Clinical characteristics and outcome of clinically diagnosed viral encephalitis in southwest China

Effects of adjunctive Chinese patent medicine on outcome of viral encephalitis in children: A multicenter retrospective study in China

BACKGROUND

Some patients with viral encephalitis in China seek treatment with Chinese patent medicine (CPM) to improve their symptoms, but few studies have focused on the impact of CPM on the prognosis of viral encephalitis (VE). The aim of this multicenter retrospective study was to assess the benefit of adjunctive CPM therapy on the outcome of children with VE in China.

METHODS

This study retrospectively included 834 children with viral encephalitis who were hospitalized at five medical institutions from 2018 to 2021. Univariate and multivariate logistic regression was used to assess the effect of CPM on sequelae in patients with VE. 1:1 propensity score matching was used to exclude the effect of confounding factors. Forest plots were used to observe the effect of CPM on the prognosis of VE in different subgroups.

RESULTS

There were fewer patients with sequelae in the group of patients using CPM regardless of whether they were matched or not. The results of multivariate logistic regression analysis showed that the use of CPM was an independent protective factor for the development of sequelae in VE patients (OR = 0.063, 95 % CI: 0.011-0.350, p = 0.002). Subgroup analyses showed that CPM was a protective factor for the development of sequelae regardless of the presence or absence of coma and comorbidities. In addition, we evaluated other outcome indicators and found shorter duration of illness, fever and headache in children with EV in the CPM group.

CONCLUSION

Adjunctive CPM therapy may significantly reduce sequelae in children with VE, as well as effectively alleviate patients' clinical symptoms. However, more prospective studies and clinical trials are needed to further evaluate its efficacy and safety.

Clinical Outcome Assessments in Encephalitis: A Systematic Review

BACKGROUND AND OBJECTIVES

Most patients with encephalitis experience persisting neurocognitive and neuropsychiatric sequelae in the years following this acute illness. Reported outcomes are often based on generic clinical outcome assessments that rarely capture the patient perspective. This may result in an underestimation of disease-specific sequelae. Disease-specific clinical outcome assessments can improve clinical relevance of reported outcomes and increase the power of research and trials. There are no patient-reported outcome measures (PROMs) developed or validated specifically for patients with encephalitis. The primary objective of this systematic literature review was to identify PROMs that have been developed for or validated in patients with encephalitis.

METHODS

We performed a systematic review of the literature published from inception until May 2023 in 3 large international databases (MEDLINE, EMBASE and Cochrane libraries). Eligible studies should have developed or validated a PROM in patients with encephalitis or encephalopathy. Methodologic quality was evaluated using the Consensus-based Standards for the selection of health status Measurement Instruments study design checklist for PROMs.

RESULTS

We identified no disease-specific PROMs developed or validated for patients with encephalitis. We identified one study on the development and validation of a disease-specific PROM for hepatic encephalopathy, although this disease course is substantially different to that of patients with encephalitis. The methodologic quality of the included study was generally rated as "doubtful." We identified 30 PROMs that have been applied in 46 studies on encephalitis or encephalopathy, although not validated in these populations. The most commonly applied PROMs for measuring Health-Related Quality of Life were the Medical Outcomes Study Short Form-36 and the Sickness Impact Profile. Emotional well-being was often assessed with the Beck Depression Inventory (BDI-II). Sporadically, PROMs were applied to address other aspects of outcome including daily functioning and sleep quality.

DISCUSSION

This systematic review confirms a critical gap in clinical outcome assessments in patients with encephalitis, failing to identify a validated measuring tool for detecting neurocognitive, functional, and health status. It is therefore essential to develop and/or validate disease-specific PROMs for the population with encephalitis to capture relevant information for patient management and clinical trials about the effects of disease that are at risk of being overlooked.

The neutrophil-to-lymphocyte and monocyte-to-lymphocyte ratios are independently associated with clinical outcomes of viral encephalitis

Background

The neutrophil-to-lymphocyte ratio (NLR) and monocyte-to-lymphocyte ratio (MLR) are used as prognostic biomarkers for many diseases. In this study, we aimed to explore the possibility of using ratios of NLR and MLR to predict the prognosis of viral encephalitis (VE).

Methods

A total of 81 patients with an initial diagnosis of VE who were admitted to our hospital from January 2018 to January 2021 were retrospectively analyzed. A routine blood test within 24 h of admission was utilized to determine the ratios of NLR and MLR for each patient. The modified Rankin Scale (mRS) at 12 months after discharge was used to evaluate patients' clinical prognosis and the patients were divided into the group of good prognosis (mRS ≤ 1) and the group of poor prognosis (mRS ≥ 2) according to the mRS scores. Univariate and multivariable regression analyses were used to differentiate and assess independent prognostic factors for the prognosis of VE.

