A case of Adult-onset Acute Flaccid Myelitis Accompanied by Rhombencephalitis which First Presented with Prominent Psychiatric Symptoms and Dysautonomia Mimicking Anti-N-methyl-d-aspartate Receptor Encephalitis

A 44-year-old woman with a subacute onset of an altered mental status, urinary retention, and fluctuating blood pressure was initially diagnosed with anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis, meeting the criteria of Graus et al. Cardiac arrest occurred, which required pacemaker placement. She subsequently showed profound flaccid limb paralysis, with magnetic resonance imaging demonstrating focal necrotic lesions localized in the anterior horn of the longitudinal segments of the spinal cord and in the pontine tegmentum. Enteroviruses or autoimmune encephalitis-associated autoantibodies were not detected. We herein report a case of acute flaccid myelitis with profound psychiatric symptoms and dysautonomia, resembling NMDAR encephalitis.

Anti-NMDA receptor encephalitis in a 73-year-old female with secondary progressive multiple sclerosis: A case report

Anti-NMDA receptor (Anti-NMDAR) encephalitis is an autoimmune disease that presents with diverse symptoms. Since literature is scarce on the overlap with multiple sclerosis (MS), this report aims to elucidate the distinctive clinical presentation and diagnostic challenges of anti-NMDAR encephalitis in MS patients. A 73-year-old woman with secondary progressive multiple sclerosis, after experiencing status epilepticus and subsequent non-convulsive status epilepticus, presented with neuropsychiatric symptoms and autonomic nervous dysfunction. Notably, the patient had not received any immunomodulatory therapy. The clinical picture together with diagnostics (MRI, EEG, cerebro-spinal fluid) let us suspect HSV-meningoencephalitis and empirically treat the patient with IV acyclovir. Due to a lack of clinical improvement, we reconsidered the diagnosis and found the diagnostic criteria for autoimmune encephalitis to be met. Antibodies in blood and CSF were positive and we diagnosed the patient with anti-NMDAR encephalitis. The patient responded well to IV prednisolone treatment, leading to a stable outcome in a six-month follow-up. This case highlights the difficulties in diagnosing anti-NMDAR encephalitis in patients with multiple sclerosis. The presence of epileptic seizures can serve as a crucial diagnostic indicator to distinguish between an MS relapse and an overlapping disease. Compared to patients with other demyelinating diseases, patients with overlapping MS appear to have a higher risk of motor seizures.

Cytokine/chemokine levels in the CSF and serum of anti-NMDAR encephalitis: A systematic review and meta-analysis

Objectives

To summarize the cytokine/chemokine levels of anti-N-methyl-Daspartate receptor encephalitis (NMDAR-E) and explore the potential role of these molecules and immune cells in the pathogenic mechanism.

Methods

The PubMed, Cochrane Library, Embase, and Web of Science databases were searched for various articles that assessed the concentrations of cytokines/chemokines in the unstimulated cerebrospinal fluid (CSF) or serum of patients with NMDAR-E in this systematic review and meta-analysis. The standardized mean difference (SMD) and 95% confidence interval (CI) were calculated by Stata17.0.

Results

A total of 19 articles were included in the systematic review from 260 candidate papers, and cytokine/chemokine levels reported in the CSF/serum were examined in each article. This meta-analysis included 17 eligible studies comprising 579 patients with NMDAR-E, 367 patients with noninflammatory neurological disorders, and 42 healthy controls from China, Spain, South Korea, Australia, Czechia, and Sweden. The results indicated that the levels of different cytokines interleukin (IL)-6, tumor necrosis factor (TNF)-α, IL-10, IL-13, IL-1β, IL-12, and IL-17 and chemokine C-X-C motif ligand (CXCL)10 in the CSF were significantly higher in NMDAR-E patients with a large effect size. In addition, B cell activating factor (BAFF), CXCL13, and interferon (IFN)-γ levels in the CSF were higher in NMDAR-E patients with a middle effect size. In contrast, levels of IL-2 and IL-4 in the CSF and CXCL13 and BAFF in the serum did not show a significant difference between cases and controls.

Conclusions

These analyses showed that the central immune response in NMDAR-E is a process that involves multiple immune cell interactions mediated by cytokines/chemokines, and T cells play an important role in the pathogenesis of immunity.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier (CRD42022342485).

