Outcome of Encephalitis in Pediatric Intensive Care Unit

Neuroimaging and neurological outcome of children with acute encephalitis

AIM

To investigate the severity of acute phase magnetic resonance imaging (MRI) findings and severity of acute illness as risk factors for disability after recovery from encephalitis.

METHOD

Children with encephalitis (n = 98; median age 6 years 10 months, interquartile range 3 years-11 years 6 months; 59 males, 39 females) treated in Turku University Hospital during the years 1995 to 2016 were identified in this retrospective cohort study. The acute phase (<2 months of symptom onset) brain MRIs were re-evaluated and classified based on the severity of neuroimaging finding by a neuroradiologist. Neurological outcome at discharge, at short-term (<3 months from discharge) follow-up, and at long-term (>1 year from discharge) follow-up was assessed from medical records using the Glasgow Outcome Scale.

RESULTS

Long-term recovery was poor in 24 of 82 (29%) children with follow-up data. Two children died, eight had severe disability, and 14 had moderate disability. Acute phase MRI was available for re-evaluation from 74 of 82 patients with follow-up data. The increasing severity of MRI findings was associated with need for ventilator therapy and with poor recovery.

INTERPRETATION

The risk for poor recovery in paediatric encephalitis is high, and it is associated with the severity of MRI findings.

WHAT THIS PAPER ADDS

Poor long-term recovery was found in 29% of children with encephalitis. Severe disability measured by Glasgow Outcome Scale was found in 8%. The most severe neuroimaging findings were a risk factor for severe acute illness and poor long-term recovery.

Epidemiology, Clinical Features, and Unusual Complications of Norovirus Infection in Taiwan: What We Know after Rotavirus Vaccines

Noroviruses (NoVs) are one of the emerging and rapidly spreading groups of pathogens threatening human health. A reduction in sporadic NoV infections was noted following the start of the COVID-19 pandemic, but the return of NoV gastroenteritis during the COVID-19 pandemic has been noted recently. Research in recent years has shown that different virus strains are associated with different clinical characteristics; moreover, there is a paucity of research into extraintestinal or unusual complications that may be associated with NoV. The genomic diversity of circulating NoVs is also complex and may vary significantly. Therefore, this short narrative review focuses on sharing the Taiwan experience of NoV infection including epidemiology, clinical features, and complications following suboptimal rotavirus immunization in Taiwan (after October 2006). We also highlight the unusual complications associated with NoV infections and the impacts of NoV infection during the COVID-19 pandemic in the literature for possible future research directions. To conclude, further research is needed to quantify the burden of NoV across the spectrum of disease severity in Taiwan. The evidence of the connection between NoV and the unusual complications is still lacking.

Clinical Characteristics and Outcomes of Acute Childhood Encephalopathy in a Tertiary Pediatric Intensive Care Unit

AIM

Childhood encephalopathy comprises a wide range of etiologies with distinctive distribution in different age groups. We reviewed the pattern of encephalopathy admitted to the pediatric intensive care unit (PICU) of a tertiary children's hospital.

METHODS

We reviewed the medical records and reported the etiologies, clinical features, and outcomes of children with encephalopathy.

RESULTS

Twenty-four admissions to the PICU between April 2019 and May 2020 were reviewed. The median (interquartile range) age was 10.0 (14.7) years and 62.5% were boys. Confusion (66.7%) was the most common presentation. Adverse effects related to medications (33.3%) and metabolic disease (20.8%) were predominant causes of encephalopathies in our study cohort. Methotrexate was responsible for most of the medication-associated encephalopathy (37.5%), whereas Leigh syndrome, pyruvate dehydrogenase deficiency and Wernicke's encephalopathy accounted for those with metabolic disease. The median Glasgow Coma Scale (GCS) on admission was 12.5 (9.0). Antimicrobials (95.8%) and antiepileptic drugs (60.9%) were the most frequently given treatment. Children aged 2 years or younger were all boys (P = 0.022) and had a higher proportion of primary metabolic disease (P = 0.04). Intoxication or drug reaction only occurred in older children. The mortality was 8.3%, and over half of the survivors had residual neurological disability upon PICU discharge. Primary metabolic disease (P = 0.002), mechanical ventilation (P = 0.019), failure to regain GCS back to baseline level (P = 0.009), and abnormal cognitive function on admission (P = 0.03) were associated with cerebral function impairment on PICU discharge.

