Isolated cerebellar involvement in posterior reversible encephalopathy syndrome in a child with acute lymphoblastic leukemia.

Parieto-occipital region is the most commonly involved site in posterior reversible encephalopathy syndrome (PRES). Cerebellar involvement has been reported with the predominant involvement of posterior cerebral regions, but isolated cerebellar involvement in PRES has been reported only once in English literature. We report here a 7-year-old boy with acute lymphoblastic leukemia who had PRES with isolated cerebellar involvement during induction chemotherapy. He presented with sudden onset headache, vomiting and hypertension followed by seizures, unconsciousness, and involuntary movements. Computed tomography scan revealed bilateral cerebellar hypodensities. He improved within few hours and reversibility of the lesions was documented on magnetic resonance imaging after 2 weeks. Awareness of atypical patterns in distribution of imaging abnormalities is important to recognize PRES more accurately and to avoid unnecessary diagnostic procedures and treatment.