Executive Functioning
All BRIEF mean T-scores were in the normal range (Table 2), although scores ranged from within the normal range to the impaired range across most scales. There were no significant correlations between the Global Executive Composite, Behavioral Regulation Index or Metacognition Index T-scores and age at baseline (p values ≥ 0.34), time interval between baseline follow-up (p values ≥ 0.29) or SES (pvalues ≥ 0.54). The mean T-scores for these three primary outcome measures were also not significantly related (p values ≥ 0.10) to the following variables: gender, histology, hydrocephalus at diagnosis, history of surgical resection, location of tumor or treatment with chemotherapy. Radiation field was not significantly related to the mean T-scores for the Global Executive Composite (F (1, 185) = 0.14,p = 0.71), Behavioral Regulation Index (F (1, 185) = 0.07, p = 0.80) or Metacognition Index (F (1, 185) = 0.22,p = 0.64). No further analyses were conducted of the interaction between radiation field and age at baseline since mean T-scores for these three measures were not significantly different by radiation field and age at baseline was not significantly related to radiation field.
Compared to the normative mean, statistically significantly elevated mean T-scores were found on the Metacognition Index (t (186) = 3.01, p < 0.01) and the Initiate (t (163) = 3.34, p < 0.01), Working Memory (t (186) = 5.51,p < 0.001), and Plan/Organize (t (185) = 2.73,p = < 0.01) scales. In contrast, mean T-scores were significantly better than expectation on the Inhibit scale (t(186) = -3.28, p < 0.01) and the Behavioral Regulation Index (t (186) = -2.36, p < 0.05). Mean T-scores were at or near the normative mean on the Global Executive Composite and the remaining clinical scales.
Rate of impairment on the Behavioral Regulation Index was similar to expected rates in the general population as were the rates of impairment on the Inhibit, Shift, Emotional Control, and Self-Monitor scales. In contrast, rates of impairment in Working Memory (25.1%), the Metacognition Index (18.7%), Initiate (18.3%), Plan/Organize (17.2%), and the Global Executive Composite (15.0%) far exceeded expectations. There were no significant differences between rates of impairment and radiation field on any scale (p values ≥ 0.09) or between rates of impairment and age at baseline on any scale (p values ≥ 0.22).