LAUSR

Abstract It is well known that neurocognition in children treated for a brain tumor can be affected. However, studies on the trajectory of these neurocognitive problems are scarce. In the present study we investigated the evolution of neurocognition between timepoints of diagnosis, 2, 4 and 6 years later. A total of 53 children diagnosed with a brain tumor were recruited in this study, of which all completed a comprehensive neuropsychological test battery at three successive timepoints and 30 at 4 timepoints. The first assessment was conducted as soon as possible after diagnosis and before initiation of chemo- and/or radiotherapy. Mean age at diagnosis was 8.06 years. The most common diagnoses were pilocytic astrocytoma (n=28) and medulloblastoma (n=10). 24.5% and 18.9% of these patient groups received focal or craniospinal irradiation, respectively. A repeated measures analysis with cranial irradiation (no, focal, craniospinal) as between-subjects factor demonstrated a significant interaction effect between time and type of irradiation for overall intelligence (p=0.02) for children with three assessments. The same interaction effect was found for overall intelligence and processing speed for children with four assessments (p=.005 and p=.002, respectively). The group who received craniospinal irradiation demonstrated the most pronounced decline. Interestingly, no main time effect or interaction effect was found for general memory functioning. Our results demonstrate that not all neurocognitive functions in children treated for a brain tumor decline after treatment. Overall IQ and processing speed are the most vulnerable outcomes in our cohort, especially for the children treated with craniospinal irradiation.