Refining the psychiatric syndrome of anti-N-methyl-d-aspartate receptor encephalitis

Abnormal global and local connectivity in patients with anti-N-methyl-D-aspartate receptor encephalitis: A resting-state functional MRI study

OBJECTIVE

We decided to investigate the changes of global and local connectivity in anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis patients based on eigenvector centrality (EC) and regional homogeneity (ReHo). We sought new biomarkers to identify the patients based on multivariate pattern analysis (MVPA).

METHODS

Functional MRI (fMRI) was performed on all participants. EC, ReHo and MVPA were used to analyze the fMRI images. The correlation between the global or local connectivity and neuropsychology tests was detected.

RESULTS

The MoCA scores of the patients were lower than those of the healthy controls (HCs), while the HAMD24 and HAMA scores of the patients were higher than those of the HCs. Increased EC values in the right calcarine (CAL.R) and decreased EC values in the right putamen (PUT.R) distinguished these subjects with anti-NMDAR encephalitis from HCs. The higher ReHo values in the left postcentral gyrus (PoCG.L) were detected in the patients. The correlation analysis showed that the EC values in the PUT.R were negatively correlated with HAMD24 and HAMA scores, while the ReHo values in the PoCG.L were negatively correlated with MoCA scores. Better classification performance was reached in the EC-based classifier (AUC = 0.80), while weaker classification performance was achieved in the ReHo-based classifier (AUC = 0.74) or the classifier based on EC and ReHo (AUC = 0.74). The brain areas with large weights were located in the frontal lobe, parietal lobe, cerebellum and basal ganglia.

CONCLUSION

Our findings suggest that abnormal global and local connectivity may play an important part in the pathophysiological mechanism of neuropsychiatric symptoms in the anti-NMDAR encephalitis patients. The EC-based classifier may be better than the ReHo-based classifier in identifying anti-NMDAR encephalitis patients.

Development of a short-term prognostic model for anti-N-methyl-D-aspartate receptor encephalitis in Chinese patients

BACKGROUND

Recognizing the predictors of poor short-term prognosis after first-line immunotherapy in patients with anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is essential for individualized treatment strategy. The objective of this study was to ascertain the factors that forecast short-term prognosis in patients with anti-NMDAR encephalitis, develop a prognostic prediction model, and authenticate its efficacy in an external validation cohort. Further, all patients were followed-up long-term to assess the factors of long-term outcome and relapses.

METHODS

A prospective enrollment of patients diagnosed with anti-NMDAR encephalitis was conducted across five clinical centers in China from June 2014 to Mar 2022. The enrolled patients were divided into the derivation and validation sets based on enrollment time. The short-term prognostic model was visualized using a nomogram. Further, all patients were followed-up long-term to assess the factors of long-term outcome.

RESULTS

This study found that poor short-term prognosis was a risk factor for poor long-term outcome (6-month prognosis, OR 29.792, 95%CI 6.507-136.398, p < 0.001; 12-month prognosis, OR 15.756, 95%CI 3.384-73.075, p < 0.001; 24-month prognosis, OR 5.500, 95%CI 1.045-28.955, p = 0.044). Abnormal behavior or cognitive dysfunction (OR 8.57, 95%CI 1.48-49.79, p = 0.017), consciousness impairment (OR19.32, 95%CI 3.03-123.09, p = 0.002), autonomic dysfunction or central hypoventilation (OR 5.66, 95%CI 1.25-25.75, p = 0.025), CSF pleocytosis (OR 4.33, 95%CI 1.48-12.65, p = 0.007), abnormal EEG (OR 5.48, 95% CI 1.09-27.54, p = 0.039) were independent predictors for a poor short-term prognosis after first-line immunotherapy. A nomogram that incorporated those factors showed good discrimination and calibration abilities. The area under the curve (AUC) for the prognostic model were 0.866 (95%CI: 0.798-0.934) with a sensitivity of 0.761 and specificity of 0.869.

CONCLUSION

We established and validated a prognostic model that can provide individual prediction of short-term prognosis after first-line immunotherapy for patients with anti-NMDAR encephalitis. This practical prognostic model may help neurologists to predict the short-term prognosis early and potentially assist in adjusting appropriate treatment timely.

Catatonia

Catatonia is a neuropsychiatric disorder characterized by motor, affective and cognitive-behavioural signs, which lasts from hours to days. Intensive research over the past two decades has led to catatonia being recognized as an independent diagnosis in the International Classification of Diseases, 11th Revision (ICD-11) since 2022. Catatonia is found in 5-18% of inpatients on psychiatric units and 3.3% of inpatients on medical units. However, in an unknown number of patients, catatonia remains unrecognized and these patients are at risk of life-threatening complications. Hence, recognizing the symptoms of catatonia early is crucial to initiate appropriate treatment to achieve a favourable outcome. Benzodiazepines such as lorazepam and diazepam, electroconvulsive therapy, and N-methyl-D-aspartate antagonists such as amantadine and memantine, are the cornerstones of catatonia therapy. In addition, dopamine-modulating second-generation antipsychotics (for example, clozapine and aripiprazole) are effective in some patient populations. Early and appropriate treatment combined with new screening assessments has the potential to reduce the high morbidity and mortality associated with catatonia in psychiatric and non-psychiatric settings.

Examining the Features of Neuroleptic Malignant Syndrome in Anti-NMDA Receptor Encephalitis: A Case-Control Study

BACKGROUND

Anti-N-methyl-D-aspartate receptor encephalitis (ANMDARE) is a neuroimmunological disorder that frequently improves with immunotherapy. Symptomatic treatment with antipsychotics is common in the early stages when psychiatric symptoms predominate, and their use has been associated with serious side effects including neuroleptic malignant syndrome (NMS). The observation of an adverse response to antipsychotics, raising the suspicion of NMS, has been included as a criterion for possible autoimmune psychosis.

METHODS

This case-control study included patients who received antipsychotics before referral to the National Institute of Neurology and Neurosurgery of Mexico, where they were diagnosed as having definite ANMDARE, and patients with ANMDARE who did not receive antipsychotics before referral. The neurologic and systemic features that are used to measure an adverse response to antipsychotics, raising the suspicion of NMS, were measured in both groups, including akinesia, autonomic instability, generalized rigidity, elevated concentrations of creatine phosphokinase, and hyperthermia. A logistic regression analysis was used to determine the relationship between the previous use of antipsychotics and the occurrence of NMS-like reactions.

RESULTS

A total sample of 112 patients with definite ANMDARE were included in the study. Fifty patients received antipsychotics before being referred to our institution. In this group, thirty-six patients (72%) were initially classified as having an adverse response, raising the suspicion of NMS, with the following features: akinesia (64%), autonomic instability (58%), generalized rigidity (52%), elevated concentrations of creatine phosphokinase (50%), and hyperthermia (14%). Six patients fulfilled the criteria for NMS (12%). The comparison with patients who did not receive antipsychotics before the clinical assessment did not show a significant difference between groups regarding the frequency of akinesia, autonomic instability, generalized rigidity, elevated concentrations of creatine phosphokinase, or hyperthermia. Among different antipsychotics, only haloperidol was significantly associated with generalized rigidity as compared to patients who did not receive antipsychotics.

