Long-term cognitive and neuropsychiatric outcomes in patients with anti-NMDAR encephalitis

Inhibition of NLRP3 inflammasome alleviates cognitive deficits in a mouse model of anti-NMDAR encephalitis induced by active immunization

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a neurological disorder, characterized by cognitive deficits as one of its vital features. The nucleotide-binding oligomerization domain-like receptor (NLRP3) inflammasome is a key contributor to neuroinflammation and cognitive deficits in neurological diseases. However, the underlying mechanism of anti-NMDAR encephalitis remains unclear, and the biological function of the NLRP3 inflammasome in this condition has not been elucidated. In this study, a mouse model of anti-NMDAR encephalitis was induced by active immunization with the GluN1356-385 peptide (NEA model). The NLRP3 inflammasome in the hippocampus and temporal cortex was investigated using real-time quantitative PCR (RT-qPCR), western blotting, and immunofluorescence staining. The impact of MCC950 on cognitive function and NLRP3 inflammation was assessed. Confocal immunofluorescence staining and Sholl analysis were employed to examine the function and morphology of microglia. In the current study, we discovered overactivation of the NLRP3 inflammasome and an enhanced inflammatory response in the NEA model, particularly in the hippocampus and temporal cortex. Furthermore, significant cognitive dysfunction was observed in the NEA model. While, MCC950, a selective inhibitor of the NLRP3 inflammasome, sharply attenuated the inflammatory response in mice, leading to mitigated cognitive deficits of mice and more regular arrangements of neurons and reduced number of hyperchromatic cells were also observed in the hippocampus area. In addition, we found that the excess elevation of NLRP3 inflammasome was mainly expressed in microglia accompanied with the overactivation of microglia, while MCC950 treatment significantly inhibited the increased number and activated morphological changes of microglia in the NEA model. Altogether, our study reveals the vital role of overactivated NLRP3 signaling pathway in aggravating the inflammatory response and cognitive deficits and the potential protective effect of MCC950 in anti-NMDAR encephalitis. Thus, MCC950 represents a promising strategy for anti-inflammation in anti-NMDAR encephalitis and our study lays a theoretical foundation for it to become a clinically targeted drug.

Disease course and psychosocial outcome for children and adolescents with anti-N-methyl-D-aspartate receptor encephalitis

OBJECTIVES

Explore psychosocial outcome and impact of persisting deficits on quality of life (QoL) and global functioning after anti-N-methyl-D-aspartate receptor encephalitis (anti-NMDARE) in children and adolescents.

METHODS

Four female patients (age 7-16y) and their caregivers participated in the study. Information was collected from the medical records and the caregivers via a questionnaire. Both the patients and their caregivers were interviewed by means of the structured clinical interview for DSM-5 disorders, junior version (SCID-5 junior). CGAS and mRS scores were defined and the Pediatric Quality of Life Inventory (PedsQL) was used to assess quality of life of patients and caregivers.

RESULTS AND CONCLUSION

After the acute phase of the disease patients go through a post-acute phase in which several persisting physical, cognitive and psychiatric symptoms gradually resolve during the following months to a year. In long-term follow up these symptoms partly resolved, but deficits persisted on several domains. Psychiatric symptoms, fatigue and mild cognitive deficits were present in three out of four patients at current assessment. In three patients their academic trajectory was altered. These deficits can have an impact on the quality of life and the global functioning of the patients and caregivers.

The T1-weighted/T2-weighted ratio as a biomarker of anti-NMDA receptor encephalitis

BACKGROUND

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis rarely causes visible lesions in conventional MRI, yet advanced imaging detects extensive white matter damage. To improve prognostic capabilities, we evaluate the T1-weighted/T2-weighted (T1w/T2w) ratio, a measure of white matter integrity computable from clinical MRI sequences, in NMDAR encephalitis and examine its associations with cognitive impairment.

METHODS

T1-weighted and T2-weighted MRI were acquired cross-sectionally at 3 Tesla in 53 patients with NMDAR encephalitis (81% women, mean age 29 years) and 53 matched healthy controls. Quantitative and voxel-wise group differences in T1w/T2w ratios and associations with clinical and neuropsychological outcomes were assessed. P-values were false discovery rate (FDR) adjusted where multiple tests were conducted.

