title: "Symptomatic" infection-associated acute encephalopathy in children with underlying neurological disorders.
abstract: BACKGROUND
  Development of infection-associated acute encephalopathy (AE) is precipitated by several factors, including viral agents, age, and genetic polymorphisms. In addition, children with prior underlying neurological disorders can also present with AE.
  
  
  METHODS
  We reviewed 55 children with AE who were referred to hospitals participating in the Status Epilepticus Study Group from 1988 to 2013. AE was classified into eight subtypes: acute encephalopathy with biphasic seizures and late reduced diffusion (AESD); hemiconvulsion-hemiplegia syndrome (HH); acute necrotizing encephalopathy; hemorrhagic shock and encephalopathy syndrome (HSES); clinically mild encephalitis/encephalopathy with a reversible splenial lesion; acute encephalitis with refractory, repetitive partial seizures; Reye-like syndrome; and unclassified.
  
  
  RESULTS
  Of the 55 AE cases, 14 (25.4%) had underlying neurological disorders, including perinatal insults (n=6) and genetic syndrome and/or brain malformations (n=8). These preceding morbidities were relatively common in AESD (6/18, 33.3%), HH (3/9, 33.3%), and HSES (3/6, 50.0%). History of epilepsy or febrile seizures were frequent in HH cases (4/9, 44.4%), whereas they were rare in other AE subtypes.
  
  
  CONCLUSIONS
  Among the AE subgroups, HH, HSES, and AESD frequently emerged in preceding etiologies with augmented neuronal excitability. These subgroups may have distinct pathomechanism from the "cytokine storm" mediated AEs during childhood.
authors: Division of Child Neurology, Department of Brain and Neurosciences, Faculty of Medicine, Tottori University, Yonago, Japan; Department of Pediatrics, Naha City Hospital, Naha, Japan.
authors: Yoshimichi
authors: Y
authors: Hirayama
authors: Division of Child Neurology, Department of Brain and Neurosciences, Faculty of Medicine, Tottori University, Yonago, Japan.
authors: Yoshiaki
authors: Y
authors: Saito
authors: Division of Child Neurology, Department of Brain and Neurosciences, Faculty of Medicine, Tottori University, Yonago, Japan. Electronic address: maegaki@med.tottori-u.ac.jp.
authors: Yoshihiro
authors: Y
authors: Maegaki
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D001927:Brain Diseases / Q000209:etiology* / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D009422:Nervous System Diseases / Q000150:complications*
keywords: Acute encephalopathy; Etiology; Neuronal excitability; Precipitating factor