Acute encephalitis

Neurocognitive outcome in children and adolescents following infectious encephalitis

Infectious encephalitis in children is fairly uncommon, but unfavorable outcomes are seen in many survivors. The aim of this study was to prospectively describe the long-term neurocognitive consequences following infectious encephalitis in childhood. Children admitted to a primary and tertiary hospital in Sweden between 2011 and 2016 were asked to participate. Fifty-nine children were assessed at a median time of 18 months (IQR 18-20) after hospitalization. Follow-up included measures of intellectual functioning, attention, working memory, and executive functions. Caregiver ratings of executive functioning and behavioral - emotional symptoms were assessed with standardized questionnaires. Neurocognitive outcome and measures of executive functions and behavioral-emotional symptoms varied greatly among participants. Basic auditory attention, working memory, and mental processing speed were affected and significantly lower compared to a standardized mean. Other domains identified as areas of vulnerability included executive functions, sustained attention, and the exert of self-control. Behavioral-emotional symptoms were less common; however, somatic complaints and behaviors related to conduct problems were seen in about one-third of individuals. This study highlights the importance of a comprehensive neurocognitive examination to identify children with unfavorable outcomes.

Seasonal Trends in the Prevalence and Incidence of Viral Encephalitis in Korea (2015-2019)

Viral infections are a common cause of encephalitis. This study investigated the relationship between the incidence of encephalitis and that of respiratory and enteric viral infections in all age groups from 2015 to 2019, using the Health Insurance Review and Assessment (HIRA) Open Access Big Data Platform. We identified monthly incidence patterns and seasonal trends using the autoregressive integrated moving average (ARIMA). The Granger causality test was used to analyze correlations between encephalitis incidence and the positive detection rate (PDR) at 1-month intervals. A total of 42,775 patients were diagnosed with encephalitis during the study period. The incidence of encephalitis was highest in the winter (26.8%). The PDRs for respiratory syncytial virus (HRSV) and coronavirus (HCoV) were associated with the trend in encephalitis diagnosis in all age groups, with a 1-month lag period. In addition, an association with norovirus was observed in patients aged over 20 years, and with influenza virus (IFV) in patients aged over 60 years. This study found that HRSV, HCoV, IFV, and norovirus tended to precede encephalitis by 1 month. Further research is required to confirm the association between these viruses and encephalitis.

Anti-N-Methyl-D-Aspartate Receptor (NMDAR) Encephalitis in Children and Adolescents: A Systematic Review and Quantitative Analysis of Reported Cases

OBJECTIVE

This pooled analysis, from a systematic review, examines anti-N-Methyl D-Aspartate Receptor (NMDAR) encephalitis presentation in children and adolescents.

METHOD

A comprehensive literature search from database inception through December 31, 2019, using PubMed, PsycInfo, and OVID was performed. Case reports and case series were included. Sample characteristics are described. Prodromal and presenting symptoms between partial recovery and full recovery are compared. The association between presenting symptoms and abnormal MRI, abnormal EEG, and tumor presence are determined.

RESULTS

The sample (n=283) had a mean age of 10.8 years with 75.3% females. The most common prodromal and presenting symptom was seizure (29.7% and 63.3%, respectively). Partial and full recovery did not differ for prodromal and presenting symptoms. Multivariate logistic regression analysis found that (1) delusion were significantly associated with higher odds and aggressive behavior was associated with lower odds for abnormal findings on magnetic resonance imaging (MRI); (2) waxing and waning of symptoms were significantly associated with higher odds for abnormal electroencephalograms (EEG), and (3) increased age and psychosis were each significantly associated with increased odds, and sleep disturbance and orofacial dyskinesia with lower odds for tumor presence.

CONCLUSION

Given the pattern of findings, routinely obtaining MRI and EEG should be considered for anti-NMDAR encephalitis in children and adolescents presenting with delusion and waxing and waning of symptoms, respectively. Investigation of tumors should be considered in patients with anti-NMDAR encephalitis especially when psychosis is present.

