Comparison of CSF and MRI Findings among Neonates and Infants with E coli or Group B Streptococcal Meningitis

The Epidemiology, Management and Therapeutic Outcomes of Subdural Empyema in Neonates with Acute Bacterial Meningitis

Background: Subdural empyema is one of the more serious complications of bacterial meningitis and therapeutic challenges to clinicians. We aimed to evaluate the clinical characteristics, treatment, and outcome of subdural empyema in neonates with bacterial meningitis. Methods: A retrospective cohort study was conducted in two medical centers in Taiwan that enrolled all cases of neonates with subdural empyema after bacterial meningitis between 2003 and 2020. Results: Subdural empyema was diagnosed in 27 of 153 (17.6%) neonates with acute bacterial meningitis compared with cases of meningitis without subdural empyema. The demographics and pathogen distributions were comparable between the study group and the controls, but neonates with subdural empyema were significantly more likely to have clinical manifestations of fever (85.2%) and seizure (81.5%) (both p values < 0.05). The cerebrospinal fluid results of neonates with subdural empyema showed significantly higher white blood cell counts, lower glucose levels and higher protein levels (p = 0.011, 0.003 and 0.006, respectively). Neonates with subdural empyema had a significantly higher rate of neurological complications, especially subdural effusions and periventricular leukomalacia. Although the final mortality rate was not increased in neonates with subdural empyema when compared with the controls, they were often treated much longer and had a high rate of long-term neurological sequelae. Conclusions: Subdural empyema is not uncommon in neonates with acute bacterial meningitis and was associated with a high risk of neurological complications, although it does not significantly increase the final mortality rate. Close monitoring of the occurrence of subdural empyema is required, and appropriate long-term antibiotic treatment after surgical intervention may lead to optimized outcomes.

The Clinical Characteristics, Microbiology and Risk Factors for Adverse Outcomes in Neonates with Gram-Negative Bacillary Meningitis

Background: We aimed to describe the clinical features of Gram-negative bacillary (GNB) meningitis in neonates and investigate the risk factors associated with final adverse outcomes of neonatal GNB meningitis. Methods: From 2003 to 2020, all neonates (aged ≤ 90 days old) with bacterial meningitis who were hospitalized in four tertiary-level neonatal intensive care units (NICUs) of two medical centers in Taiwan were enrolled. Neonates with GNB meningitis were compared with those with Streptococcus agalactiae (group B streptococcus, GBS) meningitis. Results: During the study period, a total of 153 neonates with bacterial meningitis were identified and enrolled. GNB and GBS accounted for 40.5% (n = 62) and 35.3% (n = 54) of all neonatal bacterial meningitis, respectively. In neonates with GNB meningitis, the final mortality rate was 6.5% (4 neonates died); 48 (77.4%) had neurological complications, and 26 (44.8%) of 58 survivors had neurological sequelae at discharge. Although the final outcomes were comparable between neonates with GNB meningitis and those with GBS meningitis, neonates with GNB meningitis were more likely to have more severe clinical manifestations initially and have ventriculomegaly at follow-up. After multivariate logistic regression analysis, neonates with seizure at onset, early onset sepsis, and requirement of surgical intervention for neurological complications were independently associated with final adverse outcomes. Conclusions: GNB meningitis was associated with a high risk of neurological complications and sequelae, although it did not significantly increase the final mortality rate. Close monitoring of the occurrence of neurological complications and advanced therapeutic strategies to optimize the outcomes are urgently needed in the future.

Intrauterine and Perinatal Infections

Imaging plays an important role in evaluating patients with suspected intrauterine and perinatal infections. Advances in fetal imaging including both ultrasound and MRI allow for increasingly more specific diagnosis if the radiologist is familiar with specific imaging features and patterns. Early imaging of neonates with suspected central nervous system infection is valuable to enable prompt treatment and differentiate infection from other conditions which can clinically present similarly. Ultrasound is a useful initial modality to screen for abnormalities however MRI with and without contrast remains the optimal examination to characterize infection, evaluate for potential surgical targets, and provide prognostic information.

Diagnostic Accuracy of MRI for Detection of Meningitis in Infants

PURPOSE

To determine the accuracy of MR imaging for diagnosis of meningitis in infants.