When herpes simplex virus encephalitis meets antiviral innate immunity

Herpes simplex virus (HSV) is the most common pathogen of infectious encephalitis, accounting for nearly half of the confirmed cases of encephalitis. Its clinical symptoms are often atypical. HSV PCR in cerebrospinal fluid is helpful for diagnosis, and the prognosis is usually satisfactory after regular antiviral treatment. Interestingly, some patients with recurrent encephalitis have little antiviral effect. HSV PCR in cerebrospinal fluid is negative, but glucocorticoid has a significant effect after treatment. Specific antibodies, such as the NMDA receptor antibody, the GABA receptor antibody, and even some unknown antibodies, can be isolated from cerebrospinal fluid, proving that the immune system contributes to recurrent encephalitis, but the specific mechanism is still unclear. Based on recent studies, we attempt to summarize the relationship between herpes simplex encephalitis and innate immunity, providing more clues for researchers to explore this field further.

[Clinical characteristics and short-term outcomes of autoimmune encephalitis in adults]

OBJECTIVE

To characterize clinical, paraclinical features and short-term outcomes in different types of autoimmune encephalitis (AE) in a one-center cohort of Russian patients, as well as to evaluate the frequency and significance of the joint expression of antineuronal and anti-glial antibodies (Abs) in AE.

MATERIAL AND METHODS

Forty-one patients were diagnosed with AE at the Research Center of Neurology from November 2020 to December 2022. Demographic, clinical characteristics, results of laboratory tests, MRI of brain, treatment and outcomes of disease were analyzed. The analysis of Abs to glial antigens (myelin-oligodendrocyte glycoprotein - MOG, glial fibrillar acidic protein - GFAP, aquaporin 4 - AQP-4) was performed by indirect immunofluorescence assay (Euroimmun, Germany).

RESULTS

In 24 (58.5%) patients was established definite AE, confirmed by specific Abs detection; in 2 (4.9%) - definite limbic encephalitis, in 15 (36.6%) - seronegative probable AE (including 3 cases of Hashimoto's encephalitis). GFAP-Abs in cerebrospinal fluid (CSF) were detected only in two patients - with clinical and MRI-picture of autoimmune GFAP-astrocytopathy (A-GFAP-A). GFAP- and MOG-Abs in the blood were detected in 25.7% and 6%, respectively, AQP-4-Abs were not detected. There were no correlations between co-expression with glial Abs and clinical characteristics. Systemic and antithyroid Abs were present in 15% and 31%, respectively. Paraneoplastic AE accounted for 22%. For the first time in the Russian population, 2 cases of A-GFAP-A, 6 cases of AE associated with COVID-19 were described. The most common first syndrome were epileptic seizure (34%), psychiatric (29%) and cognitive (14%) disorders. Relapses of AE was observed in 22%. Inflammatory changes in CSF were detected in 41%, focal changes on MRI in 68%. First-line immune therapy was performed in all patients, 85% of cases received pulse therapy with methylprednisolone. Second-line immune therapy (rituximab or cyclophosphamide intravenously) was performed in 19.5%, 78% of patients achieved significant improvement during treatment (scores ≤2 on the modified Rankin scale).

CONCLUSIONS

The results allow us to consider COVID-19 as a trigger of AE. The absence of detection of GFAP-Abs in CSF in patients with other types of AE contributes to the confirmation of the specificity of GFAP-seropositivity of CSF for the diagnosis of A-GFAP-A. The expression of GFAP- and MOG-Abs in AE can serve as confirmation of the immuno-mediated etiology of the disease, which is especially important for the AE diagnosis in the absence of antineuronal Abs.

Schizophrenia after remission of anti-NMDA receptor encephalitis

N-methyl-D-aspartate receptor (NMDAR) dysfunction is an attractive hypothesis regarding the etiology of schizophrenia. We present the unprecedented case of a woman diagnosed with schizophrenia without anti-NMDAR antibodies after history of NMDAR encephalitis. A first episode of psychosis was antibody-positive and was improved with steroid and immunoglobulin treatment. Second and third episodes were antibody-negative, each about three months postpartum (different pregnancies) and were improved with antipsychotics. Without NMDAR encephalitis-related findings, we diagnosed schizophrenia. After anti-NMDAR encephalitis, NMDAR dysfunction may decrease the threshold for the onset of psychosis. This case provides insight into NMDAR dysfunction on etiology of schizophrenia.

