title: Central nervous system complications of varicella-zoster virus.
abstract: OBJECTIVE
  To describe the spectrum of central nervous system complications of varicella-zoster virus (VZV) in children admitted to The Hospital for Sick Children between January 1999 and December 2012.
  
  
  METHODS
  Children aged 1 month to 18 years (n = 84) admitted with neurologic manifestations associated with a characteristic VZV rash or a confirmatory laboratory test (positive lesion scraping or cerebrospinal fluid polymerase chain reaction) were included in the study. Acute neurologic complications were included if they occurred within 4 weeks of VZV infection. Stroke was considered related to VZV if it occurred within 6 months of VZV infection, the neuroimaging was characteristic, and other causes were excluded.
  
  
  RESULTS
  Clinical syndromes included acute cerebellar ataxia (n = 26), encephalitis (n = 17), isolated seizures (n = 16), stroke (n = 10), meningitis (n = 10), Guillain-Barré syndrome (n = 2), acute disseminated encephalomyelitis (n = 2), and Ramsay Hunt syndrome (n = 1). In those with acute complications (nonstroke), neurologic symptoms occurred a median of 5 days after rash onset (range -6 to +16). The time between rash onset and stroke ranged from 2 weeks to 26 weeks (median 16.0 weeks). Three children with encephalitis died. Residual neurologic sequelae at one year occurred in 9 of 39 (23%) of children with follow-up data. Only 4 children were reported to have received the varicella vaccine.
  
  
  CONCLUSIONS
  Neurologic complications of VZV infection continue to occur despite the availability of an effective vaccine. Neurologic symptom onset can predate the appearance of the VZV exanthem and in rare cases may occur in the absence of an exanthem.
authors: Division of Infectious Diseases, Department of Pediatrics, The Hospital for Sick Children, Toronto, Ontario, Canada.
authors: Michelle
authors: M
authors: Science
authors: Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada; Division of Neurology, Department of Pediatrics, The Hospital for Sick Children, Toronto, Ontario, Canada.
authors: Daune
authors: D
authors: MacGregor
authors: Division of Microbiology, Department of Pediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
authors: Susan E
authors: SE
authors: Richardson
authors: Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada.
authors: Sanjay
authors: S
authors: Mahant
authors: Division of Infectious Diseases, Department of Pediatrics, The Hospital for Sick Children, Toronto, Ontario, Canada; Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada.
authors: Dat
authors: D
authors: Tran
authors: Division of Infectious Diseases, Department of Pediatrics, The Hospital for Sick Children, Toronto, Ontario, Canada; Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada. Electronic address: ari.bitnun@sickkids.ca.
authors: Ari
authors: A
authors: Bitnun
mesh_terms: D000293:Adolescent; D002170:Canada; D002493:Central Nervous System Diseases / Q000150:complications / Q000821:virology*; D002644:Chickenpox / Q000150:complications* / Q000517:prevention & control; D019433:Chickenpox Vaccine / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D004279:DNA, Viral / Q000032:analysis; D016208:Databases, Factual; D004660:Encephalitis / Q000150:complications / Q000821:virology; D005076:Exanthema; D005260:Female; D020275:Guillain-Barre Syndrome / Q000150:complications; D006562:Herpes Zoster / Q000150:complications* / Q000517:prevention & control; D014645:Herpesvirus 3, Human; D006801:Humans; D007223:Infant; D008297:Male; D012042:Registries; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D019433:Chickenpox Vaccine; D004279:DNA, Viral