Central nervous system complications of varicella-zoster virus.

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. STUDY DESIGN: 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. CONCLUSION: 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.