CONCLUSIONS

Primary metabolic encephalopathy was prevalent in younger children, whereas drug-induced toxic encephalopathy was common among older oncology patients. Survivors have significant neurologic morbidity. Failure to regain baseline GCS was a poor prognostic factor for neurological outcomes.

Etiological and Clinical Profile of Acute Nonbacterial Encephalitis in Children: A Single-Center Prospective Study

Encephalitis is a serious neurological syndrome caused by inflammation of the brain. The diagnosis can be challenging and etiology remains unidentified in about half of the pediatric cases. We aimed to investigate demographic, clinical, laboratory, electroencephalographic and neuroimaging findings, and outcome of acute encephalitis of nonbacterial etiology. This prospective study included children hospitalized with the diagnosis of acute encephalitis between 2017 and 2019. Microbiological investigations of the cerebrospinal fluid (CSF) were recorded. All CSF specimens were tested for anti-N methyl D-aspartate receptor (NMDAR) antibodies. In total, 31 children aged 10 months to 17 years (median = 6 years) were included. Pathogens were confirmed in CSF in three patients (9.7%): varicella zoster virus, herpes simplex virus type 1 (HSV-1), and both HSV-1 and NMDAR antibodies. Presenting features included encephalopathy (100%), fever (80.6%), seizure (45.2%), focal neurological signs (29%), and ataxia (19.4%). On clinical follow-up of median 9 (6-24) months, six patients showed neurological deficits: together with two patients who died in hospital, total eight (25.8%) patients were considered to have unfavorable outcome. Need for intubation, receiving immunomodulatory treatment, prolonged hospitalization, and high erythrocyte sedimentation rate at admission were associated with unfavorable outcome. The etiology of encephalitis remains unexplained in the majority of children. HSV-1 is the most frequently detected virus, consistent with the literature. The fact that anti-NMDAR encephalitis was detected in one child suggests autoimmune encephalitis not being rare in our center. The outcome is favorable in the majority while about one-fifth of cases suffer from sequelae.

Respiratory Syncytial Virus-Associated Neurologic Complications in Children: A Systematic Review and Aggregated Case Series

OBJECTIVES

To describe the features and frequency of respiratory syncytial virus (RSV)-associated severe acute neurologic disease in children.

STUDY DESIGN

We performed a systematic review of the literature to identify reports of severe acute neurologic complications associated with acute RSV infection in children aged <15 years (PROSPERO Registration CRD42019125722). Main outcomes included neurologic, clinical, and demographic features of cases and the frequency of disease. We aggregated available case data from the published literature and from the Australian Acute Childhood Encephalitis (ACE) study.

RESULTS

We identified 87 unique studies from 26 countries describing a spectrum of RSV-associated severe acute neurologic syndromes including proven encephalitis, acute encephalopathy, complex seizures, hyponatremic seizures, and immune-mediated disorders. The frequency of RSV infection in acute childhood encephalitis/encephalopathy was 1.2%-6.5%. We aggregated data from 155 individual cases with RSV-associated severe acute neurologic complications; median age was 11.0 months (IQR 2.0-21.5), most were previously healthy (71/104, 68%). Seizure was the most frequently reported neurologic feature (127/150, 85%). RSV was detected in the central nervous system of 12 cases. Most children recovered (81/122, 66%); however, some reports described partial recovery (33/122, 27%) and death (8/122, 7%).

CONCLUSIONS

RSV-associated neurologic complications have been widely reported, but there is substantial heterogeneity in the design and quality of existing studies. The findings from our study have implications for the investigation, management, and prevention of RSV-associated neurologic complications. Further, this systematic review can inform the design of future studies aiming to quantify the burden of childhood RSV-associated neurologic disease.

