Neuroanatomical substrates of sustained attention among pediatric patients with medulloblastoma

The present study focuses on the association between measures of the corpus callosum (CC) and measures of attention ability among survivors of pediatric medulloblastoma, within two separate but related projects. Utilizing quantitative magnetic resonance imaging (MRI) techniques in a longitudinal design, the primary objective of Project 1 was to examine the growth pattern of total CC, and 7 CC subregions, over time since the start of treatment with cranial spinal irradiation (CSI) (n = 35). A secondary objective of Project 1 was to examine the impact of two known risk factors: young age at CSI treatment and higher CSI dose. Utilizing a cross sectional design, the primary objective of Project 2 was to evaluate the potential relationship between the patients' CC measures and outcome scores derived from the Conner's Continuous Performance Test (CPT) of attention ability (n = 26).; Project 1 found that in contrast to normal neurodevelopmental maturation, statistically significant declines over time since start of CSI were found for total CC and the measures of 6 CC subregions. Those who were at or below the median age (≤6.88 years) declined at similar rates as those who were above the median age (≥6.88 years). Similarly, no significant differences in decline of CC measures over time were found between those receiving higher dose CSI (36–39.6 Gy) and those receiving lower dose CSI (23.4 Gy). Controlling for time since start of CSI, Project 2 found no significant relationships between CPT outcome scores and CC measures. However, analysis of CPT outcome scores and CC measures in relation to time since start of CSI showed both poorer CPT performance and smaller CC measures as time since start of CSI increased. A delay between physiological changes in brain tissue and clinical presentation of problems with attention ability is speculated. With such patterns of change, significant correlation between CC and CPT scores would not exist.; The results add to previous findings of declines in brain tissue volumetry as well as cognitive ability among the pediatric MB patient population. There remains a need for continued vigilant follow-up evaluation for pediatric MB patient groups beyond termination of treatment.