Risk Factors of Influenza-Associated Necrotizing Encephalopathy in Children

Research Article

Austin J Infect Dis. 2021; 8(3): 1054.

Risk Factors of Influenza-Associated Necrotizing Encephalopathy in Children

Liu G¹, Yang S², Li S¹, Chen Q¹, Xiao W³ and Li P¹*

¹Department of Pediatric Emergency, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, Guangdong, P.R. China

²Department of Pediatric Neurology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, Guangdong, P.R. China

³Department of Pediatric Radiology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, Guangdong, P.R. China

*Corresponding author: Peiqing Li, Department of Pediatric Emergency, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, Guangdong, P.R. China

Received: June 11, 2021; Accepted: July 06, 2021; Published: July 13, 2021

Abstract

Objective: A case-control study of Influenza-Associated Necrotizing Encephalopathy (IANE) in children was conducted to explore the risk factors for the diagnosis of IANE, and to provide a predictive reference for the diagnosis of IANE.

Methods: The children with IANE who received treatment in our hospital from January 2016 to December 2020 were selected as the study group, and the children with Influenza-Associated Encephalopathy (IAE) group who received treatment in the same period were selected as the control group. The blood biochemical, coagulation function and cerebrospinal fluid test results of the two groups were analyzed by univariate analysis. Receiver Operating Characteristic Curve (ROC) analysis was used to determine the optimal threshold point of each index for the indicators with statistically significant differences in univariate analysis results, and multivariate Logistic stepwise regression analysis was performed according to the optimal threshold points.

Results: In the IANE group, there were 32 children, including 20 males and 12 females, aged 58 (23, 97) months. There were 40 children in IAE group, including 26 males and 14 females, aged 58 (23, 97) months. Univariate results showed that serum Lactate Dehydrogenase (LDH), Cerebrospinal Fluid Lactate Dehydrogenase (CSF LDH) and Cerebrospinal Fluid Protein (CSF Pro) in the IANE group were significantly higher than those in the IAE group, and the difference between the two groups was statistically significant (P <0.001). The optimal threshold points of blood LDH, CSF LDH and CSF Pro by ROC curve analysis were 535U/L, 67U/L and 0.49g/L, respectively. Further Multivariate Logistic stepwise regression analysis showed that LDH >535U/L (OR=31.264, 95% CI: 5.892-165.878, P <0.001) and CSF PRO >0.49g/L (OR=7.695, 95% CI: 1.052-56.305, P=0.044) were independent risk factors for IANE.

Conclusion: For children with influenza whose neurological symptoms appear rapidly and persist in the early stages of the disease, blood LDH >535U/L and CSF PRO >0.49g/L are independent risk factors for IANE.

Keywords: Children; Influenza-associated necrotizing encephalopathy; Risk factor

Introduction

Influenza occurs frequently in winter and spring in southern China. Most infected children have fever and respiratory symptoms. In addition to fever and respiratory symptoms, some children with influenza will have neurological symptoms, manifested as convulsions, disturbance of consciousness and coma. Some cases will die after rapid progress, and the survivors will have severe neurological sequelae [1-3]. Nervous system damage caused by influenza is one of the main causes of influenza death in children, among which IANE is the most serious, with a case fatality rate of up to 30% [4,5]. However, there is currently a lack of indicators related to IANE risk factors, which delays the early identification of critical cases, leading to poor prognosis and death [6].

This study retrospectively analyzed the blood biochemical, coagulation function and cerebrospinal fluid results of children with IAE and IANE who were admitted to our hospital from January 2016 to December 2020 with neurological symptoms, to explore the possibility of predicting IANE in the early stage of the disease, so as to detect the children with IANE early, and to closely evaluate and actively intervene in these children to improve the prognosis. Reduce the nervous system sequelae and mortality.

Patients and Methods

Clinical data

The gender, age, blood biochemical results, blood coagulation function, cerebrospinal fluid results, Imaging data and prognosis of children with IAE and IANE treated in Guangzhou Women and Children’s Medical Center from January 2016 to December 2020 were retrospectively analyzed. The Ethics Committee of Guangzhou Women and Children Medical Center approved this study. All patients signed an informed consent form upon admission.

The inclusion criteria were: 1) children (<18 years); 2) admitted to the hospital with influenza virus infection; and 3) neurological manifestations during hospitalization. The exclusion criteria were: 1) admission >7 days after onset; 2) co-infected with other pathogens; 3) comorbidities like brain trauma, sequelae of viral encephalitis, or metabolic diseases; 4) missing data; or 5) neurological complications other than IAE or IANE.

IAE was defined as convulsions, acute cognitive impairment, and acute disturbance of consciousness, and coma [7-9]; without specific biochemistry abnormal, without or minor imaging changes such as slight cerebral edema [10]. IANE was defined as acute fever, frequent convulsions, acute disturbance of consciousness, coma, and multiple organ failure, with a risk of death [11-13]; biochemistry changes could be not specific [10], but imaging shows brain edema and necrosis of thalamus and other deep brain structures [10,14].

Methods

Through the data query of structured electronic medical record system, the gender, age, blood biochemical results and cerebrospinal fluid results of the first test after hospitalization, imaging data and prognosis of children diagnosed with IAE and IANE admitted to our hospital from January 2016 to December 2020 were analyzed by retrospective analysis. The collected clinical data and laboratory examination results were statistically analyzed.

Statistical analysis

All data were processed using SPSS (V26.0, IBM Corp, Armonk, NY, USA) statistical software. Enumerative data were expressed by numerical values and percentages. Differences between groups were tested by Pearson chi-square (χ²) test or Fisher’s exact test. Shapiro- Wilk method was used to test the normality of measurement data, and the interval between median and quaternary M (P25, P75) was used to represent the non-normal distribution, and the differences between groups were tested by Mann-Whitney U test. Mean±SD was used for normal distribution, and t test was used for comparison between groups. P value <0.05 on both sides was considered statistically significant. ROC curve analysis was used to calculate the area under the curve and determine the optimal threshold value. Multivariate logistic stepwise regression analysis was performed on the variables with statistically significant differences in univariate analysis.

Results

Characteristics of cases

From January 2016 to December 2020, a total of 72 children with influenza associated with neurological complications were admitted to our hospital. In the IANE group, there were 32 children, including 20 males and 12 females, aged 58 (23, 97) months, and all of them had an initial infection and persistent neurological symptoms following, such as Acute Disturbance of Consciousness (ADOC) or seizure occurred within three days after onset of the disease. There were 40 children in IAE group, including 26 males and 14 females, aged 58 (23, 97) months, whose neurological symptoms were milder and shorter than IANE group. There was no significant difference in gender ratio and age distribution between the two groups (P >0.05) (Table 1).

Imaging data

Among the 40 children with IAE, 37 (92.5%) underwent brain Computerized Tomography (CT) or Magnetic Resonance Imaging (MRI) examination, and 15 (40.5%) of them showed abnormal manifestations, slight cerebral edema mainly. Twenty-eight of the 32 (87.5%) children with IANE underwent brain CT or MRI examination, and all of them (100%) showed abnormal findings, mainly symmetrical lesions in the thalamus and other brain structures, especially in the brainstem, basal ganglia, periventricular white matter and cerebellum. Brain MRI findings of an IANE patient was showed in the Figure 1.