CONCLUSIONS

Our study supports previous observations about the high frequency of autonomic dysfunction, hyperthermia, tachycardia, rigidity, and elevated creatine phosphokinase levels in patients with anti-NMDAR encephalitis following the administration of antipsychotic medications. Nevertheless, our study does not suggest a causal link between atypical antipsychotics and the onset of these neurological symptoms, as they were equally frequent among the group of patients who did not receive antipsychotic treatment.

The relevance of anti-N-methyl-D-aspartate receptor encephalitis for psychiatrists

Psychiatrists are often the first to be consulted in patients with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. While this disease is rare, psychiatrists need to be aware of its relevant fundamental, clinical and therapeutic aspects. We begin by reviewing the connection between anti-NMDAR encephalitis and the glutamate hypothesis of schizophrenia. Next, we focus on the profile of the patient typically afflicted with this disease. Then, we tackle the limited utility of current diagnostic criteria during the early stage of the disease. After reviewing the psychiatric features, we debate the quest for finding specific psychiatric phenotypes that could facilitate early-stage diagnosis. We conclude by discussing the treatment of psychiatric symptoms and disease outcomes. As follows, this paper presents the relevance of anti-NMDAR encephalitis for psychiatrists.

Myelin oligodendrocyte glycoprotein antibody and N-methyl-d-aspartate receptor antibody overlapping syndrome: insights from the recent case reports

The overlapping of two or more types of neural autoantibodies in one patient has increasingly been documented in recent years. The coexistence of myelin oligodendrocyte glycoprotein (MOG) and N-methyl-d-aspartate receptor (NMDAR) antibodies is most common, which leads to a unique condition known as the MOG antibody and NMDAR antibody overlapping syndrome (MNOS). Here, we have reviewed the pathogenesis, clinical manifestations, paraclinical features, and treatment of MNOS. Forty-nine patients with MNOS were included in this study. They were young males with a median onset age of 23 years. No tumors were observed in the patients, and 24 of them reported prodromal symptoms. The most common clinical presentations were psychiatric symptoms (35/49) and seizures (25/49). Abnormalities on magnetic resonance imaging involved the brainstem (11/49), cerebellum (9/49), and parietal lobe (9/49). Most patients mostly responded to immunotherapy and had a good long-term prognosis. However, the overall recurrence rate of MNOS was higher than that of mono antibody-positive diseases. The existence of concurrent NMDAR antibodies should be suspected in patients with MOG antibody-associated disease having psychiatric symptoms, seizures, movement disorders, or autonomic dysfunction. Similarly, serum MOG antibody testing should be performed when patients with anti-NMDAR encephalitis present with atypical clinical manifestations, such as visual impairment and limb weakness, and neuroradiological findings, such as optic nerve, spinal cord, or infratentorial involvement or meningeal enhancement. Early detection of the syndrome and prompt treatment can be beneficial for these patients, and maintenance immunosuppressive therapy is recommended due to the high overall recurrence rate of the syndrome.

Changing landscape in the field of paraneoplastic neurology: Personal perspectives over a 35-year career

Paraneoplastic neurologic syndromes are a group of rare disorders that have fascinated neurologists for more than a century. The discovery in the 1980s that many of these disorders occurred in association with antibodies against neuronal proteins revived the interest for these diseases. This chapter first traces the history of the paraneoplastic neurologic syndromes during the era that preceded the discovery of immune mechanisms and then reviews the immunologic period during which many of these syndromes were found to be associated with antibodies against intracellular onconeuronal proteins and pathogenic cytotoxic T-cell mechanisms. Alongside these developments, investigations on the antibody-mediated disorders of the peripheral nervous system, such as the myasthenic syndromes or neuromyotonia, provided suggestions for the study of the central nervous system (CNS) syndromes. These converging areas of research culminated with the groundbreaking discovery of a new category of CNS disorders mediated by antibodies against neuronal surface proteins or receptors. These disorders are not always paraneoplastic, and the understanding of these syndromes and mechanisms has changed the landscape of neurology and neurosciences.

[A case report of anti-NMDA receptor encephalitis with mental disturbances manifestation]

Presented clinical observation of anti-NMDA-receptor encephalitis, which was first described in 2007, is rare and to date has not been sufficiently studied. The disease often manifests with psychopathological symptoms and catatonia, so patients are transferred into a mental healthcare institution and often require intensive care and resuscitation, due to the development of life-threatening respiratory and hemodynamic disorders. Diagnosis is based on detection of autoantibodies to the NR1- and NR2 subunits of the glutamate NMDA receptor in blood serum and cerebrospinal fluid. Pathogenesis-based therapy includes the administration of glucocorticoids and intravenous immunoglobulins, plasmapheresis, as well as the introduction of monoclonal antibodies in also used, and in severe cases, cytostatics are prescribed. The widespread comorbidity of anti-NMDA receptor encephalitis with ovarian neoplasms in women (up to 60%) requires appropriate diagnosis and early removal of ovarian neoplasms when they are detected. With timely diagnosis and adequate treatment strategies, the outcome of this rare disorder is usually positive.

[Autoimmune encephalitis: psychiatric aspects]

Autoimmune encephalitis is a group of diseases researched by both neurologists and psychiatrists. Despite a large number of studies and practical recommendations, the differential diagnosis and early diagnostics still remains an important issue. The most difficult to diagnose are cases that debut as mental disorders and/or occur without neurological symptoms. The literature review presents the current state of the problem with an emphasis on the practice of a psychiatrist.

A Near-Fatal Encounter with Acute Suicidal Behavior in Anti-N-methyl-D-aspartate Autoimmune Encephalitis

Anti-N-methyl-D-aspartate receptor encephalitis (anti-NMDARE) is a complex neuropsychiatric syndrome known for its diverse neurological manifestations, often involving psychiatric symptoms and seizures that elevate the risk of suicidal ideation and behavior. We present a case illustrating the potentially lethal nature of anti-NMDARE, wherein an unexpected suicide attempt occurred 10 days after the onset of seizures in a 21-year-old man. Upon arrival at the emergency room, immediate interventions addressed hypovolemic shock, followed by subsequent neurosurgical and orthopedic procedures. Six days after cessation of sedation, the patient exhibited atypical focal seizures, behavioral arrest, psychotic responses, and delusions. Despite normal brain magnetic resonance imaging and cerebrospinal fluid (CSF) analysis results, a high CSF immunoglobulin G index and posterior hypometabolism on brain F-fluorodeoxyglucose positron emission tomography raised suspicion of autoimmune encephalitis. Steroids and intravenous immunoglobulins were administered. A comprehensive evaluation ruled out other conditions. Serum and CSF tests confirmed the presence of anti-NMDAR antibodies. This case highlights the potential lethality of the acute stage of anti-NMDARE, emphasizing the absence of apparent psychiatric symptoms before a suicide attempt. Further studies on suicidality associated with anti-NMDARE are crucial, underscoring the importance of vigilance in cases involving newly diagnosed seizures or psychoses.