Disturbance of Gut Bacteria and Metabolites Are Associated with Disease Severity and Predict Outcome of NMDAR Encephalitis: A Prospective Case-Control Study

Objective

We aimed to investigate the associations between the intestinal microbiota, metabolites, cytokines, and clinical severity in anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis and to further determine the predictive value of the intestinal microbiota or metabolites in clinical prognosis.

Methods

In this prospective observational cohort study of 58 NMDAR encephalitis patients and 49 healthy controls, fecal microbiota, metabolites, and cytokines were quantified and characterized by16S rRNA gene sequencing, liquid chromatography–mass spectrometry, and the Luminex assay, respectively.

Results

There were marked variations in the gut microbiota composition and metabolites in critically ill patients. We identified 8 metabolite modules (mainly characterized by fatty acid, glycerophosphoethanolamines, and glycerophosphocholines) that were distinctly classified as negatively or positively associated with bacterial co-abundance groups (CAGs). These CAGs were mainly composed of Bacteroides, Eubacterium_hallii_group, Anaerostipes, Ruminococcus, Butyricicoccus, and Faecalibacterium, which were substantially altered in patients. In addition, these fecal and serum metabolic modules were further correlated with the serum cytokines. Additionally, the combination of clinical features, microbial marker (Granulicatella), and a panel of metabolic markers could further enhance the performance of prognosis discrimination significantly, which yielded an area under the receiver operating characteristic curve of (AUC) of 0.94 (95%CI = 0.7–0.9). Patients with low bacterial diversity are more likely to develop relapse than those with higher bacterial diversity (log-rank p = 0.04, HR = 2.7, 95%CI = 1.0–7.0).

Interpretation

The associations between the multi-omics data suggested that certain bacteria might affect the pathogenesis of NMDAR encephalitis by modulating the metabolic pathways of the host and affecting the production of pro-inflammatory cytokines. Furthermore, the disturbance of fecal bacteria may predict the long-term outcome and relapse in NMDAR encephalitis.

Cytokine/chemokine levels in the CSF and serum of anti-NMDAR encephalitis: A systematic review and meta-analysis

OBJECTIVES

To summarize the cytokine/chemokine levels of anti-N-methyl-Daspartate receptor encephalitis (NMDAR-E) and explore the potential role of these molecules and immune cells in the pathogenic mechanism.

METHODS

The PubMed, Cochrane Library, Embase, and Web of Science databases were searched for various articles that assessed the concentrations of cytokines/chemokines in the unstimulated cerebrospinal fluid (CSF) or serum of patients with NMDAR-E in this systematic review and meta-analysis. The standardized mean difference (SMD) and 95% confidence interval (CI) were calculated by Stata17.0.

RESULTS

A total of 19 articles were included in the systematic review from 260 candidate papers, and cytokine/chemokine levels reported in the CSF/serum were examined in each article. This meta-analysis included 17 eligible studies comprising 579 patients with NMDAR-E, 367 patients with noninflammatory neurological disorders, and 42 healthy controls from China, Spain, South Korea, Australia, Czechia, and Sweden. The results indicated that the levels of different cytokines interleukin (IL)-6, tumor necrosis factor (TNF)-α, IL-10, IL-13, IL-1β, IL-12, and IL-17 and chemokine C-X-C motif ligand (CXCL)10 in the CSF were significantly higher in NMDAR-E patients with a large effect size. In addition, B cell activating factor (BAFF), CXCL13, and interferon (IFN)-γ levels in the CSF were higher in NMDAR-E patients with a middle effect size. In contrast, levels of IL-2 and IL-4 in the CSF and CXCL13 and BAFF in the serum did not show a significant difference between cases and controls.

CONCLUSIONS

These analyses showed that the central immune response in NMDAR-E is a process that involves multiple immune cell interactions mediated by cytokines/chemokines, and T cells play an important role in the pathogenesis of immunity.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/PROSPERO/, identifier (CRD42022342485).

