Two children, ages 18 months and 14 months, who presented with acute hemiparesis 5 days and 3 weeks following varicella vaccination are reported from Alberta Children’s Hospital, and the University of Calgary, Ontario, Canada. CT and MRI showed unilateral infarction of the basal ganglia and internal capsule in both patients. MRA showed narrowing of the mid-Mi segment of the right middle cerebral artery in one patient. Echocardiography in both patients showed a small patent foramen ovale with left to right shunting. One patient had a severe iron-deficiency anemia. At 1 year follow-up in one patient, the neurologic examination was normal, and at 6 months in the other patient, hemiparesis was improved. Possible causes for the stroke included varicella angiopathy, small patent foramen ovale, and iron-deficiency anemia. 
COMMENT. Acute hemiplegia with lacunar stroke has previously been reported after primary varicella infection . The above case-reports are the first evidence of cerebral vasculopathy and stroke secondary to varicella vaccine. Patent foramen ovale and iron deficiency anemia were possible predisposing factors. Other neurological complications occurring in temporal association with varicella vaccination have included encephalitis, seizures, neuropathy, and ataxia (American Academy of Pediatrics Red Book 2000;25thed;633). Acute cerebellar ataxia was reported in a 2 year-old boy who developed vomiting and ataxia 10 days after vaccination. MRI showed multiple demyelinating lesions. Recovery followed in 3 weeks. (Ped Neur Briefs Feb 1996) . The neurology of the varicella-zoster virus is described in a historical perspective . VZV was first isolated in 1952, using fluorescent-labeled antibodies. 
Zoster-associated intracranial hypertension is reported in a 14-year-old girl who presented with headache, vomiting, papilledema, CSF pleocytosis and elevated protein, and herpes zoster with positive VZV DNA in the CSF. The patient had a history of varicella at 4 years of age. Intracranial hypertension is an unusual complication of the reactivation of varicella-zoster virus.