Abnormalities in modular connectivity of functional brain networks and cognitive changes in patients with anti -N-methyl-D-aspartate receptor encephalitis

OBJECTIVE

To explore potential mechanisms of cognitive changes in patients with anti-NMDAR encephalitis (ANMDARE) from intramodule and intermodule effects of brain functional networks.

METHODS

Resting-state functional MRI(rs-fMRI) imaging data was collected from 30 ANMDARE and 30 healthy controls (HCs). A brain functional matrix was constructed, and sparsity was established by module similarity. For both groups, changes in functional connectivity (FC) within and between modules was calculated, and whole-brain functional topology was analyzed. Finally, the association of brain functional with cognitive function in ANMDARE was further analyzed.

RESULTS

Compared to HCs, ANMDARE had enhanced connectivity within the modules that included the occipito-parietal-temporal and parahippocampal gyri. ANMDARE had significantly higher participation coefficients (PC) in the right inferior frontal gyrus than HCs and significantly lower PC in the left superior parietal lobule, left caudate nucleus, and right putamen. No statistically significant differences in global topological properties were found between the two groups. No correlations were found between functional and structural brain indicators and the Cognitive Assessment Scale and the Emotional Deficit Scale.

CONCLUSIONS

Patients with ANMDARE are manifested by enhanced intramodular FC and intermodular connectivity changes in the brain. This may help to understand the pathophysiological mechanisms of the disease from a global perspective.

Atypical psychiatric presentation of relapsing anti-N-methyl-D-aspartate receptor encephalitis in childhood

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune encephalitis caused by antibodies (Ab) against the GluN1 subunit of the NMDAR. The disease typically presents with a combination of psychiatric and neurological symptoms. Presentation solely with psychiatric symptoms is rare, especially in childhood. After treatment substantial recovery with mild or no residual symptoms is seen in most cases in both children and adults. Relapse occurs in 10%-25% of patients, with recurrent episodes presenting less severe than initial presentation in most cases. We herein describe a child with a pure psychiatric presentation of anti-NMDAR encephalitis. Diagnosis and treatment was delayed because of the atypical presentation. The child relapsed several times and severe residual psychiatric symptoms persisted after recovery. This case illuminates the need to consider the diagnosis of anti-NMDAR encephalitis in both adults and children with an atypical psychiatric presentation. It also demonstrates the need for a multidisciplinary approach and brings attention to the possible severe impact of the disease on long-term psychosocial functioning.

Typical metabolic pattern of 18F-FDG PET in Anti-NMDAR encephalitis in the acute and subacute phases and its correlation with T2 FLAIR-MRI features

BACKGROUND/AIMS

Early diagnosis of Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis with non-invasive imaging modalities benefiting is crucial to guarantee prompt treatments decision-making and good prognosis for patients. The present study aimed to explore the correlation of MRI features with brain metabolism characteristics of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) and to describe the metabolic patterns in Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis at acute and subacute phases. Twenty-four patients with anti-NMDAR encephalitis confirmed by serum and/or CSF tests at acute and subacute phases, 9 females and 15 males, with an age range of 6-80 years, were enrolled in this retrospective study as encephalitis group. 18F-FDG PET and MRI findings of all patients were investigated and interpreted with visual analysis. Chi-square test was performed to compare the diagnostic sensitivity between MRI and PET. Independent sample t-test was used to compare the standardized uptake value ratio (SUVR) of each ROI between the encephalitis group and control group, which consisted of 24 healthy volunteers of the same age and gender.

RESULTS

There was no statistical difference in the diagnostic sensitivity between FDG PET (23/24, 95.83%) and MRI (18/24, 75.00%) in anti-NMDAR encephalitis patients (P > 0.05). Three categories of abnormalities shown on T2 FLAIR, including shallow of sulci and swelling of brain tissue, increased signal in the sulci, increased signal on brain gray matter or adjacent white matter presented hypermetabolism on PET, excepting increased signal in brain linear structure with hypometabolism of the basal ganglia on PET. We identified 19 brain regions with hypermetabolism and 16 brain regions with hypometabolism that exhibited statistically significant changes in SUVRs between anti-NMDAR encephalitis group and control group (FDR P < 0.05).

CONCLUSION

Anteroposterior glucose metabolism gradient (frontal-temporal/parietal-occipital) is proved to be a typical pattern of anti-NMDAR encephalitis at the acute and subacute phases in both visual and statistical testing. Interestingly, the pattern is also commonly found in the anterior and posterior portions of the parietal lobe and cingular cortex, which may be a potential indicator for the diagnosis of this disorder. In addition, MRI is an important and reliable neuroimaging modality to assist in the correct evaluation of activity changes on individual 18F-FDG PET.

Psychosis Caused by a Somatic Condition: How to Make the Diagnosis? A Systematic Literature Review

BACKGROUND

First episode of psychosis (FEP) is a clinical condition that usually occurs during adolescence or early adulthood and is often a sign of a future psychiatric disease. However, these symptoms are not specific, and psychosis can be caused by a physical disease in at least 5% of cases. Timely detection of these diseases, the first signs of which may appear in childhood, is of particular importance, as a curable treatment exists in most cases. However, there is no consensus in academic societies to offer recommendations for a comprehensive medical assessment to eliminate somatic causes.

METHODS

We conducted a systematic literature search using a two-fold research strategy to: (1) identify physical diseases that can be differentially diagnosed for psychosis; and (2) determine the paraclinical exams allowing us to exclude these pathologies.

RESULTS

We identified 85 articles describing the autoimmune, metabolic, neurologic, infectious, and genetic differential diagnoses of psychosis. Clinical presentations are described, and a complete list of laboratory and imaging features required to identify and confirm these diseases is provided.

CONCLUSION

This systematic review shows that most differential diagnoses of psychosis should be considered in the case of a FEP and could be identified by providing a systematic checkup with a laboratory test that includes ammonemia, antinuclear and anti-NMDA antibodies, and HIV testing; brain magnetic resonance imaging and lumbar puncture should be considered according to the clinical presentation. Genetic research could be of interest to patients presenting with physical or developmental symptoms associated with psychiatric manifestations.

Neuropsychiatric phenotypes of anti-NMDAR encephalitis: a prospective study

BACKGROUND

Patients with anti-N-methyl-d-aspartate (NMDA) receptor encephalitis (ANMDARE) show a wide range of behavioral abnormalities and are often mistaken for primary psychiatric presentations. We aimed to determine the behavioral hallmarks of ANMDARE with the use of systematic neuropsychiatric and cognitive assessments.

METHODS

A prospective study was conducted, with 160 patients admitted to the National Institute of Neurology and Neurosurgery of Mexico, who fulfilled criteria for possible autoimmune encephalitis and/or red flags along a time window of seven years. Cerebrospinal fluid (CSF) antibodies against the NR1 subunit of the NMDAR were processed with rat brain immunohistochemistry and cell-based assays with NMDA expressing cells. Systematic cognitive, neuropsychiatric, and functional assessments were conducted before knowing NMDAR antibodies results. A multivariate analysis was used to compare patients with and without definite ANMDARE according to antibodies in CSF.

