Neurocognitive impairment in children treated for cancer: how do we measure cognitive outcomes?

As the number of childhood cancer survivors grows, more attention on the identification and management of late effects, such as neurocognitive decline, is needed. This study, investigating treatment with central nervous system (CNS) stimulants for cognitive changes related to pediatric cancer treatment, confirmed a common concern. How should neurocognitive decline be measured and followed up after cancer therapy? Multiple pediatric standardized cognitive tests are available, but there is no consensus on an efficient way to measure the most common areas of decline, specifically impaired concentration, memory, and mental processing speed. The authors' report recognized 12 pediatric patients at risk for cognitive dysfunction, of whom 3 tested positive for early neurocognitive deficits using 3 subscales of the Wechsler Intelligence Scale for Children-III (WISC-III), which measure working verbal memory (Digit Span), mental processing speed (Symbol Search), and psychomotor speed (Coding). To predict the expected level of performance on WISC-III subscales, the patients' IQ was estimated using the Wide Range Achievement Test-3 reading subtest. Patients were treated with long-acting CNS stimulants and followed up serially using the WISC-III subscales.