Abstracts

Rationale:
The National Institutes of Health Toolbox (NIHTB) Cognition Battery offers brief and easily accessible measures for participants age 3+. While the NIHTB is validated in healthy populations, validation in clinical samples is limited and there are no published studies in pediatric epilepsy populations. We examined the relationship between NIHTB and standard clinical neuropsychological measures. The NIHTB tests were 1) the Flanker Inhibitory Control and Attention test (Flanker) to assess attention and executive functioning (EF), and 2) the Pattern Comparison Processing Speed test (PC) to evaluate processing speed. Both require tapping an iPad for the response. We hypothesized that Flanker will be correlated with measures of attention and EF while the PC will be correlated with processing speed.
Method:
24 evaluations across 21 participants (11 male, range=5-20 yrs, mean age=8.8 yrs, SD=3.5 yrs) with a variety of epilepsy diagnoses (8 ESES; 11 focal; 1 generalized; 1 mixed) completed two NIHTB tests during a standard neuropsychological evaluation. Standard neuropsychological measures were selected across domains of attention, EF, processing speed, motor dexterity, and IQ. Descriptive and correlational analyses among measures were conducted. We report findings at both rigorous (corrected for multiple comparisons (p< .005)) and uncorrected (p< .05) thresholds.
Results:
Consistent with many epilepsy populations, mean patient performance was in the low average range but spanned from below to above average (Table 1). Both NIHTB tasks were significantly correlated with some standard clinical tools, ranging from moderate to strong relationships (Pearson r’s 0.45 to 0.76, Table 2). The two NIHTB tasks were moderately correlated to one another (r=.597, p=.002), although patients performed worse on PC. Using rigorous criteria, Flanker was strongly correlated with measures of processing speed and motor dexterity, which PC was correlated with at less rigorous thresholds. Nonverbal IQ was correlated with PC and Flanker. Different from PC, Flanker was correlated with the processing speed index from the Wechsler and verbal IQ.
Conclusion:
Our hypotheses were partially supported; both tasks were correlated to EF, while Flanker had stronger correlations to processing speed. Flanker, which is a more demanding task than PC, had overall stronger and more correlations with clinical measures. Both tasks correlated broadly with measures of motor and nonverbal IQ. Of the measures that were correlated with the NIHTB, the majority had an oral- or grapho-motor component (i.e. rapid naming, motor dexterity), which may reflect the NIHTB’s ability to capture motor deficits due to medication effects, frequently seen in our patients. Importantly, these tasks were not correlated with inattention—a common comorbidity in pediatric epilepsy. Our results support the use of the NIHTB as an efficient screening tool, but also raise the need for additional validation to consider its use as a replacement for standard clinical measures.
Funding:
:The Hess Foundation