RESULTS

After obtaining the CSF antibodies results in 160 consecutive cases, 100 patients were positive and classified as having definite ANMDARE. The most frequent neuropsychiatric patterns were psychosis (81%), delirium (75%), catatonia (69%), anxiety-depression (65%), and mania (27%). Cognition was significantly impaired. A total of 34% of the patients had a predominantly neuropsychiatric presentation without seizures. After multivariate analysis, the clinical hallmarks of ANMDARE consisted of a catatonia-delirium comorbidity, tonic-clonic seizures, and orolingual dyskinesia.

CONCLUSIONS

Our study supports the notion of a neurobehavioral phenotype of ANMDARE characterized by a fluctuating course with psychotic and affective symptoms, catatonic signs, and global cognitive dysfunction, often accompanied by seizures and dyskinesia. The catatonia-delirium comorbidity could be a distinctive neurobehavioral phenotype of ANMDARE.

Suicidal Thoughts and Behaviors in Anti-NMDA Receptor Encephalitis: Psychopathological Features and Clinical Outcomes

OBJECTIVE

A wide variety of neuropsychiatric symptoms are described during the acute phase of anti-N-methyl-d-aspartate receptor encephalitis (ANMDARE), including psychosis, mania, depression, and catatonia, but there are few reports on suicidal thought and behaviors in ANMDARE. To address this gap in the literature, the authors measured the presence of suicidal thoughts and behaviors among a large cohort of Mexican patients diagnosed with definite ANMDARE.

METHODS

This observational and longitudinal study included patients with definite ANMDARE hospitalized at the National Institute of Neurology and Neurosurgery of Mexico between 2014 and 2021. Suicidal thoughts and behaviors were assessed before and after treatment by means of a clinical interview with relatives and a direct clinical assessment with each patient. Thoughts of engaging in suicide-related behavior and acts of suicidal and nonsuicidal self-directed violence before and during hospitalization were recorded.

RESULTS

From a total sample of 120 patients who fulfilled the diagnostic criteria for definite ANMDARE, 15 patients (13%) had suicidal thoughts and behaviors during the acute phase of the disease. All 15 of these patients experienced psychosis and had suicidal ideation with intention. Three patients engaged in preparatory behaviors and seven carried out suicidal self-directed violence. Psychotic depression and impulsivity were more frequent among those patients with suicidal thoughts and behaviors than among those without any form of suicidality. Four patients engaged in self-directed violence during hospitalization. Remission was sustained in 14 of 15 patients, with suicidal ideation and self-directed violence persisting during follow-up in only one patient.

CONCLUSIONS

Suicidal thoughts and behaviors are not uncommon during the acute phase of ANMDARE. On the basis of our sample, the persistence of these features after immunotherapy is rare but may be observed. A targeted assessment of suicidal risk should be strongly considered in this population.

Anti-glutamic acid decarboxylase antibody screening in first-episode psychosis

OBJECTIVE

The Royal Australian and New Zealand College of Psychiatrists recommends screening for a range of antibodies in first-episode psychosis, including anti-glutamic acid decarboxylase antibodies. Glutamic acid decarboxylase antibody-associated encephalitis occurs with high antibody titres and may cause cognitive dysfunction, seizures and psychiatric symptoms. However, glutamic acid decarboxylase antibodies are more frequently found in lower titre in association with other autoimmune disorders (such as diabetes mellitus type 1) and in healthy individuals. The utility of testing unselected populations of consumers with psychosis is unclear. The psychiatric manifestations of this disorder are also poorly described.

METHODS

First, systematic review of cohort and case-control studies that tested for IgG glutamic acid decarboxylase antibodies in psychiatric populations was conducted. Random-effects meta-analysis of odds ratio for antibody positivity in cases with psychosis and controls assessed prevalence. Second, literature review of all published cases and case series of glutamic acid decarboxylase antibody-associated limbic encephalitis was assessed for frequency and description of psychotic symptoms.

RESULTS

There were 17 studies, in which 2754 individuals with psychotic disorders were tested for glutamic acid decarboxylase IgG antibodies. Thirty-one consumers with psychosis (0.7%) had positive glutamic acid decarboxylase antibodies compared to 24 controls (1.0%), all at low titre and not fulfilling diagnostic criteria for autoimmune encephalitis. Meta-analysis found no significant difference in rates of glutamic acid decarboxylase antibody positivity (odds ratio = 1.8, 95% confidence interval: [0.90, 3.63]). Literature review found 321 cases of glutamic acid decarboxylase antibody-associated limbic encephalitis, with psychosis in 15 (4.3%) cases. Clinical screening would have identified all cases that presented to psychiatric services.

CONCLUSION

Glutamic acid decarboxylase antibodies were uncommon in consumers with psychosis, with no significant difference in prevalence from controls and no cases of encephalitis identified. In cases with established glutamic acid decarboxylase antibody-associated limbic encephalitis, psychotic symptoms were uncommon and identifiable by clinical assessment. Targeted antibody testing guidelines should be further considered.

Catatonia in adult anti-NMDAR encephalitis: an observational cohort study

BACKGROUND

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is one of the most prevalent autoimmune encephalitis and is closely related to catatonia. This study aimed to investigate the clinical features and disease outcomes of adult catatonic anti-NMDAR encephalitis patients.

METHODS

Adult patients diagnosed with anti-NMDAR encephalitis between January 2013 and October 2021 were retrospectively enrolled in this study. According to the Bush Francis Catatonia screening instrument (BFCSI), patients were divided into two groups: those with catatonia and those without catatonia. The modified Rankin scale (mRS), Clinical Assessment Scale for Autoimmune Encephalitis (CASE), Neuropsychiatric Inventory (NPI), Patient Health Questionnaire-9 (PHQ-9) and 7-item Generalized Anxiety Disorder Questionnaire (GAD-7) scores were assessed at follow-up. The Mann-Whitney U test (nonparametric), Student's t test (parametric), and chi-squared test were used to analyse the differences between the two groups.

RESULTS

Eighty-four patients were recruited, including twenty-five catatonic patients and fifty-nine noncatatonic patients. Among them, 28 had positive antibody only in cerebrospinal fluid (CSF), 4 had positive antibody only in serum and 52 had positive antibody both in CSF and serum. Catatonic patients experienced more disturbance of consciousness (p = 0.01), aggression (p = 0.046) and affective disorders (p = 0.043) than noncatatonic patients. The mRS scores of the catatonia group assessed at admission (p = 0.045) were worse than those of the non-catatonia group. Catatonic patients were more inclined to develop deep vein thrombosis (p = 0.003), decubitus (p = 0.046), pneumonia (p = 0.025), and to be admitted to the intensive care unit (ICU) (p = 0.011) than noncatatonic patients. All patients in the catatonia group received first-line immunotherapy. At the 24-month follow-up, 2 patients in the catatonia group did not achieve good outcomes. At the last follow-up, the catatonia group had more relapses (p = 0.014) and more neuropsychiatric problems (p = 0.035).

