Magnetic resonance imaging of the brain and neuropsychological evaluation in children treated for acute lymphoblastic leukemia at a young age.

PURPOSE

To evaluate the adverse late effects of ALL treatment on cognitive functions and brain morphology; to integrate the results of a neuropsychological and neuroradiological study.

PATIENTS AND METHODS

Cranial magnetic resonance imaging (MRI) and neuropsychological assessments (NA) were performed in 35 children treated for acute lymphoblastic leukemia (ALL) with cranial irradiation (CI) and intrathecal and intravenous methotrexate. Patients were under the age of 7 years (MD: 3.5 years) at diagnosis; median follow-up at MRI and NA was 8 years since diagnosis.

RESULTS

MRI's were classified as definitely abnormal in 51% and as probably abnormal in another 17% of the patients. White matter damage was most frequently seen. MRI abnormalities were not related to CI dose or age at diagnosis. Patients showed significantly lower scores, compared to the norm group on measures of intelligence, verbal auditory memory, visual motor integration, and fine motor functioning. Lower scores significantly correlated with higher CI dose (25-32 Gy compared to 18-20 Gy) and younger age at diagnosis (< 4.0 years compared to > or = 4.0 years). Forty percent of the patients had to be referred to schools for learning disabled.

CONCLUSIONS

ALL treatment, including CI and MTX, at a young age is associated with persistent cognitive impairment and MRI abnormalities. However, no correlation was found between MRI results and neuropsychological or academic performance.