RESULTS

Patients with NMDAR encephalitis had significantly lower T1w/T2w ratios across normal appearing white matter (p=0.009, Hedges' g=-0.51), which was associated with worse verbal episodic memory performance (r=0.39, p=0.005, p(FDR)=0.026). White matter integrity loss was observed in the corticospinal tract, superior longitudinal fascicle, optic radiation and callosal body with medium to large effects (Cohen's d=[0.42-1.17]). In addition, patients showed decreased T1w/T2w ratios in the hippocampus (p=0.002, p(FDR)=0.005, Hedges' g=-0.62), amygdala (p=0.002, p(FDR)=0.005, Hedges' g=-0.63) and thalamus (p=0.010, p(FDR)=0.019, Hedges' g=-0.51).

CONCLUSIONS

The T1w/T2w ratio detects microstructural changes in grey and white matter of patients with NMDAR encephalitis that correlate with cognitive performance. Computable from conventional clinical MRI sequences, this measure shows promise in bridging the clinico-radiological dissociation in NMDAR encephalitis and could serve as an imaging outcome measure in clinical trials.

Brain magnetic resonance imaging as predictors in pediatric anti-N-methyl-D-aspartate receptor encephalitis

OBJECTIVE

To investigate the associations between brain magnetic resonance imaging (MRI) changes and clinical profiles in children with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis.

METHODS

Clinical data and brain MRI results of children diagnosed with anti-NMDAR encephalitis in Guangzhou Women and Children's Medical Center from October 2014 to June 2022 were retrospectively studied.

RESULTS

A total of 143 children (Male: female 54:89) were enrolled, with a mean onset age of 6.8 years (6.8 ± 3.1). 40.6 % (58/143) of patients had abnormal initial brain MRI. Lesions in temporal lobe (34.5 %, 20/58) and frontal lobe (25.9 %, 15/58) were relatively common. Children with abnormal initial brain MRI were prone to have fever (P = 0.023), dystonia (P = 0.037), positive MOG antibodies (P = 0.015), higher cerebrospinal fluid (CSF) white blood cell count (WBC) (P = 0.019) and to receive rituximab treatment (P = 0.037). There were no significant differences in modified Rankin Scale (mRS) scores before immunotherapy, after immunotherapy and at last follow-up between the normal initial brain MRI group and abnormal group. No initial brain MRI changes were found to be associated with relapses. Brain MRI was reviewed in 72 patients at last follow-up with a median follow-up time of 25.5 months and 48.6 % (35/72) of patients had abnormal brain MRI. The mRS score of the group with normal brain MRI at last follow-up was significantly lower than that of the abnormal group.

CONCLUSIONS

About 40.0 % of children with anti-NMDAR encephalitis had abnormal initial brain MRI. Initial brain MRI was associated with certain clinical profiles, but not with relapse and prognosis. Around half of patients had abnormal brain MRI at last follow-up and were prone to have higher mRS score.

Mental health outcomes of encephalitis: An international web-based study

BACKGROUND AND PURPOSE

Acute encephalitis is associated with psychiatric symptoms. Despite this, the extent of mental health problems following encephalitis has not been systematically reported.

METHODS

We recruited adults who had been diagnosed with encephalitis of any aetiology to complete a web-based questionnaire.