CONCLUSIONS

Adult anti-NMDAR encephalitis patients with catatonia present distinct clinical features in disease course and are prone to experience more relapses and long-term neuropsychiatric problems than those without catatonia.

The validity of atypical psychosis diagnostic criteria to detect anti-NMDA receptor encephalitis with psychiatric symptoms

Anti-NMDAR encephalitis has a psychotic presentation that is difficult to distinguish from primary psychosis. An atypical psychosis that is similar to schizophrenia, mood disorder, and epilepsy is unique, and the original diagnostic criteria exist only in Japan. The clinical symptoms and courses of anti-NMDAR encephalitis and atypical psychosis are very similar. We investigated whether the diagnostic criteria of atypical psychosis are useful to increase the detection rate of anti-NMDAR encephalitis with psychiatric symptoms. The presence of anti-NR1/NR2B IgG antibodies in the cerebrospinal fluid of 218 newly admitted inpatients initially diagnosed with schizophrenia (n = 151), mood disorder (n = 47), or epilepsy with psychiatric symptoms (n = 20) was assessed by cell-based assay. Of 218 patients, 123 (36.3 years ± SD 17.2, 69.9 % females) fulfilled the diagnostic criteria of category B for atypical psychosis. All 12 patients (9.8 %, 12/123) with anti-NR1/NR2B IgG antibodies fulfilled category B of atypical psychosis statistically better than the patients without anti-NR1/NR2B IgG antibodies (P = 0.0009). Of the 12 patients with anti-NMDAR antibodies, two did not fulfill either criteria of catatonia (DSM-5) or Graus' diagnostic criteria of anti-NMDAR encephalitis during the time course, and 11 patients showed good prognosis with early immunotherapies. In ROC analysis, abnormal electroencephalogram findings showed the highest sensitivity (0.833) for detection of anti-NR1/NR2B IgG antibodies, and 31.3 % of patients with category B atypical psychosis and abnormal electroencephalogram findings had anti-NMDAR antibodies. Lumbar puncture and detection of anti-NMDAR antibodies should be considered for patients who fulfill atypical psychosis diagnosis criteria with an abnormal electroencephalogram.

Paroxysmal speech disorder as the initial symptom in a young adult with anti-N-methyl-D-aspartate receptor encephalitis: A case report

BACKGROUND

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a treatable but frequently misdiagnosed autoimmune disease. Speech dysfunction, as one of the common manifestations of anti-NMDAR encephalitis, is usually reported as a symptom secondary to psychiatric symptoms or seizures rather than the initial symptom in a paroxysmal form. We report a case of anti-NMDAR encephalitis with paroxysmal speech disorder as a rare initial manifestation, and hope that it will contribute to the literature.

CASE SUMMARY

A 39-year-old man with anti-NMDAR encephalitis initially presented with paroxysmal nonfluent aphasia and was misdiagnosed with a transient ischemic attack and cerebral infarction successively. The patient subsequently presented with seizures, but no abnormalities were found on brain magnetic resonance imaging or electroencephalogram. Cerebrospinal fluid (CSF) analysis revealed mild pleocytosis and increased protein levels. Anti-NMDAR antibodies in serum and CSF were detected for a conclusive diagnosis. After immunotherapy, the patient made a full recovery.

CONCLUSION

This case suggests that paroxysmal speech disorder may be the presenting symptom of anti-NMDAR encephalitis in a young patient.

Psychiatric manifestations of autoimmune encephalitis

Autoimmune encephalitis is increasingly recognized as a cause of psychiatric symptoms. A wide spectrum of psychiatric manifestations have been described which may precede, follow or occur independently of neurologic features. Patients typically respond to immunotherapy, however diagnosis is challenging due to phenotypic heterogeneity. The aim of this review is to provide an overview of the psychiatric features associated with encephalitis mediated by autoantibodies targeting neuronal cell-surface antigens and describe indicators of potential immunopathology underlying psychiatric manifestations.

Differentiating autoimmune encephalitis from schizophrenia spectrum disorders among patients with first-episode psychosis

BACKGROUND

Although differential diagnosis between autoimmune encephalitis and schizophrenia spectrum disorders is crucial for a good outcome, the psychiatric symptoms that distinguish these two conditions have not been identified even though psychiatric symptoms are often the main manifestation of autoimmune encephalitis. Also, there are many situations in clinical psychiatry in which laboratory testing and imaging studies are not available. Because no comparative study of the psychiatric symptoms between these two conditions has been carried out, we explored diagnostically useful psychiatric symptoms in a retrospective case-control study.

METHODS

We recruited 187 inpatients with first-episode psychosis who were admitted to our psychiatric unit and categorized them into two groups: the autoimmune encephalitis group (n = 10) and the schizophrenia spectrum disorders group (n = 177). Differences in the symptoms and signs between the two groups were investigated.

RESULTS

Schneider's first-rank symptoms (e.g., verbal commenting hallucinations and delusional self-experience) were observed only in the schizophrenia spectrum disorders group, whereas altered perception was found more frequently in the autoimmune encephalitis group. Functional status was worse in the autoimmune encephalitis group, and neurological and neuropsychological signs were revealed almost exclusively in this group. A history of mental illness was more frequently reported in the schizophrenia spectrum disorders group than in the autoimmune encephalitis group.

CONCLUSIONS

The psychiatric symptoms, i.e., Schneider's first-rank symptoms and altered perception, together with neurological and neuropsychological signs, functional status, and past history, may help clinicians accurately differentiate these two conditions among patients with first-episode psychosis.

Clinical Significance of Delirium With Catatonic Signs in Patients With Neurological Disorders

OBJECTIVE

According to DSM-5, catatonia and delirium are mutually exclusive clinical syndromes. The investigators explored the co-occurrence of delirium and catatonia (i.e., catatonic delirium) and the clinical significance of this syndrome with a sample of neurological patients.

METHODS

This prospective study with consecutive sampling included patients diagnosed with delirium at the National Institute of Neurology and Neurosurgery of Mexico. DSM-5 criteria for delirium, the Confusion Assessment Method, and the Delirium Rating Scale-Revised-98 were used to select and characterize patients. Catatonia was assessed using the Bush-Francis Catatonia Rating Scale and DSM-5 diagnostic criteria. Logistic regression analysis was performed to identify etiological factors associated with catatonic delirium.

RESULTS

A total of 264 patients with delirium were included, 61 (23%) of whom fulfilled the criteria for catatonia and delirium simultaneously. Brain tumors, subarachnoid hemorrhage, acute hydrocephalus, and ischemic stroke were associated with delirium without catatonic signs. Catatonic delirium was observed among patients with encephalitis, epilepsy, brain neoplasms, and brain tuberculosis. After multivariate analysis, the association between catatonic delirium and encephalitis (both viral and anti-N-methyl-d-aspartate receptor [NMDAR]) was confirmed.

CONCLUSIONS

Delirium is a common complication of neurological diseases, and it can coexist with catatonia. The recognition of catatonic delirium has clinical significance in terms of etiology, as it was significantly associated with viral and anti-NMDAR encephalitis.