Herpesvirus encephalitis diagnosed by polymerase chain reaction at the National Institute of Neurology of Mexico

The frequency of central nervous system infections due to herpesvirus have been studied in various populations; however, studies in Mexican mestizo patients are scant. This paper documents the frequency of herpesvirus encephalitis in Mexican mestizo patients from the National Institute of Neurology and Neurosurgery (NINN) of Mexico. To study the frequency of herpetic viral encephalitis at the NINN in the period from 2004 to 2009. We reviewed clinical records from patients with clinically suspected encephalitis; polymerase chain reaction assays were done for detection of herpesviruses in cerebrospinal fluid (CSF) samples. The total number of patients studied was 502; in 59 (12%), the diagnosis of herpetic encephalitis was confirmed by PCR-based testing of CSF. Of them, 21 (36%) were positive for herpes simplex virus type 1, 15 (25%) for Epstein-Barr virus, 10 (17%) for varicella zoster virus, 8 (14%) for cytomegalovirus, 3 (5%) for human herpesvirus 6, and 2 (3%) for herpes simplex virus 2. Our results show a varied frequency of viral encephalitis in mestizo patients due to herpesviruses in a tertiary neurological center and point out the importance of modern molecular technology to reach the etiological diagnosis in cases of encephalitis.

Clinical Features and Risk Factors for Mortality in Children With Acute Encephalitis Who Present to the Emergency Department

Acute encephalitis is an important pediatric emergency that tends to be associated with neurological morbidity, critical illness, and mortality. Few data have specifically focused on evaluating various early clinical parameters in the pediatric emergency department as candidate predictors of mortality. The present retrospective study assessed the clinical, laboratory, and neuroimaging findings of children with acute encephalitis who presented to the emergency department. Of 158 patients diagnosed with encephalitis, 7 (4.4%) had mortality. Compared to the survivors, a multivariate analysis revealed that an initial Glasgow Coma Scale score ≤ 5 (odds ratio [OR]: 8.3, P = .022), acute necrotizing encephalitis (OR: 12.1, P = .01), white blood count level ≤ 5.2 × 10⁹ cells/L (OR: 28.7, P < .001), aspartate aminotransferase level > 35 U/L (OR: 14.3, P = .022), and influenza A infection (OR: 7.7, P = .027) were significantly associated with mortality. These results indicate that the early recognition of preliminary clinical features and the development of more specific etiologies for encephalitis are important for early treatment strategies.

Arterial spin-labeling perfusion imaging of childhood encephalitis: correlation with seizure and clinical outcome

PURPOSE

In childhood encephalitis, perfusion abnormalities have been infrequently reported to associate with clinical status. We investigated whether perfusion abnormalities correlated with seizure and clinical outcome in encephalitis.

METHODS

We retrospectively analyzed the MR studies of 77 pediatric patients with encephalitis. Pseudo-continuous arterial spin-labeling (ASL) imaging was performed on a 3-T scanner. The patients were divided into five groups according to ASL perfusion imaging pattern: normal perfusion (NP), focal hypoperfusion (Lf), extreme global hypoperfusion (LE), focal hyperperfusion (Hf), and extreme global hyperperfusion (HE). Clinical outcome at 3 weeks was dichotomized to unfavorable or favorable outcome according to the Glasgow outcome scale. Multivariate logistic regression was conducted to predict unfavorable outcome and presence of seizure separately, based on explanatory variables including age, sex, and ASL pattern.

RESULTS

Twenty-seven (35%) patients were designated as in group Hf, five (7%) in group Lf, 11 (14%) in group LE, none in group HE, and 34 (44%) in group NP. Multivariate logistic regression analysis showed that ASL pattern was significantly associated with unfavorable outcome (P = 0.005) and with presence of seizure (P = 0.005). For ASL pattern, group LE was 17.31 times as likely to have an unfavorable outcome as group NP (odds ratio confidence interval [CI] 3.084, 97.105; P = 0.001). Group Hf was 6.383 times as likely to have seizure as group NP (CI 1.765, 23.083; P = 0.005).

CONCLUSIONS

In childhood encephalitis, patients with extreme global hypoperfusion had poor neurological outcome and those with focal hypoperfusion were more likely to have seizure.

Pediatric Emergency Magnetic Resonance Imaging: Current Indications, Techniques, and Clinical Applications

MR imaging plays an important role in the detection and characterization of several pediatric disease entities that can occur in the emergent setting because of its cross-sectional imaging capability, lack of ionizing radiation exposure, and superior soft tissue contrast. In the age of as low as reasonably achievable, these advantages have made MR imaging an increasingly preferred modality for diagnostic evaluations even in time-sensitive settings. In this article, the authors discuss the current indications, techniques, and clinical applications of MR imaging in the evaluation of pediatric emergencies.