Autoimmune Encephalitis in Children: From Suspicion to Diagnosis

There are several well-described and studied autoimmune diseases that affect different organ systems, and a limited number of these affect the central nervous system. Autoimmune encephalitis represents a disease with a wide spectrum of clinical manifestations and different levels of severity, from mild cognitive impairment to complex encephalopathy. Immune-mediated encephalitis refers to a diverse and rare group of conditions in children associated with nonspecific symptomatology, altered mental state, and recalcitrant seizures. Infectious etiology must be excluded. Immune-mediated encephalitis syndromes could be associated with paraneoplastic or primarily autoimmune mechanisms. The newest scientific advantages have concluded that autoimmune encephalitis may be further divided into different groups of diseases depending on the immune response; examples are antibodies to cell surface proteins, antibodies to intracellular synaptic proteins, T-cell response with antibodies to intracellular antigens, among others. Treatment consists of supportive therapy, ranging from supplemental oxygen, fluid restriction to mechanical circulatory support. Specific treatment includes immunoglobulin infusion, plasmapheresis, and pulse steroid treatment. Prognosis is poor if specific treatment is not timely instituted. The diagnosis of autoimmune encephalitis could be challenging to clinicians due to its diverse clinical features, which can mimic a variety of other pathologic processes. Screening for cancer and proper management that includes immune therapy are fundamental, although some patients will need immune suppression for weeks or months as autoimmune encephalitis may relapse; therefore, follow-up is always necessary.

Childhood Infectious Encephalitis: An Overview of Clinical Features, Investigations, Treatment, and Recent Patents

BACKGROUND

Infectious encephalitis is a serious and challenging condition to manage. This overview summarizes the current literature regarding the etiology, clinical manifestations, diagnosis, management, and recent patents of acute childhood infectious encephalitis.

METHODS

We used PubMed Clinical Queries as a search engine and used keywords of "encephalitis" AND "childhood" Patents were searched using the key term "encephalitis" in google.patents.- com and patentsonline.com.

RESULTS

Viral encephalitis is the most common cause of acute infectious encephalitis in children. In young children, the clinical manifestations can be non-specific. Provision of empiric antimicrobial therapy until a specific infectious organism has been identified, which in most cases includes acyclovir, is the cornerstone of therapy. Advanced investigation tools, including nucleic acid-based test panel and metagenomic next-generation sequencing, improve the diagnostic yield of identifying an infectious organism. Supportive therapy includes adequate airway and oxygenation, fluid and electrolyte balance, cerebral perfusion pressure support, and seizure control. Recent patents are related to the diagnosis, treatment, and prevention of acute infectious encephalitis.

CONCLUSION

Viral encephalitis is the most common cause of acute infectious encephalitis in children and is associated with significant morbidity. Recent advances in understanding the genetic basis and immunological correlation of infectious encephalitis may improve treatment. Third-tier diagnostic tests may be incorporated into clinical practice. Treatment is targeted at the infectious process but remains mostly supportive. However, specific antimicrobial agents and vaccines development is ongoing.

A Population-based Observational Study of Childhood Encephalitis in Children Admitted to Pediatric Intensive Care Units in England and Wales

BACKGROUND

Encephalitis is a serious neurologic condition that can result in admission to intensive care. Yet, there are no studies on pediatric intensive care unit (PICU) admission rates and usage of intensive care resources by children with encephalitis in England and Wales. The objectives of this study were to (1) define the PICU incidence and mortality rates for childhood encephalitis, (2) describe the usage of intensive care resources by children with encephalitis admitted to PICU and (3) explore the associated cost from PICU encephalitis admissions.

METHODS

Retrospective analysis of anonymized data for 1031 children (0-17 years) with encephalitis admitted (January 2003 to December 2013) to PICU in England and Wales.

RESULTS

The PICU encephalitis incidence was 0.79/100,000 population/yr (95% confidence interval [CI]: 0.74-0.84), which gives an annual total of 214 bed days of intensive care occupancy for children admitted with encephalitis and an estimated annual PICU bed cost of £414,230 (interquartile range: 198,111-882,495) for this cohort. PICU encephalitis admissions increased during the study period (annual percentage change = 4.5%, 95% CI: 2.43%-6.50%, P ≤ 0.0001). In total, 808/1024 (78.9%) cases received invasive ventilation while 216/983 (22.0%) and 50/890 (5.6%) cases received vasoactive treatment and renal support, respectively. There were 87 deaths (8.4%), giving a PICU encephalitis mortality rate of 0.07/100,000 population (0-17 years)/yr (95% CI: 0.05-0.08).