Case Report: Anti-NMDAR Encephalitis Presenting With Catatonic Symptoms in an Adolescent Female Patient With a History of Traumatic Exposure

INTRODUCTION

Catatonia is a severe syndrome associated with a high proportion of underlying organic conditions including autoimmune encephalitis. The link between catatonia and psychiatric conditions such as mood disorders and schizophrenia spectrum disorders is well established while the causative effect of Post-Traumatic Stress Disorders and stress related disorders remains speculative.

CASE REPORT

Here we describe the clinical case of a 14-year-old female patient presenting to the Emergency Department of a Pediatric University Hospital with acute changes in behavior five days after a sexual abuse. Acute stress reaction was suspected. Afterwards she developed catatonic symptoms alternating from stupor to excitement, resistant to the usual treatment with benzodiazepines. The first line examinations (PE, MRI, EEG) were inconclusive. The final diagnosis of anti-NMDARE was made 22 days after her admission in a University Department of Child and Adolescent Psychiatry. Her state improved after first- and second-line immunotherapy, with no signs of relapse at this day (8 months of clinical follow-up).

DISCUSSION

The diagnosis of anti-NMDARE is challenging, involving a multidisciplinary approach. The neuropsychiatric features are complex, with no specific psychiatric phenotype. Several hypotheses are discussed to determine the role of an acute environmental stressors in the emergence of such complex neuropsychiatric clinical presentation (i.e., shared vulnerability, precipitators, consequences of preexisting psychiatric symptoms).

CONCLUSION

Child and adolescent psychiatrists and pediatricians should be aware of the overlap between neurological and psychiatric features in the setting of anti-NMDARE. Catatonia should not be dismissed as a primary psychiatric disorder even in the context of recent traumatic exposure.

Efficacy and tolerability of intravenous immunoglobulin versus intravenous methylprednisolone treatment in anti- N-methyl-D-aspartate receptor encephalitis

OBJECTIVES

To compare the effectiveness and safety of intravenous immunoglobulin (IVIg) or intravenous methylprednisolone (IVMP) vs and IVIg plus IVMP (IPI) as initial therapy in anti- N-methyl-D-aspartate receptor (NMDAR) encephalitis.

METHODS

A multicenter study of prospectively identified NMDAR encephalitis individuals who presented from October, 2011, to August, 2020, to the study hospitals of western China, with a median follow-up of 3.9 years. Prespecified candidate variables were the prescriptions of IVIg, IVMP, or a combination of both. Propensity score matching was also performed to control potential confounders.

RESULTS

A total of 347 NMDAR encephalitis patients were finally analyzed in this study. After the TriMatch for NMDAR encephalitis, 37 triplets were generated. Compared to IVIg or IVMP, the administration of IPI exhibited a significant benefit of a higher response rate (86.5% vs. 55.6% vs. 68.7%, p^corr <0.01); improved mRS score at 3, 6, and 12 months (p^corr <0.05); and reduced further recurrence rate (10 of 37 [27.0%] vs 9 of 37 [24.3%] vs 2 of 37 [5.4%]; p log rank = 0.01). There was no association between treatment superiority and patient sex or the presence of tumors (p≥0.05). Patients treated with IVMP had a significantly higher number of adverse events, but 99% of adverse events were mild to moderate and did not lead to a change in treatment.

CONCLUSION

In patients with NMDAR encephalitis, adequate response, favorable outcome, and less recurrence were each more likely to occur in individuals treated with a combined immunotherapy than in monotherapy individuals.

Lyme Disease and Associated NMDAR Encephalitis: A Case Report and Literature Review

We present a case of a patient with positive N-methyl-D-aspartate receptor (NMDAR) IgG antibodies in their serum and cerebrospinal fluid (CSF) associated with neuroborreliosis. Clinically, the patient presented with symptoms of confusion, as well as behavioral and speech impairments. Regardless of antibacterial treatment, no significant improvement was achieved. Methylprednisolone provided a marked improvement in the patient’s clinical signs and CSF findings. The screening did not reveal any underlying neoplasm. Taking into account the marked clinical improvement after treatment with glucocorticosteroids, we suggest that NMDAR encephalitis is a possible autoimmune complication in neuroborreliosis patients requiring additional immunotherapy.