Characterizing the features and course of psychiatric symptoms in children and adolescents with autoimmune encephalitis

Autoimmune encephalitis (AE) can present like a psychiatric disorder. We aimed to illustrate the psychiatric manifestations, course and management of AE in a paediatric cohort. Neuropsychiatric symptoms, investigations and treatment were retrospectively retrieved in 16 patients (mean age 11.31, SD 2.98) with an AE diagnosis at the liaison psychiatry services in two UK tertiary paediatric centres. Psychiatric presentation was characterised by an acute polysymptomatic (predominantly agitation, anger outbursts/aggressiveness, hallucinations, and emotional lability) onset. Antipsychotics produced side effects and significant worsening of symptoms in four cases, and benzodiazepines were commonly used. This psychiatric phenotype should make clinicians suspect the diagnosis of AE and carefully consider use of treatments.

Immunopsychiatry: An Update on Autoimmune Encephalitis for Neuropsychiatrists

INTRODUCTION

Autoimmune encephalitis (AIE) is a group of immune-mediated inflammatory processes of the brain with marked psychiatric features. Although relatively rare, they might offer difficult differential diagnosis with psychiatric conditions, especially catatonia and psychotic syndromes. Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis is the most common AIE, presenting with psychiatric syndromes in 90% of cases. The associated psychopathology is complex, pleomorphic and best characterized when there is involvement of a psychiatrist in the assessment.

AREAS COVERED

This text will review the main aspects of AIE to psychiatrists and/or neuropsychiatrists.

EXPERT OPINION

Immune system dysfunction has been implicated in the pathophysiology of psychiatric symptoms and disorders. The use of diagnostic criteria of possible AIE, especially when specific antibodies of AIE are not available, allows early diagnosis and prompt treatment which are associated with better clinical outcomes. The study of the psychiatric aspects of AIE can broaden our knowledge of the underlying mechanisms of various psychiatric manifestations.

Anti-NMDA receptor encephalitis in older adults: A systematic review of case reports

OBJECTIVE

To ascertain the clinical characteristics of anti-NMDA receptor encephalitis (NMDARE) in older patients.

METHOD

A systematic literature review using PubMed and Scopus of all published case reports of NMDARE was undertaken, from database inception to June 2020. From this, cases reporting on patients older than 65 years of age and whose diagnosis was confirmed by the presence of anti-NMDAR antibodies in CSF were selected.

RESULTS

23 case reports fulfilling the study's criteria were found. Median age was 70.1 years (range 65-84), fourteen were female (60.9%), and mostly presented with acute behavioral and cognitive changes (95.7%). Atypical psychosis occurred in eleven patients (47.8%) with a sudden onset and fluctuating clinical pattern of delusions (39.1%), hallucinations (30.4%), and motility disturbances (34.8%) including catatonia (17.4%). Nine patients presented with seizures (39.1%). Pleocytosis in CSF (>5 WBC) was described in twelve cases (52.2%). Eleven cases (47.8%) had abnormal brain magnetic resonance imaging (MRI) scans with limbic inflammatory lesions. Thirteen patients had an abnormal EEG (56.5%).

CONCLUSION

NMDARE should be included in the differential diagnosis of older patients who present with new psychiatric episodes, especially when characterized by sudden onset psychotic polymorphic symptomatology, fluctuating course with marked cognitive decline, and with catatonic features.

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.

Autoimmune Neurology: The Need for Comprehensive Care

Autoimmune neurology is a rapidly developing specialty driven by an increasing recognition of autoimmunity as the cause for a broad set of neurologic disorders and ongoing discovery of new neural autoantibodies associated with recognizable clinical syndromes. The diversity of clinical presentations, unique pathophysiology, and the complexity of available treatments requires a dedicated multidisciplinary team to diagnose and manage patients. In this article, we focus on antibody-associated autoimmune encephalitis (AE) to illustrate broader themes applicable to the specialty. We discuss common diagnostic challenges including the utilization of clinical assessment tools along with the determination of the prognostic significance of certain autoantibodies, with a focus on implications for long-term management. A growing body of literature demonstrates the long-term cognitive, behavioral, and physical sequelae of AE. Dedicated resources are needed to effectively manage these patients. These resources may be best provided by experienced neurology clinics in partnership with other neurologic subspecialists, as well as psychiatrists, neuropsychologists, and physical medicine and rehabilitation providers.

Anti-N-Methyl-D-Aspartate Receptor Encephalitis: A Detailed Review of the Different Psychiatric Presentations and Red Flags to Look for in Suspected Cases

Anti-N-methyl-D-aspartate receptor encephalitis is a rare autoimmune disorder that involves N-methyl-D-aspartate (NMDA) receptors. It is the most common autoimmune encephalitis, and early detection and treatment are crucial for morbidity-free recovery. Distinguishing this disorder from a primary psychiatric illness is quite challenging as this disorder classically presents with psychiatric manifestations that often resemble schizophrenic psychosis. Therefore, this review intended to scope the psychiatric manifestations this disorder could present with and dissect how they differ from primary psychiatric disorders. A PubMed database search was done. The results yielded were analyzed; eventually, 50 papers were used to review the different signs and symptoms the disease can present with, including common and rare disease presentations. Diagnostic challenges and helpful clinical clues to recognize the disorder were reviewed as well.

Anti N-Methyl-D-Aspartate (NMDA) receptor encephalitis: from psychosis to cognitive impairment

In this study, while presenting a clinical case with early psychiatric manifestations, we emphasized the need to pay attention to neurological diagnoses such as Anti N-Methyl-D-Aspartate Receptor (NMDAR) encephalitis at the time of manifestation of these common symptoms.

Cotard syndrome in anti-NMDAR encephalitis: two patients and insights from molecular imaging

Cotard syndrome is a clinical condition defined by the presence of nihilistic delusions. We report two patients with Cotard syndrome in whom anti-NMDAR encephalitis (ANMDARE) was confirmed. Both cases showed features of affective psychosis, developed catatonic syndrome, and worsened after the use of antipsychotics. 18F-FDG PET brain studies showed a bilateral hemispheric pattern of hypometabolism in posterior regions, mainly in the cingulate cortex and in the medial aspects of parietal and occipital lobes. A more severe hypometabolism was observed in the right hemisphere of both patients. Both cases remitted with the use of specific immunotherapy for ANMDARE.

Cycloid psychosis as a psychiatric expression of anti-NMDAR encephalitis. A systematic review of case reports accomplished with the authors' cooperation

OBJECTIVE

We reviewed the psychotic symptoms of anti-NMDA receptor encephalitis (NMDARE) to differentiate its presentation from those found in a primary psychiatric disorder. We hypothesized that the cycloid psychosis (CP) phenotype would be a frequent clinical presentation in the psychiatric phase of NMDARE.

METHOD

A systematic literature review in PubMed of all case reports published on NMDARE was performed from database inception to March 2020. We included all cases where psychotic symptoms were reported and whose diagnoses were confirmed by the presence of anti-NMDAR antibodies in the cerebrospinal fluid (CSF). An email including a short test (CP phenotype, Perris and Brockington's criteria) was sent to all case report authors asking them to describe the psychotic symptoms.

