A 4-year-old male child who presented with right middle cerebral artery (MCA) infarction 2 months after varicella is reported from the University of British Columbia, Children’s Hospital, Vancouver, Canada. He awoke from sleep complaining of nausea, vomited, and within 30 minutes developed left facial, arm, and leg weakness that partially resolved over 4 hours. On admission, he had a left hemiparesis and a right gaze preference. CT demonstrated the right MCA infarction. Cerebral angiography with catheterization of all major arteries 48 hours after admission showed an isolated 89% stenosis of the proximal right MCA. Within 24 hours he deteriorated acutely, with coma and a left focal seizure. Attempts to control raised intracranial pressure with mannitol and hyperventilation were unsuccessful. At surgery to relieve transtentorial herniation, infarcted brain tissue was evacuated. Pathologic studies showed small vessel vasculitis, lymphocytic infiltration, and white matter demyelination. No viral inclusions were identified, and immunohistochemical staining was negative for herpes simplex virus. Polymerase chain reaction on brain tissue was negative for varicella. After surgery he developed decorticate posturing and a right fixed dilated pupil. At 2 year follow-up he was severely incapacitated with spastic quadriparesis, bulbar dysfunction, and cortical visual impairment. 
COMMENT. The present case of middle cerebral artery infarction was considered to be a late complication of the mild varicella infection occurring 2 months previously. Angiography that was followed by an acute deterioration of the stroke, with massive brain swelling and coma, failed to reveal stenosis and beading, signs of vasculitis that were evident in small vessels on pathological examination. The value of cerebral angiography in cases of acute stroke with suspected vasculitis is questionable. Several case reports are cited that demonstrate an association between “idiopathic” arterial strokes in childhood and varicella infection.