Results

Neutrophil-to-lymphocyte ratio and MLR of the poor prognosis group were significantly higher than that of the good prognosis group. Multivariate logistic regression analysis results showed that NLR [odds ratio (OR): 1.421, 95% confidence interval (CI): 1.105-1.827; P < 0.05] and MLR (OR: 50.423, 95% CI: 2.708-939.001; P < 0.05) were independent risk factors for the poor prognosis of VE. NLR > 4.32 and MLR > 0.44 were suggested as the cutoff threshold for the prediction of the poor prognosis of VE.

Conclusion

Neutrophil-to-lymphocyte ratio and MLR obtained from blood tests done at hospital admission have the potential to predict poor prognosis in patients with VE.

Construction of an Assisted Model Based on Natural Language Processing for Automatic Early Diagnosis of Autoimmune Encephalitis

Introduction

Early diagnosis and etiological treatment can effectively improve the prognosis of patients with autoimmune encephalitis (AE). However, anti-neuronal antibody tests which provide the definitive diagnosis require time and are not always abnormal. By using natural language processing (NLP) technology, our study proposes an assisted diagnostic method for early clinical diagnosis of AE and compares its sensitivity with that of previously established criteria.

Methods

Our model is based on the text classification model trained by the history of present illness (HPI) in electronic medical records (EMRs) that present a definite pathological diagnosis of AE or infectious encephalitis (IE). The definitive diagnosis of IE was based on the results of traditional etiological examinations. The definitive diagnosis of AE was based on the results of neuronal antibodies, and the diagnostic criteria of definite autoimmune limbic encephalitis proposed by Graus et al. used as the reference standard for antibody-negative AE. First, we automatically recognized and extracted symptoms for all HPI texts in EMRs by training a dataset of 552 cases. Second, four text classification models trained by a dataset of 199 cases were established for differential diagnosis of AE and IE based on a post-structuring text dataset of every HPI, which was completed using symptoms in English language after the process of normalization of synonyms. The optimal model was identified by evaluating and comparing the performance of the four models. Finally, combined with three typical symptoms and the results of standard paraclinical tests such as cerebrospinal fluid (CSF), magnetic resonance imaging (MRI), or electroencephalogram (EEG) proposed from Graus criteria, an assisted early diagnostic model for AE was established on the basis of the text classification model with the best performance.

Results

The comparison results for the four models applied to the independent testing dataset showed the naïve Bayesian classifier with bag of words achieved the best performance, with an area under the receiver operating characteristic curve of 0.85, accuracy of 84.5% (95% confidence interval [CI] 74.0–92.0%), sensitivity of 86.7% (95% CI 69.3–96.2%), and specificity of 82.9% (95% CI 67.9–92.8%), respectively. Compared with the diagnostic criteria proposed previously, the early diagnostic sensitivity for possible AE using the assisted diagnostic model based on the independent testing dataset was improved from 73.3% (95% CI 54.1–87.7%) to 86.7% (95% CI 69.3–96.2%).

Conclusions

The assisted diagnostic model could effectively increase the early diagnostic sensitivity for AE compared to previous diagnostic criteria, assist physicians in establishing the diagnosis of AE automatically after inputting the HPI and the results of standard paraclinical tests according to their narrative habits for describing symptoms, avoiding misdiagnosis and allowing for prompt initiation of specific treatment.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40120-022-00355-7.

Etiological and epidemiological features of acute meningitis or encephalitis in China: a nationwide active surveillance study

BACKGROUND

Acute meningitis or encephalitis (AME) results from a neurological infection causing high case fatality and severe sequelae. AME lacked comprehensive surveillance in China.

METHODS

Nation-wide surveillance of all-age patients with AME syndromes was conducted in 144 sentinel hospitals of 29 provinces in China. Eleven AME-causative viral and bacterial pathogens were tested with multiple diagnostic methods.