CONCLUSIONS

These data suggest that encephalitis places a significant burden to the healthcare service. More work is needed to improve outcomes for children with encephalitis.

Effects of Acyclovir and IVIG on Behavioral Outcomes after HSV1 CNS Infection

Herpes simplex virus 1 (HSV) encephalitis (HSE) has serious neurological complications, involving behavioral and cognitive impairments that cause significant morbidity and a reduced quality of life. We showed that HSE results from dysregulated central nervous system (CNS) inflammatory responses. We hypothesized that CNS inflammation is casually involved in behavioral abnormalities after HSE and that treatment with ACV and pooled human immunoglobulin (IVIG), an immunomodulatory drug, would improve outcomes compared to mice treated with phosphate buffered saline (PBS) or ACV alone. Anxiety levels were high in HSV-infected PBS and ACV-treated mice compared to mice treated with ACV + IVIG, consistent with reports implicating inflammation in anxiety induced by lipopolysaccharide (LPS) or stress. Female, but not male, PBS-treated mice were cognitively impaired, and unexpectedly, ACV was protective, while the inclusion of IVIG surprisingly antagonized ACV's beneficial effects. Distinct serum proteomic profiles were observed for male and female mice, and the antagonistic effects of ACV and IVIG on behavior were paralleled by similar changes in the serum proteome of ACV- and ACV + IVIG-treated mice. We conclude that inflammation and other factors mediate HSV-induced behavioral impairments and that the effects of ACV and IVIG on behavior involve novel mechanisms.

Mortality, length of stay, bloodstream and respiratory viral infections in a pediatric intensive care unit

OBJECTIVES

We investigated whether diagnostic categories and presence of infections were associated with increased mortality or length of stay (LOS) in patients admitted to a pediatric intensive care unit (PICU).

METHODS

A retrospective study of all PICU admissions between October 2002 and April 2016 was performed. Oncologic vs nononcologic, trauma/injuries vs nontraumatic, infectious (gram-positive, gram-negative, fungal bloodstream infections, common respiratory viruses) vs noninfectious diagnoses were evaluated for survival and LOS.

RESULTS

Pediatric intensive care unit admissions (n = 2211) were associated with a mortality of 5.3%. Backward binary logistic regression showed that nonsurvival was associated with leukemia (odds ratio [OR], 4.81; 95% confidence interval [CI], 2.2-10.10; P < .0005), lymphoma (OR, 21.34; 95% CI, 3.89-117.16; P < .0005), carditis/myocarditis (OR, 7.91; 95% CI, 1.98-31.54; P = .003), encephalitis (OR, 6.93; 95% CI, 3.27-14.67; P < .0005), bloodstream infections with gram-positive organisms (OR, 5.32; 95% CI, 2.67-10.60; P < .0005), gram-negative organisms (OR, 8.23; 95% CI, 4.10-16.53; P < .0005), fungi (OR, 3.93; 95% CI, 1.07-14.42; P = .039), and pneumococcal disease (OR, 3.26; 95% CI, 1.21-8.75; P = .019). Stepwise linear regression revealed that LOS of survivors was associated with bloodstream gram-positive infection (B = 98.2; 95% CI, 75.7-120.7; P < .0005).

CONCLUSIONS

Patients with diagnoses of leukemia, lymphoma, cardiomyopathy/myocarditits, encephalitis, and comorbidity of bloodstream infections and pneumococcal disease were significantly at risk of PICU mortality. Length of stay of survivors was associated with bloodstream gram-positive infection. The highest odds for death were among patients with leukemia/lymphoma and bloodstream coinfection. As early diagnosis of these childhood malignancies is desirable but not always possible, adequate and early antimicrobial coverage for gram-positive and gram-negative bacteria might be the only feasible option to reduce PICU mortality in these patients. In Hong Kong, a subtropical Asian city, none of the common respiratory viruses were associated with increased mortality or LOS in PICU.