RESULTS

In total, 445 respondents from 31 countries (55.1% UK, 23.1% USA) responded. Infectious encephalitis constituted 65.4% of cases, autoimmune 29.7%. Mean age was 50.1 years, 65.8% were female, and median time since encephalitis diagnosis was 7 years. The most common self-reported psychiatric symptoms were anxiety (75.2%), sleep problems (64.4%), mood problems (62.2%), and unexpected crying (35.2%). Self-reported psychiatric diagnoses were common: anxiety (44.0%), depression (38.6%), panic disorder (15.7%), and posttraumatic stress disorder (PTSD; 21.3%). Severe mental illnesses such as psychosis (3.3%) and bipolar affective disorder (3.1%) were reported. Self-reported diagnosis rates were broadly consistent with results from the Psychiatric Diagnostic Screening Questionnaire. Many respondents also reported they had symptoms of anxiety (37.5%), depression (28.1%), PTSD (26.8%), or panic disorder (20.9%) that had not been diagnosed. Rates of psychiatric symptoms did not differ between autoimmune and infectious encephalitis. In total, 37.5% respondents had thought about suicide, and 4.4% had attempted suicide, since their encephalitis diagnosis. More than half of respondents (53.5%) reported they had no, or substandard, access to appropriate mental health care. High rates of sensory hypersensitivities (>75%) suggest a previously unreported association.

CONCLUSIONS

This large international survey indicates that psychiatric symptoms following encephalitis are common and that mental health care provision may be inadequate. We highlight a need for proactive psychiatric input.

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.

Persistent psychosis associated with extreme delta brush in anti-NMDA receptor encephalitis: a case report

BACKGROUND

Anti-NMDAR encephalitis is an emerging differential diagnosis of first episode and persistent psychosis in the psychiatric community, as clinical manifestations include psychiatric symptoms, cognitive dysfunction, seizures, decreased consciousness, and dyskinesias. This disease is associated with extreme delta brush (EDB), but the significance and temporal course of this EEG pattern still needs to be determined. Herein, we report a case of anti-NMDAR encephalitis with persistent psychosis associated with EDB occurrence on multiple occasions during a 5-year disease course.

CASE PRESENTATION

A 15-year-old girl was diagnosed with anti-NMDAR encephalitis and treated with progressive improvement. Four years after initial manifestations, an EDB pattern was seen on electroencephalogram (EEG) without new neurological symptoms. She had residual symptoms of episodic auditory hallucinations and impulsivity. One year later, the patient had a recurrence of neurological symptoms (seizures, dyskinesias and impaired attention), persisting with EDB on EEG. Clinical symptoms and EDB resolved after second-line treatment with rituximab.

CONCLUSION

We describe the first case of persistent psychosis in anti-NMDAR encephalitis associated with extreme delta brush on multiple EEGs on prolonged follow-up. Electroencephalographic patterns such as EDB may serve as markers of residual disease activity, including psychiatric symptoms. Further studies with prolonged EEG monitoring are needed to better understand these findings.

Epilepsy, Immunity and Neuropsychiatric Disorders

Several studies have focused on the emerging role of immunity and inflammation in a wide range of neurological disorders. Autoimmune diseases involving central nervous system share well defined clinical features including epileptic seizures and additional neuropsychiatric symptoms, like cognitive and psychiatric disturbances. The growing evidence about the role of immunity in the pathophysiologic mechanisms underlying these conditions lead to the concept of autoimmune epilepsy. This relatively-new term has been introduced to highlight the etiological and prognostic implications of immunity in epileptogenesis. In this review, we aim to discuss the role of autoimmunity in epileptogenesis and its clinical, neurophysiological, neuroimaging and therapeutic implications. Moreover, we wish to address the close relationship between immunity and additional symptoms, particularly cognitive and psychiatric features, which deeply impact clinical outcomes in these patients. To assess these aspects, we first analyzed Rasmussen's encephalitis. Subsequently, we have covered autoimmune encephalitis, particularly those associated with autoantibodies against surface neuronal antigens, as these autoantibodies express a direct immune-mediated mechanism, different from those against intracellular antigens. Then, we discussed the connection between systemic immune disorders and neurological manifestations. This review aims to highlight the need to expand knowledge about the role of inflammation and autoimmunity in the pathophysiology of neurological disorders and the importance to early recognize these clinical entities. Indeed, early identification may result in faster recovery and a better prognosis.

Brain magnetic resonance imaging predictors in anti-N-methyl-D-aspartate receptor encephalitis

OBJECTIVE

Brain magnetic resonance imaging (MRI) findings in anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis are nonspecific and rarely have obvious associations with clinical characteristics and outcomes. This study aimed to comprehensively describe the MRI features of patients with NMDAR encephalitis, examine their associations with clinical characteristics, and evaluate their predictive power for disease recurrence and prognosis.