FINDINGS

Between 2009 and 2018, 20,454 AME patients were recruited for tests. Based on 9,079 patients with all-four-virus tested, 28.43% (95% CI: 27.50%‒29.36%) of them had at least one virus-positive detection. Enterovirus was the most frequently determined virus in children <18 years, herpes simplex virus and Japanese encephalitis virus were the most frequently determined in 18-59 and ≥60 years age groups, respectively. Based on 6,802 patients with all-seven-bacteria tested, 4.43% (95% CI: 3.94%‒4.91%) had at least one bacteria-positive detection, Streptococcus pneumoniae and Neisseria meningitidis were the leading bacterium in children aged <5 years and 5-17 years, respectively. Staphylococcus aureus was the most frequently detected in adults aged 18-59 and ≥60 years. The pathogen spectrum also differed statistically significantly between northern and southern China. Joinpoint analysis revealed age-specific positive rates, with enterovirus, herpes simplex virus and mumps virus peaking at 3-6 years old, while Japanese encephalitis virus peaked in the ≥60 years old. As age increased, the positive rate for Streptococcus pneumoniae and Escherichia coli statistically significantly decreased, while for Staphylococcus aureus and Streptococcus suis it increased.

INTERPRETATION

The current findings allow enhanced identification of the predominant AME-related pathogen candidates for diagnosis in clinical practice and more targeted application of prevention and control measures in China, and a possible reassessment of vaccination strategy.

FUNDING

China Mega-Project on Infectious Disease Prevention and the National Natural Science Funds.

Comparison of functional outcome scales in paediatric acute encephalitis: Responsiveness and outcome predictors

PURPOSE

To compare scoring systems and their ability to capture short and long-term recovery of paediatric patients with acute encephalitis. To identify clinical predictors of short-term outcomes by correlating functional outcome measures at 1 month post diagnosis of acute encephalitis.

METHODS

Patients with encephalitis diagnosed between July 2011 and 2016 based on Granerod's criteria were studied in this retrospective cohort study. Functional outcome scores on WeeFIM, LOS, GOS-E, mRS and ICF at initial presentation and 1, 3, 6 and 12 months later were compared.

RESULTS

WeeFIM and LOS scores both showed maximum change in the first 3 months, reflecting highest recovery in this period. With WeeFIM, the greatest change occurred within the first month following diagnosis. On univariate analysis, seizure frequency in the first month, presence of movement disorder, presence of autonomic dysfunction and lower baseline functional score was associated with poorer WeeFIM scores at 1 month. The latter three variables remained statistically significant on multivariate analysis.

CONCLUSION

WeeFIM is a potentially preferred functional outcome assessment tool as it demonstrated greatest recovery within the first month due to a trend of high responsiveness and relatively low ceiling effect. Presence of autonomic dysfunction and movement disorders at diagnosis correlated with poorer outcome at 1 month post diagnosis.

Seizures and epilepsy secondary to viral infection in the central nervous system

Viral infection in the central nervous system (CNS) is a common cause of seizures and epilepsy. Acute symptomatic seizures can occur in the context of almost all types of acute CNS viral infection. However, late unprovoked seizures and epilepsy may not be frequent after viral infection of the CNS. The incidence of seizures and epilepsy after CNS viral infection is mainly dependent on the brain region of infection. It remains to be determined whether treatment of CNS viral infection using antiepileptic drugs (AEDs) can prevent seizures and subsequent epilepsy in patients, particularly with regard to the timing, drug choice and dosage, and duration of AEDs. The postoperative outcome of seizures in patients with intractable epilepsy caused by viral encephalitis primarily depends on the epileptogenic zone. In addition, neuroinflammation is known to be widely involved in the generation of seizures during CNS viral infection, and the effects of anti-inflammatory therapies in preventing seizures and epilepsy secondary to CNS viral infection require further studies. In this review, we discuss the incidence, mechanisms, clinical management and prognosis of seizures and epilepsy secondary to CNS viral infection, and summarize common CNS viral infections that cause seizures and epilepsy.

Predictors of Outcome in Clinically Diagnosed Viral Encephalitis Patients: A 5-Year Prospective Study

Background

Viral encephalitis is the most common infectious disease of the central nervous system and is associated with high morbidity, mortality, and disability. The objective of this study was to analyze the clinical characteristics, auxiliary examinations, therapeutic management, and outcomes of patients clinically diagnosed with viral encephalitis and identify the outcome predictors.

Methods

We conducted a prospective observational study by collecting information from patients clinically diagnosed with viral encephalitis at the First Affiliated Hospital of Chongqing Medical University and Yongchuan Hospital of Chongqing Medical University from January 2013 to December 2018. Univariate and multivariate analyses were performed to identify factors that influenced good patient outcomes (mRS < 3) and poor patient outcomes (mRS ≥ 3) at discharge.

