Neurocognitive Effects of Treatment of Pediatric Acute Lymphocytic Leukemia: A Neuroimaging Analysis
Acute Lymphocytic Leukemia (ALL) is the most prevalent form of cancer diagnosed in children. The current survival rate is approximately 85% and has been rising over the last two decades. The standard treatment regimen involves intrathecal chemotherapy in addition to corticosteroid drugs. Intrathecal chemotherapy has been shown to cause neurocognitive effects in executive function and IQ. The current study investigates differences in brain activation patterns that could account for the differences in neurocognitive function observed between ALL survivors and healthy controls. In this study, neurocognitive function of ALL survivors was assessed using a test battery that consisted of the Wechsler Intelligence Test for Children-Fourth Edition (WISC-IV) and the Delis-Kaplan Executive Function System (D-KEFS). ALL survivors showed significant deficits on these tests compared to matched, healthy controls. Survivors demonstrating the poorest performance on this battery participated in the neuroimaging component of the study in which brain activation during an inhibitory control task, the Simon task, was measured using functional magnetic resonance imaging (fMRI). ALL survivors demonstrated a compensatory mechanism of cortical recruitment during the Simon task, while performing worse than their matched, healthy controls. There was a significant difference in activation between survivors and healthy controls in the anterior cingulate cortex (BA 24), as predicted, although no differences were found between groups in the prefrontal cortex.