METHODS

We retrospectively extracted the clinical data and brain MRI findings of 144 patients with NMDAR encephalitis. Patients underwent a 2-year follow-up to assess disease outcomes. We evaluated the associations of brain MRI findings at the onset with clinical characteristics, recurrence, and prognosis.

RESULTS

Initial MRI showed typical abnormalities in 65 patients (45.1%); of these, 34 (29.3%) developed recurrence and 10 (9.4%) had poor prognosis (mRS ≥3). Binary logistic regression analyses revealed that insula abnormalities were associated with acute seizure (odds ratio [OR] = 3.048, 95% confidence interval [CI]: 1.026-9.060) and white matter lesions were associated with cognitive impairment (OR = 2.730, 95% CI: 1.096-6.799). Risk factors for a poor 2-year prognosis included a higher number of brain MRI abnormalities (OR = 1.573, 95% CI: 1.129-2.192) and intensive care unit (ICU) admissions (OR = 15.312, 95% CI: 1.684-139.198). The risk factors for 2-year recurrence included abnormalities of the thalamus (HR = 3.780, 95% CI: 1.642-8.699).

INTERPRETATIONS

Brain MRI features of patients with NMDAR encephalitis were associated with clinical manifestations, prognosis, and recurrence. Higher numbers of MRI abnormalities and ICU admissions were predictive of poor prognosis. Abnormalities of the thalamus constituted a recurrence-related risk factor.

A systematic review and quantitative synthesis of the long-term psychiatric sequelae of pediatric autoimmune encephalitis

BACKGROUND

Long-term neuropsychiatric sequelae of autoimmune encephalitis (AE) remain understudied, particularly in pediatric-onset AE. We aimed to synthesize the published data on ongoing psychiatric symptoms in pediatric-onset AE.

METHODS

The Pubmed, PyscINFO, Web of Science databases were searched from their inception years to August 23, 2021, and 29 studies were identified and analyzed. We also performed a quantitative synthesis of available patient data from the 29 studies combined with a cohort of anti-NMDA receptor (NMDAR) AE from our institution to examine the associations between acute treatment course and long-term psychiatric outcome.

RESULTS

At long-term follow up, 52.4% of the cases with pediatric-onset AE had any persistent symptom and 36.0% had at least one psychiatric symptom. Pooled data found that 36.3% of pediatric-onset anti-NMDAR AE had ongoing psychiatric symptoms. Using a univariate logistic regression analysis, we found that abnormal initial EEG, use of certain immunotherapies, and persistent cognitive impairments were associated with ongoing psychiatric symptoms.

LIMITATIONS

Limitations of the existing literature included a significant paucity of outcomes measured using consistent, objective methods. Limitations of the systematic review included the wide variability among the studies reviewed, which rendered a meta-analysis impossible and beyond the scope of the paper.

CONCLUSION

Chronic psychiatric and behavioral problems remain present in one-third of children months to years after onset of AE. Larger scaled prospective observational studies with a consistent standardized battery of testing are needed to examine impact of specific clinical features and immunotherapies on long-term mental health outcomes.

HLA-DRB1*03:01 is associated with female sex and younger age of anti-LGI1 encephalitis

OBJECTIVE

To investigate the association between human leukocyte antigen (HLA) genotype and clinical characteristics of anti-LGI1 encephalitis.

METHODS

HLA genotyping was performed in 34 patients with anti-LGI1 encephalitis admitted to West China Hospital between April 2014 and May 2021, as well as in 305 healthy controls. The on-line tool NetMHCIIpan 4.0 and AutoDock Vina software were used to predict binding between LGI1 peptide and HLA Class II molecules.

