous system (CNS) autoimmunity, and provide an overview of current treatment modalities.

RECENT FINDINGS

The field of autoimmune neurology is rapidly expanding due to the increasing number of newly discovered autoantibodies directed against specific CNS targets. The clinical syndromes associated with these autoantibodies are heterogeneous but frequently share common, recognizable clinical, and MRI characteristics. While the detection of certain autoantibodies strongly suggest the presence of an underlying malignancy (onconeural autoantibodies), a large proportion of cases remain idiopathic. Cognitive decline and encephalopathy are common manifestations of CNS autoimmunity, and can mimic neurodegenerative disorders. Recent findings suggest that the frequency of autoimmune encephalitis in the population is higher than previously thought, and potentially rivals that of infectious encephalitis. Moreover, emerging clinical scenarios that may predispose to CNS autoimmunity are increasingly been recognized. These include autoimmune dementia/encephalitis post-herpes simplex virus encephalitis, post-transplant and in association with immune checkpoint inhibitor treatment of cancer. Early recognition of autoimmune cognitive impairment is important given the potential for reversibility and disability prevention with appropriate treatment. Autoimmune cognitive impairment is treatable and may arise in a number of different clinical settings, with important treatment implications. Several clinical and para-clinical clues may help to differentiate these disorders from dementia of other etiologies.

Emerging role of prodromal headache in patients with anti-N-methyl-D-aspartate receptor encephalitis

Background

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis patients often present with psychiatric symptoms, cognitive dysfunction, epilepsy and memory deficits. A previous study has suggested that headache can occurr during the early stages of anti-NMDAR encephalitis. However, the exact association between headache and anti-NMDAR encephalitis has hardly been investigated, apart from a few case studies. This is probably due to the severity of encephalitis symptoms, and the mechanism underlying headache-associated anti-NMDAR encephalitis remains largely unclear.

Objective

This study aimed to investigate the role of prodromal headache in 28 patients diagnosed with anti-NMDAR encephalitis.

Methods

Clinical data related to the prodromal headache characteristics of anti-NMDAR encephalitis patients were prospectively collected from January first 2017 to June first 2018. Autoimmune antibodies in the cerebrospinal fluid (CSF) of anti-NMDAR encephalitis patients were detected by an indirect immunofluorescence staining kit. The differences between age, sex, clinical symptoms (fever, epilepsy, psychiatric symptoms, cognitive impairment, disturbance of consciousness), CSF, brain MRI abnormalities, and modified Rankin Scale (mRS) score were compared between patients with and without headache. In addition, the association of headache severity with brain MRI abnormalities, antibody titers, and mRS score was examined.

Results

Twenty-eight patients with anti-NMDAR encephalitis (median, 29 years; range, 15–62 years) reported headache. Among them, 18 (64%) were female, 24 (86%) had fever, 21 (75%) were positive for serum virus antibody, 19 (68%) had severe pain intensity (scored 4–7 out of 10 on the visual analog scale), 18 (64%) presented with pulsating character, and 5 (18%) patients accompanied by vomiting. Moreover, headache was detected in the frontal lobe of 14 (50%) patients and temporal lobe of 12 (43%) patients. Encephalitic symptoms (psychiatric symptoms, cognitive dysfunction, epilepsy, and memory deficits) appeared in 23 patients at average 5.5 days (range, 1–21 days) followed by headache attack. In five patients, the headache was lasted for 21 days.

Conclusion

Prodromal headache is commonly found in the temporal lobe and frontal lobe of young patients, and hardly accompanied by vomiting. Headache is rapidly substituted by encephalitis symptoms in the majority of patients, while gradually relieved in a few patients after the recovering from encephalitis symptoms. The results strongly suggest that the NR1 subunit of NMDAR is involved in prodromal headache. In sum, the symptom of prodromal headache is crucial for the diagnosis of anti-NMDAR encephalitis.

Limbic Encephalitis following Guillain-Barré Syndrome Associated with <b><i>Mycoplasma</i></b> Infection

A 12-year-old girl was admitted to the authors’ hospital due to muscle weakness, gait disturbance, dysarthria, dysphagia, and diplopia. She experienced prodromal fever 10 days before admission. On examination, deep tendon reflex was absent in the extremities, and nerve conduction velocity was decreased in the ulnar nerve. She was diagnosed with Guillain-Barré syndrome (GBS). Despite steroid pulse therapy following administration of intravenous high-dose γ-globulin, clinical manifestations remained unchanged. Therefore, plasma exchange was performed on day 10 of the illness. The titer of serum <i>Mycoplasma</i> immunoglobulin M level was increased. Immunological testing was positive for serum anti-galactocerebroside C antibody. On day 18 of the illness, however, she developed generalized convulsion. Brain magnetic resonance imaging revealed high intensity in the medial temporal lobes, including the hippocampus and thalamus on T2-weighted intensity imaging, which was consistent with limbic encephalitis. Further immunological tests revealed positivity for anti-N-methyl-D-aspartate-type glutamate receptor antibody in the cerebrospinal fluid. She was treated with additional plasma exchange; however, she exhibited residual manifestations including short-term memory disorder, emotional incontinence, and convulsions. This article describes a notable case of limbic encephalitis following GBS associated with prodromal <i>Mycoplasma</i> infection. It is interesting that autoimmune encephalopathy is concomitant with autoimmune polyneuropathy subsequent to <i>Mycoplasma</i> infection.