MATERIALS AND METHODS

Retrospective review of infants less than 1 year of age who underwent a brain MR imaging for meningitis from 2010-2018. Gold standard for diagnosis of bacterial meningitis was a positive bacterial CSF culture or a positive blood culture with an elevated CSF WBC count, and diagnosis of viral meningitis was a positive CSF PCR result and elevated CSF WBC count. Sensitivity, specificity, PPV, NPV, and accuracy for MR imaging diagnosis of meningitis were calculated.

RESULTS

Two hundred nine infants with mean age 80 days (range 0-347 days) were included. There were 178 true positives with the most common pathogens being: Group B Streptococcus (58), E. coli (50), Streptococcus pneumoniae (21), H. influenzae (4); Herpes simplex virus 1 or 2 (18); Enterovirus (4); and other (23). There were 31 true negatives. Range of sensitivity, specificity, PPV, NPV, and accuracy of MR imaging for detection of meningitis was 67.4-83.5%, 92.3-95.7%, 95.0-98.6%, 33.3-76.5%, and 71.3-86.5% respectively. MR imaging sensitivity decreased after 10 days from time of presentation while specificity remained stable. Among individual MR imaging findings, leptomeningeal enhancement was the most sensitive finding, while cerebritis, infarction, ventriculitis, abscess, and intraventricular purulent material were the most specific findings.

CONCLUSIONS

MR imaging of the brain demonstrates high specificity and moderate sensitivity for diagnosis among infants presenting with signs and symptoms of meningitis. The results reflect current standard of care for imaging of infants with meningitis however a selection bias for imaging of more severe meningitis may affect these results.

Group B Streptococcal Neonatal Meningitis

Neonatal bacterial meningitis is a devastating disease, associated with high mortality and neurological disability, in both developed and developing countries. Streptococcus agalactiae, commonly referred to as group B Streptococcus (GBS), remains the most common bacterial cause of meningitis among infants younger than 90 days. Maternal colonization with GBS in the gastrointestinal and/or genitourinary tracts is the primary risk factor for neonatal invasive disease. Despite prophylactic intrapartum antibiotic administration to colonized women and improved neonatal intensive care, the incidence and morbidity associated with GBS meningitis have not declined since the 1970s. Among meningitis survivors, a significant number suffer from complex neurological or neuropsychiatric sequelae, implying that the pathophysiology and pathogenic mechanisms leading to brain injury and devastating outcomes are not yet fully understood. It is imperative to develop new therapeutic and neuroprotective approaches aiming at protecting the developing brain. In this review, we provide updated clinical information regarding the understanding of neonatal GBS meningitis, including epidemiology, diagnosis, management, and human evidence of the disease's underlying mechanisms. Finally, we explore the experimental models used to study GBS meningitis and discuss their clinical and physiologic relevance to the complexities of human disease.

Expert consensus on the clinical practice of neonatal brain magnetic resonance imaging

In recent years, magnetic resonance imaging (MRI) has been widely used in evaluating neonatal brain development, diagnosing neonatal brain injury, and predicting neurodevelopmental prognosis. Based on current research evidence and clinical experience in China and overseas, the Neonatologist Society of Chinese Medical Doctor Association has developed a consensus on the indications and standardized clinical process of neonatal brain MRI. The consensus has the following main points. (1) Brain MRI should be performed for neonates suspected of hypoxic-ischemic encephalopathy, intracranial infection, stroke and unexplained convulsions; brain MRI is not considered a routine in the management of preterm infants, but it should be performed for further evaluation when cranial ultrasound finds evidence of brain injury; as for extremely preterm or extremely low birth weight infants without abnormal ultrasound findings, it is recommended that they should undergo MRI examination at term equivalent age once. (2) Neonates should undergo MRI examination in a non-sedated state if possible. (3) During MRI examination, vital signs should be closely monitored to ensure safety; the necessity of MRI examination should be strictly evaluated for critically ill neonates, and magnetic resonance compatible incubator and ventilator can be used. (4) At present, 1.5 T or 3.0 T equipment can be used for neonatal brain MRI examination, and the special coil for the neonatal head should be used to improve signal-to-noise ratio; routine neonatal brain MRI sequences should at least include axial T1 weighted image (T1WI), axial T2 weighted imaging (T2WI), diffusion-weighted imaging, and sagittal T1WI or T2WI. (5) It is recommended to use a structured and graded reporting system, and reports by at least two reviewers and multi-center collaboration are recommended to increase the reliability of the report.