Anti-N-methyl-D-aspartate receptor encephalitis presenting as atypical psychosis in multiple sclerosis: a case report

BACKGROUND

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is an autoimmune disorder which often presents with neuropsychiatric symptoms. A large proportion of cases are associated with an identifiable tumor, most commonly ovarian teratoma. However, recent literature has also described an overlap of anti-NMDAR encephalitis and demyelinating syndromes. Cases have been reported of anti-NMDAR encephalitis in patients with ADEM, optic neuritis, myelitis and multiple sclerosis. This link is considered rare, however has important clinical implications as treatments and prognosis may differ.

CASE PRESENTATION

A 33-year-old female with a history of multiple sclerosis presented with new-onset neuropsychiatric symptoms. After substance-induced psychosis was ruled out, she was admitted to the medical ward for work up of psychosis secondary to multiple sclerosis. However, the consultation-liaison psychiatry service noted atypical symptoms which were concerning for autoimmune encephalitis. Admission to a psychiatric inpatient ward was deferred. Anti-NMDAR encephalitis was diagnosed with CSF analysis demonstrating lymphocytic pleocytosis and anti-NMDAR antibodies. In addition to first-line treatment of encephalitis with steroids, second-line immunotherapies were also implemented given the patient's underlining demyelinating syndrome. The patient's neurologic and psychiatric symptoms began to improve.

CONCLUSIONS

There is literature to demonstrate a possible connection between anti-NMDAR encephalitis and demyelinating syndromes. As such, autoimmune encephalitis should be considered in patients with multiple sclerosis presenting with atypical symptoms. Determining the correct diagnosis is crucial to inform the appropriate treatment protocol, and to improve prognosis.

Decreased inflammatory cytokine production of antigen-specific CD4+ T cells in NMDA receptor encephalitis

Anti-N-methyl-D-aspartate-receptor (NMDAR) encephalitis is the most common autoimmune encephalitis with psychosis, amnesia, seizures and dyskinesias. The disease is mediated by pathogenic autoantibodies against the NR1 subunit that disrupt NMDAR function. Antibody infusion into mouse brains can recapitulate encephalitis symptoms, while active immunization resulted also in strong T cell infiltration into the hippocampus. However, whether T cells react against NMDAR and their specific contribution to disease development are poorly understood. Here we characterized the ex vivo frequency and phenotype of circulating CD4⁺ T helper (T_H) cells reactive to NR1 protein using antigen-reactive T cell enrichment (ARTE) in 24 patients with NMDAR encephalitis, 13 patients with LGI1 encephalitis and 51 matched controls. Unexpectedly, patients with NMDAR encephalitis had lower frequencies of CD154-expressing NR1-reactive T_H cells than healthy controls and produced significantly less inflammatory cytokines. No difference was seen in T cells reactive to the synaptic target LGI1 (Leucine-rich glioma-inactivated 1), ubiquitous Candida antigens or neoantigens, suggesting that the findings are disease-specific and not related to therapeutic immunosuppression. Also, patients with LGI1 encephalitis showed unaltered numbers of LGI1 antigen-reactive T cells. The data reveal disease-specific functional alterations of circulating NMDAR-reactive T_H cells in patients with NMDAR encephalitis and challenge the idea that increased pro-inflammatory NMDAR-reactive T cells contribute to disease pathogenesis.

Antibodies to the α3 subunit of the ganglionic-type nicotinic acetylcholine receptors in patients with autoimmune encephalitis

Since autonomic dysfunction is closely associated with autoimmune encephalitis (AE), the objective of this study was to determine the autonomic symptoms and the prevalence of anti-α3 subunit of the ganglionic-type nicotinic acetylcholine receptor (gAChRα3) antibodies in the patients with AE. We reviewed the clinical features of 19 AE patients, and specifically analyzed sera for anti-gAChRα3 antibodies using the luciferase immunoprecipitation system (LIPS) assay. Cardiovascular autonomic symptoms were found to be common in patients with AE, and hypersalivation was seen only in patients with NMDAR encephalitis. LIPS detected anti-gAChRα3 antibodies in the sera from patients with AE (5/29, 26%). This study is the first to demonstrate that clinical characteristics including autonomic symptoms of AE patients with seropositivity for gAChR autoantibodies. It will be important to verify the role of gAChR antibodies in autonomic dysfunction and brain symptoms to clarify the pathogenesis of AE.

