Influenza-associated neurological complications during 2014-2017 in Taiwan

Seasonal influenza-associated neurological complications had high mortality and morbidity rates in recent studies. We reported influenza-associated encephalitis/encephalopathy in children during 2014-2017 in Taiwan, focusing on neurological presentations, neuroimaging correlations, and critical care managements.

During January 1st 2014 to June 30th 2017, pediatric patients reported to the Taiwan Centers for Disease Control surveillance system for severe complicated influenza infections in the hospital were retrospectively reviewed. Children with influenza-associated encephalitis/encephalopathy were inspected for clinical presentations, laboratory data, neuroimaging studies, treatment modalities, and neurological outcomes.

Ten children with median age 5.9 years were enrolled for analysis. Influenza-associated encephalitis/encephalopathy appeared in the spring and summer, with a delayed peak comparing with the occurrence of pneumonia and septic shock. The neurological symptoms developed rapidly within median 1 day after the first fever episode. All patients had consciousness disturbance. Seven patients (70%) had seizures at initial presentation, and six of them had status epilepticus. Anti-viral treatments were applied in all patients, with median door-to-drug time 0.9 h for oseltamivir and 6.0 h for peramivir. Multi-modality treatments also included steroid pulse therapy, immunoglobulin treatment, and target temperature management, with 85.2% of the major treatments administered within 12 h after admission. Nine of the ten patients recovered without neurological sequelae. Only one patient had epilepsy requiring long-term anticonvulsants and concomitant cognitive decline.

In highly prevalent area, influenza-associated encephalitis/encephalopathy should be considered irrespective of seasons. Our study suggested the effects of timely surveillance and multi-modality treatments in influenza-associated encephalitis/encephalopathy.