Posterior reversible encephalopathy syndrome in children with cancer

Purpose. To identify predisposing factors, radiologic features, and clinical outcome of posterior reversible leucoencephalopathy (PRES) in children receiving cancer treatment. Methods. We identified 11 patients (7 female) who had radiological and clinical features consistent with PRES and were treated for cancer at St. Jude Children's Research Hospital between January 1995 and January 2005. Clinical and radiographic data were abstracted from their records. Results. The average age at the time of PRES onset was 10.4 years. Primary diagnoses were acute leukemia (n = 8), non-Hodgkin lymphoma (n = 2), and Ewing sarcoma (n = 1). PRES occurred in 8 patients during the induction phase of treatment, and all 11 patients had hypertension (5 chronically). Seizure activity was proximate to cytarabine and tacrolimus administration in three patients and further seizures occurred with re-administration of these medications in two patients. Coagulation and chemistry studies were normal. Concurrent brain magnetic resonance imaging (MRI) demonstrated T2 signal abnormalities in all 11 patients, restricted diffusion in 4, and hemorrhage in 3. Follow-up MRI showed chronic changes consistent with a previous hemorrhage in three and evidence of prior parenchymal ischemia in one. Three patients developed epilepsy and remain on chronic anticonvulsant therapy. Conclusions. PRES is an increasingly recognized complication of pediatric cancer treatment. Risk factors for PRES in pediatric cancer patients include hypertension (not necessarily acute), remission induction chemotherapy, and administration of tacrolimus. MR images often show atypical findings, some of which are irreversible. A significant number of patients develop epilepsy despite clinical and radiographic evidence of recovery.