NMDA Receptor Autoantibodies in Autoimmune Encephalitis Cause a Subunit-Specific Nanoscale Redistribution of NMDA Receptors

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a severe neuropsychiatric disorder mediated by autoantibodies against the GluN1 subunit of the NMDAR. Patients' antibodies cause cross-linking and internalization of NMDAR, but the synaptic events leading to depletion of NMDAR are poorly understood. Using super-resolution microscopy, we studied the effects of the autoantibodies on the nanoscale distribution of NMDAR in cultured neurons. Our findings show that, under control conditions, NMDARs form nanosized objects and patients' antibodies increase the clustering of synaptic and extrasynaptic receptors inside the nano-objects. This clustering is subunit specific and predominantly affects GluN2B-NMDARs. Following internalization, the remaining surface NMDARs return to control clustering levels but are preferentially retained at the synapse. Monte Carlo simulations using a model in which antibodies induce NMDAR cross-linking and disruption of interactions with other proteins recapitulated these results. Finally, activation of EphB2 receptor partially antagonized the antibody-mediated disorganization of the nanoscale surface distribution of NMDARs.

The autoantibody-mediated encephalitides: from clinical observations to molecular pathogenesis

The autoimmune encephalitis (AE) syndromes have been characterised by the detection of autoantibodies in serum and/or cerebrospinal fluid which target the extracellular domains of specific neuroglial antigens. The clinical syndromes have phenotypes which are often highly characteristic of their associated antigen-specific autoantibody. For example, the constellation of psychiatric features and the multi-faceted movement disorder observed in patients with NMDAR antibodies are highly distinctive, as are the faciobrachial dystonic seizures observed in close association with LGI1 antibodies. These typically tight correlations may be conferred by the presence of autoantibodies which can directly access and modulate their antigens in vivo. AE remains an under-recognised clinical syndrome but one where early and accurate detection is critical as prompt initiation of immunotherapy is closely associated with improved outcomes. In this review of a rapidly emerging field, we outline molecular observations with translational value. We focus on contemporary methodologies of autoantibody detection, the evolution and distinctive nature of the clinical phenotypes, generalisable therapeutic paradigms, and finally discuss the likely mechanisms of autoimmunity in these patients which may inform future precision therapies.

NMDAR encephalitis presenting as akinesia in a patient with Parkinson disease

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

Sleep disturbances are common in patients with autoimmune encephalitis

OBJECTIVES

Autoimmune encephalitis (AE) is increasingly recognized as an important cause of subacute cognitive decline, seizures, and encephalopathy, with an ever-broadening clinical phenotype. Sleep disturbances are reported in AE patients, including rapid eye movement sleep behavior disorder, hypersomnia, fragmented sleep, and sleep-disordered breathing; however, the prevalence of sleep disturbances and contributions to outcomes in AE patients remain unknown. There is a need to determine the prevalence of sleep disturbances in AE patients, and to clarify the relationship between specific autoantibodies and disruptions in sleep.

METHODS

Clinical history, results of serum and cerebrospinal fluid testing, electroencephalography, and neuroimaging were reviewed from 26 AE patients diagnosed and managed at our tertiary care hospital. Polysomnography was performed in patients with clinical indications, yielding data from 12 patients.

RESULTS

The median age of AE patients was 53 years (range 18-83). Autoantibodies against intracellular antigens (including Ma and Hu autoantibodies) were identified in 6/26 (23%) patients, while autoantibodies against cell-surface neuronal antigens (including NMDAR and LGI1) were identified in 20/26 (77%) patients. New sleep complaints were reported by 19/26 (73%) AE patients, including gasping or snoring (9/19, 47%), dream enactment behavior (6/19, 32%), insomnia (5/19, 29%), hypersomnia (4/19, 21%), other parasomnias (4/19, 21%), and dream-wake confusional states (2/19, 11%). Dream enactment behaviors were particularly common in AE associated with LGI1 autoantibodies, reported in 4/7 (57%) patients. Polysomnography showed reduced total sleep time, stage 3 and rapid eye movement sleep, and prominent sleep fragmentation.

CONCLUSION

Sleep disturbances are common in AE, warranting active surveillance in affected patients. Improved identification and treatment of sleep disorders may reduce morbidity associated with AE and improve long-term outcomes.