N-Methyl-d-aspartate Receptor Antibody Encephalitis: A Concise Review of the Disorder, Diagnosis, and Management

Anti-NMDA ( N-methyl-d-aspartate) receptor (anti-NMDAR) encephalitis is one of the most common paraneoplastic encephalitides. It occurs in both sexes, across all age ranges, and may occur in the presence or absence of an associated tumor. Its pathogenesis and clinical presentation relate to the presence of IgG1 or IgG3 antibodies targeting the NR1 subunit of the NMDA receptor, leading to a disinhibition of neuronal excitatory pathways. Initial clinical manifestations may be nonspecific, resembling a viral-like illness; however, with disease progression, symptoms can become quite severe, including prominent psychiatric features, cognitive problems, motor dysfunction, and autonomic instability. Anti-NMDAR encephalitis may even result in death in severe untreated cases. Diagnosis can be challenging, given that initial laboratory and radiographic results are typically nonspecific. The majority of patients respond to first or second-line treatments, although therapeutic options remain limited, usually consisting of tumor removal (if there is confirmation of an underlying malignancy) in conjunction with prompt initiation of immunosuppressive medications along with intravenous immunoglobulins and/or plasma exchange. Although the clinical presentation of anti-NMDAR encephalitis overlaps with several other more common neurological and psychiatric disorders, early diagnosis and treatment is essential for a positive prognosis. Here, we concisely review the pathogenesis, diagnosis, and clinical management of this disease.

A score that predicts 1-year functional status in patients with anti-NMDA receptor encephalitis

OBJECTIVE

To construct a grading score that predicts neurologic function 1 year after diagnosis of anti-NMDA receptor (NMDAR) encephalitis.

METHODS

Three hundred eighty-two patients with detailed information and functional status at 1 year were studied. Factors associated with poor status (defined as modified Rankin Scale score ≥3) were identified and incorporated into a multivariate logistic regression model. This model was used to develop a 5-point prediction score, termed the anti-NMDAR Encephalitis One-Year Functional Status (NEOS) score.

RESULTS

Intensive care unit admission (p < 0.001), treatment delay >4 weeks (p = 0.012), lack of clinical improvement within 4 weeks (p < 0.001), movement disorder (p = 0.001), central hypoventilation (p < 0.001), elevated CSF white blood cell count (p < 0.001), elevated CSF protein level (p = 0.027), and abnormal MRI (p = 0.002) were associated with 1-year functional status in univariate analysis. Intensive care unit admission, treatment delay >4 weeks, lack of clinical improvement within 4 weeks, abnormal MRI, and CSF white blood cell count >20 cells/μL were independent predictors for outcome in multivariate regression modeling. These 5 variables were assigned 1 point each to create the NEOS score. NEOS score strongly associated with the probability of poor functional status at 1 year (3% for 0 or 1 point to 69% for 4 or 5 points, p < 0.001).

CONCLUSIONS

The NEOS score accurately predicts 1-year functional status in patients with anti-NMDAR encephalitis. This score could help estimate the clinical course following diagnosis and may aid in identifying patients who could benefit from novel therapies.

Limbic encephalitis: Experience of a moroccan center

OBJECTIVES

Histologically defined as an inflammation-degeneration of limbic structures, limbic encephalitis (LE) is a rare disease and often difficult to diagnose particularly in institutions with limited access to laboratory tests such as antineuronal antibodies or HSV-PCR, and functional imaging. We aimed to describe the demographic, clinical, paraclinical, and etiological features of LE, as well as its medium-term prognosis in Moroccan patients.

MATERIALS AND METHODS

We collected retrospectively all patients diagnosed with LE in the Department of Neurology of the University Hospital Hassan II of Fez (Morocco) between September 2008 and December 2016. We analyzed their demographic features, clinical manifestations, magnetic resonance imaging and laboratory findings, etiologies, and medium-term prognoses.

