Neurological complications of pandemic influenza (H1N1) in children.

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.