RESULTS

Risk of anti-LGI1 encephalitis was strongly associated with the DRB1*03:01 allele (OR 4.31, 95% CI 1.96-9.25, Pc = 2.75×10^-4 ) and the DRB1*03:01-DQB1*02:01 haplotype (OR 4.45, 95% CI 2.02-9.59, Pc = 2.94×10^-4 ). Compared to carriers of the DRB1*07:01 allele, those with the DRB1*03:01 allele were more likely to be female (93.3% vs 33.3%; P = 0.004) and to be younger (median age, 38 vs 65 years; P < 0.001). DRB1*03:01 carriers showed stronger response to immunotherapy than carriers of the DRB1*07:01 allele, based on median score decrease on the modified Rankin scale [2 (interquartile range, 1-2) vs. 1 (interquartile range, 0-1); P = 0.03] at 4 weeks after immunotherapy. Prediction and docking algorithms suggested that the LGI1 peptide can bind to the DRB1*03:01 molecule strongly.

CONCLUSIONS

The strong association between anti-LGI1 encephalitis and certain HLA class II alleles supports a primary autoimmune origin for the disease. Carriers of the DRB1*03:01 allele in Chinese patients with anti-LGI1 encephalitis are more likely to be female, to suffer earlier disease onset and to respond better to immunotherapy.

Long-Term Prognosis of Patients With Anti-N-Methyl-D-Aspartate Receptor Encephalitis Who Underwent Teratoma Removal: An Observational Study

Objective

This study aimed to evaluate the clinical characteristics and long-term surgical outcomes of patients with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis with teratoma.

Methods

Patients who were admitted to West China Hospital from June 2012 to June 2019 and diagnosed with anti-NMDAR encephalitis were enrolled in the study. Medical records were reviewed prospectively to gather clinical characteristic data. Patients were followed up at long-term every 3 months.

Results

This study included 192 patients, among whom 21 (10.9%) were detected with having a teratoma. Patients included 20 women, with a mean age of 24.62 ± 7.61 years. Seizure and psychiatric symptoms were the most dominant symptoms in both groups, followed by memory deficits. Central hypoventilation (52.4 vs. 17%, p < 0.001) and decreased consciousness (71.4 vs. 31.3%, p = 0.002) were significantly more frequent in patients with teratoma than in those without. Moreover, the anti-NMDAR antibody titer was higher (p = 0.021) and the baseline modified Rankin scale score was lower (p = 0.004) in patients with teratoma than in those without. First-line immunotherapy was performed in 21 (100%) patients with teratoma and 167 (97.7%) patients without teratoma. All patients with teratoma had the tumor removed. During follow-up, two (9.5%) patients with teratoma and 11 (6.4%) patients without teratoma died, whereas 1 (4.8%) patient with teratoma and 37 (21.6%) patients without teratoma had relapses. Overall, 19 (90.5%) patients with teratoma and 151 (88.3%) patients without teratoma achieved favorable clinical outcomes at the final follow-up.

Conclusions

With early detection and removal of teratoma, most patients with anti-NMDAR encephalitis and teratoma achieved a favorable long-term prognosis.

Relapse factors of patients of anti-N-methyl-D-aspartate receptor encephalitis

BACKGROUND

The factors associated with anti-N-methyl-D-aspartate (NMDA) receptor encephalitis relapse are yet to be elucidated.

AIMS OF THE STUDY

To investigate the factors associated with relapse and prognosis of anti-NMDA receptor encephalitis.

METHODS

This retrospective study included patients diagnosed with anti-NMDA receptor encephalitis admitted to the First Affiliated Hospital of Zhengzhou University from January 2013 to October 2019. The clinical features, auxiliary examinations, treatment regimens, and follow-up were recorded. The outcomes were relapse and 2-year disease prognosis.

RESULTS

A total of 160 patients were included. Consequently, 6 (5%) deaths, 34 (25.4%) relapses, and 19 (15.2%) patients had a poor prognosis (modified Rankin score (mRS) ≥3) were recorded. The multivariable analyses showed that age (p = .011), abnormal magnetic resonance imaging (MRI) (p = .019), glucocorticoid pulse (p = .009), and intracranial pressure (p = .023) were independently associated with the relapse, while age (p = .030) and central hypoventilation (p = .020) were independently associated with a poor prognosis at 2 years.