RESULTS

We included 22 men and 9 women aged 14-76 years (mean age: 45.8 years). In 64.5% of cases, the onset of symptoms was acute. The clinical manifestations included generalized status epilepticus (16.1%), confusional syndrome (29%), epileptic seizures (38.7%), psychiatric disorders (48.4%), and memory disorders (45.2%). The nonlimbic symptoms were nuchal stiffness (22.6%), headaches (9.7%), fever (61.3%), vesicular rash (3.2%), and language disorders (6.5%). The different etiologies found were herpes simplex virus (6.5%), syphilis (16.1%), tuberculosis (3.2%), varicella (3.2%), paraneoplastic autoimmune LE (22.6%), anti-NMDA-R LE (6.5%), and sarcoidosis (3.2%). We found 12 cases (38.7%) of LE without definite etiology and with an incomplete diagnostic workup. The medium-term clinical course includes a complete remission in 45.2% of cases and partial remission in 45.1% of cases. The different sequelae were temporal lobe epilepsy (9.7%), anterograde amnesia (16.1%), and severe cognitive impairment (19.4%). The mortality rate was 9.7% (3 patients).

CONCLUSION

Our study shows a wide diversity of etiologies of LE in Morocco with essentially an acute mode of onset of symptoms.

Anesthesia for patient with anti-N-methyl-D-aspartate receptor encephalitis: A case report with a brief review of the literature

RATIONALE

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis is an immune-mediated syndrome caused by the production of antibodies against NMDA receptors. As NMDA receptors are important targets of many anesthetic drugs, the perioperative management of patients with anti-NMDA receptor encephalitis is challenging for anesthesiologists.

PATIENT CONCERNS

A 31-year-old woman presented with akinesia and aphasia, which worsened despite steroid therapy.

DIAGNOSIS

Anti-NMDA receptor encephalitis associated with ovarian teratoma.

INTERVENTIONS

Laparoscopic ovarian cystectomy was performed under total intravenous anesthesia (TIVA) with peripheral nerve block (PNB).

OUTCOMES

The patient recovered without postoperative complications or any adverse events after surgery.

LESSONS

Ideal anesthesia for a patient with anti-NMDA receptor encephalitis is still under discussion. We decided to perform TIVA with PNB because the effect of propofol on NMDA receptors is considered less than that of volatile anesthetics; moreover, PNB may reduce the amount of propofol and opioids required for anesthesia. To conclude, TIVA with PNB may be the most appropriate method for anesthesia in a patient with anti-NMDA receptor encephalitis undergoing ovarian cystectomy.

Anesthesia for patient with anti-N-methyl-D-aspartate receptor encephalitis: A case report with a brief review of the literature

RATIONALE

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis is an immune-mediated syndrome caused by the production of antibodies against NMDA receptors. As NMDA receptors are important targets of many anesthetic drugs, the perioperative management of patients with anti-NMDA receptor encephalitis is challenging for anesthesiologists.

PATIENT CONCERNS

A 31-year-old woman presented with akinesia and aphasia, which worsened despite steroid therapy.

DIAGNOSIS

Anti-NMDA receptor encephalitis associated with ovarian teratoma.

INTERVENTIONS

Laparoscopic ovarian cystectomy was performed under total intravenous anesthesia (TIVA) with peripheral nerve block (PNB).

OUTCOMES

The patient recovered without postoperative complications or any adverse events after surgery.

LESSONS

Ideal anesthesia for a patient with anti-NMDA receptor encephalitis is still under discussion. We decided to perform TIVA with PNB because the effect of propofol on NMDA receptors is considered less than that of volatile anesthetics; moreover, PNB may reduce the amount of propofol and opioids required for anesthesia. To conclude, TIVA with PNB may be the most appropriate method for anesthesia in a patient with anti-NMDA receptor encephalitis undergoing ovarian cystectomy.

Clinical variability of children with anti-N-methyl-D-aspartate receptor encephalitis in southern Brazil: a cases series and review of the literature

PURPOSE

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an immune-mediated disease of the central nervous system (CNS). The aim of this study was to describe the variability of clinical presentation in anti-NMDAR encephalitis, treatment and outcomes in a case series of children and adolescents.

METHODS

Retrospectively analyse patients diagnosed with anti-NMDAR encephalitis, from 2010 to 2018.

RESULTS

The study population consisted of nine children with anti-NMDAR encephalitis from southern Brazil, six females and three males, aged 5 months to 16 years (mean 5 years). The time of follow-up varied between 1 and 7 years, with a mean of 3 years. The most frequent first manifestation consisted of seizures. All patients described had psychiatric symptoms and a wide spectrum of neurologic findings. Five patients had unilateral symptoms. Magnetic resonance imaging and electroencephalogram were normal in most patients. Cerebrospinal fluid pleocytosis occurred in five patients. All patients were administered immunoglobulin and/or steroids. Seven patients (78%) required cyclophosphamide and/or rituximab. Almost half of the patients fully recovered from all symptoms.