Viral Encephalitis

Viruses are a frequent cause of encephalitis. Common or important viruses causing encephalitis include herpesviruses, arboviruses, enteroviruses, parechoviruses, mumps, measles, rabies, Ebola, lymphocytic choriomeningitis virus, and henipaviruses. Other viruses may cause an encephalopathy. Host factors and clinical features of infection are important to consider in identifying the cause for encephalitis. Cerebrospinal fluid evaluation, serologic/polymerase chain reaction studies, and neuroimaging are cornerstones of diagnostic evaluation in encephalitis. Treatable forms of encephalitis are important to consider in all cases. Central nervous system inflammation may also occur because of postinfectious autoimmunity, such as acute disseminated encephalomyelitis or antibody-mediated encephalitis after herpes simplex virus encephalitis.

Biomarkers of Neurodegeneration in Autoimmune-Mediated Encephalitis

Progranulin (PGRN), Total-Tau (t-tau), and Neurofilament light chain (NfL) are well known biomarkers of neurodegeneration. The objective of the present study was to investigate whether these parameters represent also biomarkers in autoimmune-mediated Encephalitis (AE) and may give us insights into the pathomechanisms of AE. We retrospectively examined the concentration of PGRN in the cerebrospinal fluid (CSF) and serum of 38 patients suffering from AE in acute phase and/or under treatment. This AE cohort comprises patients with autoantibodies against: NMDAR (n = 18 patients), Caspr2 (n = 8), Lgi-1 (n = 10), GABAB(R) (n = 1), and AMPAR (n = 1). Additionally, the concentrations of NfL (n = 25) and t-tau (n = 13) in CSF were measured when possible. Follow up data including MRI were available in 13 patients. Several age-matched cohorts with neurological diseases besides neuroinflammation or neurodegeneration served as control groups. We observed that PGRN was significantly elevated in the CSF of patients with NMDAR-AE in the acute phase, but normalized at follow up under treatment (p < 0.01). In the CSF of other patients with AE PGRN was in the range of the CSF levels of control groups. T-tau was highly elevated in the CSF of patients with temporal FLAIR-signal in the MRI and in patients developing a hippocampal sclerosis. NfL was exceptionally high initially in Patients with AE with a paraneoplastic or parainfectious cause and also normalized under treatment. The normalizations of all biomarkers were mirrored in an improvement on the modified Rankin scale. The data suggest that the concentration of PGRN in CSF might be a biomarker for acute NMDAR-AE. Pathological high t-tau levels may indicate a risk for hippocampal sclerosis. The biomarker properties of NfL remain unclear since the levels decrease under treatment, but it could not predict severity of disease in this small cohort. According to our results, we recommend to measure in clinical practice PGRN and t-tau in the CSF of patients with AE.

Autoimmune encephalitis (NMDAR antibody) in a patient receiving chronic post-transplant immunosuppression

Autoimmune encephalitis associated with antibodies (Abs) directed against the synaptic ligand-gated ion channel NMDA receptor (NMDAR) was first described as a paraneoplastic disorder in association with ovarian teratoma. Other forms of neoplasia have subsequently been reported although many patients do not have a tumour. Tumour removal, where applicable, and immunotherapy form the mainstays of treatment. We present a patient who developed NMDAR-Ab encephalitis despite being chronically immunosuppressed following organ transplantation, and who was eventually found to have an occult malignancy in the form of non-Hodgkin's lymphoma.

Anti-NMDA receptor encephalitis due to large-cell neuroendocrine carcinoma of the uterus

A 44-year-old woman presented with a large-cell neuroendocrine carcinoma and uterine endometrioid carcinoma with anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis. Following the diagnosis of uterine cancer, the patient suddenly developed psychosis with abnormal behaviors, delusions, irritability, and forgetfulness. The cerebrospinal fluid tested positive for anti-NMDAR antibodies (encoding the NR1 subunit). The patient was diagnosed with paraneoplastic limbic encephalitis due to uterine cancer. Histology of multiple abdominal metastatic samples revealed a neuroendocrine tumor. Her consciousness improved temporarily after tumor resection and comprehensive immunomodulatory therapy. On day 104 after admission, the patient died of multiple organ failure. The autopsy revealed a perivascular infiltration of inflammatory cells in the amygdala and NMDAR-positive cells in the primary uterine cancer. Our findings demonstrated that neuroendocrine tumors can induce anti-NMDAR encephalitis, which is consistent with three previous reports. A comprehensive treatment with resection of the carcinoma, immunoglobulins, and plasma exchange can induce a partial improvement of the symptoms.

