Cognitive Biomarkers in Pediatric Brain Tumor Patients

The investigators will focus on two cohorts of brain tumor patients aged, 4-18 years, to
answer two critical questions: 1) Can the investigators acquire high quality data relevant to
cognitive function during the peri-diagnostic period and, 2) can the investigators develop
predictive models for cognitive outcomes using serial examination of functional imaging and
cognitive function. Any patient with a newly diagnosed brain tumor aged 4-18 will be eligible
for enrollment in cohort 1. Only patients with previously diagnosed tumors of the posterior
fossa will be eligible for cohort 2. The rationale for of the focus on these patients is that
first, the posterior fossa is the most common location for pediatric brain tumors and
therefore this focus will impact the largest segment of this patient population. Second,
three tumors commonly occur here, medulloblastoma, ependymoma and pilocytic astrocytoma.
These are treated with surgery, radiation and chemotherapy (medulloblastoma), surgery and
radiation therapy (ependymoma) or surgery only (pilocytic astrocytoma). Thus, this focus will
provide a platform to analyze the impact that different tumor types and different standard
treatments have on cognitive dysfunction. Finally, the fact that all subjects will have
tumors of the same brain region will control for the effect that tumor location will have on
cognitive testing and rsfcMRI. Here, repeated evaluations on and off therapy will provide the
necessary data points to establish trajectories of cognitive development and recovery in this
population.