CONCLUSIONS

A wide variety of symptoms were observed in this study and, although unilateral symptoms are rarely reported in the literature, a high frequency was observed among Brazilian children. Alternatives to first-line therapy should be considered in patients with clinical suspicion, even if they have not had a good response with first-line therapy.

A Case of Severe Anti-N-Methyl D-Aspartate (Anti-NMDA) Receptor Encephalitis with Refractory Autonomic Instability and Elevated Intracranial Pressure

Patient: Female, 21

Final Diagnosis: Anti-NMDA receptor encephalitis

Symptoms: Altered mental status • headache

Medication: Intravenous immunoglobulin • methylprednisolone • cyclophosphamide • rituximab

Clinical Procedure: Cardiac pacemaker • bilateral salpingo-oophorectomy

Specialty: Neurology • Critical Care

Toxic Epidermal Necrolysis in a Patient with Autoimmune Limbic Encephalitis with Anti-Glutamate Receptor Antibodies

We report on a 44-year-old woman who was diagnosed with toxic epidermal necrolysis (TEN) during the recovery phase from autoimmune limbic encephalitis with anti-glutamate receptor antibodies. Both, autoimmune limbic encephalitis and TEN are very rare diseases. The co-existence of the two diseases has not yet been reported. We speculate that the total of 18 drugs needed for the treatment of encephalitis might have increased the risk of TEN. Similar reports would be required to elucidate the pathophysiology of the co-existence.

Teratoma-negative anti-NMDA receptor encephalitis presenting with a single generalized tonic-clonic seizure

Herein, we describe a case report of anti-NMDA receptor encephalitis characterized by a single generalized tonic–clonic seizure and predominantly psychiatric symptoms, persisting long after EEG abnormalities had resolved. We discuss common presentations of anti-NMDA receptor encephalitis and advocate for the inclusion of this disease entity in the differential diagnosis of patients presenting with one generalized tonic–clonic seizure and prominent psychiatric symptoms.

•

Teratoma-negative anti-NMDA receptor encephalitis presented with a single GTC seizure and prominent psychiatric symptoms.

•

We emphasize the importance of early treatment with immunotherapy in autoimmune epilepsy.

•

The literature on acute anti-NMDA receptor encephalitis presenting with one GTC seizure is reviewed.

Prodromal headache in anti-NMDAR encephalitis: An epiphenomenon of NMDAR autoimmunity

OBJECTIVE

To investigate the nature of prodromal headache in anti-NMDA receptor (NMDAR) encephalitis.

METHODS

Retrospective review of the clinical information of 39 patients with anti-NMDAR encephalitis admitted between January 1999 and September 2017. Five patients with an atypical presentation were excluded. Thus, in 34 patients (median 27 years [range, 12-47 years]; 28 [82%] female), the clinical features were compared between patients who initially reported headache and those who did not report.

RESULTS

Twenty-two patients (65%) reported headache either transiently (n = 5) or continuously (n = 17). Encephalitic symptoms (psychobehavioral memory alterations, seizure, dyskinesias, or altered level of consciousness) developed in 20 patients with median 5.5 days (range, 1-29 days) after headache onset. In one patient, NMDAR antibodies were detected in CSF 3 days after headache onset. Patients with headache had more frequently fever (14/22 [64%] vs. 2/12 [17%] p = 0.013) and higher CSF pleocytosis (median white blood cells 79/μl [range, 6-311/μl] vs. 30/μl [range, 2-69/μl], p = 0.035) than those without headache, but there was no difference in gender, age at onset, seizure, migraine, CSF oligoclonal band detection, elevated IgG index, tumor association, or brain MRI abnormalities between them.

CONCLUSIONS

Headache often developed with fever and pleocytosis, but it was rapidly replaced by psychiatric symptoms. Based on current knowledge on the antibody-mediated mechanisms that cause a decrease of synaptic NMDAR through crosslinking and internalization leading to a state mimicking "dissociative anesthesia," we speculated that prodromal headache is not likely caused by direct effect of the autoantibodies but rather meningeal inflammation (noninfectious aseptic meningitis) that occurs in parallel to intrathecal antibody synthesis as an epiphenomenon of NMDAR autoimmunity. Psychobehavioral alterations following headache is an important clue to the diagnosis.

Primary lateral sclerosis-like picture in a patient with a remote history of anti-N-methyl-D- aspartate receptor (anti-NMDAR) antibody encephalitis

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a well-recognised disorder, first fully characterised in 2007. The long-term sequelae reported thus far include relapses with typical, as well as partial aspects of the well-defined neuropsychiatric syndrome. Rarely, isolated atypical symptoms (diplopia, ataxia and tremor) have been reported as relapse phenomenon. We report a case of a patient with a remote history of likely anti-NMDAR encephalitis with the longest follow-up reported in the literature to date (22 years). The relapse presentation was of a purely upper motor neuron syndrome with a primary lateral sclerosis-like picture.