RESULTS

We identified 335 case reports fulfilling our criteria, and the authors of 200 replied. Our analyses were based exclusively on those answers and data extracted from the articles. Median patient age was 25 years (+-11.4), 81% were female, and 39% had an ovarian teratoma. A complete CP phenotype was identified in 175 patients (87%). These were acute psychotic episodes with a sudden onset and a fluctuating clinical pattern mostly characterized by confusion (97%), delusions (75%), hallucinations (69%), motility disturbances (87%), and mood oscillations (80%).

CONCLUSION

The complete CP phenotype was frequently the expression of psychotic symptoms in NMDARE. We suggest that patients with a first psychotic episode who initially exhibit the CP phenotype should undergo CSF analysis to determine whether antibodies against neuronal cell surface or synaptic receptors are present to rule out a possible diagnosis of autoimmune encephalitis.

Psychiatric management of anti-NMDAR encephalitis: a cohort analysis

BACKGROUND

Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis is an immune-mediated disorder which requires multi-disciplinary treatment including immunomodulation therapy. First presentation is most commonly to psychiatric services and continuing psychiatric care is required to treat disabling symptoms, such as behaviour disturbance, psychosis and catatonia. There is minimal available evidence to guide symptomatic treatment and concern for increased sensitivity to antipsychotics complicates traditional approaches.

METHODS

All cases of cerebrospinal fluid positive anti-NMDAR encephalitis tested in Queensland, Australia were identified. Demographic, clinical and therapeutic data were collected and reviewed by two independent clinicians. Pre-specified variables reflecting possible treatment side effects were compared.

RESULTS

The majority of the 30 cases (83%) had early psychiatric symptoms and were treated with antipsychotics (67%), average daily olanzapine equivalence dose of 11.5 mg, prior to immunomodulation therapy. Although there was an 88% reduction in cases with aggression, there was little improvement in psychosis, affective symptoms or catatonia with antipsychotics alone. In the cases with psychiatric symptoms, there was no significant difference in the rate of occurrence of neurological and autonomic symptoms between cases prescribed and not prescribed antipsychotics.

CONCLUSIONS

Psychiatric input is imperative for both acute and longer-term management of anti-NMDAR encephalitis. Primary symptomatic treatment should remain immunotherapy and surgery. Antipsychotic medications have particular value in managing agitation and aggression. Potential side effects from antipsychotic treatment are difficult to differentiate from progression of anti-NMDAR encephalitis but there was no evidence in this cohort of increased antipsychotic sensitivity. Treatment with psychotropic medication should be individualised and adjusted during the course of the illness.

Paraneoplastic and autoimmune encephalitis: Alterations of mood and emotion

Autoimmune encephalitis often produces signs and symptoms that appear to be at the interface between neurology and psychiatry. Since psychiatric symptoms are often prominent, patients are often first seen in a psychiatric setting. Therefore it is important that psychiatrists, as well as neurologists, be able to recognize autoimmune encephalitis, a task that is often difficult. Early diagnosis of autoimmune encephalitis is crucial as this will usually result in a better outcome for the patient. This chapter provides an introduction to various autoimmune encephalitides and describes their pathophysiology and the possible associated neuropsychiatric, neuropsychological (cognitive), and neurological (sensory-motor) signs and symptoms. This chapter also reviews the possible treatments of these associated signs and symptoms.

Case Report: Severe Adolescent Major Depressive Syndrome Turns Out to Be an Unusual Case of Anti-NMDA Receptor Encephalitis

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a neuroinflammatory condition mediated by autoantibodies against the GluN1 subunit of the receptor. Clinically, it is characterized by a complex neuropsychiatric presentation with rapidly progressive psychiatric symptoms, cognitive deficits, seizures, and abnormal movements. Isolated psychiatric manifestations of anti-NMDAR encephalitis are rare and usually dominated by psychotic symptoms. We present a case of an 18-year-old female high school student-without a previous history of psychiatric disorders-with a rapid onset severe depressive syndrome. Surprisingly, we found pleocytosis and anti-NMDAR autoantibodies in the cerebrospinal fluid (CSF), despite an otherwise unremarkable diagnostic workup, including blood test, clinical examination, and cranial magnetic resonance imaging (MRI). After intravenous immunoglobulins treatment, a complete remission of the initial symptoms was observed. In a follow-up 5 years later, the young woman did not experience any relapse or sequelae. Anti-NMDAR encephalitis can present in rare cases as an organic disorder with major depressive symptoms without distinct concomitant psychotic or neurological symptoms. A clinical presentation such as a rapid onset of symptoms, distinct disturbance in the thought process, restlessness, and cognitive deficits should prompt screening for NMDAR- and other neural autoantibodies to rule out this rare but debilitating pathology.

Serum and CSF Anti-NMDAR Antibody Testing in Psychiatry

OBJECTIVE

The authors examined and compared the clinical presentation of CSF positive and negative N-methyl-d-aspartate receptor (NMDAR) antibody.

METHODS

The investigators performed a retrospective chart review of NMDAR-antibody-positive cases (serum or CSF) involving patients presenting to psychiatric services from 2010 to 2018 in Queensland, Australia. Presentation, progress, investigations, and efficacy of treatment are detailed.

RESULTS

There were 24 serum or CSF NMDAR-antibody-positive cases and three equivocal serum results. High rates of prodromal cognitive deficits, catatonia, speech disturbance, and antipsychotic sensitivity were observed in the 16 CSF NMDAR-antibody-positive case patients and two CSF NMDAR-antibody-negative case patients, all evident before neurological deterioration with seizures, movement disorder, and autonomic disturbance occurring in the weeks following admission. The majority of these patients (N=17) were treated successfully with immunomodulatory therapy. The nine remaining patients, who were CSF NMDAR antibody negative or equivocal, did not demonstrate any of these features and improved with psychiatric care alone.

CONCLUSIONS

These findings suggest that traditional psychiatric care may be appropriate for patients with isolated psychiatric symptoms who have positive serum NMDAR testing when CSF is negative and there are no key clinical features such as cognitive deficits, catatonia, speech disturbance, and antipsychotic sensitivity. However, if these key features are present, a trial of immunomodulatory treatment should be considered with repeated examination of CSF for neuronal antibodies.

Pharmacologic Treatment and Early Rehabilitation Outcomes in Pediatric Patients With Anti-NMDA Receptor Encephalitis

OBJECTIVES

To describe the immunotherapy and pharmacologic treatments administered to pediatric patients with N-methyl-D-aspartate receptor encephalitis (NMDARE) during inpatient rehabilitation as well as to examine clinical and demographic variables associated with early functional outcomes.

DESIGN

Retrospective chart review and post hoc analysis.

SETTING

Pediatric inpatient rehabilitation unit.

PARTICIPANTS

Pediatric patients (N=26; mean age, 10.79±5.17y) admitted to an inpatient rehabilitation unit with a confirmed diagnosis of NMDARE.

INTERVENTIONS

Inpatient rehabilitation; pharmacologic treatments.

MAIN OUTCOME MEASURE

FIM for Children (WeeFIM) Developmental Functional Quotient (DFQ).