CONCLUSION

Glucocorticoid pulse therapy reduces the relapse of anti-NMDA receptor encephalitis. Age, abnormal MRI, and intracranial pressure are risk factors for relapse, while age and central hypoventilation are independently associated with poor prognosis.

Long-term seizure outcomes in patients with autoimmune encephalitis: A prospective observational registry study update

OBJECTIVE

To update and evaluate long-term seizure outcomes in patients with autoimmune encephalitis (AE) based on a large cohort study with long follow-up.

METHODS

In this prospective observational registry study, we analyzed data from patients with AE mediated by common types of neuronal surface antibodies (anti-NMDAR, anti-LGI1/Caspr2, anti-GABA_B R). All patients were recruited from the Department of Neurology at the West China Hospital between October 2011 and June 2019, and data were collected prospectively on their demographic and clinical characteristics, treatment strategy, and seizure outcomes with a median follow-up of 42 months (range 6-93 months). Potential risk factors associated with seizure recurrence were also assessed.

RESULTS

Of 320 AE patients, 75.9% had acute seizures, among whom more than 90% of patients had their last seizure within 12 months of disease onset. During our follow-up, 21 (9.3%) patients experienced seizure recurrence. Patients with anti-GABA_B R encephalitis had a higher cumulative incidence of seizure recurrence than those with anti-NMDAR (log-rank P = 0.03) or anti-LGI1/Caspr2 encephalitis (log-rank P = 0.04). Among patients with anti-NMDAR encephalitis, women had a significantly higher cumulative incidence of seizure recurrence than men (log-rank P = 0.01). Interictal epileptiform discharges (IEDs) or seizures captured on continuous EEG in the acute phase were identified as potential risk factors for seizure recurrence (P=0.04; P=0.007). Among 163 patients with ≥ 24 months of follow-up, five (3.1%) showed persistent seizures and required ongoing anti-seizure medications (ASMs) despite aggressive immunotherapy.

SIGNIFICANCE

Seizure recurrence occurred in a small number of patients and chronic epilepsy occurred in 3.1% of patients during prolonged follow-up. Across all types of AE, risk factors for seizure recurrence were IEDs or seizures captured on EEG in the acute phase; for anti-NMDAR encephalitis, female sex was also a risk factor.

Validation of the Clinical Assessment Scale in Autoimmune Encephalitis in Chinese Patients

Background and Objectives

The Clinical Assessment Scale in Autoimmune Encephalitis (CASE) is a scale for assessing severity in autoimmune encephalitis. We aimed to validate the CASE score in a Chinese population and evaluate its clinical significance.

Methods

Patients diagnosed with autoimmune encephalitis were recruited between June 2014 and May 2019 from two hospitals. CASE and modified Rankin Scale (mRS) scores were obtained. Data regarding clinical features, treatment, and available information were gathered from the hospital information system.

Results

Of the 176 patients with autoimmune encephalitis, 11 died and 14 had tumors. Ten patients received second-line treatment. The CASE scores of patients receiving second-line treatment were significantly higher (median CASE: 15) than in those receiving first-line treatment (median CASE: 8) (p<0.001). Twenty-two patients had poor functional status (mRS>2). Areas under the curve of CASE on whether functional status was poor at 1 year were 0.89 (p<0.001). Sixty patients were admitted to the intensive care unit (ICU), and the CASE scores were positively correlated with days in the ICU (r=0.58, p<0.001). There was no statistically significant association between the CASE scores and relapse (p=0.39>0.05). Additionally, the CASE scores were positively associated with the mRS scores (r=0.85 p<0.001).

Conclusions

The CASE score is suitable for the comprehensive assessment of Chinese patients with autoimmune encephalitis, which may help clinicians to select the appropriate intervention and estimate the disease severity and prognosis.

