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).