Analysis of Influenza Related Neurologic Complications for Recent 3 Years

ABSTRACT

OBJECTIVE: Influenza infection can stimulate secretion of proinflammatory cytokine and induce neurological symptoms due to post-infection immunity reaction. This study attempts to study clinical aspects of patients with neurologic complication and their difference to other patients with no neurological complication. METHODS: From January of 2012 to May of 2014, 535 patients diagnosed to have influenza in Soonchunhyang University Bucheon Hospital were included as subjects. They were classified into two groups based on existence of neurologic complication and retrospectively analyzed of clinical features and lab results. RESULTS: Thirty (5.6%) out of 535 patients showed neurologic complication and there were no significant difference in annual incidence of neurologic complication. Despite that the patient group with neurologic complication had history of neurological disorders and high admission rate, they did not show difference in age, gender, fever duration, and influenza A infection rate as compared with no neurologic complication group. In blood test, erythrocyte sedimentation rate and C-reactive protein was significantly low in patients with neurologic complication, but white blood cell count was not significantly different between two groups. Neurological complication was mostly seizure with 25 patients. Four patients showed encephalopathy and 1 patient was diagnosed with meningitis. CONCLUSION: Five point six percent among infants infected with influenza A were accompanied with neurologic complication, but none showed long-term sequelae. There was no difference in the annual incidence and incidence of neurological complication was higher in patients with history of neurologic disorder, but there were no other risk factors.