P22: Intravenous Immunoglobulin In Influenza A H1N1-Associated Acute Necrotizing Encephalopahy: A Case Report

Acute necrotizing encephalopathy of childhood (ANEC) affects healthy children commonly following respiratory infections including influenza A infections. Treatment is largely symptomatic although high dose corticosteroids are recommended for severe cases. We describe a 3-year old Malay boy who presented with status epilepticus following 3 days of fever, cough and rhinorrhea during the recent Influenza A H1N1 pandemic. Physical examination revealed a drowsy child with Glasgow coma scale of 12/15 with generalized hypertonia, hyperreflexia and bilateral upgoing plantar reflexes. He had neutrophilic leucocytosis (WCC 31,000, neutrophils 84%), liver impairment (ALT 3075 iu/L, AST 7632 iu/L) and renal impairment (creatinine 89umol/L). Throat swab for influenza A H1N1 PCR was positive. His brain computerized tomography scan showed ventriculomegaly, cerebral edema and bilateral thalamic hypodensities classical for ANEC. He was treated with oral oseltamivir, iv ceftriaxone, iv acyclovir, anticonvulsants, mannitol, inotropic agents and ventilation. On day 2 of admission, he was started on intravenous immunoglobulin (IVIg) 1g/kg/day x 2 days, and subsequently a further third dose given. He was extubated after 1 week and had signs of pseudobulbar palsy and mixed spastic dystonic quadriparesis with truncal ataxia. He was discharged home on day 20 on nasogastric feeding and unable to walk. At 2 weeks after discharge, he was able to walk aided unsteadily and was feeding by mouth. Six months after his illness, he showed almost complete recovery with minor neurological sequelae. Conclusion : Influenza A H1N1 associated ANEC which normally has a poor prognosis may be successfully treated with IVIg.