Identifying patterns of neurocognitive dysfunction through direct comparison of children with leukemia, central nervous system tumors, and sickle cell disease.

PURPOSE: To quantify and compare the magnitude and type of neurocognitive dysfunction in at-risk children with central nervous system (CNS) tumors, acute lymphoblastic leukemia (ALL), and sickle cell disease (SCD) using a common instrument and metric to directly compare these groups with each other. METHODS: Fifty-three participants between the ages of 7 and 12 years (n = 27 ALL, n = 11 CNS tumor, n = 15 SCD) were enrolled and assessed using the NIH Toolbox Cognition Battery (NIHTCB). Participants with ALL or CNS tumor were 0-18 months posttherapy, while participants with SCD possessed the SS or Sß0 genotype, took hydroxyurea, and had no known history of stroke. RESULTS: Independent sample t-tests showed that participants with ALL and CNS tumor experienced greatest deficits in processing speed (ALL d = -0.96; CNS tumor d = -1.2) and inhibitory control and attention (ALL d = -0.53; CNS tumor d = -0.97) when compared with NIHTCB normative data. Participants with SCD experienced deficits in cognitive flexibility only (d = -0.53). Episodic memory was relatively spared in all groups (d = -0.03 to -0.32). There were no significant differences in function when groups were compared directly with each other by analysis of variance. CONCLUSIONS: Use of a common metric to quantify the magnitude and type of neurocognitive dysfunction across at-risk groups of participants by disease shows that participants perform below age-expected norms in multiple domains and experience dysfunction differently than one another. This approach highlights patterns of dysfunction that can inform disease- and domain-specific interventions.

Reduced Hedonic Capacity/Approach Motivation Relates to Blunted Responsivity to Gain and Loss Feedback in Children.

Adolescents and adults with major depressive disorder or elevated depressive symptoms show reduced reward responses and tend to show enhanced responses to negative stimuli. However, reward-related behaviors and adaptive responses to negative feedback undergo dramatic changes across puberty. Thus, key questions remain regarding how altered incentive processing relates to depressive and anhedonic symptoms in prepubertal child populations. Twenty-four nonclinical prepubertal children 7-10 years of age (15 male; 16 Caucasian) completed two signal detection tasks that assessed behavioral responsivity to candy gain and loss feedback, respectively. These tasks were based on Pizzagalli's probabilistic reward task where asymmetric feedback leads to greater bias toward the more frequently rewarded response in more hedonic or nondepressed adults. We further modified the task to create a version where incorrect responses could result in losses from an original allotment of candy. Children and parents/guardians also completed individual difference questionnaires to assess the child's depressive symptoms, general affect, and hedonic capacity/approach motivation. Regressions indicated a relation between hedonic capacity/approach motivation (child self-report) and response bias in both gain and loss tasks. No significant relations were observed between depressive (child self-report), internalizing (parent report), or externalizing symptoms (parent report) and bias in either the gain or loss task in this small sample. These results suggest that reduced hedonic capacity/approach motivation is associated with blunted responses to both gain and loss feedback in prepubertal children.