Results

In total, 216 patients were enrolled in the study. The multivariate analysis suggested that the following factors were associated with a poor outcome: Glasgow Coma Scale (GCS) score (OR 0.154, 95% CI (0.078-0.302), and P < 0.001), focal neurological deficits (OR 9.403, 95% CI (1.581-55.928), and P = 0.014), and total length of hospital stay (OR 1.119, 95% CI (1.002-1.250), and P = 0.045). However, neurological intensive care unit (NICU) treatment, status epilepticus, and abnormal electroencephalogram (EEG) findings did not influence the prognosis of patients.

Conclusion

Our study suggests that low GCS scores at admission, focal neurological deficits at admission, and a prolonged total hospital stay are predictors of a poor outcome at discharge in clinically diagnosed viral encephalitis patients. Whether early and effective neurological rehabilitation can improve the prognosis of viral encephalitis patients with focal neurological deficits remains to be confirmed in further studies.

Seizure Characteristics, Outcome, and Risk of Epilepsy in Pediatric Anti-N-Methyl-d-Aspartate Receptor Encephalitis

BACKGROUND

We identified seizure characteristics, long-term outcome, and predictors of persistent seizures in children with anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis.

METHOD

Data were analyzed from patients with anti-NMDAR encephalitis who presented with seizures at our center between August 2012 and June 2018.

RESULTS

Sixty-two of 86 patients with anti-NMDAR encephalitis experienced seizures. Seizures occurred within two weeks of disease onset in 58 of 62 (93.6%) patients; 36 of 62 (58.1%) had seizures as the initial symptom. Males were more likely to exhibit seizures as the initial symptom (P = 0.039). More than a quarter of patients (17 of 62, 27.4%) manifested two or more seizure types. Focal seizures were the most common (46 of 62, 74.2%). Status epilepticus occurred in 27 of 62 (43.5%) patients, and nonconvulsive status epilepticus, in two of 62 (3.2%) patients. No patient developed refractory status epilepticus. No systemic tumors were found. Electroencephalographic abnormalities included background slowing (77.4%), absence of a posterior dominant rhythm (62.9%), interictal epileptic discharges (50.0%), and extreme delta brush (6.5%). In the acute phase, 45 patients (45 of 62, 72.6%) received antiepileptic drugs. Persistent seizures occurred in only five of 62 (8%) patients. On univariate analysis, status epilepticus and combination antiepileptic drug treatment were associated with persistent seizures, but neither independently predicted persistent seizures.

CONCLUSIONS

Multiple seizure types may develop at any stage of anti-N-methyl-d-aspartate receptor encephalitis. Refractory status epilepticus, systemic tumors, and extreme delta brush in electroencephalography are rare in pediatric patients. Anti-NMDAR encephalitis-associated seizures appear to have good prognosis, without the need for long-term antiepileptic drug treatment.

Evaluation of the BioFire FilmArray meningitis/encephalitis panel for the detection of bacteria and yeast in Chinese children

Background

Meningitis and encephalitis are life-threatening syndromes with high morbidity and mortality in children. Due to limitations of traditional laboratory approaches in etiological diagnosis, the rate of misdiagnoses is unacceptably high.

Methods

We retrospectively compared the potential clinical impact of the FilmArray meningitis/encephalitis (ME) panel vs. conventional cerebrospinal fluid (CSF) culture in children with central nervous system (CNS) infections. Sixty-eight pediatric patients (<18 years of age) with an initial diagnosis of meningitis or encephalitis were enrolled at 2 children's hospital from January to October 2017.

Results

Fifteen specimens were found to be positive after CSF culture, with a positive rate of 22.1% (15/68). For the FilmArray ME panel, 26 bacteria and fungi from 25 samples were detected, and the positive rate was 36.8% (25/68). The FilmArray ME panel identified 14 pathogens in previously pathogen-negative patients.

Conclusions

This study demonstrated the capability of the FilmArray ME panel in the diagnosis of bacterial and fungal meningitis and therefore its potential use in facilitating enhanced patient care.

Evaluation of Clinical and Paraclinical Findings for the Differential Diagnosis of Autoimmune and Infectious Encephalitis