Antecedent anti-NMDA receptor encephalitis in two patients with multiple sclerosis

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune disorder characterised by psychiatric symptoms, movement disorder and seizures often evolving into a severe encephalopathy. An overlap has recently been recognised between anti-NMDAR encephalitis and inflammatory demyelinating disorders, particularly neuromyelitis optical spectrum disorder (NMOSD). In this case report, we describe two patients with an initial presentation consistent with anti-NMDAR encephalitis who have subsequently developed relapsing-remitting multiple sclerosis (MS) and discuss the literature pertaining to potential overlap between NMDAR encephalitis and inflammatory demyelinating disorders.

Sudden and isolated Broca's aphasia: a new clinical phenotype of anti NMDA receptor antibodies encephalitis in children

BACKGROUND

Anti NMDA receptor (anti NMDAR) encephalitis is a well-characterized entity in children associating movement disorders, psychiatric features and speech difficulties. Novel phenotypes have been described in adults.

METHODS AND RESULTS

A 4-year-old girl presented partial seizures which evolved towards sudden and isolated Broca's aphasia. Anti NMDAR antibodies were positive in CSF and serum confirming anti NMDAR encephalitis. Clinical recovery was observed after a specific treatment.

CONCLUSION

This case widens the clinical spectrum of anti-NMDAR encephalitis in children and awareness of this newly identified symptom is important as early treatment is a predictor of good outcome.

Anti-NMDAR encephalitis, a mimicker of acute infectious encephalitis and a review of the literature

Anti-N-methyl-d-aspartate receptor encephalitis has become an increasingly recognized etiology of acute psychosis in young patients. The diverse constellation of symptoms allows for misdiagnosis as an infectious, psychological, or toxicological entity resulting in delays in treatment with increasing morbidity. We describe a case of anti-NMDAR encephalitis that was a particular challenge to diagnose. Practitioners should maintain a high index of suspicion for anti-NMDAR and related neuroautoimmune syndromes, especially in young patients that present with acute mental status decline or dyskinesia.

Anti-NMDA receptor encephalitis presenting with total insomnia--a case report

Fatal insomnia (FI) is the first diagnosis to be considered by most neurologists when approaching a patient presenting with total insomnia followed by personality and cognitive changes, disturbance of alertness, autonomic hyperactivation and movement abnormalities. We report the case of a 30 year-old male patient who presented with total insomnia followed by episodes of psychomotor restlessness resembling anxiety attacks. Twenty days later, he developed refractory convulsive status epilepticus with admission to Intensive Care Unit. He progressed to a state of reduced alertness and responsiveness, presenting periods of agitation with abnormal dyskinetic movements, periods of autonomic instability and central hypoventilation. Workup revealed antibodies against N-methyl-d-aspartate receptor (NMDAR). Immunotherapy treatment led to a very significant improvement with the patient presenting only slight frontal lobe dysfunction after one year of recovery. To the best of our knowledge this is the first report of a patient with anti-NMDAR encephalitis first presenting with total insomnia. Our aim is to alert that anti-NMDAR encephalitis must be considered in the differential diagnosis of FI, especially in sporadic cases. Distinguishing the two conditions is very important as, contrarily to the fatal disclosure of FI, anti-NMDAR encephalitis is potentially reversible with adequate treatment even after severe and prolonged disease.

Catatonia from its creation to DSM-V: Considerations for ICD

Catatonia was delineated only as a type of schizophrenia in the many American Psychiatric Association DSM classifications and revisions from 1952 until 1994 when "catatonia secondary to a medical condition" was added. Since the 1970s the diagnosis of catatonia has been clarified as a syndrome of rigidity, posturing, mutism, negativism, and other motor signs of acute onset. It is found in about 10% of psychiatric hospital admissions, in patients with depressed and manic mood states and in toxic states. It is quickly treatable to remission by benzodiazepines and by ECT. The DSM-V revision proposes catatonia in two major diagnostic classes, specifiers for 10 principal diagnoses, and deletion of the designation of schizophrenia, catatonic type. This complex recommendation serves no clinical or research purpose and confuses treatment options. Catatonia is best considered in the proposed ICD revision as a unique syndrome of multiple forms warranting a single unique defined class similar to that of delirium.