Contemporary advances in anti-NMDAR antibody (Ab)-mediated encephalitis

The study of antibody (Ab)-mediated encephalitis has advanced dramatically since the discovery of antibodies directed against the N-methyl-D-aspartate receptor (NMDAR) in association with a unique neuro-psychiatric syndrome, over a decade-and-a-half ago. Anti-NMDAR Ab-mediated encephalitis now represents the most well characterised form of autoimmune encephalitis. The disease most commonly manifests in young women, but all ages and both sexes can be affected. Autoantibodies may arise in the context of two well-recognised disease triggers in a proportion of patients, and ultimately facilitate NMDAR displacement from synapses. Various CSF cytokines, chemokines, and other molecules have been explored as candidate biomarkers but are limited in sensitivity and specificity. The clinical spectrum is diverse, with evolution and a combination of neuro-psychiatric abnormalities at disease nadir common. Anti-NMDAR Ab-mediated encephalitis is immunotherapy responsive, and a near-majority ultimately acquire a broadly favourable clinical outcome. The diagnosis, and more particularly, the management of the disease can still hold considerable challenges. Moreover, well-defined biomarkers remain elusive. The present review will therefore delineate pathogenic and clinical advances to date in anti-NMDAR antibody-mediated encephalitis.

Progressive cortical and sub-cortical alterations in patients with anti-N-methyl-D-aspartate receptor encephalitis

BACKGROUND

Advanced structural analyses are increasingly being highly valued to uncover pathophysiological understanding of anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. Therefore, we aimed to explore whether and how antibody-mediated NMDAR dysfunction affected cortical and sub-cortical brain morphology and their relationship with clinical symptoms.

METHODS

We performed surface-based morphometry analyses, hippocampal segmentation, and correlational analyses in 24 patients with anti-NMDAR encephalitis after acute disease stage and 30 normal controls (NC) in this case-control study.

RESULTS

Patients showed significantly decreased cortical alterations mainly in language network (LN) and default mode network (DMN), as well as decreased gray matter volume in left cornu ammonis 1 (CA1) body of hippocampus. Further correlation analyses showed that the decreased cortical thickness in the right superior frontier gyrus was associated with decreased cognitive scores, the decreased cortical volume in the right pars triangulari and decreased surface area in the right pars operculari were associated with decreased memory scores, whereas decreased gray matter volume in the left CA1 body was significantly correlated with longer time between first symptom and imaging in the patients.

CONCLUSION

These results suggested that cognitive impairments resulted from long-term sequelae of the encephalitis were mainly associated with cortical alterations in LN and DMN and sub-cortical atrophy of left CA1 body, which can be served as effective features to assess disease progression in clinical routine examination.

Neurofunctional outcomes in patients with anti-leucine-rich glioma inactivated 1 encephalitis

OBJECTIVE

To evaluate the cognitive and neurofunctional outcomes in patients with anti-leucine-rich glioma inactivated 1 (LGI1) encephalitis.

METHODS

A cohort follow-up study was performed after a median of 33 months (range 6-78) from disease onset to the last follow-up in patients diagnosed with anti-LGI1 encephalitis, to assess the neurofunctional outcomes using modified Rankin Scale (mRS), activities of daily living (ADL), neuropsychiatric inventory (NPI) and modified telephone interview for cognitive status (TICS-M). Remote symptomatic seizure and clinical relapses were also recorded. The clinical, laboratory features, and treatment responses that characterize the disability were analyzed.

RESULTS

The results showed that 81 of 86 (94.2%) patients with anti-LGI1 encephalitis were successfully followed up, while eight (9.9%) died after discharge. Among the 73 survivors, clinical relapses occurred in 18 (24.7%) patients, and those with relapses were at a higher risk of developing remote symptomatic seizure (p = .019). Although 85.2% of the patients became functionally independent (mRS ≤2), the sequelae of symptomatic seizure, neuropsychiatric symptoms, and cognitive deficits were found in 11.0%, 21.9%, and 39.7% of the patients, respectively. Residual cognitive deficits primarily occurred in the elderly subjects as well as those with symptoms of memory deficit, psychiatric disorders, sleep disturbance, disturbance of consciousness at diagnosis, and higher CSF protein levels.

CONCLUSIONS

Although most patients survived and became functionally independent, a subset of patients could not return to all premorbid activities. They may have clinical relapses or suffer from remote symptomatic seizure, neuropsychiatric symptoms, and cognitive impairment.

