Cognitive, behavioral, and social outcome in survivors of childhood stem cell transplantation.
To evaluate prospectively the cognitive functioning and to obtain ratings of cognitive, behavioral, and social functioning for children receiving stem cell transplantation (SCT). Forty-seven children treated with SCT for malignant or nonmalignant disorders who had no previous cranial radiation therapy, no central nervous system tumors, and were aged birth to 16 years were administered the Bayley Scales of Infant Development or IQ test before SCT and an intelligence test 1 and 2 years after SCT. Children and parents rated behavior and social functioning, and parents reported on everyday cognitive abilities (including academic ability) 2 to 6 years after SCT. There were no statistically significant differences in IQ over the course of time (before SCT to 2 years after SCT). Only parent ratings of academic ability were significantly lower than the normal standardization sample. Mean mental scale scores for children younger than 3 years were lower than mean IQ scores for children older than 3 years at the pre-SCT assessment. Mean test scores not only decreased for younger children but also were 16 points lower than mean scores for older children at 2 years after SCT. The cognitive, behavioral, and social functioning of children 3 years and older is not detrimentally affected 2 years after SCT. Parents of older children report no cognitive ability problems but lower academic ability. Children younger than age 3 years may be at risk for decreased cognitive skills.