Leptomeningeal enhancement in multiple sclerosis and other neurological diseases: A systematic review and Meta-Analysis

BACKGROUND

The lack of systematic evidence on leptomeningeal enhancement (LME) on MRI in neurological diseases, including multiple sclerosis (MS), hampers its interpretation in clinical routine and research settings.

PURPOSE

To perform a systematic review and meta-analysis of MRI LME in MS and other neurological diseases.

MATERIALS AND METHODS

In a comprehensive literature search in Medline, Scopus, and Embase, out of 2292 publications, 459 records assessing LME in neurological diseases were eligible for qualitative synthesis. Of these, 135 were included in a random-effects model meta-analysis with subgroup analyses for MS.

RESULTS

Of eligible publications, 161 investigated LME in neoplastic neurological (n = 2392), 91 in neuroinfectious (n = 1890), and 75 in primary neuroinflammatory diseases (n = 4038). The LME-proportions for these disease classes were 0.47 [95%-CI: 0.37-0.57], 0.59 [95%-CI: 0.47-0.69], and 0.26 [95%-CI: 0.20-0.35], respectively. In a subgroup analysis comprising 1605 MS cases, LME proportion was 0.30 [95%-CI 0.21-0.42] with lower proportions in relapsing-remitting (0.19 [95%-CI 0.13-0.27]) compared to progressive MS (0.39 [95%-CI 0.30-0.49], p = 0.002) and higher proportions in studies imaging at 7 T (0.79 [95%-CI 0.64-0.89]) compared to lower field strengths (0.21 [95%-CI 0.15-0.29], p < 0.001). LME in MS was associated with longer disease duration (mean difference 2.2 years [95%-CI 0.2-4.2], p = 0.03), higher Expanded Disability Status Scale (mean difference 0.6 points [95%-CI 0.2-1.0], p = 0.006), higher T1 (mean difference 1.6 ml [95%-CI 0.1-3.0], p = 0.04) and T2 lesion load (mean difference 5.9 ml [95%-CI 3.2-8.6], p < 0.001), and lower cortical volume (mean difference -21.3 ml [95%-CI -34.7--7.9], p = 0.002).

CONCLUSIONS

Our study provides high-grade evidence for the substantial presence of LME in MS and a comprehensive panel of other neurological diseases. Our data could facilitate differential diagnosis of LME in clinical settings. Additionally, our meta-analysis corroborates that LME is associated with key clinical and imaging features of MS. PROSPERO No: CRD42021235026.

Predictors of Neurodevelopmental Impairment After Neonatal Bacterial Meningitis

BACKGROUND

Neonatal bacterial meningitis has high rates of morbidity and mortality. Early clinical signs and neuroimaging suggest adverse outcomes, but little is known about their combined predictive properties. We evaluated the combination of findings most associated with death and neurodevelopmental impairment.

METHODS

Single-center retrospective cohort study of term and late preterm neonates with bacterial meningitis. Predictors of death and neurodevelopmental impairment were identified on univariate analysis and incorporated into Lasso models to identify variables best predicting adverse outcomes.

RESULTS

Of 103 neonates, 6 died acutely; 30% of survivors had neurodevelopmental impairment. Clinical variables (seizures, pressor support) predicted death and neurodevelopmental impairment better than the neuroimaging or combined findings (area under the curve 0.88 vs 0.79 and 0.83, respectively). Among survivors, neuroimaging findings (cerebrovascular lesions, ventriculomegaly) predicted neurodevelopmental impairment better than clinical or combined findings (area under the curve 0.82 vs 0.80 and 0.77, respectively).

CONCLUSIONS

Seizures are important predictors of adverse outcomes in neonatal bacterial meningitis. Among survivors, neuroimaging findings help predict neurodevelopmental impairment.

Neonatal encephalopathy: Etiologies other than hypoxic-ischemic encephalopathy

Neonatal encephalopathy (NE) describes the clinical syndrome of a newborn with abnormal brain function that may result from a variety of etiologies. HIE should be distinguished from neonatal encephalopathy due to other causes using data gathered from the history, physical and neurological exam, and further investigations. Identifying the underlying cause of encephalopathy has important treatment implications. This review outlines conditions that cause NE and may be mistaken for HIE, along with their distinguishing clinical features, pathophysiology, investigations, and treatments. NE due to brain malformations, vascular causes, neuromuscular causes, genetic conditions, neurogenetic disorders and inborn errors of metabolism, central nervous system (CNS) and systemic infections, and toxic/metabolic disturbances are discussed.