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.

Long-term Functional Outcomes and Relapse of Anti-NMDA Receptor Encephalitis: A Cohort Study in Western China

Objective

To study the factors associated with relapse and functional outcomes in patients with anti-NMDA receptor encephalitis in Western China.

Methods

The Outcome of the anti-NMDA receptor Encephalitis Study in Western China was initiated in October 2011 to collect prospective observational data from consecutively enrolled patients with anti-NMDA receptor encephalitis.

Results

We consecutively enrolled 244 patients (median age: 26 years, range: 9–78 years; females: 128 [52.45%]) between October 2011 and September 2019. Fatality occurred in 17 (6.96%) patients, and tumors were found in 38 (15.57%) patients. The median follow-up duration was 40 (6–96) months. Of these patients, 84.8% showed clinical improvements within 4 weeks after immunotherapy, with a median modified Rankin Scale of 2 (interquartile range [IQR]: 2–3), and 80.7% (median: 1, IQR: 0–2) and 85.7% (median: 0, IQR: 0–1) had substantial recovery (i.e., mild or no residual symptoms) at 12 and 24 months, respectively. The overall prognosis was still improving at 42 months after onset. Disturbance of consciousness during the first month was the only independent predictor (OR: 2.91, 95% CI: 1.27–6.65; p = 0.01) of a poor functional neurologic outcome. Overall, 15.9% of the patients had one or multiple relapses, with 82.0% experiencing the first relapse within 24 months and 76.9% experiencing relapses that were less severe than the initial episodes. Relapse-related risk factors included the female sex and delayed treatment (p < 0.05).

Conclusions

Most patients achieved favorable long-term functional outcomes. Some patients experienced one or multiple relapses, especially female patients. Timely immunotherapy at onset may reduce the risk of relapse.

Long-term cognitive and neuropsychiatric outcomes of anti-GABABR encephalitis patients: A prospective study

Long-term cognitive and neuropsychiatric outcomes of anti-gamma-aminobutyric-acid B receptor (anti-GABA_BR) encephalitis are unclear. In this prospective study, 31 patients with anti-GABA_BR encephalitis were underwent cognitive and neuropsychiatric evaluations every 6 months. At 24 months' follow-up, cognitive impairments were observed in 80% of patients that mainly included deficits in memory, executive functions and nonverbal reasoning; and neuropsychiatric symptoms were observed in 50% of patients that mainly included depressive symptoms and irritation. The risk factors associated with cognitive deficits was age > 45 years. This study demonstrated that most patients with anti-GABA_BR encephalitis had persistent cognitive deficits and neuropsychiatric symptoms.

Direct economic burden of patients with autoimmune encephalitis in western China

Objective

To analyze the cost of autoimmune encephalitis (AE) in China for the first time.

Methods

Patients who were newly diagnosed with antibody-positive AE (anti-NMDA receptor [NMDAR], anti-γ aminobutyric acid type B receptor [GABA_BR], antileucine-rich glioma-inactivated 1 [LGI1], and anticontactin-associated protein-2 [CASPR2]) at West China Medical Center between June 2012 and December 2018 were enrolled, and a cost-of-illness study was performed retrospectively. Data on clinical characteristics, costs, and utilization of sources were collected from questionnaires and the hospital information system.

Results

Of the 208 patients reviewed, the mean direct cost per patient was renminbi (RMB) 94,129 (United States dollars [USD] 14,219), with an average direct medical cost of RMB 88,373 (USD 13,349). The average inpatient cost per patients with AE was RMB 86,810 (USD 13,113). The direct nonmedical cost was much lower than the direct medical cost, averaging RMB 5,756 (USD 869). The direct cost of anti-LGI1/CASPR2 encephalitis was significantly lower than that of anti-NMDAR encephalitis and anti-GABA_BR encephalitis. The length of stay in the hospital was significantly associated with the direct cost.

Conclusions

The financial burden of AE is heavy for Chinese patients, and there are significant differences between different types of AE.