Elsevier

Pediatric Neurology

Volume 49, Issue 2, August 2013, Pages 97-101
Pediatric Neurology

Original Article
Neurological and Muscular Manifestations Associated With Influenza B Infection in Children

https://doi.org/10.1016/j.pediatrneurol.2013.04.004Get rights and content

Abstract

Background

Influenza viruses have been associated with various neurological and muscular symptoms. The aim of this study was to evaluate the pediatric neurological and muscular manifestations of influenza B during a 5-month epidemic at a single center.

Methods

We retrospectively reviewed the medical records of 355 pediatric patients with laboratory-confirmed influenza B infection.

Results

Neurological and muscular symptoms were exhibited by 28 patients (7.9%). The mean age was 48.7 ± 25.2 months. The mean time between respiratory symptoms and neurological symptoms was 2.2 ± 1.5 days. The most common symptom was seizure (19/28, 67.9%), followed by myositis (5/28, 17.9%), increased intracerebral pressure (1/28, 3.6%), delirium (1/28, 3.6%), and severe headache (1/28, 3.6%). There was one severe case of meningitis with myocarditis (1/28, 3.6%). All seizures were febrile: 15 simple febrile seizures (78.9%), three complex febrile seizures (15.8%), and one febrile status epilepticus (5.3%). The mean age of nine patients with their first seizures was 37.9 ± 22.2 months, which was older than the typical age of onset for febrile seizure. All the patients, except one, were treated with oseltamivir. There were no deaths or chronic debilitating sequelae.

Conclusions

The neurological and muscular complications of influenza B infection in children are relatively mild, and febrile seizure is the most common. However, clinicians should be alert to the possibility of rare severe complications during influenza B outbreaks.

Introduction

Each year, about 20% of children worldwide develop symptomatic influenza A and B infections [1]. Although most of the clinical manifestations are respiratory in nature, influenza infection is also associated with various neurological and muscular symptoms, which include seizure (febrile and afebrile), encephalopathy, encephalitis, aseptic meningitis, Guillain-Barré syndrome, Reye syndrome, extrapyramidal syndromes, myelitis, myositis, and myocarditis [2], [3]. The majority of studies on influenza-related neurological manifestations were concerned with influenza A, and recently H1N1 [4], [5], [6], [7]. Influenza B has been considered to have fewer complications, and most reported cases involved sporadic encephalopathies [8], [9], [10]. There are few large-scale studies on the neurological and muscular manifestations of influenza B infection [11], [12].

Our university hospital is located in Guri City, Kyung-ki province, South Korea, and serves the surrounding areas. The number of pediatric admissions in 2012 was 2041. During the first half of 2012, there was a seasonal outbreak of influenza B in South Korea. During this time, we conducted influenza antigen tests on children suspected of having influenza infection and found that a small but significant portion of the infected patients developed neurological or muscular symptoms. The purpose of this report is to describe these manifestations in children with influenza B infection in a community hospital during the 2012 winter/spring influenza epidemic.

Section snippets

Patients

The medical records of children treated in the Pediatric Department of Hanyang University Guri Hospital between September 1, 2011, and August 31, 2012, were retrospectively reviewed. All laboratory-confirmed influenza B patients with neurological and muscular manifestations were included in the study. Patients with underlying severe neurological disease or were previously diagnosed with epilepsy were excluded. The demographic data, neurological and muscular manifestations, medical histories,

Demographic data

In our hospital, influenza B was detected from week 3 of January 2012 to week 1 of May 2012 (Fig 1). The number of patients with influenza B peaked in late March. The occurrence trend was similar to the 2011-2012 influenza sentinel surveillance report of Korea Centers for Disease Control and Prevention.

There were 355 patients with laboratory-confirmed influenza B in our department. Of these, 28 (7.9%) had neurological or muscular complications. All patients were Korean. Twenty of the 28

Discussion

The wide spectrum of effects resulting from influenza infection ranges from asymptomatic and mild respiratory infection to severe pulmonary, neurological, and muscular system complications [2], [3], [4], [5], [6], [7], [13]. Neurological manifestations may be the only symptom or may appear after the respiratory symptoms. In children, the complications of influenza infection are more frequent and severe than in adults. Although both influenza A and B are associated with neurological

References (32)

  • R. Tarkka et al.

    Risk of recurrence and outcome after the first febrile seizure

    Pediatr Neurol

    (1998)
  • M. Munakata et al.

    Combined therapy with hypothermia and anticytokine agents in influenza A encephalopathy

    Brain Dev

    (2000)
  • S.M. Maricich et al.

    Neurologic complications associated with influenza A in children during the 2003-2004 influenza season in Houston, Texas

    Pediatrics

    (2004)
  • L.E. Davis

    Neurologic and muscular complications of the 2009 influenza A (H1N1) pandemic

    Curr Neurol Neurosci Rep

    (2010)
  • J.A. McCullers et al.

    Influenza B virus encephalitis

    Clin Infect Dis

    (1999)
  • J. Straumanis et al.

    Influenza B infection associated with encephalitis: Treatment with oseltamivir

    Pediatr Infect Dis J

    (2002)
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