Background. - Chickenpox encephalitis is usually mild and often presen
ts as an acute cerebellar ataxia. Seizures and coma are uncommon. Case
report. - A 4-year old girl presented generalized seizures. Two days
after the onset of chickenpox, she developed ataxia and left hemipares
is on day 3, followed by left hemiplegia after 24 hours. The cerebral
scan showed areas of subcortical hypodensity compatible with leuko-enc
ephalitis. The EEG showed lesions of acute leuko-encephalitis located
in the right sub-cortical temporo-fronto-parietal area, The patient wa
s given cortico-steroids and recovered slowly but completely. Conclusi
ons. - Hemiplegia, an exceptional event during the course of chickenpo
x, makes the diagnosis of chickenpox leuko-encephalitis difficult; IRM
appears to be a contributing factor.