Colibactin in avian pathogenic Escherichia coli contributes to the development of meningitis in a mouse model

Colibactin is synthesized by a 54-kb genomic island, leads to toxicity in eukaryotic cells, and plays a vital role in many diseases, including neonatal sepsis and meningitis. Avian pathogenic Escherichia coli (APEC) is speculated to be an armory of extraintestinal pathogenic Escherichia coli and can be a potential zoonotic bacterium that threatens human and animal health. In this study, the APEC XM meningitis mouse model was successfully established to investigate the effect of colibactin in in vivo infection. The clbH-deletion mutant strain induced lower γ-H2AX expression, no megalocytosis, and no cell cycle arrest in bEnd.3 cells, which showed that the deletion of clbH decreased the production of colibactin in the APEC XM strain. The deletion of clbH did not affect the APEC XM strain’s ability of adhering to and invading bEnd.3 cells. In vitro, the non-colibactin-producing strain displayed significantly lower serum resistance and it also induced a lower level of cytokine mRNA and few disruptions of tight junction proteins in infected bEnd.3 cells. Meningitis did not occur in APEC ΔclbH-infected mice in vivo, who showed fewer clinical symptoms and fewer lesions on radiological and histopathological analyses. Compared with the APEX XM strain, APEC ΔclbH induced lower bacterial colonization in tissues, lower mRNA expression of cytokines in brain tissues, and slight destruction of the brain blood barrier. These results indicate that clbH is a necessary component for the synthesis of genotoxic colibactin, and colibactin is related to the development of meningitis induced by APEC XM.

Risk Factors for Hydrocephalus in Neonatal Purulent Meningitis: A Single-Center Retrospective Analysis

OBJECTIVE

Hydrocephalus is a potentially lethal complication of neonatal purulent meningitis. Early detection of hydrocephalus helps to determine optimal treatment, improve prognosis, and reduce financial burden. We aimed to analyze the risk factors for hydrocephalus in neonates with purulent meningitis and discuss the characteristics of the disease.

METHODS

The records of neonatal purulent meningitis admitted to the Children Hospital of Fudan University from January 2013 to September 2019 were retrospectively included in the study cohort. The data of clinical, laboratory, and cranial magnetic resonance images (MRIs) were collected and analyzed (except discharge data) by univariate analysis, and P values <.05 were further analyzed by multivariate logistic regression.

RESULTS

A total of 197 children who met the inclusion criteria were enrolled in the study cohort. Overall, 39.6% (78/197) of the patients had positive pathogen cultures, and 60.4% (119/197) of patients had clinical diagnosis of meningitis with negative pathogen cultures. Among 197 children, 67 of them experienced hydrocephalus, and the factors that were significantly associated with hydrocephalus in multivariate analysis were female sex, cerebrospinal fluid glucose <2 mmol/L, periventricular leukomalacia, punctate white matter lesions, and pyogenic intraventricular empyema. Children with hydrocephalus had a lower cure rate of meningitis (31.3% vs 75.4%), and poor discharge outcomes. In addition, they had longer length of hospital stay and higher hospital cost.

CONCLUSIONS

Female sex, cerebrospinal fluid glucose <2 mmol/L, periventricular leukomalacia, punctate white matter lesions, and pyogenic intraventricular empyema were identified as risk factors for hydrocephalus in neonatal purulent meningitis. Children with hydrocephalus had poor discharge outcomes and increased financial burden on their families.

Fatal Multiorgan Failure Syndrome in a Strongyloides-HTLV-1 Coinfected Patient, after Treatment with Ivermectin

Because of its characteristic features of autoinfection, the parasitic nematode Strongyloides stercoralis can infect patients for years. An acceleration of its autoinfective cycle can be triggered by human T-lymphotropic virus-1 (HTLV-1) infection, mainly by the deviation of the protective Th2- to Th1-type immune response and can lead to severe disease by dissemination of Strongyloides stercoralis larvae carrying intestinal bacteria to multiple organs. Meningitis caused by enteric Gram-negative bacteria is a potentially fatal complication of disseminated strongyloidiasis. Herein, we present the case of a Strongyloides-HTLV-1 coinfected patient, admitted for E. coli meningitis. One day after initiation of ivermectin, the patient developed significant S. stercoralis dissemination, complicated by multiorgan failure syndrome, and died from neurological failure. While the initial clinical scenario of our case has already been well described in the literature, its course after antihelminthic treatment initiation remains unclear and needs to be discussed.