RESULTS

All patients received first-line immunotherapies to treat NMDARE, and 69% also received second-line immunotherapies. Patients were prescribed an average of 8 medications for symptom management (range, 3-15 per patient), most often for the treatment of agitation (100%), psychiatric symptoms (92%), and seizures (65%). Sixty-five percent of patients demonstrated an improvement in Total WeeFIM DFQ over the course of inpatient rehabilitation, with 35% demonstrating limited to no change in Total WeeFIM DFQ ("unfavorable early outcome"). Those with unfavorable early outcome were significantly younger than those showing more favorable outcome. Pharmacologic treatment for seizures, movement disorders, and decreased arousal or level of consciousness were each associated with unfavorable early outcome independent of age differences.

CONCLUSION

Findings highlight the symptomatic heterogeneity and polypharmacy involved in the care and treatment of patients with NMDARE, with patients receiving a variety of immunotherapies and medications for symptom management. The presence of (and treatment for) seizures, movement disorders, and deteriorated neurologic status may each be associated with poor early outcomes in this population. Further investigation is needed to better classify presentations and treatments for this disease and to determine how differences are associated with long-term outcomes.

Catatonia revived: a unique syndrome updated

Catatonia was buried within the confines of schizophrenia for over a century- deterring study, appropriate diagnosis and treatment for many years. With revised changes in the classification of this distinct neuropsychiatric syndrome, it is becoming more recognized clinically and in ongoing research. Catatonia occurs among various psychiatric, metabolic or neurologic conditions. It may present in many forms, including neuroleptic malignant syndrome. Treatment with benzodiazepines or electroconvulsive therapy usually produces dramatic and rapid response, although systematic, randomized trials are lacking. The role of antipsychotic agents in treatment is controversial as they may worsen the syndrome. An important unresolved clinical question is the diagnosis and treatment of catatonia in the setting of delirium.

Catatonia secondary to anti-N-methyl-D-aspartate receptor (NMDAr) encephalitis: a review

Anti-N-methyl-D-aspartate receptor (NMDAr) encephalitis is a relatively recent autoimmune entity, as it was first described in 2007. Given that it is a condition with neuropsychiatric symptoms, its initial symptom is frequently psychiatric in nature. Hence, psychiatrists are often the first physicians to assess these patients and, as so, must recognize this type of encephalitis as a possible cause. Catatonia may be inaugural or develop throughout the course of the disease. Management of patients with anti-NMDAr encephalitis is based on etiologic treatment with immunotherapy and removal of the associated tumor, if any. However, these catatonic patients may have variable responses to etiologic treatment, sometimes with refractory catatonic symptoms, which attests to the necessary urgency to know how to manage these patients. In the clinical setting, physicians appear to be using guidelines originally created to the management of catatonia due to primary psychiatric conditions. In this literature review, catatonia was historically contextualized and anti-NMDAr encephalitis overall described. Finally, catatonia secondary to this type of encephalitis was discussed.

Evaluation of the proposed anti-N-methyl-d-aspartate receptor encephalitis clinical diagnostic criteria in psychiatric patients

OBJECTIVE

The gold standard for diagnosing anti-NMDAR encephalitis is demonstration of the antibody in CSF. Clinical diagnostic criteria have been proposed for when this is not available in a timely manner which is evaluated, in this study, for a psychiatric population.

METHODS

This study retrospectively assessed the proposed criteria in patients presenting to psychiatric services for the first time with known anti-NMDAR antibody status. Antibody-positive cases were derived from the literature (conception to December 2019) and a state-wide (Queensland, Australia) cohort. Antibody-negative cases were derived from a service-wide (Metro South, Queensland, Australia) cohort of psychiatric cases which underwent antibody testing for routine organic screening. Sensitivity and specificity were calculated at 1 week following admission and the point of discharge.

RESULTS

The proposed criteria were applied to 641 cases (500 antibody-positive and 141 antibody-negative), demonstrating a sensitivity which increased from around 19% after 1 week to 49% by the point of discharge. Specificity was 100% at both time points. The mean average time to become positive using the proposed criteria was 19.5 days compared to 34.9 days for return of antibody testing.

CONCLUSIONS

High specificity of the proposed criteria, seen in this study, suggests that cases which are positive can be considered for expedited commencement of treatment. However, if clinical suspicion is high despite criteria being negative, it is essential to test CSF for anti-NMDAR antibody.

Searching for autoimmune encephalitis: Beware of normal CSF

OBJECTIVE

To determine the prevalence of cerebrospinal fluid (CSF) markers associated with inflammation (i.e., elevated white blood cell count, protein concentration, and CSF-specific oligoclonal bands) in patients with early active autoimmune encephalitis (AE).

METHODS

CSF characteristics, including WBC count, protein concentration, and oligoclonal banding, were analyzed in patients diagnosed with AE at two tertiary care centers.

RESULTS

Ninety-five patients were included in the study. CSF white blood cell counts and protein levels were within normal limits for 27% (CI_95%: 19-37) of patients with AE. When results of oligoclonal banding were added, 14% (CI_95%: 6-16) of patients with AE had "normal" CSF. The median CSF white blood cell count was 8 cells/mm³ (range: 0-544) and the median CSF protein concentration was 0.42 g/L (range: 0.15-3.92).

CONCLUSIONS

White blood cell counts and protein levels were within normal limits in the CSF of a substantial proportion of patients with early active AE. Inclusion of CSF oligoclonal banding identified a higher proportion of patients with an inflammatory CSF profile, especially when CSF was sampled early in the disease process.

Screening for anti-NMDAR encephalitis in psychiatry

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

Delirious mania as a frequent and recognizable neuropsychiatric syndrome in patients with anti-NMDAR encephalitis

BACKGROUND

Previous case reports showed that delirious mania could be one of the many neuropsychiatric presentations of Anti-N-methyl-d-aspartate receptor encephalitis (ANMDARE).

OBJECTIVE

To evaluate the frequency of delirious mania and its associated factors in ANMDARE.

METHOD

A prospective study, including all patients with ANMDARE admitted to the National Institute of Neurology and Neurosurgery of Mexico, from January 2014 to April 2019. The diagnosis of delirious mania was established when diagnostic criteria for mania and delirium were fulfilled simultaneously.

RESULTS

79 patients with definitive ANMDARE were included. Delirious mania was identified in 20 (25.3%) of these patients. Catatonia, psychomotor agitation, disinhibition, impulsivity, and grandiose delusions were significantly associated with delirious mania. Also, a lower frequency of EEG abnormalities, absence of extreme delta brush, and a shorter hospital stay was observed in these patients.

CONCLUSION

Delirious mania proved to be a frequent neuropsychiatric presentation of ANMDARE, and its presence should warn the physician about the possibility of this diagnosis. It was mainly associated with higher rates of catatonia, psychomotor agitation, disinhibition, and psychotic symptoms. The lack of recognition of delirious mania as a neuropsychiatric presentation in ANMDARE may be a source of diagnostic and therapeutic errors, as most physicians associate this with bipolar disorder.