Objective:HSCT is increasingly used for curative therapy for patients with high risk hematologic diseases. Existing research regarding the neurocognitive impact of HSCT on pediatric patients is notably variable. One area of identified risk is attention/working memory (WM) [Perkins et al., 2007]. The current study examines the degree to which difficulties in attention/WM are present prior to HSCT, as assessed using parent-report of working memory and cognitive tests of attention span and working memory.
Participants and Methods:Participants were 19 children and adolescents ages 6-17 years (M= 9.63, SD= 3.22) who were enrolled in a prospective longitudinal study monitoring neurocognitive outcomes in children undergoing HSCT. Participants were eligible for this study if they were 2-18 years old at the time of transplant and had a diagnosis that qualified for an allogenic HSCT. Participants were ineligible if they had a pre-HSCT developmental delay, were non-English speaking, and had a prior HSCT or prior CAR T-cell therapy. Participants were 53% female and 95% Caucasian. Diagnoses in the current study sample included acute lymphoblastic leukemia (n=10), acute myeloid leukemia (n=8), and myelodysplastic syndrome (n=1).
Measures included were the Working Memory Index score from the Behavior Rating Inventory of Executive Function (BRIEF; Gioia et al., 2000) and the Digit Span subtest from the Wechsler Intelligence Scale for Children, Fourth Edition (WISC-IV; Wechsler, 2003) and the Wechsler Adult Intelligence Scale, Fourth Edition (WAIS-IV; Wechsler, 2008).
Results:Mean scores on parent-reported WM scores and cognitive measures of attention/WM fell within normal limits, including the Digit Span Total score (M = 48.42, SD= 6.33), Digit Span Forward score (M = 47.28, SD = 9.9.83), and Digit Span Backward score (M = 48.94, SD = 6.31). However, further analyses suggested that between 11-32% of patients had scores falling at least one standard deviation below the mean on these measures, with more than half of the sample (52.6%) identified with at least one measured weakness in attention and WM. The most commonly identified weakness (33.3% of patients) was Digit Span Forward. Correlations between parent-reported WM issues and cognitive measures of attention and WM were generally strong, with parent report of WM significantly correlated with the Digit Span Total score (r(18)= -0.52, p=.02) and the Digit Span Forward score (r(18) = -0.51, p=.03). No correlations were found between Digit Span Backward and other measures of attention and WM.
There were no significant differences in WM scores between patients with ALL and AML. Additional analyses will examine potential contribution of medical factors (e.g., pre-HSCT treatment) to pre-HSCT performance on measures of attention and WM.
Conclusions:These results suggest that, prior to undergoing HSCT, pediatric patients present with attention and WM issues. This finding has implications for research related to neurocognitive outcomes in HSCT, indicating the need to obtain pre-HSCT cognitive data in this area in order to fully understand potential change after HSCT. In addition, providers may need to consider adapting communication methods with patients during their transplant stay, given potential attention and WM issues within this population.