Neurological complications of pandemic influenza (H1N1) in children

Department of Pediatric Intensive Care, Çukurova University School of Medicine, Adana, Turkey.
European Journal of Pediatrics (Impact Factor: 1.98). 11/2010; 170(6):779-88. DOI: 10.1007/s00431-010-1352-y
Source: PubMed

ABSTRACT The aim of this study was to determine the clinical characteristics of children demonstrating neurological complications with pandemic influenza (H1N1). We reviewed the medical and laboratory records of all children who were hospitalized with neurological symptoms and who had proven influenza virus infection by reverse transcriptase-polymerase chain reaction on nasal and throat swabs. Eight children aged between 10 months and 7 years had neurological complications due to pandemic influenza (H1N1) and five of them were female. Four of them were previously healthy; there was chronic renal failure (CRF) in one and neurologic disease in three patients. Seven of them had seizure and altered consciousness. Seven of them were followed in pediatric intensive care units. We performed lumbar puncture in four patients and their cerebrospinal fluid examinations showed pleocytosis in one and no cell in three specimens. Neuroimaging was performed in four patients and three of them had abnormalities. We diagnosed aseptic meningitis in one, acute disseminated encephalomyelitis (ADEM) in one, acute necrotizing encephalopathy (ANE) in one, meningoencephalitis in one, and status epilepticus in four patients. All patients were treated with oseltamivir and antiepileptic drugs. One patient with CRF died; four previously healthy patients recovered fully, and three patients who had neurologic disorder returned to their previous neurological status. In conclusion, during pandemic influenza (H1N1) infection, neurological complications may be seen in addition to the respiratory infection. The type of neurological involvement may be variable such as triggering seizure, aseptic meningitis, encephalitis, ADEM, and ANE. Neurological complications frequently recover fully especially in previously healthy children, but sometimes a severe clinical course occurs.

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    ABSTRACT: Objective. To report a case of refractory status epilepticus (SE) as an unusual early manifestation of H1N1 influenza infection. Introduction. H1N1 neurological complications have been reported and consist mainly of seizures or encephalopathy occurring in children. However, we only found a single report of an adult developing complex partial SE with H1N1 infection. Case Report. A 21-year-old previously healthy man was brought to the emergency room (ER) after a witnessed generalized tonic clonic seizure (GTCS). He was fully alert and afebrile upon ER arrival, but a second GTCS prompted treatment with Lorazepam and Fosphenytoin. The initial EEG showed diffuse slowing, but a repeat one requested as the patient failed to regain consciousness revealed recurrent focal seizures of independent bihemispheric origin, fulfilling the criteria for nonconvulsive SE. Chest X-ray, followed by chest CT scan, showed a left upper lobe consolidation. H1N1 infection was confirmed with PCR on bronchoalveolar lavage material. Despite aggressive treatment with Midazolam, Propofol, and multiple high dose antiepileptic drugs, the electrographic seizures recurred at every attempt to reduce the intravenous sedative drugs. The patient died two weeks after his initial presentation. Conclusion. H1N1 should be added to the list of rare causes of refractory SE, regardless of the patient's age.
    01/2014; 2014:585428. DOI:10.1155/2014/585428
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    ABSTRACT: Introduction: In 2009, pandemic influenza A H1N1 emerged in Mexico and subsequently spread worldwide. In Malaysia, there were more than a thousand of confirmed cases among children. The general clinical characteristics of these children have been well-published. However, the description of neurologic complications is scarce. Objective: This study aims to describe the characteristics of neurologic manifestations and complications in a national paediatric cohort with pandemic influenza A H1N1. Methods: During the pandemic, children (12years or less) admitted for novel influenza A H1N1 in 68 Malaysian public hospitals, were prospectively enrolled into national database. The clinical, laboratory and neuro-imaging data for children with neurologic manifestations, hospitalized from 15th June 2009 till 30th November 2009, was reviewed. Results: Of 1244 children with influenza A H1N1 during the study period, 103 (8.3%) presented with influenza-related neurological manifestations. The mean age of our study cohort was 4.2years (SD: 3.3years). Sixty percent of them were males. Sixty-nine (66.9%) were diagnosed as febrile seizures, 16 (15.5%) as breakthrough seizures with underlying epilepsy, 14 (13.6%) as influenza-associated encephalopathy or encephalitis (IAE) and 4 (3.9%) as acute necrotizing encephalopathy of childhood (ANEC). All 4 available CSF specimens were negative for influenza viral PCR. Among 14 children with brain-imaging done, 9 were abnormal (2: cerebral oedema, 4: ANEC and 3: other findings). There were four deaths and three cases with permanent neurological sequelae. Conclusion: About one-tenth of children with pandemic influenza A H1N1 presented with neurologic complications. The most common diagnosis was febrile seizures. One-fifth of those children with neurologic presentation had IAE or ANEC, which carried higher mortality and morbidity. This large national study provides us useful data to better manage children with neurologic complications in the future pandemic influenza outbreaks.
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