Background: The differential diagnosis of autoimmune and infectious encephalitis is notoriously difficult. For this study, we compare the presenting clinical symptoms and paraclinical test results of autoimmune and infectious encephalitis patients. A clinical algorithm for the diagnosis of autoimmune encephalitis has recently been published. We test these Graus criteria on our cohort for diagnostic sensitivity and specificity within the first week of presentation. Methods: We included all patients seen at our department within a 10-year-period who were diagnosed with encephalitis. The discharge diagnoses served as the reference standard for testing the clinical algorithm for two conditions: use of all the clinical information available on a patient during the first week of hospital admission assuming undefined autoantibody status and microbiological test results (C1) vs. consideration of all the information available on a patient, including the results of serological and microbiological testing (C2). Results: Eighty-four patients (33 autoimmune, 51 infectious encephalitis) were included in the study. Fifty-one (17 autoimmune, 34 infectious) had a definite clinical diagnosis. The two groups differed significantly for the presence of headache, fever, epileptic seizures, and CSF cell-count at presentation. Application of the clinical algorithm resulted in a low sensitivity (58%) and very low specificity (8%) for the diagnosis of possible autoimmune encephalitis. The latter increased considerably in the subgroups of probable and definite autoimmune encephalitis. Whereas the sensitivity of the individual diagnostic categories was clearly time-dependent, the specificity rested foremost on the knowledge of the results of microbiological testing. Anti-CASPR2- and -LGI1-associated autoimmune encephalitis and tick-borne virus encephalitis presented particular diagnostic pitfalls. Conclusions: We define clinical symptoms and paraclinical test results which prove valuable for the differentiation between infectious and autoimmune encephalitis. Sensitivity and specificity of the clinical algorithm clearly depended on the amount of time passed after hospital admission and knowledge of microbiological test results. Accepting this limitation for the acute setting, the algorithm remains a valuable diagnostic aid for antibody-negative autoimmune encephalitis or in resource-poor settings. The initiation of immune therapy however should not be delayed if an autoimmune etiology is considered likely, even if the diagnostic criteria of the algorithm are not (yet) fulfilled.

Low TT4 as a predictor of poor outcomes in severe encephalitis: a multivariate analysis of 94 patients

BACKGROUND

To investigate the prognostic value of acute thyroid function in patients with severe encephalitis.

METHODS

We retrospectively analyzed information from patients with severe encephalitis from June 2012 to June 2017. Using multivariate logistic regression analysis, we examined predictors of poor outcomes in these patients after 6 months.

RESULTS

A total of 94 patients with severe encephalitis were included in the study. Univariate analysis showed that patients with good or poor outcomes had significantly different total thyroxine (TT4) (P = 0.012) and free triiodothyronine (FT3) (P = 0.049) levels, mechanical ventilation requirements (P < 0.001), pulmonary infection complications (P = 0.001), lengths of neurological intensive care unit (P = 0.003) and total hospital (P = 0.012) stay, and Acute Physiology and Chronic Health Evaluation (APACHE II) (P = 0.005) and Glasgow Coma Scale (GCS) (P = 0) scores. The results of multivariate analysis suggested the following factors to be associated with a poor outcome: a low TT4 level (OR 0.303, 95% CI 0.100-0.923) and a low GCS score (OR 0.683, 95% CI 0.506-0.923).

CONCLUSIONS

Low TT4 has a predictive value for the adverse outcomes of severe encephalitis; further study is needed for verification.

Etiology and prognosis of acute viral encephalitis and meningitis in Chinese children: a multicentre prospective study

BACKGROUND

In China, there were few studies about the pathogens of acute viral encephalitis and meningitis in children in recent years. The aims of this study were to characterize the etiology and prognosis of acute viral encephalitis and meningitis in Chinese children.

METHODS

This was a multicentre prospective study. Two hundred and sixty one viral encephalitis patients and 285 viral meningitis patients were enrolled. The mean age of viral encephalitis and meningitis were 5.88 ± 3.60 years and 6.39 ± 3.57 years, respectively. Real-time reverse transcription PCR and multiplex PCR were used to detect human enteroviruses and herpes viruses in cerebrospinal fluid (CSF) of patients with encephalitis or meningitis. The enzyme-linked immune absorbent assay (ELISA) was used for detecting IgM antibody against Japanese encephalitis virus (JEV) in CSF and against mumps virus, tick-borne encephalitis virus (TBEV), dengue virus and rubella virus in acute serum. The clinical and outcome data were collected during patients' hospitalization.

RESULTS

The etiology of viral encephalitis was confirmed in 52.5% patients. The primary pathogen was human enteroviruses (27.7%) in viral encephalitis. The incidence of sequelae and the fatality rate of viral encephalitis with confirmed etiology were 7.5% and 0.8%, respectively. The etiology of viral meningitis was identified in 42.8% cases. The leading pathogen was also human enteroviruses (37.7%) in viral meningitis. The prognosis of viral meningitis was favorable with only 0.7% patients had neurological sequelae.

CONCLUSIONS

Human enteroviruses were the leading cause both in acute viral encephalitis and viral meningitis in children. The incidence of sequelae and fatality rate of viral encephalitis with confirmed etiology were 7.5% and 0.8%, respectively. The prognosis of viral meningitis was favorable compared to viral encephalitis.